INTERNATIONAL SYMPOSIUM
ON NEW TECHNOLOGIESFOR URBAN SAFETY
OF MEGA CITIES IN ASIA
Organized byInternational Center for Urban Safety Engineering (ICUS),
Institute of Industrial Science (IIS),The University of Tokyo, JapanIn Cooperation with
United Nations International Strategy for Disaster Reduction
Asian Disaster Reduction Center
Disaster Reduction and Human Renovation Institution
Graduate School of Global Environmental Studies, Kyoto University
Research Center for Urban Safety and Security, Kobe University
United Nations Centre for Regional Development
United Nations University Institute for Sustainability and PeaceGlobal warming and its impacts on Asia
- From the IPCC AR4
Tsuneo KATAYAMA
Professor, Tokyo Denki University, Japankatayama@cck.dendai.ac.jp
ABSTRACTThe summer 2010 was characterized by extreme weathers all over the world.
Since its establishment in 1988, the Intergovernmental Panel on Climate Change(IPCC) has produced a series of Assessment Reports, ARs, (1990, 1995, 2001 and2007), which have become standard works and have played a major role inassisting governments to adopt and implement policies in response to climatechange. This article is based on the materials contained in the AR4: WG1 report
on “The Physical Sciences Basis”, WG2 report on “Impacts, Adaptation and
Vulnerability”, WG3 report on “Mitigation of Climate Change”, and theSynthesis Report with its Summary for Policymakers. The assessment confirmsthat climate change is occurring now, mostly as a result of human activities; itillustrates the impacts of global warming already under way and to be expected infuture, and describes the potential for adaptation of society to reduce its
vulnerability. The assessment and projections of climate change and associatedsocio-economic consequences are vital for the future of Asian region, particularlyin the developing countries and countries with economies in transition.
Keywords: IPCC, AR4, global warming, Asia
1. WARMING IS UNEQUIVOCAL
Warming of the climate system is now evident from observations of increases in
global average air and ocean temperatures, widespread melting of snow band ice
and rising global average sea level, says the AR4 (Assessment Report 4, 2007).
Eleven of the last twelve years (1995-2006) rank among the twelve warmest years
in the instrumental record of global surface temperature since 1850. Figure 1 wastaken from WGⅠreport of AR4. Average Northern Hemisphere temperatureduring the second half of the 20th century were very likely (> 90% probability)
higher than during any other 50-year period in the last 500 years and likely (>66% probability) the highest in at least the past 1,300 years.
According to the news release by the Japan Meteorological Agency (JMA) on
June 15, 2010, the seasonal anomaly of the global mean surface temperature forMarch to May (boreal spring season) in 2010 hit the highest record with +0.41°C
on a par with the same months in 1998 since 1981, the earliest year for which the
JMA estimated global temperature anomalies (Figure 2). Seen from a longer
perspective, the global mean temperature for March to May have been on a rising
trend at a rate of +0.73°C per century. According to the JMA, the warming is0ctober 2010, Kobe, Japan

mainly caused by the global buildup of anthropogenic GHGs in the atmosphere,
but the El Nino episode that started summer 2009, as well as natural climate
fluctuations of various durations, partly attributed to the warmer globe.
The AR4 states that some extreme weather events have changed in frequency
and/or intensity over the last 50 years. It is very likely (> 90% probability ofoccurrence) that, during the past 50 years, cold days, cold nights and frosts havebecome less frequent over most land areas, and hot days and hot nights havebecome more frequent. It is likely (> 66% probability) that heat waves havebecome more frequent over most land areas, that the frequency of heavy
precipitation events has increased over most areas, and that the incidence of
extreme high sea level has increased worldwide since 1975.

Figure 1: Global Mean Temperature

Figure 2: Long-term surface temperature anomalies for March to May overthe globe (JMA) - Anomalies are deviations from the normal (19712000 average). The bars indicate annual anomalies, the blue line 5year running mean, and the red line a long-term linear trend.

New Technologies for Urban Safety of Mega Cities in Asia

2. MOST GHG INCREASE IS DUE TO ANTHROPOGENIC ORIGIN
Global GHG emissions due to human activities have grown since pre-industrial
times, with an increase of 70% between 1970 and 2004. Carbon dioxide (CO2)emissions have grown between 1970 and 2004 by about 80%, from 21 to 38 gigatonnes (Gt), and represented 77% of total anthropogenic GHG emissions in 2004.
The rate of growth of CO2-eq emissions was much higher during the recent 10year period of 1995-2004 (0.92 GtCO2-eq per year) than during the previous
period of 1970-1994 (0.43 GtCO2-eq per year). Figures 3 and 4 were taken fromthe WG1 report, with the latter in a slightly modified form that appears in theSynthesis Report.
Advances since the 2001 Third Assessment Report (TAR) show that discernible
human influences extend beyond average temperature to other aspects of climate.
Recent studies have allowed a broader and more confident assessment of therelationship between observed warming and impacts than was made in the TAR(2001) which could only conclude that “there is high confidence that recent
regional changes in temperature have had discernable impacts on physical andbiological systems.”

Figure 3: Atmospheric concentrations of long-lived GHGs
over the last 2,000 years.

Figure 4: Global Anthropogenic GHG Emissions (Synthesis Report of AR4)(a) Global annual emissions of anthropogenic GHGs from 1970 to 2004,(b) Share of different anthropogenic GHGs in total emissions in 2004
in terms of CO2-eq, and (c) Share of different sectors in total anthropogenic
GHG emissions in 2004 in terms of CO2-eq (Forestry includes deforestation.)
Global warming and its impacts on Asia – From the IPCC AR40ctober 2010, Kobe, Japan

3. WARMING IS DUE TO ANTHROPOGENIC GHG CONCENTRATIONSThe AR4 concludes that most of the observed increase in global averagetemperatures since the mid-20th century is very likely (> 90% probability) due tothe observed increase in anthropogenic GHG concentrations. This is an advancesince the TAR’s conclusion: Most of the observed warming over the last 50 years
is likely to have been due to the increase in GHG concentrations.
Observational evidence from all continents and most oceans shows that many
natural systems are being affected by regional climate changes, particularly
temperature increases due to anthropogenic causes.
Changes in the ocean and on land, including observed decreases in snow coverand Northern Hemisphere sea ice extent, thinner sea ice, shorter freezing seasonsof lake and river ice, glacier melt, decreases in permafrost extent, increases in soil
temperatures and borehole temperature profiles, and sea level rise, provide
additional evidence that the world is warming. There is high confidence (About 8
out of 10 chances) that natural systems related to snow, ice and frozen ground(including permafrost) are affected. Examples are:● enlargement and increased numbers of glacial lakes● increasing ground instability in permafrost regions and rock avalanches
in mountain regions● changes in some Arctic and Antarctic ecosystems, including those in
sea-ice biomes, and predators at high levels of the food web.
Based on growing evidence, there is high confidence (About 8 out of 10 chances)that the following effects on hydrological systems are occurring: increased runoff
and earlier spring peak discharge in many glacier- and snow-fed rivers, andwarming of lakes and rivers in many regions, with effects on thermal structure andwater quality.
According to the AR4, human influences have:● very likely (> 90% probability) contributed to sea level rise during thelatter half of the 20th century,● likely (> 66% probability) contributed to changes in wind patterns,
affecting extra-tropical storm tracks and temperature patterns,● likely (> 66% probability) increased temperatures of extreme hot nights,
cold nights, and cold days,● more likely than not (33 to 66% probability) increased risk of heat waves,area affected by droughts since the 1970s and frequency of heavy
precipitation events.
Following cautious examinations of past persisting anomalies of weather, theWG1 report of the AR4 lists the following 6 climate events as extreme weathers:● Drought in Central and Southwest Asia, 1998-2003● Drought in Australia, 2002-2003● Drought in Western North America, 1999-2004● Floods in Europe, Summer 2002
● Heat Wave in Europe, Summer 2003
● The 2005 Tropical Storm Season in the North Atlantic
To the question “Are extreme events, like heat waves, droughts or floods,
expected to change the Earth’s climate changes?” the AR4 answers “Yes.”
Although the type, frequency and intensity of extreme events are expected to varyas Earth’s climate changes, these changes could occur even for relatively small
New Technologies for Urban Safety of Mega Cities in Asia

mean climate changes (Chapter 10, WG1 report). But, when asked how likely
major or abrupt climate changes are, the report answers that, although theoccurrence of such changes becomes increasingly more likely, such abrupt
climate changes are not considered to occur in the 21st century (Chapter 10, WG1
report).
4. GENERAL IMPACTS OF GLOBAL WARMING
By the mid- to late-21st century, it is projected virtually certain (> 99%
probability) that, over most land areas, there will be warmer and more frequent
hot days and nights due to changes in extreme weather and climate events. These
do not take into account any changes or developments in adaptive capacity.
Examples of major projected impacts in different sectors associated with theabove climate change are:
● In agriculture, forestry and ecosystems: Increased yields in colder
environments, decreased yields in warmer environments, decreased
yields in low-altitudes due to reduced water availability, and increased
insect outbreaks● In water resources: Effects on water resources in some dry regions at
mid-latitudes and in the dry tropics, due to changes in rainfall andevapotranspiration, and in areas dependent on snow and ice melt
● In human health sector: Reduced human mortality from decreased cold
exposure, ill-effects to human health in populations with low adaptive
capacity● In industry, settlement and society: Reduced energy demand to heating,increased demand for cooling, declining air quality in cities, reduced
disruption to transport due to snow/ice, effects on winter tourism,
and in general,● In low-lying coastal systems: Various kinds of effects due to sea level
rise and increased risk from extreme weather events.
5. IMPACTS ON ASIA
5.1 Recent and Future Trends
Asia is the most populous continent with its total population in 2002 reported to
be about 3.9 billion, of which almost 61% lives in rural areas and 38.5% within
100 km of the coast. The population growth projections for Asia range between
1.54 billion people in 2050 and 4.5 billion people in 2100.
Increasing surface air temperature trends have been observed all across of Asia.
The observed increases during recent decades ranged between less than 1°C to
3°C per century. Recent trends show the increasing tendency in the intensity andfrequency of extreme weather events in Asia. Severe heat waves withsignificantly longer duration have been observed in many countries. Generally,
the frequency of occurrence of more intense rainfall events in many parts of Asia
has increased, causing severe floods, landslides, and debris and mud flows, while
the number of rainy days and total annual amount of precipitation has decreased.

Global warming and its impacts on Asia – From the IPCC AR40ctober 2010, Kobe, Japan

Increasing frequency and intensity of droughts in many parts of Asia are attributed
largely to a rise in temperature particularly during the summer and normally driermonths. In parts of China, the rise in temperature and decreases in precipitation,
along with increasing water use, have caused water shortages that led to drying upof lakes and rivers. In India, Pakistan, Nepal and Bangladesh, water shortages
have been attributed to rapid urbanization and industrialization, population growthand inefficient water use, which are aggravated by changing climate. Decreasing
precipitation and increasing temperature commonly associated with ENSO havebeen reported to increase water shortage, particularly in parts of Asia where water
resources are already under stress from growing water demands and inefficientwater use. Production of rice, maize and wheat has declined in the past few
decades in many parts of Asia due to increasing water stress arising partly fromincreasing temperature, increasing frequency of El Nino and reduction in thenumber of rainy days.
The coastlines in monsoon Asia are cyclone-prone, and about 42% of the world’s
total tropical cyclones occur in this region. The combined extreme climatic andnon-climatic events caused coastal flooding, resulting in substantial economic
losses and fatalities. Wetlands in the major river deltas have been significantly
altered in recent years due to large scale sedimentation, and use conversion,
logging and human settlement. Salt water from the Bay of Bengal is reported tohave penetrated 100 km or more inland during the dry season. Severe droughts
and unregulated groundwater withdrawal have also resulted in sea-water intrusionin the coastal plains of China.
A large number of deaths due to heat waves mainly among the poor, elderly andlaborers have been reported in India during the past five years. Serious healthrisks associated with extreme summer temperatures and heat waves have beenreported in Siberian cities. In South Asia, endemic morbidity and mortality due todiarrhoeal disease and outbreaks of other infectious diseases is linked to poverty
and poor hygiene, such as lack of access to safe drinking water and poor seweragesystem, compounded by the effect of high temperatures on bacterial proliferation.
Increasing intensity and spread of forest fires in Asia were observed in the past 20
years, largely attributed to the rise in temperature and decline in precipitation in
combination with increasing intensity of land uses. Fires in Siberian peat lands
have increased dramatically. The 1997/98 ENSO event in Indonesia triggered
forest and bush fires, with serious domestic and trans-boundary pollutionconsequences.
5.2 Future Impacts
Food security: Half the world’s population is located in Asia. There are serious
concerns about the prevalence of malnutrition among poorer and marginal groups,
particularly rural children, and about the large number of people below thepoverty line in many countries.
The net cereal production in South Asian countries is projected to decline at least
between 4 to 10% by the end of this century under the most conservative climatechange scenario. Climate change can affect not only crop production per unit
area but also the area of production. Most of the arable land that is suitable forcultivation in Asia is already in use.

New Technologies for Urban Safety of Mega Cities in Asia

Consumption of animal products such as meat and poultry has increased steadilyin Asia. However, cool temperate grassland is projected to shift northward withclimate change and the net primary productivity will decline. The Asia-Pacificregion is the world's largest producer of fish. Future changes in ocean currents,
sea level, sea-water temperature, salinity, wind speed and direction, strength of
upwelling, the mixing layer thickness and predator response to climate change
have the potential to substantially alter fish breeding habitats and food supply forfish and ultimately the abundance of fish populations in Asian waters.
Increasing urbanization and population in Asia will likely result in increased fooddemand and reduced supply due to limited availability of cropland area and yield
declines projected in most simulations. Food supply or ability to purchase fooddirectly depends on income and price of the products. The global cereal prices
have been projected to increase more than three-fold by the 2080s. The risk ofhunger is likely to remain very high in several developing countries.
Water availability and quality: Changes in seasonality and amount of waterflows from river systems are likely to occur due to climate change. Changes inrunoff of river basins could have a significant effect on the power output ofhydropower generating countries. Likewise, surface water availability from majorrivers may also be affected by alteration of river flows. In North China, irrigationfrom surface and groundwater sources will meet only 70% of the waterrequirement for agricultural production, due to the effects of climate change andincreasing demand. The maximum monthly flow of the Mekong is estimated toincrease by 35 to 41% in the basin and by 16 to 19% in the delta, with lower value
estimated for years 2010 to 38 and higher value for years 2070 to 99, comparedwith 1961 to 90 levels. In contrast, the minimum monthly flows are estimated to
decline by 17 to 24% in the basin and 26 to 29% in the delta. There could be
increased flooding risks during wet season and an increased possibility of water
shortage in dry season.
Over-exploitation of groundwater in many countries of Asia has resulted in a dropin its level, leading to ingress of sea water in coastal areas making the sub-surface
water saline. India, China and Bangladesh are especially susceptible to increasing
salinity of their groundwater as well as surface water resources, especially along
the coast, due to increases in sea level as a direct impact of global warming.
Increasing frequency and intensity of droughts in catchment areas will lead tomore serious and frequent salt-water intrusion in the estuaries and thus deteriorate
surface and groundwater quality.
Droughts and floods: Global warming would cause an abrupt rise of water
quantity as a result of snow or glacier melting that, in turn, would lead to floods.
The duration of seasonal snow cover in alpine areas will shorten and snow cover
will thaw out in advance of the spring season, leading to a decline in volume andresulting in severe spring droughts. Intense rain occurring over fewer days, which
implies increased frequency of floods during the monsoon, will also result in lossof the rainwater as direct runoff, resulting in reduced groundwater recharging
potential. Expansion of areas under severe water stress will be one of the mostpressing environmental problems in South and South-East Asia in the foreseeable
future as the number of people living under severe water stress is likely toincrease substantially. Different scenarios estimate that 120 million to 1.2 billion,and 185 to 981 million people will experience increased water stress by the 2020s,
and the 2050s, respectively. The gross per capita water availability in India will

Global warming and its impacts on Asia – From the IPCC AR40ctober 2010, Kobe, Japandecline from about 1,820 m3/yr in 2001 to as low as about 1,140 m3/yr in 2050.
India will reach a state of water stress before 2025 when the availability falls
below 1,000 m3 per capita. The decline in annual flow of Mekong River by 16 to
24% by the end of 21st century will contribute to increasing water stress.
Coastal erosion and inundation: Average global sea-level rise over the second
half of the 20th century was 1.8 ± 0.3 mm/yr, and sea-level rise of the order of 2 to
3 mm/yr is considered likely during the early 21st century. The rising rates of sea
level vary considerably from 1.5 to 4.4 mm/yr along the East Asia coast, due toregional variation in land surface movement. The projected relative sea-level riseis 70 to 90 cm in the Huanghe delta by the year 2050. It was reported that theregional sea-level rise over the north-western Pacific Ocean would be much moresignificant compared with the global average mainly due to exceptionally large
warming near the entrance of the Kuroshio extension.
In Asia, erosion is the main process that will occur to land as sea level continues
to rise. As a consequence, coast-protection structures will usually be destroyed by
the sea while the shoreline retreats. In some coastal areas of Asia, a 30 cm rise in
sea level can result in 45 m of landward erosion. Climate change and sea-level
rise will tend to worsen the currently eroding coasts. The coastal recession can
add up to 500 to 600 m in 100 years, with a rate of between 4 to 6 m/yr. In
monsoonal Asia, decreasing sediment flux is generally a main cause of coastal
erosion. Available evidence suggests a tendency of river sediment to further
decline that will tend to worsen coastal erosion in Asia.
Projected sea-level rise could flood the residence of millions of people living in
the low lying areas of South, South-East and East Asia such as in Vietnam,
Bangladesh, India and China. Even under the most conservative scenario, sealevel will be about 40 cm higher than today by the end of 21st century which will
increase the annual number of people flooded in coastal populations from 13
million to 94 million. Almost 60% of this increase will occur in South Asia
(along coasts from Pakistan, through India, Sri Lanka and Bangladesh to
Myanmar), while about 20% will occur in South-East Asia, specifically fromThailand to Vietnam including Indonesia and the Philippines. The potential
impacts of 100 cm sea-level rise include inundation of 5,763 km2 and 2,339 km2
in India and in some big cities of Japan, respectively. For 100 cm sea-level risewith high tide and storm surge, the maximum inundation area is estimated to be
2,643 km2 or about 1.2% of total area of the Korean Peninsula. In China, a 30 cm
sea-level rise would inundate 81,348 km2 of coastal lowland. In Japan, an area of
861 km2 of coastal lowland is located below high water level mainly in large cities
like Tokyo, Osaka and Nagoya. A 100 cm rise in sea level could put up to 4.1
million people at risk. Damages in flooded areas are largely dependent on the
coastal protection level. They can be very high such as in coastal areas of South
Asia where the protection level is low. Case studies indicate that the current
protection level is insufficient to protect the coasts from high sea-level rise.
Further warming may lead to an increase in tropical cyclone destructive potential,
and with an increasing coastal population substantial increase in hurricane-related
losses in the 21st century is likely.
Deltas, estuaries and wetland: There are 11 mega-deltas with an area greaterthan 10,000 km2 in the coastal zone of Asia which are home to millions of people,
especially the seven mega cities that are located in these deltas. Future evolutionof the major deltas in monsoonal Asia depends on changes in ocean processes and
New Technologies for Urban Safety of Mega Cities in Asia

0ctober 2010, Kobe, Japan

river sediment flux. Coastal erosion of the major deltas will be caused by sealevel rise, intensifying extreme events (e.g., storm surge) due to climate change
and excessive pumping of groundwater for irrigation and reservoir construction
upstream. Annual mean sediment discharge in the Huanghe delta during the
1990s was only 34% of that observed during the 1950s and 1970s. Saltwater
intrusion in estuaries due to decreasing river runoff can be pushed 10 to 20 km
further in by the rising sea level. Many mega cities in Asia are located on deltas
formed during sea-level change in the Holocene period. These Asian mega cities
with large populations and intensified socio-economic activities are subject tothreats of climate change, sea-level rise and extreme climate event. For a 100 cm
rise in sea level, half a million square hectares of Red River delta and from 15,000
to 20,000 km2 of Mekong River delta is projected to be flooded. In addition,
approximately 1,000 km2 of cultivated farm land and sea product culturing area
will become salt marshes. If abnormally high sea-surface temperatures (SST)
continue to cause major bleaching events, and reduce the capacity of reefs tocalcify due to CO2 increase, most human efforts will be futile.
Air and water pollution: Climate change poses substantial risks to human health.
Global burden (mortality and morbidity) of climate-change attributable diarrhoea
and malnutrition are already the largest in South-East Asian countries in 2000,
and the relative risks for these conditions for 2030 are expected to be the largest.
In India and China, the excess mortality due to heat stress is projected to be very
high, although this projection did not take into account possible adaptation andpopulation change. There is already evidence of widespread damage to humanhealth by urban air quality and enhanced climate variability. Throughout newly
industrialized areas in Asia, air quality has deteriorated significantly and will
likely contribute to widespread heat stress and smog induced illnesses in theregion. The negative influence of temperature anomalies on public health has
been established in Russia, and serious problems are connected with the impact of
air pollution due to Siberian forest fires on human health.
A warmer and more humid climate would be favorable for propagation andinvasiveness of infectious insect, and natural habitats of vector-borne diseases arereported to be expanding. Warmer water will be excellent habitats for survival
and spread of infectious bacterial diseases such as cholera. Precipitation increase
and frequent floods, and sea-level rise will degrade the surface water quality
owing to more pollution and, hence, lead to more water-borne infectious diseases.
The risk factor of climate-related diseases will depend on improved environmental
sanitation, the hygienic practice and medical treatment facilities.
Population growth, migration, and development activities: The pressure onland in the 21st century will increase in Asia, due to the increasing food graindemand for the growing population, the booming economic development, as well
as climate change. In the developing regions, the remaining natural flood plains
are disappearing at an accelerating rate, primarily as a result of changes in land
use and hydrological cycle, particularly changes in stream flows due to climaticand human-related factors. The most threatened flood plains will be those inSouth and South-East Asia. In some parts of South-East Asia, population growth,particularly in the uplands, continues to exert pressure on the remaining forests in
the region.
In Asia, migration accounts for 64% of urban growth. Climate-related disruptionsof human populations and consequent migrations can be expected over the
New Technologies for Urban Safety of Mega Cities in Asia

0ctober 2010, Kobe, Japan

coming decades. Periods when precipitation shortfalls coincide with adverse
economic conditions for farmers (such as low crop prices) would be those most
likely to lead to sudden spikes in rural-to-urban migration levels in China andIndia. Climatic changes in Pakistan and Bangladesh would likely exacerbate
present environmental conditions that give rise to land degradation, shortfalls infood production, rural poverty and urban unrest. Such changes would likely affectnot only internal migration patterns, but also migration movements to otherwestern countries. Although food can be produced on currently cultivated land if
sustainable management and adequate inputs are applied, attaining this situation
would require substantial improvements of socio-economic conditions of farmers
in most Asian countries to enable access to inputs and technology. The
production losses due to climate change may drastically increase the number ofundernourished in several developing countries in Asia, severely hindering
progress against poverty and food insecurity.
Development, to a large extent, is responsible for much of the GHGs emitted into
the atmosphere that drives climate change. On the other hand, development
greatly contributes to reducing vulnerability to climate change and in enhancing
the adaptive capacities. Rates of both total forest loss and forest degradation are
higher in Asia than anywhere else in the world, because of its increasing economy
and fast development in recent years. In many developing countries of Asia,
small scale fuel wood collection and industrial logging for exports of timber andconversion of forests into estate crop plantation and mining are also responsiblefor deforestation. It is likely that climate change would aggravate the adverse
impacts of forest cover loss.
Urban and financial aspects: The compounding influence of future rises intemperature due to global warming, along with local urban heat-island effects,
makes cities more vulnerable to higher temperatures than would be expected due
to global warming alone. It has been suggested that climate change will
exacerbate the existing heat-island phenomenon in cities of Japan by absorbing
increased solar radiation, leading to further increases in temperatures withnegative implications for energy and water consumption, human health anddiscomfort, and local ecosystems. South Asia is expected to account for one-fifthof the world's total energy consumption by the end of 21st century. It is likelythat climate change will influence the pattern of change in energy consumptionthat could have significant effects on CO2 emission in this region.
The damages from floods, typhoons and other climate related hazards will likely
increase in the future. According to the European insurer Munich Re, the annual
cost of climate change-related claims could reach US $300 billion annually by
2050. The Association of British Insurers examined the financial implications ofclimate change through its effects on extreme storms. The projected increase ininsured losses due to the most extreme storms (with current return periods of 100
to 250 years) by the 2080s would be more than twice the reported losses of the2004 typhoon season, the costliest in terms of damage during the past 100 years.
The cost of direct damage in Asia caused by tropical cyclones has increased morethan five times in the 1980s as compared with those in the 1970s and about 35
times more in the early 1990s than in 1970s. These trends are likely to persist in
the future.
Vulnerability of the poor: The poor, particularly in urban and urbanizing cities
of Asia, are highly vulnerable to climate change because of their limited access to
New Technologies for Urban Safety of Mega Cities in Asia

profitable livelihood opportunities and limited access to areas that are fit for safeand healthy habitation. Consequently, the poor sector will likely be exposed tomore risks from floods and other climate-related hazards in areas they are forced
to stay in. This also includes the rural poor who live in the lower Mekong
countries and are dependent on fisheries as their major livelihood, along withthose living in coastal areas who are likely to suffer heavy losses without
appropriate protection. Protection from the social forces that create inequitable
exposure to risk will be as important if not more important than structuralprotection from natural hazards in reducing the vulnerability of the poor.
6. ADAPTATION AND CONSTRAINTS IN ASIAN SCENES
As most mega-cities of Asia are located and substantial socio-economic activities
and populations are currently highly concentrated in the coastal zones in Asia,
protection from sea-level rise should remain a key focus in Asia. Future
constructions should be done at elevated levels.
To assess the impact of climate change on human health, the disease monitoring
system is essential as the basic data source. The monitoring of diseases should bedone along with related ecological factors, because the relation between weather
factors and vector- borne diseases are complicated and delicate. Disease
monitoring is necessary in assessing the effectiveness and efficiency of theadaptation measures. Implementation of heat watch and warning system will
likely be helpful in reducing the impacts of climate change on human health.
Rapid population growth, urbanization and weak land-use planning andenforcement are some of the reasons why poor people move to fragile and highrisk areas which are more exposed to natural hazards. Moreover, the rapid growthof industries in urban areas has induced rural-urban migration.
Ruraldevelopment together with networking and advocacy, and building alliancesamong communities is a prerequisite for reducing the migration of people to cities
and coastal areas in most developing countries of Asia.
Effective adaptation and adaptive capacity in Asia, particularly in developing
countries, will continue to be limited by low level of awareness among decision
makers of the local and regional impacts of the impacts of climate change andresponses of natural systems to climate change. Poverty is identified as the largest
barrier to developing the capacity to cope and adapt. The poor usually have avery low adaptive capacity due to their limited access to information, technology
and other capital assets which make them highly vulnerable to climate change.
It is very likely that in countries of Asia facing serious domestic conflicts,
pervasive poverty, hunger, epidemics, terrorism and other pressing and urgent
concerns, attention may be drawn away from the dangers of climate change andthe need to implement adaptation. The existing legal and institutional framework
in most Asian countries remains inadequate to facilitate implementation ofcomprehensive and integrated response to climate change in synergy with the
pursuit of sectoral development goals. It is important to mainstream climatechange into development planning at all scales, levels and sectors.
Coupled with illiteracy, poverty subverts the ability of the people to pursue theusually long-term sustainable development goals in favor of the immediate goal of
meeting their daily subsistence needs. With climate change, the poor sectors will

Global warming and its impacts on Asia – From the IPCC AR40ctober 2010, Kobe, Japanbe most vulnerable and, without appropriate measures, climate change will likely
exacerbate the poverty situation and continue to slow down economic growth indeveloping countries of Asia.
Rapid economic growth characterized by increasing urbanization andindustrialization in several countries of Asia will likely drive the increase in thealready high demand for raw materials such as cement, wood, steel and otherconstruction materials in Asia. Consequently, the use of forests, minerals andother natural resources will increase along with the increase in carbon emission.
The challenge here is finding the development pathways wherein GHG emission
is minimized while attaining high economic growth. Equally vital in this regard is
the promotion of equity in spreading the benefits that will arise from economic
growth so as to uplift the condition of the poor sector to a state of enhanced
capacity to adapt to climate change. Another concern related to economic growthis that use of land for farm-agricultural purposes is becoming to be considered lessprofitable than for industrial and commercial purposes. In the absence ofappropriate regulatory intervention, this can undermine the production of adequate
food supply and further jeopardize the access of the poor to food support.
Sustaining economic growth in the context of changing climate in many Asian
countries will require the pursuit of enhancing preparedness and capabilities interms of human, infrastructural, financial and institutional dimensions with theaim in view of reducing the impacts of climate change on the economy. For
instance, in many developing countries, instituting financial reforms could likely
result in a more robust economy that is likely to be less vulnerable to changing
climate.
REFERENCES
Climate Change 2007 – The Physical Science Basis, Contribution of Working
Group I to the Fourth Assessment Report of the IPCC, Cambridge University
Press.
Climate Change 2007 – Impacts, Adaptation and Vulnerability, Contribution ofWorking Group Ⅱ to the Fourth Assessment Report of the IPCC, Cambridge
University Press.
Climate Change 2007 – Mitigation of Climate Change, Contribution of Working
Group Ⅲ to the Fourth Assessment Report of the IPCC, Cambridge University
Press.
Climate Change 2007 – Synthesis Report, Cambridge University Press.
News Release: The Warmest Global Mean Surface Temperature Observed forMarch to May 2010, Japan Meteorological Agency, 15 June 2010.

New Technologies for Urban Safety of Mega Cities in Asia

Promotion systems for PP-band retrofittingof weak masonry houses in developing countries
Kimiro MEGURO1 and Naoki SORIMACHI2
1
Director, Professor, ICUS, IIS, The University of Tokyo, Japanmeguro@iis.u-tokyo.ac.jp
2
Tokyo Electric Power Company, Japan

ABSTRACT
Seismic retrofitting of vulnerable masonry houses is the key to reduce earthquake
damage – especially casualties – in developing countries. However, retrofitting
has not been promoted mainly due to lack of economic resources. In this paper,
four seismic retrofitting promotion systems, making use of insurance andmicrofinance, were proposed and validated. Systems were proposed based on thecorrespondence analysis of 83 masonry houses’ data, and were validated by using
earthquake risks and fragility function. Results showed the economic effect for the
stakeholders in each promotion system, for 25 earthquake risk levels and fourmasonry structure types, which therefore can be used as an index for seismic
retrofitting promotion.
Keywords: PP-band method, seismic retrofitting, socio-economic conditions,
incentive systems, earthquake insurance

1. INTRODUCTION
Seismic retrofitting of low earthquake-resistant houses is essential to reduce bothhuman and economic losses in earthquake disasters. However, in developing
countries, lack of economic resources is a critical issue to promote seismic
retrofitting. Therefore, a cheap and easy retrofitting method utilizing PP-bands has
been proposed in Meguro laboratory as a locally acceptable and available solution(Mayorca & Meguro, 2003; Meguro, 2006). The retrofitting cost is approximately
30 US$ per housing unit if installed by the house owners. In case of hiring masons,the cost will still be no more than 5% of the total building cost. However, in many
parts of the world, this amount of money may still be unaffordable.
To solve the issues above, previous studies have proposed a two-step incentive
system by the government for promoting PP-band retrofitting for masonry houses(Iritani et al, 2008). The first step of this system is to provide materials for
retrofitting and a subsidy, which is given after the house has been checked to be
retrofitted properly. This subsidy is for preventing the house owners from selling
the provided materials and to give an incentive to retrofit. The second step is to
give compensations to those whose houses were damaged due to earthquake inspite of retrofitting. The validation showed if this two-step incentive system was
implemented before the 2003 Bam, 2005 Kashmir and 2006 Java earthquakes, theOctober 2010, Kobe, Japan

expenditure of the government for compensation for the people whose houses
were damaged would have been decreased by 95.8%, 81.4% and 75.6%,
respectively, as well as decreasing human fatalities by at least 80% to 90% in allcases. However, in this system, the remaining problems are the funding sourcethat government should prepare for the initial cost and proper prioritization by thegovernment on the selection of the area and houses to which this system is applied.
This study aims to propose some systems that can solve these problems topromote seismic retrofitting, focusing on the economic aspect of the stakeholders.

2. ANALYSIS OF MASONRY HOUSES
Masonry houses have been divided by structural details in the previous studies;
however, little attention has been paid to the social details. To promote retrofittingby making use of the cheapness and simplicity of PP-band retrofitting method, theeconomic situation of the residents and the construction situation of the houses
must be analyzed.
Data on the economic situation of the residents and the construction situation of
83 masonry house samples were collected from the World Housing Encyclopedia(EERI, 2009), and correspondence analysis was done. Table 1 shows thecategories for each sample.
Table 1: Categories of masonry houses
Housing condition
1. Single family
2. Multi family
3. Urban
4. Rural
5. With modification
6. Without modification

Building cost :annual income
7. 5:1
8. 4:1
9. 3:1
10. 1:1

Construction
process
Owner finance
17. Engineered
Personal saving
18. NonInformal network
engineered
Microfinance
19. Code
Commercial bank 20. No code
Government
owned

Resident’s financing
11.
12.
13.
14.
15.
16.

Insurance
21. Insured
22. Not insured

From the correspondence analysis, masonry houses were grouped into four groups,
i.e. Urban, Semi-urban, Rural, and Microfinance (MF) groups as shown in Figure
1. In the figure, the horizontal axis shows the construction conditions and thevertical axis shows the economical situation by ratio of building cost to annual
income. Cases with relatively good conditions are located on the right hand sideand relatively expensive houses are located in the upper part of the figure.
The Urban group has relatively sufficient construction and economic situations,such as the role of engineer and architect during the construction, code
enforcement and access to commercial banks or insurance. In addition, the ratio ofbuilding cost to annual income is about 5:1, which means they live in relatively
expensive houses. On the other hand, the Semi-urban group does not have accessto insurance due to lack of economic resources. Their ratio of building cost toannual income is about 4:1. The Rural group does not have sufficient construction
or economic situation. Informal extensions of houses are seen, and residents

New Technologies for Urban Safety of Mega Cities in Asia

usually do not have any access to commercial banks or insurance, so they rely on
personal savings or owner financing. Their ratio of building cost to annual income
is about 1:1. On the other hand, some of them are making use of microfinance(MF group). For the MF group, the ratio of building cost to annual income isabout 5:1. However, this means that their annual income is very low, which also
explains why they are using microfinance.

large

MF
Rural

Building cost/
Annual income

Urban

insufficient construction, social security sufficient

Semi-urban
small
Figure 1: Grouping of masonry houses
After considering the categorization explained above, we proposed appropriate
retrofitting promotion systems to each group considering the economic and social
situations, as shown in Table 2.
Table 2: Proposed promotion systems for each masonry category
Masonry Type

Proposed promotion system

Urban Group

Micro Earthquake Insurance (MEI) based Promotion System

Semi-urban Group

Government Micro Earthquake Reinsurance based Promotion
System I (GMER I)

Rural Group

Government Micro Earthquake Reinsurance based Promotion
System II (GMER II)

MF Group

Micro Credit based Promotion System (MC System)

3. PROPOSAL OF SEISMIC RETROFITTING PROMOTION SYSTEMSIn the following proposed systems, premium is either set at a low price or none bymaking use of micro insurance and microfinance. Also, these systems aredesigned for all stakeholders to each have their own benefits, as introduced below.
In each system, three kinds of workers for retrofit are considered, i.e. selfretrofitting by the house owners themselves, by local masons, and by PP-band
method-licensed masons. Although we considered these three subsystems, only
the self-retrofitting model is introduced here due to space limitation.

Promotion System for PP-band Retrofitting of Non-Engineering Masonry Houses

October 2010, Kobe, Japan

3.1 Micro Earthquake Insurance based Promotion System (MEI System)
In this system, residents who have performed PP-band retrofitting using materials
provided freely by the insurance companies will be insured, and when theirhouses are damaged due to earthquake, they will receive insurance money worth
their house rebuilding cost. The premium will include the retrofitting cost andinsurance money, but since PP-band retrofitting is cheap and the damage can be
reduced drastically, the premium can be set at a low price. The insurance premium
was estimated in the validation.
Insurance

Insurance

Government

Government

4. Insurance
2. Material

EQ

6. Insurance money 7. Compensation

1. Premium

3. Self-retrofit

Non-retrofit

5. damagedamageFigure 2: Micro Earthquake Insurance based Promotion System (MEI System)
3.2 Micro Earthquake Government Reinsurance
based Promotion System I (MEGR I)This system is basically the same as the MEI System, but the premium will belower because it will not include the retrofitting cost. Insurance companies willbear the retrofitting cost at the initial stage and collect the cost back from thegovernment when an earthquake occurs. The insurance premium was estimated in
the validation.
0. Reinsurance contract
Insurance
Government

6. Reinsurance money + α
Insurance
Government

4. Insurance
2. Material

EQ

1. Premium

3. Self-retrofit

Non-retrofit

expected
7. Insurance money< compensation
without retrofit

5. damagedamageFigure 3: Micro Earthquake Government Reinsurance based Promotion System I(MEGR I)
3.3 Micro Earthquake Government Reinsurance
based Promotion System II (MEGR II)
In this system, the insurance companies will bear the retrofitting cost and theresidents will be insured. Insurance companies will receive reinsurance moneyfrom the government and collect retrofitting cost and insurance money forresidents, together with their profit. Reinsurance money will be paid within therange of the amount of compensation money which was reduced for damaged
New Technologies for Urban Safety of Mega Cities in Asiapeople due to retrofitting, which can be considered as government’s benefit. The
insurance money for residents and profit for insurance companies were estimatedin the validation.
0. Reinsurance contract
Insurance
Government

1. Material + 3. Insurance

2. Self-retrofit

5. Reinsurance money + α
Insurance
Government

EQ

Non-retrofit

expected
7. Insurance money< compensation
without retrofit

4. damagedamageFigure 4: Micro Earthquake Government Reinsurance based Promotion System II(MEGR II)
3.4 Microfinance based Promotion System (MF System)
In this last system, MFIs (Microfinance Institutes) will collect retrofitting costthrough investment and perform retrofitting. Residents who have performed
retrofitting will receive micro credit loan as an incentive. MFIs will collectinsurance money from the government, collect outstanding loan balance, and also
give return to the investors. For the investors, this extra dividend will be an
incentive to invest, as well as the clear social contribution in terms of earthquake
disaster mitigation. The expected amount of collection on outstanding loanbalance for MFIs and ROI (rate of return) per investment (= retrofitting cost) were
estimated in the validation.
Government
Investors
0. Insurance contract
Investors
MFIs
1. Invest
2. Material + 4. Loan

3. Self-retrofit

Non-retrofit

Government
6. Payout
MFIs

Investors
Investors
7. ReturnEQ

5. damagedamageFigure 5: Microfinance based Promotion System (MF System)

4. VALIDATION OF THE PROPOSED SYSTEM
Validation focused on the economic aspects of the stakeholders in each system.
First, earthquake risk was defined at 25 levels as shown in Figure 6. Second,fragility functions were used to estimate the earthquake damage for each
earthquake risk. Fragility functions of 1) adobe and/or mud, 2) brick and/or stone,3) brick 1-2F, 4) brick 3F and 5) concrete block houses were used for comparative
study among the different structures. For PP-band retrofitted structures, 1) selfretrofit (retrofitted by house owners), 2) local mason-retrofit (retrofitted by local
masons) and 3) licensed-retrofit (retrofitted by PP-band licensed masons) wereused, considering upper (+) and lower (-) bounds. Finally, the economic effects

Promotion System for PP-band Retrofitting of Non-Engineering Masonry Houses

October 2010, Kobe, Japanfor the stakeholders were estimated for each system. The results shown below arefor each structure type in the case of self-retrofitting.
50 years exceedance probability （return period）
PGV [㎝
2%
5%
10%
39%
62%
/s]
(2745 yrs)
(975 yrs)(475 yrs)(100 yrs)(50 yrs)

JMA
4

8.1

5-

16

5+

31

6-

60

6+

116

KashmirJava
Kashiwazaki

Tokyo
Shizuoka

Figure 6: Earthquake risk

Figure 7: Fragility functions (JICA, 2005 & JICA and IMM, 2002)

Building cost
(US$)
3,000

Table 3: Costs used for analysis
Retrofitting cost (US$)
Self-retrofit
by local mason
By licensed mason30
150(30+120)
270(30+120x2)

annual premium (US$/unit)+annual premium (US$/unit)+

63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

16

10

10

8

8

6

6

4

4

2

2

0

0

8.1

PGV

116

Micro Insurance (self-retrofit)

Figure 8: Premium for MEI system

63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

16

8.1

PGV

116

Government + Insurance (self-retrofit)

Figure 9: Premium for GMER I system

New Technologies for Urban Safety of Mega Cities in Asia

Table 4: Comparison of the earthquake insuranceJapan
California
New ZealandPremium rate (%)
0.50-3.15
0.46-8.05
0.50
Insurance money limit (US$)
550,000
100,000
61,000
The annual premium was estimated to be less than 10 US$ at all 25 earthquake
risk levels under the condition that residents will receive insurance money equal
to the building cost. Compared to the other earthquake insurances in the world, as
shown in Table 4, this system is valuable to the residents.
Insurance money for residents was more than 2,000 US$ per year at highearthquake risk levels. If the contract is made for 10 years, insurance money willbe 20,000 US$, which is sufficient for rebuilding a house. For insurancecompanies, annual profit by reinsurance money was estimated, which was in thepositive for all earthquake risk levels. This means that this system has an incentive
to both the residents and the insurance companies. Furthermore, insurancecompanies have a chance to spread insurance to low income people by this system.
When we calculated the amount of collection on outstanding loan balance for
MFIs, it became positive at all earthquake risk levels. In addition, ROI (rate of
return on investment) per investment (= retrofitting cost) was estimated to bepositive at all earthquake risk levels. For the MFIs, this means they may be able tocollect their outstanding loans within less than 10 years in most cases, as shown in
Table 5.

5. CONCLUSIONSTo promote seismic retrofitting of low earthquake-resistant houses by PP-band
retrofitting method, four promotion systems for seismic retrofitting
implementation were proposed and validated for their economic effects. With theMicro Earthquake Insurance (MEI) based Promotion System and the Government
Micro Earthquake Reinsurance based Promotion System I (GMER I), the annual
premium was estimated to be no more than 10 US$ per unit at 25 different
earthquake risk levels. With the Government Micro Earthquake Reinsurance based
Promotion System II (GMER II), insurance money was enough to rebuild a house,even at relatively high earthquake risk levels. In addition, profit for insurancecompanies was estimated under the condition that residents will receive insurancemoney sufficient for reconstruction. With Micro Credit (MC) based Promotion
System, the amount of collection on outstanding loan for MFIs, and ROI for
investors were estimated, both of which proved to be in the positive. Furthermore,
validation was done for five different structures and three different retrofitting
conditions, which allows consideration of implementation in areas with combined
structures. Therefore, we conclude that this study has proposed effective
promotion systems, together with an index for implementation.

Promotion System for PP-band Retrofitting of Non-Engineering Masonry Houses

October 2010, Kobe, Japan

expected annual insurance money (US$/unit)+

expected annual profit (US$/unit)+

3500
3000
2500
2000
1500
1000
500
0
63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

116

16

8.1

60
50
40
30
20
10
0
63%

PGV

adobe, mud (self-retrofit)

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

expected annual insurance money (US$/unit)+

116

16

PGV

adobe, mud (self-retrofit)

expected annual profit (US$/unit)+

3500
3000
2500
2000
1500
1000
500
0
63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

116

16

63%

8.1

39%

50 yrs exceedance
probability

PGV

8.1

10%

5%

60
2%

31

16

8.1

PGV

116

adobe, mud (self-retrofit)

brick, stone (self-retrofit)

expected annual insurance money (US$/unit)+

expected annual profit (US$/unit)+

500

60

400

50
40

300

30

200

20

100

10

0
63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

116

16

0

8.1

63%

PGV

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

brick 1-2F (self-retrofit)

116

16

8.1

PGV

brick 1-2F (self-retrofit)

expected annual profit (US$/unit)+

expected annual insurance money (US$/unit)+
300
250
200
150
100
50
0
63%

39%

50 yrs exceedance 10%
probability

60
50
40
30
20
10
0
-10

31
5%

60
2%

116

16

63%

8.1

39%

50 yrs exceedance
probability

PGV

10%

5%

60
2%

31

16

8.1

60
50
40
30
20
10
0
-10

PGV

116

brick 3F (self-retrofit)

brick 3F (self-retrofit)

expected annual insurance money (US$/unit)+

expected annual profit (US$/unit)+

400

60
50

300

40

200

30
20

100

10

0
63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

116

16

8.1

PGV

concrete block (self-retrofit)

0
63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

116

16

8.1

PGV

concrete block (self-retrofit)

Figure 10: GMER II system (left: insurance money, right: profit)

New Technologies for Urban Safety of Mega Cities in Asia

annual collection on outstanding loan (US$/unit)+annual ROI (per investment)+

60

200%

50

150%

40
30

100%

20

50%

10
0
63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

116

16

0%

8.1

63%

PGV

adobe, mud (self-retrofit)

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

annual collection on outstanding loan (US$/unit)+

63%

39%

50 yrs exceedance
probability

10%

5%

60
2%

31

16

8.1

60
50
40
30
20
10
0
-10

PGV

8.1

PGV

adobe, mud (self-retrofit)

annual ROI (per investment)+
200%
150%
100%
50%
0%
63%

39%

50 yrs exceedance
probability

116

116

16

10%

5%

60
2%

31

16

8.1

PGV

116

brick, stone (self-retrofit)

brick, stone (self-retrofit)

annual collection on outstanding loan (US$/unit)+annual ROI (per investment)+

60

200%

50

150%

40
30

100%

20

50%

10
0
63%

39%

50 yrs exceedance 10%
probability

31
5%

60
2%

116

16

0%

8.1

63%

PGV

39%

50 yrs exceedance 10%
probability

31
5%

60
2%

brick 1-2F (self-retrofit)

116

16

8.1

PGV

brick 1-2F (self-retrofit)

annual ROI (per investment)+

annual collection on outstanding loan (US$/unit)+
60

200%

50

150%

40
30

100%

20

50%

10
0
63%

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

116

16

0%

8.1

63%

PGV

39%

50 yrs exceedance
probability

10%

31
5%

60
2%

brick 3F (self-retrofit)

116

16

8.1

PGV

brick 3F (self-retrofit)

annual ROI (per investment)+

annual collection on outstanding loan (US$/unit)+
60

200%

50

150%

40
30

100%

20

50%

10
0
63%

39%

50 yrs exceedance 10%
probability

-50%

31
5%

60
2%

116

16

8.1

PGV

concrete block (self-retrofit)

0%
63%

39%

50 yrs exceedance 10%
probability

31
5%

60
2%

116

16

8.1

PGV

concrete block (self-retrofit)

Figure 11: MF system (left: collection on outstanding loan, right: ROI)

Promotion System for PP-band Retrofitting of Non-Engineering Masonry Houses

October 2010, Kobe, Japan

Table 5: Amount of the outstanding loan
(Microfinance Information Exchange, 2008)
Africa
Asia
ECA
LAC
MENA

2005 (US$)
174
120
1,127
642
241

2006(US$)
241
139
1,404
684
264

2007(US$)
325
164
1,931
848
345

REFERENCES
Earthquake Engineering Research Institute and International Association for
Earthquake Engineering (2009). “World Housing Encyclopedia”, http://worldhousing.net/
Iritani, S., Mayorca, P., and Meguro, K. (2008). “Proposal of a system to promote
retrofitting of vulnerable masonry houses in developing countries.” Bulletin ofEarthquake Resistant Structure Research Center, No. 41, 55-60.
Japan International Cooperation Agency (2005). “The Study on Seismic
Microzoning of the Greater Teheran Area in the Islamic Republic of Iran.”
JICA and IMM (2002). “The Study on A Disaster Prevention/Mitigation Basic
Plan in Istanbul including Seismic Microzonation in the Republic of Turkey.”
Meguro, K. (2006) “Damage to non-engineered structures due to the 2005
Northern Pakistan Earthquake and development of low cost and feasible
retrofit method for masonry structures.” Journal of Japan Society for Natural
Disaster Science, No. 25-3, 381-392.
Microfinance Information Exchange (2008), Micro Banking Bulletin: 2005-2007
benchmarks.
P.Mayorca and K.Meguro (2003), Proposal of a new economic retrofitting method
for masonry structures, Proc. of the 27th JSCE Symposium of Earthquake
Engineering.

New Technologies for Urban Safety of Mega Cities in Asia

DIAGNOSIS OF THE SEISMIC
VULNERABILITY OF BUILDINGS AT DHAKAUSING NON-DESTRUCTIVE TESTING
MD. SAIDUR RAHMAN
Research Engineer, BNUS, BUET, Bangladesh
BUSHRA ISLAM
Research Engineer, JBSIP, BUET, Bangladesh
MEHEDI AHMED ANSARY
Professor, Department of Civil Engineering &Director, BUET-JIDPUS, BUET, Dhaka, Bangladesh
ansary@ce.buet.ac.bd

ABSTRACT
Bangladesh has been identified as a moderate earthquake vulnerable country
according to the World Seismic Map. The frequency of earthquake occurrence
points to the probability of facing a serious seismic hazard. Unfortunately, fromthe studies performed in six important locations of Dhaka city the discrepancy
between seismic design according to Bangladesh National Building Code and thesurveyed buildings at different areas in the capital of Bangladesh has been
observed. Furthermore, infrastructure construction by land fill has been marked
as the potential risk for seismic hazard due to liquefaction of these reclaimed soils.
In addition, some buildings are found to be risky due to the unavailability of
appropriate building documents. All these factors are clearly jeopardizing to theoverall safety of Dhaka city.
The main objective of the paper is to ascertain the details survey of building
including the dimension of structural elements, structural irregularities andreinforcement detailing which consists of spacing, bar number, clear cover for
beam, column and slab. Basically two non-destructive testing, Ferroscan
measurement and microtremor observations have been executed in order tocollect data. Ferroscan is used to obtain reinforcement diameters and location
within the RC buildings and MICROTREMOR has been used to determine thenatural frequency of the Buildings. Some major findings are obtained from theanalysis of the surveyed data. Most of the buildings do not have proper
reinforcement arrangement, lack anti seismic design etc. In a few cases, thenatural frequency of building is close to that of soil. There is a possibility ofresonance. Seismic vulnerability of a few studied buildings has also been
evaluated based on the Provision of Japanese RC Building Seismic Evaluation
criteria. It shows the same threatening condition as found from the nondestructive testings. It can be said that if the effective step is not taken right now
the people of Dhaka city may suffer greater seismic risk, in which most of thefaulty building may collapse.
Keywords: seismic hazard, retrofitting, structural element, natural frequency

0ctober 2010, Kobe, Japan

1. INTRODUCTION
The purpose of this study is to analyze the seismic vulnerability of buildings at
various locations in Dhaka city. In order to do this, checking structural elements
in light of seismic design and analysis of resonance phenomena between building
and soil on the basis of natural frequency has been executed. Therefore, two nondestructive tests have been carried out in this project. In addition, the seismic
evaluation of buildings according to the first level of screening procedure of theJapanese RC building seismic evaluation provision has also been performed.
Ferroscanner, the electromagnetic detector to record image of reinforcements inconcrete up to 100 mm depth, is the efficient device for the identification ofreinforcement if there is no found basic design document or having contradiction
to design in this building. Column and Lift Core are the most important elements
in any structural system. This is why the above two structural elements along withslabs have been surveyed properly using Ferroscanner. In this survey, detection ofreinforcement includes number of reinforcement, spacing of reinforcement, barnumber and cover over the reinforcement. Eighty three buildings have been
selected at six locations in Dhaka city as shown in Figure 1. These are Old Dhaka,
BUET campus, Lalmatia, Mirpur, Banani and Uttara.

Figure 1: Survey site at Dhaka city (Source: Google map)
In addition, Microtremor is also used to record the fundamental frequency andperiod of those buildings and soil. The dynamic properties are the important factor
for seismic design. Response of building mainly depends on the characteristics ofboth excitation forces and dynamic properties of buildings. This is why the natural

New Technologies for Urban Safety of Mega Cities in Asia

frequency and period is taken on the top of the roof of those building to identify
the dynamic properties of buildings. Furthermore, the vibration characteristics insoil are different from building. Hard soil gives high frequency and soft soil gives
low frequency. A structure may experience a vibration period at which it
oscillates in the earthquake vibration motion and will tend to response to that.
Natural frequency of structure is obtained based on the spectral ratio of horizontal
component of the building to that of ground. Meanwhile, practical application of
Microtremor in the field of engineering has advanced tremendously. One of thepowerful and simplest applications of Microtremor observation is in seismic
micro zoning (see Figure 2).

Figure 2: Seismic Microzonation Map for Dhaka City
(after Rahman, 2004)
From the data analysis of these building, most of the building are vulnerable due
to moderate seismic activity. In Old Dhaka, the majority of buildings are notconstructed according to proper seismic design code. Some of these buildings arelikely to be damaged because of lower intensity of earthquake. In BUET campus,
about twenty nine buildings natural period are not close to that of soil. So, they
are out of danger of resonance and natural period of the remaining twenty one
buildings are close to that of soil, so their seismic response can be considerably
amplified. Results obtained from Ferroscan are not satisfactory. Variation of coverand spacing of lateral ties in columns and stirrups in beam from design are above
acceptable limit. The buildings of three places like Lalmatia, Mirpur and Uttara
are vulnerable due to medium seismic force. There is a significant variation in
reinforcement in those buildings. Some of them are vulnerable due to resonance.
2. CHECKING OF STRUCTURAL ELEMENTS USING FERROSCAN
Ferro-scanner, which detects reinforcements in concrete, is efficient device for thedetection of structural elements in a concrete building. There are many methods
for the diagnosis of the rebar arrangement like Electromagnetic method, X-ray
measurement, and High energy X-ray CT Scan and Radar inspection. In our
survey, Electromagnetic method in Ferroscanner has been utilized in the surveyedbuilding.

Diagnosis of the Seismic Vulnerability of Buildings at Dhaka using non-destructive testing

0ctober 2010, Kobe, Japan

When electric current run through a coil of the apparatus, magnetic field is formed.
Electric current is produced in the reinforcement bar because of the magnetic field.
The field induces electric current in the secondary coil to be measured. Whenelectric current runs through a coil of the electro-magnetic sensor, magnetic flux
is measured. Electromotive force of coil changes due to magnetic flux. Thicknessof clear cover or diameter of the reinforcement bar can be estimated frommagnetic flux change. Induced magnetic field depends on the distance between
sensor and reinforcement. When bars are too close, it becomes difficult to identify
the numbers of bar. The rebar detection ranges usually 120-150mm depending on
bar size and maximum depth is 180mm. Depth measurement ranges 100-140 mm
depending in bar size. However, depth accuracy is ±2.5 mm for most bars at
common depth.
The Hilti PS 200 is a system used for high-end reinforcement detection. The
important elements of the system are the scanner, the monitor and the software.
Scanner (PS 200 S) is used to scan the reinforced concrete element whereas
Monitor (PS 200 M) is used to show the bar and to analyze on site (see figure3(a)).
For Ferroscan observation the team identified the column and marked them indrawing as well as in the structural part of the building. Then they scan it carefully
with the scanner and store the data. The collected raw data were analyzed withhelp of the Ferroscan software. Sometimes hardboard has been used to execute thescan efficiently. Figure 3(b) shows the process of Ferroscan and the reinforcement
data in Villa Vatia.

Figure 3(a): PS 200 Ferroscan system

Figure 3(b): Column and slab checking using Ferroscan

New Technologies for Urban Safety of Mega Cities in Asia

3. MICROTREMOR OBSERVATIONFor Microtremor observation, sensors have been fixed on the floor of building at
the beginning. The sensor has been placed on the basis of long side and short sideof building. Three sensors have been located at different places to find out
structural stiffness and natural period. One sensor has been fixed at the top of thebuilding, one at the free field near the building and other at any floor level ofbuilding. In this survey, approximately 60,000 data points with sampling
frequency 100 have been recorded. Sometimes observation of the two building
has been taken to save time. After taking the observation with the help of aprogram the time domain velocity data is converted to frequency domain data andfind out the natural period of the buildings. Microtremor measurement instrument
is shown below in Figure 4.
SensorBatterCable
LaptopFigure 4: Microtremor data recording at Ameralo, Banani
Soil characteristics can be assessed by Microtremor measurement. Hard soil gives
high frequency and soft soil gives long period. A structure may experience avibration period at which it oscillates in the earthquake vibration motion and willtend to response to that. Natural frequency of structure is obtained based on the
spectral ration of horizontal component of the building to that of ground. The
velocity time histories along three directions and Fourier spectrums at different
time interval in KING SHOPTAK RAJONIGANDA (MIRPUR) are shown in Figures 5
and 6 respectively.

X-direction

Y-direction

Z-direction

Figure 5: Velocity time history at X, Y and Z directions

Figure 6: Fourier spectrums of two time intervals of 20 seconds each (from90 to 110 seconds and from 400 to 420 seconds)

Diagnosis of the Seismic Vulnerability of Buildings at Dhaka using non-destructive testing

0ctober 2010, Kobe, Japan

Wave propagation mechanism of Microtremor and its relation with groundvibration characteristics were studied from the beginning of Microtremor studies(Aki, 1957; Kanai and Tanaka, 1961). There are two types of Microtremor
observations. These are point and array observations of microtremors (Ansary etal., 1996). From the array observation of Microtremor of period greater than 1 sec,
Rayleigh-wave and Love-wave originating from natural sources, such as sea wave,
variation of air and wind pressure can be recognized. On the other hand, shortperiod Microtremor of period less than 1 sec is thought to be generated byartificial noises such as traffic vehicles, industrial plants, household appliances,
etc. Some researches (Sato et al., 1991; Tokimatsu and Miyadera, 1992;
Tokimatsu et al., 1994) have showed that microtremors are mainly composed ofRayleight-wave and some (Nakamura, 1989; Wakamatsu and Yasui, 1995) haveshowed that short-period Microtremor bears resemblance to shear-wave
characteristics. Nevertheless, Microtremor can also be dominated by Love–wave(Tamura et al., 1993). Recently, Suzuki et al. (1995) have applied Microtremor
measurements to the estimation of earthquake ground motions based on ahypothesis that the amplitude ratio defined by Nakamura can be regarded identicalwith half of the amplification factor from bedrock to the ground surface. However,
the real generation and nature of microtremors have not yet been established.
4. DATA ANALYSIS
In this study, about eighty three buildings have been checked on various points ofview, such as structural element checking using Ferroscan, resonance and stiffness
criteria using Microtremor, and the first level of screening procedure of Japanese
RC building seismic evaluation provisions (2001).
Table 1 shows the probability of resonance in surveyed places. On the other hand,
Table 2 gives the structural vulnerability of building on the basis of Ferroscan. In
addition to these, Table 3 and Table 4 represent Seismic index of structure IS andof non-structural elements IN. The most of the building in BUET campus arevulnerable in consideration of resonance because the predominant period of thesebuildings is close to that of the soil. However, some of them are unlikely to cause
resonance phenomena. But there is structural disparity from various points ofview in according to our National Building Code (BNBC, 1993). The building has
major structural irregularities such as soft story, re-entrant corner, torsional
irregularity, soft story and story mass irregularity. Moreover, variation of clear
cover is high. Spacing of lateral ties in column is not as per code.
The buildings in Old Dhaka are likely to be occurred severe seismic hazard. Mostof the building, residential as well as religious purposes, is not built according to
BNBC (1993). In those areas, resonance phenomena are not analyzed, but,
structural vulnerability has been investigated properly. Variation of clear cover ishigh in most of the building. Spacing of lateral ties in column is not as per code.
But, there are a few buildings in those areas which are quite good in considerationof seismic activities. However, majority of the buildings are vulnerable not only
for the seismic activity, but also fire or any other hazard.

New Technologies for Urban Safety of Mega Cities in Asia

The building in others areas, like Banani, Mirpur, Lalmatia and Uttara, arevulnerable due structural irregularity as well as resonance. But, there are a few
buildings in those areas which are quite good in consideration of two importantseismic activities. Furthermore, the construction quality of those buildings is notvery well. Some buildings are not constructed according to our National Building
Code.
Table 1: Predominant period of buildings from Microtremor observations
Building Name andLocation
AMARELO
H#77/B, R#3, BLOCK#F, BANANIKing Shoptak
Rajoniganda, 2
2/C, AVENUE-3, PLOT3, HAZI ROAD,
MIRPUR-2
MI-NIBASH
H# 1/3, R#19,BLOCK#B,
SECTION #10,
MIRPUR, DHAKA-1216
NHB
15/3, Ibrahimpur,Mipur14
RIDGE VALLEY
H#29, R#7, BLOCK#F,
BANANI MODELTOWNVILLA VATIA
H#3/8,BLOCK#E,LALMATIA,DHAKA-1207
SUVASTU SARINA
H#1/4,BLOCK#F,LALMATIA, DHAKA-1207
TOTAL GODHULI
PLOT-16, SECTOR-10,
ROAD-11, UTTARA
R/A, DHAKAIFCDR Building, BUET
Eleven Storey Tower
Building, BUET
Civil Engineering
Building, BUETEME Building, BUET
Library Building, BUET
Architecture Building,
BUET
URP Building, BUETARC Building, BUET
New Academic Building,
BUET
Controller of

0.6

Observed period(sec)
XYdirection direction
0.44
0.35

Xdirection
0.2

Ydirection
0.2

7

0.7

0.34

0.45

0.25

0.25

No

9

0.9

0.32

0.39

0.30

0.30

YES

6

0.6

0.41

0.43

0.30

0.30

No

10

1

0.51

0.30

0.25

0.25

No

7

0.7

0.35

0.37

0.20

0.20

No

8

0.8

0.31

0.43

0.20

0.20

No

6

0.6

0.5

0.3

0.26

0.26

YES

4
11

0.4
1.1

0.5
0.4

0.5
0.4

0.7
0.3

0.65
0.3

No
No

7

0.7

0.26

0.39

0.5

0.33

No

7
5
5

0.7
0.5
0.5

0.37
0.33
0.26

0.37
0.36
0.38

0.25
0.25
0.4

0.25
0.26
0.4

YES
No
YES

5
5
12

0.5
0.5
1.2

0.27
0.18
0.27

0.3
0.3
0.18

0.4
0.5
0.32

0.4
0.26
0.35

YES
No
No

5

0.5

NA

NA

0.3

0.35

YES

Storeyof
Building

T=
N/10

6

Site period (sec)

ProbabilityofResonance
No

Diagnosis of the Seismic Vulnerability of Buildings at Dhaka using non-destructive testing

0ctober 2010, Kobe, Japan

Building Name andLocation
Examination building,
BUET
Engg. University School
Building, BUET
Titumir Hall, BUET
Sher-e-Bangla Hall,
BUET
Dr. M.A. Rashid Hall,
BUET
Building Number 47
BUET
Building Number 62
BUET
Fire Service Station(Head Office, Dhaka)
BUET
Ban Bhaban Main
Building, BUET
Fire Service Station,
Lalbag, BUET
Shahid Smirity Hall
middle Building, BUET
Shahid Smrity Hall north
Building, BUETStoreyof
Building

T=
N/10

Observed period(sec)
XYdirection direction

Xdirection

Ydirection

4

0.4

NA

NA

NA

0.52

YES

4
4

0.4
0.4

0.24
0.32

0.27
0.27

0.38
0.38

0.52
0.31

NO
YES

4

0.4

0.32

0.32

0.32

0.38

YES

6

0.6

0.39

0.34

0.38

0.32

YES

6

0.6

0.32

0.28

0.3

0.3

YES

6

0.6

0.4

0.38

0.3

0.3

YES

5

0.5

0.3

0.3

0.3

0.23

YES

4

0.4

0.27

0.25

0.07

0.06

YES

4

0.4

0.3

0.28

0.18

0.07

YES

5

0.5

0.2

0.2

0.32

0.3

No

Site period (sec)

ProbabilityofResonance

Note: X = Long direction and Y = Short direction
Table 2: Data analysis (Ferroscan)
Building Name andLocation
TEACHERS' QUARTER
47/1-6, BUET campus
AMARELO
H#77/B, R#3, BLOCK #F,
BANANI
King Shoptak Rajoniganda,
2/C, AVENUE-3, PLOT-3,
HAZI ROAD, MIRPUR-2
MI-NIBASH
H# 1/3, R#19,BLOCK#B,
SECTION #10, MIRPUR,DHAKA-1216
NHB 15_3
15/3, Ibrahimpur,Mipur-14
RIDGE VALLEY
H#29, R#7, BLOCK#F,
BANANI MODEL TOWNVILLA VATIA
H#3/8, BLOCK#E,
LALMATIA, DHAKA1207

Adequacy of Reinforcement

Structural
Vulnerability

ColumnSlabBeam/shear wall

not okok

not tested

moderateokok

not tested

moderate

not okok

not tested

moderate

not oknot oknot tested

high

not oknot oknot tested

high

ok

ok

not okmoderate

not okok

not tested

moderate

New Technologies for Urban Safety of Mega Cities in Asia

Building Name andLocation
SUVASTU SARINA
H#1/4,BLOCK#F,
LALMATIA, DHAKA1207
TOTAL GODHULI
PLOT-16, SECTOR-10,
ROAD-11, UTTARA R/A,
DHAKA
Islampur Jame Mosque
57, 58; Islampur road
Jhubbu Khanam Jame
Mosque, 24, Islampur road
Kamranga Jame Mosque
Zindabahar 1st Lane
Mahuttuli Jame Mosque
55,Sharat Chandra
Chakrobarti Road
Malibagh(Bangshal) Peyala
Mosque, Bongshal Road

Adequacy of Reinforcementokok

not tested

Structural
Vulnerability
moderate

not okok

not okhigh

not oknot tested

not tested

high

not oknot tested

not testedHigh

not oknot oknot okhigh

not oknot tested

not tested

high

ok

not oknot tested

moderate

Kosaituli Old Jame Mosque
26/27, K.P. Ghosh Street
Bangshal RokonUddin
Jame Mosque, Bongshal
Road
Anondomoyee Girls's HighSchool, 17-18 Kazi Muddin
Siddque Street
Haybotnagar Primary
School13,'Haibat Nagar Dewan
Jummon Community Centre
19-1,19-2(I),'Hazi Abdur
Rashid Lane
Mokimbaza school
Mahuttuli primary School
27, Sharat Chandra
Chakrobarti Road
Nobab Yousuf Market
Mosque Nobab Eusuf Road
ShahjadaMia Jame Mosque
24, Shahjada Mia Lane
Jindabahar Jame Mosque
54, Zindabahar 1st Lane
Maulana Mosque
97/98, K.P. Ghosh Street
Shahjadi Begum Jame
Mosque, 45, Bagdasha Lane
Samsabad Boro Mosque
K.P. Ghosh Street
Kosaituli panchayet
Committee and School
9, Kazi Muddin Siddque
StreetBabubazar Ghat Jame
MosqueRay Eshar Chandra Ghoshokok

not tested

moderate

not okok

not tested

moderateok

not oknot tested

moderate

not okok

not tested

moderate

Not oknot oknot tested

moderateok
not oknot testedok

not tested
not tested

quite goodmoderate

not oknot oknot okhigh

not okok

not tested

moderate

not oknot oknot okhigh

not okok

not tested

moderateok

not oknot tested

moderateok

not oknot tested

moderateokok

not tested

moderateokok

not tested

moderate

Diagnosis of the Seismic Vulnerability of Buildings at Dhaka using non-destructive testing

0ctober 2010, Kobe, Japan

Building Name andLocation
Ahmed Bawani School andCollege
3/4, K.P. Ghosh Street
Samsabad Primary School
79, K.P. Ghosh Street
Kona Party Centre
11-12,S.C.C Road
Ahmedabad school
3/4, K.P. Ghosh Street
Mosjid-e-Baitul-Mamur
69 French Road, Mosjid-eBaitul-Mamur
IFCDR Building, BUET

Adequacy of Reinforcement
not okok

not tested

Structural
Vulnerability
moderate

not okok

not okmoderate

not oknot oknot okhigh

not okokok

not oknot tested

moderateokok

not okmoderate

Eleven Storey Tower
Building, BUET
Civil Engineering Building
BUET
EME Building, BUET

not okok

not okmoderate

not okok

not okmoderate

not okok

not okmoderate

Library Building, BUET

not okok

not tested

moderate

Architecture Building
BUET
URP Building, BUET

not okok

not okmoderate

not okok

not okmoderate

ARC Building, BUET

not okok

not okmoderate

New Academic Building
BUET
Controller of Examinationbuilding, BUET

not okok

not okmoderate

not okok

not okhighEngg. University School
Building, BUET
Titumir Hall, BUET
Sher-e-Bangla Hall, BUET

not oknot tested

not okmoderate

not oknot oknot oknot oknot oknot okmoderate
moderate

Dr. M.A. Rashid Hall
BUET
Building Number 47, BUET

not oknot oknot okmoderateok

not testedokmoderate

Building Number 62, BUET

ok

ok

ok

moderate

Fire Service Station (Head
Office, Dhaka)

not oknot oknot okmoderate

Ban Bhaban Main Buildingok

not tested

not okmoderate

Ban Bhaban Extended
PortionFire Service Station, Lalbag

ok

not tested

not okhighok

not oknot tested

moderate

Ahsan-Ullah hall, BUET

not oknot oknot okhigh

Shahid Smirity Hall middle
Building, BUET

not okokokmoderate

Shahid Smrity Hall north
Building, BUET

not okokokmoderate

moderate

New Technologies for Urban Safety of Mega Cities in Asia

5. SEISMIC EVALUATION FOLLOWING THE FIRST LEVEL OFSCREENING PROCEDURE
The provisions of the Standard of Japanese RC building evaluation (2001) isapplied to seismic evaluation of existing reinforced concrete buildings of Dhaka.
The seismic evaluation is done based on both site inspection and structural
calculation to represent the seismic performance of a building in terms of seismicindex of structure IS and seismic index of non-structural elements IN. The seismic
safety of the building shall be judged based on standard for judgment on seismic
safety wherein seismic performance demands are prescribed.
The standard is applied to the seismic evaluation and the verification of seismic
retrofitting of existing low-rise and medium-rise reinforced concrete buildings.
Three levels of screening procedures, namely the first, the second, and the thirdlevel screening procedures, are available for the seismic evaluation according tothis standard. In the present study first level of screening procedure is used.
The seismic index of structure IS can be calculated at each story and in eachprincipal horizontal direction of a building. Here the index has been calculated fora typical story in weak direction. The seismic index of structure includes basic
seismic index of structure EO, irregularity index SD and time index T. The basic
seismic index of structure EO evaluates the basic seismic performance of thebuilding. It is calculated at each story and each direction based on the ultimate
strength, failure mode and ductility of the building. These effects are consideredby applying the strength index C, the ductility index F and the effective strength
factor α. The vertical structural members are classified into three categories ascolumn, extremely short columns and wall, according to the provision. The
strength index in the first level of screening procedure is calculated approximately
using the cross sectional area of walls and columns. The irregularity index SD andtime index T are used commonly for all stories and directions in the first level ofscreening procedure. The irregularity index SD is to modify the basic seismicindex of structure EO by quantifying the effects of the shape complexity and thestiffness unbalance distribution, and the seismic performance of a structure withengineering judgment. The time index T evaluates the effects of the structuraldefects such as cracking, deflection, aging and like on the seismic performance ofa structure.
Seismic index of non-structural elements IN is to judge the safety of human lives
or the security of evacuation routes against the fall-down or the spall-off of nonstructural elements, especially external walls. IN shall be calculated by following
the procedures provided for the first level screening procedure for each wall ineach story. In current seismic evaluation IN is calculated for the walls based on the
representative condition present in a specific story of a building. The seismicindex of non-structural elements includes construction index and human risk
index which shall be adopted for the external walls considering the mostvulnerable construction method, that is, which gives the maximum value of theconstruction index, among the walls concerned. The construction index is
calculated from conformability index and deterioration index. The conformability
index is determined in combination of ductility grade of the primary structure andDiagnosis of the Seismic Vulnerability of Buildings at Dhaka using non-destructive testing

0ctober 2010, Kobe, Japan

ductility grade of non-structural elements. The deterioration index is based on
aging and past damages. The human risk index is based on the condition of usage
below the external wall and the existence of guard such as the eaves, set back andthe like.
Seismic safety of a building shall be judged by comprehensive assessment basedon the seismic evaluations separately conducted on the structure and nonstructural elements. Seismic safety of structure is judged by comparing theseismic index of structure and the seismic demand index of structure ISO. The
building may be assessed to be safe if the building possesses the seismic capacity
required against the expected earthquake motions. Otherwise the building should
be assessed to be uncertain in seismic safety. The seismic demand index ofstructure ISO is calculated for first level of screening, based on the basic seismic
demand index of structure ES taken as 0.8, zone index Z as 1.2 (Rahman, 2004),
ground index as 1.0 and usage index as 1.0, regardless of the story in the building.
The index calculated for the seismic evaluation of a few selected buildings isenumerated in Table 3 and comment on their safety judgment is shown in Table 4.
Table 3: Seismic index of structure IS and of non-structural elements IN

44

No of Storyfor
Evaluation, i
2
2

12

2

5
4
4

2
2
2

1.494
0.702
1.148
0.761

7

2

0.902

No. ofStories, n

Building
IFCDR Building
Titumir Hall
New Academic
Building
M A Rashid Hall
Library Building
ARC Building
Civil Engineering
Building

EO

SD

T

IS

B

H

IN

0.602
0.458

1.2
1.14

0.9
0.8

0.65
0.42

0.8
0.8

0.5
0.5

0.6
0.6

1.14

1.70

0.8

0.5

0.6

1.14
1.14
1.2

1
0.8
0.8
1

0.64
1.05
0.91

0.8
0.8
0.8

0.5
0.5
0.5

0.6
0.6
0.6

1.14

0.8

0.82

0.8

0.5

0.6

Table 4: Comment on safety judgment
Building
IFCDR
Building
Titumir Hall
New
Academic
Building
M A RashidHall
Library
Building
ARC Building
Civil
Engineering
Building

No ofStories,n

Seismic
Index of
Structure,
IS

Seismic Index of
Non-Structural
Elements,
IN

Seismic
Demand Indexof Structure,ISO

SafetyJudgment

4

0.65

0.6

0.96

Uncertain

4

0.42

0.6

0.96

Uncertain

12

1.70

0.6

0.96

Safe

5

0.64

0.6

0.96

Uncertain

4

1.05

0.6

0.96

Safe

4

0.91

0.6

0.96

Uncertain

7

0.82

0.6

0.96

Uncertain

New Technologies for Urban Safety of Mega Cities in Asia

6. CONCLUSIONSIn this study, the seismic vulnerability of low and medium-rise reinforced
concrete buildings within six major locations of Dhaka city was investigated. The
seismic evaluation has been accomplished by performing two non-destructive
tests, Ferroscan and Microtremor measurements and also following the Japanese
RC building seismic evaluation provision. The inspection was done by observing
the structural elements and building configuration along with the resonancephenomena of the building.
Total 84 buildings have been selected for the study. Most of the buildings in
BUET campus are vulnerable in consideration of resonance. Those buildings have
major structural irregularities such as soft story, re-entrant corner, torsional
irregularity, and mass irregularity. The poor structural quality has been identified
in most of the building in Old Dhaka. These buildings have higher probability toface seismic hazard. Consequently, it could be greater threat for the people ofthese areas. Buildings in other areas, like Banani, Mirpur, Lalmatia and Uttara, arevulnerable due to structural irregularity as well as resonance.
On the other hand, the vulnerability assessment of the seven buildings has been
performed according to the first level of screening procedure of the Japaneseprovision. Among these buildings, two buildings may be declared as safe on thebasis of seismic safety of structural elements since they have the required seismic
capacity against the expected earthquake motions. While other five buildings may
be evaluated as uncertain in seismic safety and detail analysis is required toconfirm this situation.
Therefore, in light of this study, it may be concluded that proper planning andbetter construction quality need to be ensured for future buildings of Bangladesh
to survive earthquakes. For existing buildings retrofitting techniques may be
applied.

REFERENCES
Aki, K. (1957). Space and time spectra of stationary stochastic waves, withspecial reference to microtremors, Bull. Of earthquake research institute, 35, 415456.
Ansary, M.A., Yamazaki, F. and Katayama, T. (1996). Application of
Microtremor Measurements to the estimation of site amplification characteristics,
Bulletin of ERS, Vol 29, PP: 96-113.
Bangladesh National Building Code (1993). Housing and Building ResearchInstitute, 1st ed., Dhaka.
Kanai, K. and Tanaka T. (1961). On Microtremor VIII, Bull.Earthq. Res.Inst. Tokyo
University, Vol.39, pp.97-114.
Nakamura, Y. (1989). A method for dynamic characteristics estimation of
subsurface using microtremor on the ground surface, QR of RTRI, 30, 25-33

Diagnosis of the Seismic Vulnerability of Buildings at Dhaka using non-destructive testing

0ctober 2010, Kobe, Japan

Rahman G.F. (2004), Seismic Damage Scenario for Dhaka City, M. Sc. Thesis,
Department of Civil Engineering, Bangladesh University of Engineering andTechnology.
Standard for Seismic Evaluation of Existing Reinforced Concrete Buildings(2001).
Tamura, T., O. Nagai, H. Kikubo, and H. Sumita (1993). Charactesistics of wave
group microtremors obtained by array measurement, J. Struct. Consr. Eng. AIJ
449, 83-91 (in Japanese).
Toshinawa, T., Inoue M., Yoneyama N., Hoshino Y., Mimura K., and Yokoi Y.
(2003),Geologic-profile estimates of Kofu Basin, Japan, by making use of
microtremor observations,Geophysical Research Abstracts, Vol. 5, 02079.
Sato, T. H. Kawase, M. Matsui, and S. Kataoka (1991). Array measurement ofhigh frequency microtremors for underground structure estimation, proc. 4th int.
conf. on seismic zonation, 11,409-416.

New Technologies for Urban Safety of Mega Cities in Asia

Development of simple system for measuring
vibration by iPhone and iPad andit’s evaluation by shaking table
Muneyoshi NUMADA1, Kenji OHTA2, Akio KOBAYASHI3,
Takahiro KOMATSU4 and Kimiro MEGURO5
1
Research Associate, ICUS, IIS, The University of Tokyo, Japannuma@iis.u-tokyo.ac.jp
2
Chief Engineer, OYO Seismic Instrumentation Corporation, Japan
3
President, Art Data Corporation, Japan
4
System Engineer, Art Data Corporation, Japan
5
Professor, Director, ICUS, IIS, The University of Tokyo, Japan
ABSTRACTThis research investigated the potential usage of iPhone (OS 3.1.2) and iPad (OS3.2) for measuring vibration such as earthquake response of structure. An
application was developed and which used the smart phone’s built inaccelerometer for collecting vibration data, and the sensor’s performance was
examined experimentally. The XYZ acceleration data were stored in text form andcould be forwarded to an outside PC as an email attachment. The frequency
response and reproducibility of seismic waves were evaluated using a small
shaking table based on the pulse motor.
The developed application was installed on an iPhone and iPad, and theresolution of each acceleration sensor was compared. The frequency response ofeach sensor was obtained to take the spectrum ratio to the denominator of thelaser displacement sensor. Though iPhone and iPad had same characteristics
with the laser displacement sensor from the range of 1-10Hz, there was someinfluence due to noise. The reproducibility of seismic waves was evaluated for
four past earthquake record. The acceleration wave could be reproduced with theacceleration sensor of Smart Phone, and the possibility of using Smart Phone toevaluate a rough seismic ground motion could be shown.
The conclusion of this research was that the iPhone and iPad can be used as thedata logger of a personal acceleration sensor, which may help increase
observation density during earthquakes.
Keywords: Smart Phone, iPhone, iPad, accelerograph, shaking table

1. INTRODUCTION
The strong motion observation of our country has started from the installation of
the SMAC type strong motion seismograph in 1953 at Earthquake ResearchInstitute of the University of Tokyo. The main purpose of this observation was tograsp of the seismic force acting to the structures such as the building and the civil
infrastructure. As a strong motion seismograph at that time was extremely

0ctober 2010, Kobe, Japan

expensive, only four places by the private cooperation and two places by national
expenditures. As for the plan of nationwide development of the strong motion
seismograph, the total number of the strong motion seismograph by the national
expenditure increased to 16 places in 1958. Afterwards, a strong motion
observation by the private company greatly exceeded the installation by thenational expenditure with the high economic growth of our country, and then the
total number of strong motion observation went up to about 2000 total in 1990.
And, the situation of the strong motion observation intended for the ground in ourcountry has changed greatly with the occurrence of Kobe earthquake in 1995. In
1996 Ministry of Education, Culture, Sports, Science and Technology set theseismograph network (K-NET) with 1000 seismograph of 25km interval.
Moreover, KiK-net was set about 700 places in the whole country. The
Meteorological Agency sets up the seismic intensity meter of 95 theMeteorological Agency types every about 600 places in the whole country, and isobserving the seismic intensity.
However the strong motion observation network for the building and theindividual residence, etc. is still insufficient situations to enhance the abovementioned strong motion observation network. One of these backgrounds is thatthe seismograph is still expensive, and the individual cannot equip it to the housewith the seismograph under the current cost. However, it pays attention to an
efficient, low-cost MEMS acceleration sensor in recent years, and a basic
evaluation to use it for the seismograph is conducted. Though the low-cost MEMS
acceleration sensor has already been used for a domestic game machine and thecar, etc, in recent year, to use it as a seismograph, the performance gain isnecessary. A considerably cheap seismograph can be achieved compared with theacceleration such as the servo type sensor if low resolution of the performance ofthe MEMS sensor (about 1 Gal) can be allowed.
This research investigated the potential usage of smart phone for measuring
vibration such as earthquake response of structure. The developed application
which utilized the smart phone’s built in accelerometer for collecting vibration
data, and the sensor’s performance was examined experimentally. If Smart Phone
can bear a part of the strong motion observation, the formation of the observation
network can be built such as the analysis of strong motion occurrence, theevaluation of the regional characteristics of earthquake response immediately.
2. DEVELOPMENT OF APPLICATION
2.1 OVERVIEW OF APPLICATION
To use the acceleration sensor built into Smart Phone, the application that
preserves acceleration data, display it as waveform and transmit it to the outside
PC was developed with Mac mini equipped with Intel CPU. Mac OS X snow
leopard 10.6.4 was used as OS, and Xcode 3.2.3 and iPhone SDK 4 were used asa development setting.
The acceleration data in real time shape of waves displayed three components (X,Y, and Z) on the screen of Smart Phone as time history. The collection of data
began with "Record" button, and stopped with "Stop" button, and then outputs
acceleration value (G) of three elements of the data acquisition time and XYZ to
New Technologies for Urban Safety of Mega Cities in Asia

the file by the text form. The XYZ acceleration data was stored in text form andcould be forwarded to an outside PC as an email attachement, and a detailed
analysis on PC becomes possible (Figure 1).
2.2 RESOLUTION
The developed application was installed in iPad (OS 3.2) and iPhone (OS 3.1.2),
and the resolution of each acceleration sensor was compared. The result of
acquiring the maximum value, minimum value, and resolution of each axis X, Y,
and Z axially from the measurement data are shown in Table 1.
As for iPad, the range of the resolution of each axis is roughly 0.001G because it
becomes from 0.000992 to 0.001007 with unsteady of each XYZ axis.
The number of the AD converter bit of iPad and iPhone can be evaluated as 8 bit
and 12 bit. The sampling frequency was both 100Hz.

Text data

Time

X

Y

Z

E-mailRecordStop

Send

Figure 1: Smart Phone application
Table 1: Property of iPhone and iPad

iPhone
3.1.2

iPad
3.2

Min [G]
Max [G]
Resolution [G]Bit
Sampling frequency [Hz]Min [G]
Max [G]
Resolution [G]Bit
Sampling frequency [Hz]X
-2.300247
2.318359
0.0181128100-2.039993
2.046997
0.000992
12
100

Y-2.300247
2.318359
0.0181128100-2.046997
2.039993
0.000992
12100

Z-2.300247
2.318359
0.0181128100-2.047989
2.038986
0.000992
12100

Development of simple system for measuring vibration by iPhone and iPad andit’s evaluation by shaking table0ctober 2010, Kobe, Japan

3. SHAKING TABLE TEST
3.1 OVERVIEW OF SHAKING TABLE TESTThe vibration property of the acceleration with built-in Smart Phone sensor was
examined by using a small shaking table based on the pulse motor (Figure 2).
This small shaking table is an evaluation system for a simple vibration sensor
by the pulse motor drive. The fixed table on the sliding base is driven by timing
belt controlled by the high-speed switching of the pulse motor of CW (Clock
Wise) and CCW (Counter Clock Wise) rotation. A peculiar pulse noise to thepulse motor even in the low-frequency area is unremarkable because the gearsystem is not used, and high resolution was achieved with the micro-stepmechanism. This shaking table has been developed to measure the frequency
response of the velocity and the acceleration sensor for the main purpose, and it
can drive especially by controlling the pulse motor with the micro-stepmechanism in the low frequency until about 100 cycles per seconds. On the other
hand, in the range of high-frequency, maximum frequency range from 15Hz to
20Hz due to the low-speed element such as the restrict of an internal torque of the
motor and data transfer speed of USB controller. Because the frequency response
characteristics of the speed and the acceleration sensor is normally constant(linearity) for the size of the amplitude within the wide range of the frequency inmany cases, the comparative large amplitude can be evaluated.
Smart Phone used for the shake table experiment is two models of iPhone(OS3.1.2) and iPad(OS 3.2), and the accelerometer (JA40GA, 2V/G output, 1mgal
resolution) and the laser displacement sensor (5mm/V output) are used for thecomparison of Smart Phone characteristics as same time. The two differential ofthe displacement obtained by the laser displacement sensor is used as a standardof the acceleration. The shaking pattern is a linear sweep wave with half
amplitude of 0.5mm and the frequency from 0.1 to 20Hz. And then, the four
observation seismic waves (Mexico earthquake, 1985, Hyogoken-nanbu
earthquake, 1995, Tokachioki earthquake, 2003 and Niigata-chuetsu earthquake,2004) are applied.

Laser displacement

iPhone

JA40GA

iPad(b) PC controlling shaking table(a) Sensor on the shaking tabel
Figure 2: Photo of shaking table test
New Technologies for Urban Safety of Mega Cities in Asia

3.2 Result of shaking table test
3.2.1 Sweep test
Figure 3 shows the vibration response of iPhone, iPad, the laser displacement
sensor and JA40GA by the linear sweep wave from 0.1 to 20Hz. The
measurement was conducted twice. The first measurement case, it was upper one
and second case it was bottom one. A big difference was seen in the amplitude ofeach sensor, and the difference of the response lead-time was not seen. The time
to obtain the maximum value of the amplitude was the almost same.
The frequency response of each sensor was obtained to take the spectrum ratio tothe denominator of the laser displacement sensor (Figure 4). Though iPhone andiPad had same characteristics with the laser displacement sensor from the range of
1-10Hz, there was some influence due to noise.
On the other hand, JA40GA as for the comparison to iPhone and iPad shows thehigh accuracy to the laser displacement sensor in the range of 1 to 10Hz.
Figure 5 shows the resolution of the acceleration sensor of iPhone and iPad readfrom the silence part. The resolution of the sensor with built-in iPhone and iPadare about 18 Gal and 1 Gal respectively.
iPhone (first)

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Figure 3: Response of sweep test

Development of simple system for measuring vibration by iPhone and iPad andit’s evaluation by shaking table

140

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0ctober 2010, Kobe, Japan

1e+0063.43e+008

ipad

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Figure 4: Spectrum ratio to the denominator of the laser displacement sensor)

iPhone120

iphone 18gal sensitivity

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Figure 5: Resolution of iPhone and iPad
3.2.2 Seismic wave test
Figure 6 shows the input data of seismic wave for the shaking table test. These
input data are used to drive the pulse motor as a velocity that the acceleration
earthquake records are integrated.

New Technologies for Urban Safety of Mega Cities in Asia

The response of each sensor to the input seismic wave is shown in Figure 7. Samemeasurements are conducted twice. The upper part shows the first measurement
result and the result of second time is shown in the lower part.
As the large amplitude was obtained in the Mexico case and Tokachi-oki
earthquake case due to the noise partially, however the appearance of seismic
wave was reproduced.
Figure 8 shows the fourier spectrum of each sensor in the case of Niigata-chuetsu
earthquake.
As the shape of the fourier spectrum in iPad case is similar to the case of JA40GA,
the response of iPad with better re-productivity to JA40GA, perform better thanthat of iPhone. The performance of iPad has improved compared with iPhone.
Therefore, iPhone and iPad are available to evaluate the seismic wave roughly,
because the past seismic wave motion can be re-produced by these sensor by thesmall shaking table test as long as fixation is steady.
There are some problems of Smart Phone such as the limitation of the operatingtime depending on the OS etc. However, these tools are worth to examine thepossibility to collect the seismic data from the following advantages; thecheapness, easy operating and widely distributed in out society.

40
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Tokachi-oki

Figure 6: Input seismic wave to shaking table test

Development of simple system for measuring vibration by iPhone and iPad andit’s evaluation by shaking table

Hyogoken-nanbu

0ctober 2010, Kobe, Japan

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Figure 7: Response of shaking table test (vertical axis: Gal, Horizontal axis: time,
upper side: first test, bottom side: second test)
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Figure 8: Fourie spectrum in the case of Niigata- chuetsu earthquake

New Technologies for Urban Safety of Mega Cities in Asia

4. CONCLUSION
This research investigated the potential usage of iPhone (OS 3.1.2) and iPad (OS3.2) for measuring vibration such as an earthquake response of structure. The
developed application, which utilized the smart phone’s built in accelerometer forcollecting vibration data, and the sensor’s performance was examined
experimentally.
The conclusion of this research was that the iPhone and iPad can be used as thedata logger of a personal acceleration sensor, which may help increase
observation density during earthquakes.
Current Smart Phone cannot utilize the seismograph of high/enough accurate,
however it is possible to apply it as a data logger of a personal acceleration sensor
as a tool that reinforced a high density system of the current observation network.
The applicability to disaster prevention measure system and the education will be
examined by using the characteristics of Smart Phone which are thetelecommunication facility, easy user interface and the great number of users.
REFERENCES
Fukuwa, N., Koide, E., and Itoigawa, K. 2003. Development of low-coast
seismograph, Summaries of Technical Papers of Annual Meeting Architectural
Institute of Japan, Architectural Institute of Japan, 871-812.
Kurata, N., Saruwatari S., Horie S., Morikawa H., and Aoyama T., 2006.
Development of Acceleration Sensor Module for Ubiquitous Sensor Networks,
Summaries of Technical Papers of Annual Meeting Architectural Institute ofJapan, Architectural Institute of Japan, 419-420.
Nakamura, M., Yanase, T., Ikegaya, S., En, K., and Yoneyama, K., 2008.
Development of smart vibration sensor for the structural health monitoring(Structures), AIJ Journal of technology and design 14(27), 153-158.
Strong motion observation subcommittee of Architectural Institute of Japan, 2003.
The future concerning strong motion observation in building (discussion)，Strong
motion observation subcommittee report.

Development of simple system for measuring vibration by iPhone and iPad andit’s evaluation by shaking table

Geotechnical Database for the 2007 Niigataken
Chuetsu-Oki EQ Study
Hajime Tanaka1, Eric Thompson2, Yasuo Tanaka3,
Robert Kayen4, Kazuo Konagai5
1
former researcher, Dept. of Civil & Environmental Engineering,
Tufts University, US
hajime_create@gmail.com
2
Research Professor, Dept. of Civil & Environmental Engineering,
Tufts University, US
3Professror, RCUSS, Kobe University, Japan
4
Chief Researcher, United States Geological Survey, California, US.
5
Professor, Institute of Industrial Science,
The University of Tokyo, Japan

ABSTRACTThe 2007 Niigataken Chuetsu-Oki Earthquake at the central north coast of Japan
has resulted in a large variety of geotechnical damages in the Kashiwazaki Cityand surroundings, such as very strong ground shaking at the downtown ofKashiwazaki City and ground deformations at the Kariwa Nuclear Plant site.
This paper presents a GIS geotechnical information system that is developed forthe study of the 2007 Niigataken Chuetsu-Oki Earthquake. This is a web based
geotechnical information system that uses the same platform of web based“Kobe JIBANKUN”. To identify the dynamic properties of ground, not only theborehole data but also other dynamic measurement data such as SASW data
gathered in and around the Kashiwazaki City were also included in the system.
Through the use of this geotechnical database, a study was made on the dynamic
response of the downtown, particularly to identify the geotechnical and seismic
profiles of the ground in and around the Kashiwazaki City. Also detailed
stratigraphic and seismic profiles beneath the downtown were identified by using
the GIS geotechnical database.

Keywords: earthquake, geotechnical database, GIS

1. INTRODUCTION
The M6.8 Niigataken Chuetsu-Oki Earthquake occurred in July 16th, 10:13 am,and large aftershock soon followed 3:37 pm. The mainshock had an estimatedfocal depth of 17 km and the epicentre is located in the Japan Sea offshore of the
Kariwa village, at N-37degree 33.4’, E-138degree 36.5’ (JMA, 2007), 20 km
north of the Kashiwazaki City as shown in Fig. 1. A large nuclear plant, theKariwa Nuclear Plant of the Tokyo Electric Company (TEPCO), is located closer
to the epicentre, and this was first time that a nuclear plant has been hit by a large
earthquake with significant operational damages. The Kashiwazaki City was hit

October 2010, Kobe, Japan

most severely and 14 of residents were killed with the housing damages of over
1100 collapses. The Kariwa village near the nuclear plant was also severely

Figure 1: Epicenters of the 2007 Earthquake, and other earthquakes in Niigata
affected with one death toll and over 150 houses collapsed. The downtown of theKashiwazaki City is located on the sand dune and there were measureable grounddeformation in the downtown that resulted in many housing damages. Also there
have been many liquefaction damages in and around the City as two rivers, theSabaishi River and the U River, run north and south sides of the City respectively
by forming a river delta along them.
It is also to be noted that there have been several strong earthquakes over the
past 50 years in nearby areas of the Niigata Prefecture. The most recent
earthquake was the M6.8 Niigataken Chuetsu Earthquake of 2004 of which
epicentre is located about 25 km east of Kashiwazaki. Also the 1964 Niigata
earthquake has given a huge liquefaction damage to the Niigata City which islocated about 75 km north-east of Kashiwazaki. The locations of theseearthquakes are also shown in Fig. 1. The Kashiwazaki City suffered somedamages from both of these past earthquakes. Thus it is very important for thisarea to have a good earthquake preparedness to minimize the damages and losses
from the future earthquake disasters. Because the ground condition in
Kashiwazaki and around is rather poor with respect to the earthquake shaking, it
would be vital for the area to have a good knowledge base for a seismic study,
such as of constructing a detailed seismic and geotechnical information databaseby using GIS system to disseminate and share the information among thoseconcerned.
In the summer and fall of 2008, field investigation of SASW tests wereconducted by the authors to further identify the dynamic properties of ground. A
visit to the Kashiwazaki City civil engineering office was made subsequent to thefield tests, and a large number of borehole investigation data were given to theauthors from which a geotechnical database as discussed in this paper wasconstructed. The objectives of this study is to summarize the findings madethrough the above field testing and the construction of geotechnical database tofurther enrich the earthquake risk assessment study to minimize the future seismic
risks.

New Technologies for Urban Safety of Mega Cities in Asia

2. OUTLINE OF GEOTECHNICAL DAMAGES AT THE DOWNTOWN
AND AT AROUND THE KASHIWAZAKI CITYThis earthquake has resulted in an abundance of ground damages around theKashiwazaki City and also at the downtown. The downtown area of Kashiwazaki
City is built on the sand dune that had a height of 10 m approximately above thehorizon. The downtown area of the Kashiwazaki City was heavily damaged due to
noticeable ground movements from the higher ground to the lower parts of thesand dune.
Fig. 2 is a map of cracks that appeared on pavements in the downtown area. Red

Figure 2: Pavement Cracks of the Kashiwazaki City Downtown
and blue lines show respectively open cracks (photo 1) and compressed marks(including those colliding over the others, buckled up; see photo 2). Most clustersof open cracks are found along ridges of the sand dunes while many compressedmarks were found along toes of the dunes and some were found along an Sshaped sagged zone among the sand dunes. These cracks and compressed marks
show that the steep slopes of these sand dunes have subsided towards wet
flatlands and sagged zones.
A housing damage study in Kashiwazaki downtown was carried out by Higuchi etal. (2007) of Nagaoka Institute of Technology, and they also have shown thatmost of housing damages are located where the ground movements are in
expansions mode and these are located along the top edges of sand dune.
Northern part of Kashiwazaki, the Nishiyama and Arahama areas, is also hit by
the earthquake. In these areas, there is a thick deposit of soft clays being deposited
against a steep hill of sand dune and uplifted basal rock at the west. The Arahama
railway station and a DIY store, “Plant5”, were heavily damaged by strong motion.

A survey on residents’ response to earthquake early warning at the 2008….

October 2010, Kobe, Japan

3. THE KASIWAZAKI GEO-HAZARD STUDY MAP
As noted earlier, the Kashiwazaki City civil engineering office has provided theauthors the borehole data available in and around the City, Hajime Tanaka (2008).
Also we have conducted SASW tests at fourteen sites. In order to study theseismic response and the cause of ground damage at Kashiwazaki, it was thought
best to create a geotechnical database using a GIS system that can be used easily
to locate and examine the geotechnical data at the damage site. A similar work ofcreating a geotechnical GIS database has been in progress to examine the geohazards of the 1995 Kobe Earthquake (http://gdc.cee.tufts.edu/) through acollaborative study between the Tufts University of USA and the Kobe Universityof Japan. It was thus decided to create a geotechnical GIS to study the geohazards during the 2007 Niigataken Chuetsu-Oki Earthquake by using the same
GIS software to integrate the given borehole data and the SASW tests. Fig. 3
shows an example page of such GIS database system developed to illustrate thelocations of fourteen SASW test sites and also the borehole data at in and aroundthe Kashiwazaki City. The borehole log and the SASW test results can be easily
examined by clicking the borehole or SASW site name as listed in the data list
box in the right side of the figure. In the followings, the geotechnical conditions at
the Kashiwazaki downtown and the lowland east of the Kariwa Nuclear Plant is
examined by using these SASW test results and borehole data to demonstrate the

Figure 3: Locations of SASW test sites and available borehole data (i.e.,orange circles) at Kashiwazaki
advantage of using such GIS geotechnical database for seismic hazard study.
3.1 NIED Seismic Monitoring Station at Kashiwazaki Downtown
As noted earlier, the downtown of the Kashiwazaki City was hit most severely,
and 14 of residents were killed with the housing damages of over 1100 collapses.
The major reason for this damage is thought to be the soft ground condition of
Kashiwazaki downtown as it is located on a sand dune deposit, about 10 meter
New Technologies for Urban Safety of Mega Cities in Asia

high, overlying a thick soft delta deposit. The seismic amplification on suchground condition would be very severe. The seismic record at the downtown isobtained at one of seismic monitoring stations of the K-NET (Kyoshin-Net),
which is a strong ground motion monitoring system run by National ResearchInstitute for Earth Science and Disaster Prevention (NIED) to cover seismic
activities all over the Japan.
Fig. 4 shows the seismic record at the K-NET station, NIGO18, that was locatedat the downtown city office. The maximum acceleration as computed from all
three components was nearly 800 gals (JMA 2007). It is also significant that theseismic waves after about 24 seconds have a spike shape response indicating
possible occurrence of liquefaction due to cyclic mobility.

Figure 4: Seismic records as measured
at K-NET.NIGO18, station

Figure 5: Geotechnical profile at K-Net

The SASW test was performed at this site to examine the seismic profile ofground. Also at the K-NET NIGO18 station, a velocity logging data during its
installation is available so that a comparison with the SASW test result is possible.
Fig. 5 shows the geotechnical profile as obtained from the K-NET site
investigation, and the exploration depth only covers 20m. The velocity data of Fig.
5 is obtained using either downhole test or suspension type test. As can be seenfrom Fig. 5, a 13 m thick sand layer overlies the clay layer below. Both the SPT
values and the shear wave velocity, Vs, value show that the underlying clay issofter than the sand layer above. The seismic ground profile as obtained from the
SASW test was much deeper than that shown in Fig. 5 and thus the GIS
geotechnical data base is used to compare the SASW seismic profile to thoseborehole data with deeper soil profile as shown in Fig. 6. The comparison of Vs
profile between the PS logging of K-NET and that from the SASW test is in good
agreement although the Vs value for the underlying clay is lower for the SASW
test. The Vs value of underlying clay increases from the depth of 22 m
approximately, while the SPT values as given in the borehole testing data do notshow a sharp increase as the Vs value of the SASW test indicates.
In the Kashiwazaki area, the thick deposit of underlying clay is consisted ofseveral soil strata with two different geological background. The upper clay
stratum being the most recent Holocene deposit, while the lowest clay being the
Pleistocene deposit. The agreement in the thickness of lower Vs layer and that of
the uppermost soft Holocene clay layer is clear from the figure, and the Vs value
seems to increase at lower deposit with depth. The existence of lower Vs layer
beneath the sand deposit was also found at other SASW test sites in the downtown.
Fig. 7 shows a continuous zone of low Vs stratum that would indicate the
A survey on residents’ response to earthquake early warning at the 2008….

October 2010, Kobe, Japan

Figure 6: Comparison of the SASW seismic profile with nearby deeper boreholes

Figure 7: A low Vs layer beneath sand layer
existence of soft clay layer. The above SASW test result is useful in analyzing theseismic record at the K-NET station, but the engineering seismic base for the area
is not yet to be defined.

3.2 Lowland East of the Kariwa Nuclear Plant
At the north of the Kashiwazaki City, extensive liquefaction sites were observed
along the Sabaishi River. Also there have been various geotechnical damages
along the west end of the lowland, north of the Sabaishi River, where the soft
Holocene materials are deposited against the dipping slope of a mass of sand duneand sedimentary rock that forms the highland of the Kariwa Nuclear Plant. The
typical damages found are the JR Arahama station where sharp bends of railway
track, the collapse of the Arahama Station’s platform, and a large lateral
movement of foundation at PLANT 5, DIY store that resulted in a buckling of
concrete floor slab as reported by Kayen et al. (2007).
At this site, five SASW testing have been carried out to investigate the dynamic
properties of ground and these locations are shown in Fig. 8. Also shown in the
figure are the borehole logs nearby the SASW test sites. The ground at thelowland consists of very soft clay showing very low N values, and the thicknessof soft clay reaches nearly 40 meters. In both the JR Arahama and the PLANT 5,
New Technologies for Urban Safety of Mega Cities in Asia

there were evidence of liquefaction, but these boreholes indicate mostly clayey

Figure 8: Locations of SASW testing and nearby boreholes

Figure 9: Depth profile of Vs from SASW testing.
deposits except for a very thin layer of sand at 5 meter below. The cause of large
ground movements at these sites needs to be studied further. Fig. 9 shows thedepth profile of Vs at the lowland area, and the Vs value for the soft clay ranges
from 50 to 150 m/sec. Also the Vs value is larger at the depth deeper than about
20 m from the surface, but such increase of Vs value is not clearly found from the
N-value profile of the boreholes. It may be noted the 340 SASW site is located on
the sloping ground to the lowland, and the increase of Vs value at 20 m may
indicate the presence of sand dune and sedimentary rock at the depth.
Along the perimeter road of the Kariwa Nuclear Plant, there is a vertical array
seismometer is installed at Service Hall as noted earlier. A SASW test was also

A survey on residents’ response to earthquake early warning at the 2008….

October 2010, Kobe, Japan

conducted at this site. Fig. 10
presents a comparison between theVs profiles from the SASW and thatobtained by TEPCO during theseismometer installation. Although
the Vs profile of SASW test varies
depending on the assumed waterlevel, these Vs profiles are very
similar except for lower Vs values
near the ground surface. A dynamic
response analysis based on a moredetailed Vs profile is needed to study
the effect of detail Vs variation withdepth on the seismic response of theground.
4. CONCLUSIONSA GIS geotechnical information Figure 10: Depth profile of Vs atsystem is developed for the study of Service Hall near the Kariwa Plant.
the 2007 Niigataken Chuetsu-Oki
Earthquake based on the borehole data given from the Kashiwazaki City. The
dynamic properties of ground based on the SASW test and borehole data gatheredin and around the Kashiwazaki City were also included in the system. Through theuse of this geotechnical database, the dynamic properties of the grounds at the
downtown and the north of the Kashiwazaki City, and also stratigraphic andseismic profiles were identified by using the GIS geotechnical database. These
data would be useful for carrying out further dynamic response studies.
REFERENCES
Committee on Geology Map of Niigataken (2000): “Geology map of Niigataken
and report”, Chamber of Commerce and Promotion, Niigata prefecture (inJapanese)
JMA 2007: “A quick report on disaster and tsunami - 2007 Niigataken ChuetsuOki Earthquake”, JMA Report on natural phenomenon during disaster, No.3,
2007 (in Japanese).
Kayen, Robert, et. al. (2007) : “Investigation of the M6.6 Niigata Chuetsu Oki,Japan, Earthquake of July 16, 2007”, Open FIle Report 2007-1365, U.S.
Department of the Interior, U.S. Geological Survey
Tanaka, Hajime (2009) : “Spectral Analysis of Surface Wave (SASW) at
Kashiwazaki City and its vicinity severely hit by the Niigataken Chuetsu Oki
earthquake,and interpretation of its result”, Master Thesis, Dept. of Civil Eng.,
Univ. of Tokyo
Tomiyasu, Y., Nomura, F., Konagai, K. (2008): Pavement damages at
Kashiwazaki City during the Niigataken Chuetsuoki EQ., annual meeting of JSCE,
I-258, p. 515~p. 516 (in Japanese)

New Technologies for Urban Safety of Mega Cities in Asia

Retrofitting by High Sophisticated Bonded
Anchorage Systems
Andreas UNTERWEGER1, Konrad BERGMEISTER2 and Yoshiaki NAKANO3
1

Ph.D., Research Fellow, Japan Society for the Promotion of Science, The
University of Tokyo, Japan, andreas.unterweger@boku.ac.at
2
Professor, Institute for Structural Engineering, University of Natural Resourcesand Applied Life Sciences, Vienna, Austria
3
Professor, Deputy Director, IIS, The University of Tokyo, Japan
ABSTRACT
Anchorages afford an economic way to connect retrofitting systems with existing
concrete structures. Especially bonded anchorage systems are applied frequently
in the last years because of its flexible use. The connection between the existingbuilding and the rebar, which is easy accessible on the site, is made by a drilledhole and adhesive. New technology of adhesive has developed bond strengths inexcess of 30 MPa combined with stable long term behavior under sustained loads.
This offers a new application range for strong connections between existing
structures and retrofitting systems. State-of-the-art fastening solutions such as
rigid connections between steel or concrete and existing structures arehighlighted and their advantage is discussed in this paper. Based on that, finallycodes and approvals are focused and the opportunity of their adaption is
discussed.
Keywords: retrofitting, adhesive, fastenings, anchorage, Japanese guideline,
European guideline, ETAG
1.

INTRODUCTION

Post installed anchorage in concrete is applied frequently because of its flexible
use in all kinds of connections in concrete structures. It finds widespread
application for the fastening of nonstructural elements to structures and isfrequently used to connect new structural elements to existing structures inearthquake retrofit schemes. Although the majority of fasteners on the market
today are designed and tested for use in non-seismic environments, they arecommonly used for applications in structures located in earthquake regions.
Inadequately tested or inappropriately used fasteners can lead to unanticipatedbehavior that can compromise structural performance during an earthquake andendanger human life. Recently the field of maintenance and retrofitting of
concrete buildings has grown, therefore post installed adhesives are used more
often, and also their requirement of long term behavior has been increased(Mihala et al., 2009).

0ctober 2010, Kobe, Japan

Both the fastening industry and practicing engineers have recognized theadvantages of standardized qualification of fasteners for specific applications.
Qualification is the process by which products are tested using standardized
methods and granted an approval based on prescribed acceptance criteria (Hoehler,
2006). In Europe these approvals are regulated by the relevant European
Technical Approval (ETA).
1.1. Applications for fasteners in earthquake regions
Basically anchorage can be used for nonstructural or structural usage (Figure 1). In thecase of retrofitting the application is typically structural, increasing the demand on longterm behavior and safety. The global behavior of the structure is influenced by theretrofitting structure and in the case of large earthquakes it is basically used for a seldom
event.

Figure 1: Structural and nonstructural applications for fastenings (Hoehler, 2006)
One common way of strengthening an existing concrete building is to increase theshear capacity. This can be accomplished by shear walls or steel braces shown in
Figure 2, and the connection of the secondary structure is frequently made bybonded anchors. The difficulty of drilling the holes into the existing concrete
depends on the level of reinforcement and on the required borehole depth. In somecases the borehole depth is limited by the thickness of the existing concrete
member. Hence efficient ways of load transfer by high sophisticated adhesives
facilitate the application.

Retrofitting by High Sophisticated Bonded Anchorage Systems

Figure 2: Example of the use of post installed anchorage for retrofitting, steel
brace, (Guidelines for Seismic Retrofit, 2001)
Most of those secondary structures are applied for the rare case of large
earthquakes. The deformation of such a structure (steel brace or shear wall) is
shown in Figure 3. Experiments (Comitée Euro-International du Béton, 1995)
have shown that the best result occurs if the shear wall is connected uniformly
with the existing structure. First of all the deformed structure shows a diagonalcompression strut which is introduced into the existing structure. The otherdiagonal under tension produces gaps which have to be minimized through the useof anchorage as connectors. In addition to the shear transfer the transfer of tension
forces plays a serious impact on the global behavior.

Figure 3: Deformed post installed shear wall at earthquake loading (Guidelines for
Seismic Retrofit, 2001)
Mainly these connectors are located close to the edge, and without proper
guidelines it is a difficult situation for the design engineers to estimate the proper
way of installation. The current Japanese guideline is compared with thecorresponding European standards and the case of tension load is focused in thefollowing.

Retrofitting by High Sophisticated Bonded Anchorage Systems

0ctober 2010, Kobe, Japan

2.

POST INSTALLED ANCHORS UNDER AXIAL LOAD

The development of efficient drilling methods made it possible to install post
installed anchors in a fast and safe way. Especially bonded anchors are used close
to edge because of their flexible use and lower splitting force compared to
expansion anchors or even cast in place rebars (Figure 4).

Figure 4: Application of bonded post installed anchorage
2.1. Tensile capacity of bonded anchors and failure modes
The basic failure modes without edge influence are shown in Figure 5. If theembedment depth is large, and the diameter of the anchor is small, the decisive
failure mode of post installed bonded anchors in concrete occurs in the anchor
itself (Figure 5 a). Due to the well known material behavior of steel, this failuremode has a low mean variation and a sufficient ductility which is desirable in thecase of earthquakes. Concrete cone failure (Figure 5 b) depends on theembedment depth and concrete strength, and pull out failure (Figure 5 c) depends
on both, the embedment depth and the used adhesive.
T

a)

T

b)

c)

T

T

T

Figure 5: Failure modes of bonded anchors under tension load T: a) steel failure;b) concrete cone failure, c) bond failure; (Hoehler, 2006)

Retrofitting by High Sophisticated Bonded Anchorage Systems

When using post installed anchoring systems these basic failure modes have to betaken into account. Due to the high ductility of steel, steel failure should be thegoverning failure mode which governs the tension capacity of the fastening.
3.

COMPARISION OF JAPANESE AND EUROPEAN GUIDELINE

In order to compare the different calculation methods in the end of this chapter,first of all we have to consider two different safety concepts. In Europe the partial
safety concept is already used while in Japan a global factor of safety is applied.
In order to exclude the influence of those different safety concepts, the meanvalues of the ultimate loads are used in the following.
3.1. Guidelines for Seismic Retrofit of Existing Reinforced Concrete
Buildings in Japan
According to the Guidelines for Seismic Retrofit of Existing Reinforced Concrete
Buildings, 2001, the tensile capacity Ta is defined as the capacity resisted by asingle anchor at the concrete interface. Tensile capacity shall be the smallest valueof Ta1 which is determined by steel strength, Ta2 which is determined by concretecone failure, and in case of bonded anchor additionally Ta3 which is determined bybond strength.
Ta = min (Ta1, Ta2, Ta3)

(1)

Ta1 ........ Tensile capacity of an anchor determined by yielding of steel material[N]
Ta2 ........ Tensile capacity of an anchor determined by concrete cone failure [N]Ta3 ........ Tensile capacity of an anchor determined by bond failure [N]3.1.1. Steel failure
Steel failure, sketched in Figure 5 (a), is calculated according to equation (2) bymultiplication of the yield strength of the anchor and the cross section area.
Ta1 = σy · a0(2)

σy.......... yield strength of anchor
a0 ......... effective cross section area of threaded steel bar, or nominal cross section
area of anchorage bar [mm²]3.1.2. Concrete cone failure
Anchorage for retrofitting is frequently applied in groups and close to the edge.
Hence the projected area Ac (see Figure 6) usually is reduced. In order to exclude
the influence of the different calculation methods of the projected areas, one
single anchor without edge influence is taken into account in the following. As in
the Japanese guideline just the capsule type adhesive anchor with a 45 degree cut
bolt is taken into account, concrete cone failure can be calculated according toequations (3) - (5).

Retrofitting by High Sophisticated Bonded Anchorage Systems

0ctober 2010, Kobe, Japan

Ta2 = 0.23 σ B · Ac

(3)

σB.......... concrete compressive strength of existing concrete [MPa], 150 mm x
300 mm cylinder
Ac.......... projected area of concrete cone failure surface of a single anchor [mm²]according to Figure 6
Ac = π · le (le + da)(4)

le ........... effective embedment length of an anchor [mm]da .......... nominal diameter of anchorage bar for bonded anchor
le = l – da(5)l ............ embedment length of bonded anchor [mm]Figure 6: Projected area of concrete cone failure surface of a single anchor (45degree cut bolt) Ac
3.1.3. Pull-out failure
The bond strength τa in equation (6) is calculated according to equation (7) inrelation to the concrete compressive strength σB. Hence for pull-out failure, thetrue bond strength of the anchorage system is not fully utilized.
Ta3 = τa · π · da · le(6)

τa .......... bond strength of bonded anchor against pull out force [MPa]τa = 10 σ B / 21

(7)

3.2. Guideline for European Technical Approvals (ETAG)
Because of the traditional long term philosophy of buildings, there is a basic
experience with cementitious materials (stone, masonry, concrete) and connectors
in Europe. Furthermore solid contribution from the industry (e.g. the international

Retrofitting by High Sophisticated Bonded Anchorage Systems

federation for structural concrete “fib”) with the normalizing institutions offers
proper inclusion of state of the art concepts into the governing guidelines (ETAG
001, 2006).
3.2.1. Steel failure
As in chapter 3.1.1 steel failure is calculated according to equation (8) bymultiplication of the yield strength of the anchor and the area of the cross section.
Hence there is no difference in the two guidelines.
Nu,s = As · fy [N](8)Nu,s ....... ultimate load for steel failure (corresponds to Ta1)As ......... stressed cross section of steel (corresponds to a0)
fy .......... steel yield strength (corresponds to σy)3.2.2. Concrete cone failure
Concrete cone breakout under axial loads is described in detail in the frameworkof the Concrete Capacity Design (CCD) Method (Fuchs e. al., 1995). Although
the mechanical processes of this failure type is highly nonlinear, equation (9) can
properly express the resulting ultimate resistance for a single anchor without
influence of the boundary.
N u ,c = 13.5 ⋅0

f cc.200 ⋅ hef

1.5

(9)

Nu,c0...... ultimate axial resistance of a single anchor for concrete cone failure(corresponds to Ta2 without influence of edges or other anchors)
fcc.200........ 200 mm cube compressive strength of concrete [MPa]fcc.200 = 1.1875 · σB (for strengths around 21 MPa)
hef .............. effective anchor’s length (corresponds to le)
3.2.3. Pull-out failure
The resistance in case of failure by pull-out, N , shall be taken from the relevant
ETA (European Technical Approval). The calculation by equation (10) is similar
to chapter 3.1.3 of the Japanese guideline, but by contrast according to the ETA
every anchorage system has its own value of bond resistance τp.
Rk,pNu,p = τp · π · d · hef(10)Nu,p ........... ultimate load for pullout failure (corresponds to Ta3)
τp .......... bond resistance (corresponds to τa), taken from relevant ETA [MPa]d ................. diameter of anchor bolt or thread diameter (corresponds to da)
3.3. Comparison between Japanese and European guideline
As mentioned above, the different safety concepts are not taken into account inthis comparison, hence only the mean values of the resistance of a single anchor
in non-cracked concrete without edge influence are used.
Figure 7 shows a graph of the resistance T plotted against the nominal diameter of
the anchorage bar da. In the Japanese design concept in the case of tension load
the effective embedment length shouldn’t be lower then 10 da. Hence theRetrofitting by High Sophisticated Bonded Anchorage Systems

0ctober 2010, Kobe, Japanembedment length is chosen to le = 10 da and a concrete compressive strength ofσB = 21 MPa is used. An adhesive with a relatively low bond strength of τb =15 MPa is applied. But even so, a large difference between the two guidelines isshown.
350
300

Ta [kN]

250
200
150
100
50
0
10 d a [mm] 15
N_u,s

N_u,c

20
N_u,p

25
T_a1

T_a2

30
T_a3

Figure 7: Comparison between guidelines in Japan (T) and Europe (Nu); σB =21 MPa; le = 10 da; bond strength τb = 15 MPa; Ta1 = Nu,s3.3.1. Steel failure
In the case of steel failure the two guidelines, Nu,s in equation (2) and Ta1 inequation (8), get the same results and are plotted on the same line in Figure 7.
3.3.2. Concrete cone failure
The calculation of the resistance at concrete cone failure shows the first relevant
difference. The Japanese curve of Ta2 starts quite conservative at small diameters,
but with increasing embedment depths the resistance rises faster compared to theEuropean curve of Nu,c. This is caused by the consideration of the embedment
length le to the power of 2 in the Japanese guideline equation (3) and (4)compared to 1.5 in the European guideline equation (9). At a diameter of da =10 mm (le = 100 mm) the difference is quite significant; 46 %, however, for larger
diameters of da = 30 mm (le = 300 mm) the discrepancy is reduced to 6 %,resulting in a more conservative estimation of ultimate capacity for shallower
anchor embedments compared to deeper ones.
3.3.3. Pull-out failure
Qualitatively the major difference is the calculation of the pull out failure. In
equation (7) of the Japanese guideline the bond strength of bonded anchor against
pull out force τa is limited to 10 MPa at concrete strengths of σB = 21 MPa. It justhas a smooth connection to different concrete strengths. The bond strength of theactual anchorage system is not taken into account.
By contrast the European guideline provides the bond strength given in therelevant ETA for each anchorage system. That way the calculated resistance andsafety also depends on the specific adhesive anchoring system selected for theapplication. Consequently, the Japanese guideline forces bond failure to be thedecisive failure mode at a level roughly 16% below the concrete cone capacity.
By contrast the European guideline allows the use of a system’s bond strength of
15 MPa to be taken into account. Due to the 50 % higher considered bond strength
Retrofitting by High Sophisticated Bonded Anchorage Systems

the curve is magnified by the same ratio for all diameters irrespective ofembedment depths.
3.3.4. Decisive Failure
At this calculation according to the Japanese guideline the decisive failure mode ispull out failure, because the “true” bond strength of the selected anchorage system
is disregarded.
In the case of earthquake the ductility should be a maximum. That means thedesired decisive failure mode is steel failure. In order to achieve that steel failure
governs the calculation, the concrete and bond capacity need to increase. Thatmeans deeper embedment depths, more options to hit a reinforcement bar or eventhe opposite edge.
According to the European guideline steel failure is the decisive failure mode fordiameters between 8 and 29 mm and lays 20 % over the values of the Japaneseguideline in the same diameter range.
4.

CONCLUSION AND OUTLOOKIn numerous retrofitting applications for connections between steel and concrete,fastening by use of anchor bolts is often required. As connector between theexisting and the new structure post installed anchorage is one of the importantparts of retrofitting concerning strength, ductility and long-term behavior.
Comparing the Japanese and European guidelines the main differences are thefollowing ones:¾ The bond strength of a specific adhesive anchoring system is not taken into
account at the Japanese guideline¾ For concrete cone failures the Japanese guideline considers the embedment
depth to the power of 2 instead of 1.5. With the conservative calculation of theJapanese guideline this way the safety of shallow embedment depths is higher
than of deeper ones.
¾ At the Japanese guideline the decisive failure at le = 10 da is bond failure due tothe bond strength limitation of 10 MPa in comparison to steel failure at theEuropean guideline.
If there is a lack of guidelines, the executing engineer is responsible for thesuitability and soundness of the connection, but in the case of bond failure, theexisting Japanese guideline with the consideration of the low bond strength of
10 MPa, makes the calculation with higher bond strengths impossible. Better
adhesive quality can be used for maintenance and retrofit reasons in structural aswell as non-structural applications. That way many options of efficient use of post
installed anchorage are denied which leads to fewer options and higher costs ofretrofitting.
It should be possible to apply high sophisticated anchorage systems if they areneeded by the executing engineer. That way also the developing of new fastening
products is made attractive for the fastening industry. In Europe because of theeasy accessible ETA, the executing engineer can choose the best suited systemamong an ample range of products. In Japan this process is limited and shows theneed of an adapted guideline.

Retrofitting by High Sophisticated Bonded Anchorage Systems

0ctober 2010, Kobe, Japan

REFERENCE
CEN – European Committee for Standardization. CEN/TS 1992-4, 2009
Prestandard, Design of fastenings for use in concrete. Parts 4-1 to 4-5, Brussels.
Comitée Euro-International du Béton, 1995. Fastenings for Seismic Retrofitting.
CEB Bulletin, Switzerland.
ETAG 001, Annex C, 2006, Design Methods for Anchorages.
Fuchs, W., Eligehausen, R. & Breen, J.R. 1995. Concrete Capacity Design (CCD)
Approach for Fastening to Concrete. ACI Structural Journal V. 92, No.1 January February 1995, pp. 73-94.
Hoehler, M.S., 2006. Behavior and Testing of Fastenings to Concrete for use in
Seismic Applications. Dissertation, University of Stuttgart, Germany.
Hofmann, J., 2004, Tragverhalten und Bemessung von Befestigungen unter
beliebiger Querbelastung in ungerissenem Beton. Dissertation. University of
Stuttgart.
Mihala, R., Strauss, A., Bergmeister, K., Kränkel, T., Lowke, D., Schießl, P.,
2009. Durability and Reliability Assessment of Adhesive Anchors. University of
Natural Resources and Applied Life Sciences, Departmental Series Nr. 18, Vienna,
Austria.
Tsuneo, O., Masaya, M. e.a., 2001. Guidelines for Seismic Retrofit of Existing
Reinforced Concrete Buildings. The Japan Building Disaster Prevention
Association, Japan.

Retrofitting by High Sophisticated Bonded Anchorage Systems

Web-based “Kobe JIBANKUN” System forthe 1995 Kobe Earthquake StudyYasuo Tanaka 1, Yasuo Ariki1, Hajime Tanaka2, Toru Nakashika3,
Eric Thompson4, Rober Kayen51Profs., Research Center for Urban Safety & Security (RCUSS),
Kobe University, Kobe, Japanytgeotec@tiger.kobe-u.ac.jp
2
former researcher, Dept. of Civil & Environmental Engineering,
Tufts University, US
3Graduate Student, Graduate School of Engineering,
Kobe University, Kobe, Japan
4
Research Professor, Dept. of Civil & Environmental Engineering,
Tufts University, US
5
Chief Researcher, United States Geological Survey, California, US.

ABSTRACTThe 1995 Kobe Earthquake has left us a great wealth of knowledge to further
improve our earthquake engineering studies, especially on the strong groundmotion at urban areas of the Kobe City and the liquefaction problems along thecoast. The Kobe City has build a geotechnical database system, locally known as“Kobe JIBANKUN”, to study the cause of earthquake damages by gathering
nearly 7000 boreholes and the earthquake damages data.
The “ Kobe JIBANKUN ” database has been until now built on a CD-ROM
platform so that the study work can only be done on an individual computer basis,
without the web sharing capability. A new web base system for “ Kobe
JIBANKUN” is built so that the earthquake engineering researchers can shareand collaborate, and further promote the earthquake preparedness throughworking on this web based “Kobe JIBANKUN”. The system is built on open
source programs so that a similar system can be easily developed without anexcessive investment. This paper describes some examples of the use of the web
based “Kobe JIBANKUN” to delineate the dynamic properties of inland andcoastal grounds of the Kobe City, and also to promote the earthquake
preparedness & awareness through a combined use of the web based database
and the mobile terminals.
Keywords: Great Hanshin Awaji Earthquake, geotechnical database, web-system

1. INTRODUCTION
The Great Hanshin-Awaji Earthquake (or Hyogoken Nambu Earthquake) has hit
the city of Kobe in early morning of January 17th, 1995. This was the first time inJapanese history after the Second World War to experience such a huge anddevastating earthquake at a modern & well developed urban city. The Kobe City

October 2010, Kobe, Japan

has suffered extensive earthquake damages due to the Earthquake, and theconcentration of extremely heavy damages of residential houses along a narrow
band of area within the City has resulted in a creation of the highest seismic
intensity “Level 7” in JMA (Japan Meteorological Agency) scale.
The mechanism of earthquake damages, for example a study on narrowconcentration of damages in the City, has been studied extensively by many
researchers in Japan, including a research group in Kobe, “Research Group of
Kobe Ground”. This Kobe research group consisted of those from universities,
practicing geotechnical engineers and administration officers in Kobe City Office,has started its research activities in 1998. The main focus of study of this group
was to examine how the ground condition in the City has affected the variation ofearthquake damages over the area, i.e., the local site effects. The research group
has also made extensive use of geotechnical database, locally known as“KOBEJIBANKUN”that contained nearly 7000 borehole data in the City. Using thisgeotechnical database, dynamic response analyses have been made to examine thevarious earthquake damages in the City. Until now the“KOBE JIBANKUN”
database has been built on a CD-ROM platform so that the study work can only
be done on an individual computer basis, without the web sharing capability.
Because extensive earthquake damage and reconnaissance data are alreadyavailable elsewhere for this 1995 Earthquake, the geotechnical dataset, which has
previously not been publically available, is a remarkable collection to study the
Earthquake. By disseminating the dataset in the context of the seismic hazard of
the 1995 Kobe Earthquake through a web-based information system, there will behuge benefits to the research community, students, and practicing engineers. Inview of this, a collaborative project has started in early 2009 between Tufts
University and Kobe University to create a web based geotechnical database of
the “KOBE JIBANKUN”. The Japanese contents of the database and boreholelogs were translated into English. When creating the web based database,additional geotechnical data of dynamic field testing, such as over 100 SASW
(Spectrum Analysis of Surface Wave) test data obtained by the authors(Thompson 2010), were integrated into the database.
This paper discusses the use of “ KOBE JIBANKUN ” for the studies ofearthquake engineering and also to promote the earthquake preparedness &awareness through an effective use of the information.

2. DYNAMIC PROPERTIES OF GROUNG BASED ON JIBANKUN
The methodology of carrying out an earthquake engineering study at a particularsite can vary very significantly because there are many variables to consider, e.g.,strong ground motion, landslides and/or liquefaction, and the site amplification
alone can have various levels of analysis to be performed, e.g., simple method
based on geomorphology to more sophisticated non-linear analysis by using soilmodels based on geotechnical studies. The information of damaged structures isalso important, and its structural details need to be considered when theearthquake damage assessment is to be carried out.
Such integration of earthquake related information can be effectively made byusing a GIS based digital information system, because the GIS system can provide

New Technologies for Urban Safety of Mega Cities in Asia

the users not only the geographic information at the point of interest but also otherinformation together such as geotechnical, geological, geomorphologic and evenhistorical & descriptive information of past earthquake damages.
Fig. 1 presents an example of web pages of “KOBE JIBANKUN” which is
produced as a collaborative work between Tufts University and Kobe University.
The figure presents the location of available boreholes and also SASW test sites
over a seismic intensity variation map which was produced by Fujimoto andMidorikawa (1999). The number of boreholes is large enough to cover the entire
area of Kobe City. In the figure, a 10 meter mesh digital elevation data of GSI

Figure 1: Location of boreholes and SASW sites with seismic intensity map

Figure 2: Location of boreholes and SASW sites in the Higashinada Ward

A survey on residents’ response to earthquake early warning at the 2008….

October 2010, Kobe, Japan(Geospatial Information Authority of Japan) is used to illustrate the background
topography, but various other publically digital map such as Google map &satellite can be used. Fig. 2 illustrates a comparison between a borehole data and a
nearby SASW test at the eastern part of Kobe (i.e., Higashinada Ward). The depth
variation of Vs can be cross-examined against the variation in soil stratigraphy.
2.1 Depth Profile of Vs Based on SASW test
The depth variation of Vs is a key information for studying the site amplification
characteristics, but commonly such depth profile of Vs is not available at many
places. As noted earlier, there have been extensive SASW tests being performedin this area so as to examine a local variation of Vs profile. Fig. 3 illustrates
examples of examining the variation in Vs depth profiles at two different lines(i.e., one along the coastal area and the other at slightly inland from the coast).

inland from coast

along coast

Figure 3A: Lines of SASW test sites in the Higashinada Ward

Fig. 3B: Vs depth profile at inlandFig. 3C: Vs depth profile along coast

Figs. 3B and 3C are produced by combining the SASW data along these two lines.
It is clearly seen that at the coastal area, the Vs value is low and there is no
significant increase of Vs with depth. Thus the seismic engineering base at thearea near coast should be located at further depth. On the other hand, the Vs
profile along the inland area away from coast increases significantly beyond a
depth of 20 m and this depth can be set for the seismic engineering base fordynamic response analysis.

New Technologies for Urban Safety of Mega Cities in Asia

2.2 Correlation between Vs and SPT (N-value)
Although the delineation of dynamic property through the Vs profiling is moredesirable, more commonly available soil data for studying the dynamic propertiesof ground is the N-value from the standard penetration test (SPT). Thus it would
be useful to examine the relationship between the Vs value from the SASW and
the N-value from borehole data. Examples of such correlation study are illustrated
in Fig. 4 and Fig. 5 for the data available along the lines near the coast and theinland respectively. As can be seen from these figures, the Vs profile from the

Figure 4: Comparison of N-value and Vs profiles along the coast

Figure 5: Comparison of N-value and Vs profiles along the inland

A survey on residents’ response to earthquake early warning at the 2008….

October 2010, Kobe, Japan

SASW indicate a gradual change of stiffness with depth, while the N-value profile
indicate a rather scattering of stiffness changes. It is to be noted that the Vs profile
from SASW test is obtained through a back analysis of surface wave transmission
through elastic multi-layers, and therefore the gradual change of Vs with depth isinevitable. On the other hand, the scattering of N-value could also be affected bymany unknown factors, such as inclusion of gravels or the dynamic nature of
testing (e.g., the impact changes of falling head). Thus a good judgment isnecessary to identify the true dynamic properties of ground from these test results.
The correlation between the Vs value and the N-value can be more specifically
identified by sorting the data for different soil types. Fig. 6 (a) & (b) present thecorrelations between the Vs and the N-value for the Holocene gravelly sand andfor the Holocene sands respectively. Also included are the data points based on
the previously available results (purple diamond in Fig. 6a, and hollow triangle inFig.6b) through the Vs data obtained from the down-hole testing although thenumber of data points is much less. The Vs value as can be inferred from the newdataset seems to be slightly higher than those previously estimated.

(a) Holocene gravel(b) Holocene sandFigure 6: Comparison of N-value and Vs for the Holocene Gravel and Holocene Sand
3. USE OF WEB-BASED GEOTECHNICAL DATABASE FOR
EARTHQUAKE RISK REDUCTION
The prime objectives of building a geotechnical database of the Great HanshinAwaji Earthquake is to share globally the engineering knowledge accumulated
about the earthquake, geotechnical, and structural situations of the disaster.
Through this global learning and research processes, it is hoped that the
researchers, engineers, students, and moreover ordinary people can gain betterknowledge on how to reduce future earthquake disasters. For such a wider
spectrum of the target individuals to utilize this geotechnical database for different
usages, the web-sharing capability of the data is essential, but also othercapabilities such as user interface software and hardware of the database need tobe carefully designed and developed. In the following sections, the present web
system of current “KOBE JIBANKUN” is described and then possible future useof the database for the earthquake disaster risk reduction and preparedness &awareness is discussed.
3.1 Present Web System of KOBE JIBANKUNNew Technologies for Urban Safety of Mega Cities in Asia

The web system of KOBE JIBANKUN is built as a collaborative work between
Tufts Univ. and Kobe Univ., and the details of the system can be found at a URL
site of “gdc.cee.tufts.edu”. The web system is created by using open-source
software as listed below, and the web page using current “OpenLayers” is notcapable of handling “Multitouch” function for mobile tablet devices, such as iPador other devices based on the Android operating system.
Table 1: Open source softwares and their functions
SoftwareFunctionR
ka-Map

For statistical computing and graphics
A javascript API for developing highlyinteractive web-mapping interfaces
OpenLayers
JavaScript library for displaying map data in web
browsers
MapServer
For generating images from the spatial database(stored in PostgreSQL)
PostgreSQL/PostGIS Spatial database in PostgreSQL
3.2 Possible Interface Software and Hardware Developments
Presently, the Kobe Jibankun is mainly used by individual researcher to study thecause of earthquake damages by accessing to the geotechnical database. To more
effectively use the database, a platform to exchange and share the knowledge
gained through such research activities is required although the current webpageis created to perform this task. More recognition on the importance of building
such geohazard database is needed, and similar activities need to be campaigned.
Also to fully utilize the potential of GIS system that store a large knowledge base,critical review is necessary as to its function. Fig. 7 is an example of potential
usages of the web based GIS system, and the passive usage is mainly to retrieve
Web-based Kobe Jibankun

Passive use of database

Active use of database- Analysis of EQ damages.

- During EQ reconnaissance,- EQ awareness of house holders

Locate BH using mobile tablet PC.

Figure 7: Active and passive usages of the GIS database
A survey on residents’ response to earthquake early warning at the 2008….

October 2010, Kobe, Japanthe data and the active usage is to use the GIS system, through a mobile tablet
device, in finding the user’s location and accessing interactively to the relevant
data in the system. For the latter, a mobile device with GPS capability is mostsuitable. As noted earlier, current “OpenLayer” program does not have“Multitouch” function such as finger manipulations of touch screen and further
improvements on the software interface are needed. After the introduction of iPadin 2010, a rapid development is taking place for similar mobile tablet devices
based on “Android” OS and thus a new hardware interface may be developed
especially for the active usage.

4. CONCLUSIONS
A web based geotechnical database that contains a huge dataset of the 1995 Great
Hanshin Awaji Earthquake and relevant dynamic as well as static soil properties iscreated. Web dissemination of the dataset in the context of the seismic hazard
study is hoped to be huge benefits to the research community, students, andpracticing engineers. Some examples of using the database to examine the groundmotion amplification properties are given by comparing the Vs profile from
SASW and the N-value profile from borehole dataset.
Further developments to the present web based GIS system are needed both insoftware and hardware interfaces in order to fully be utilized as a tool forearthquake disaster risk reduction. Some discussion are made on the possible
areas of future developments.
REFERENCES
Fuijmoto, K. and Midorikawa, S., (1999): Isoseismal map of the 1995 hyogo-ken
nanbu earthquake estimated from damage distributions, Journal of structural andconstruction engineering. Transactions of AIJ (523), 71-78, 1999-09-30,
Architectural Institute of Japan (in Japanese)
Thompson, E. M., Baise, L.G. Kayen, R.E., Tanaka, Y., Tanaka, H. (2010): A
geostatistical approach to mapping site response spectral amplifications,
Engineering Geology 114, pp 330–342

New Technologies for Urban Safety of Mega Cities in Asia

The mitigation strategy for Taiwan HSR
passing through the land subsidence area of
Yunlin County
Jet-Chau WEN1, Chia-Chen HSU2, Shao-Yang HUANG3and Ju-Huang LEE4
1
Director, Research Center for Soil & Water Resources and Natural Disaster
Prevention, National Yunlin University of Science & Technology, Taiwan, R.O.C.
wenjc@yuntech.edu.tw
2
Research Assistant, Research Center for Soil & Water Resources and Natural
Disaster Prevention, National Yunlin University of Science & Technology,
Taiwan, R.O.C.
3
Research Assistant & Chief, Research Center for Soil & Water Resources andNatural Disaster Prevention, National Yunlin University of Science & Technology,
Taiwan, R.O.C.
4
Section Manager, Hydrology & Technology Department of Water Resources
Agency, Ministry of Economic Affairs of Republic of China, Taipei,
Taiwan, R.O.C.

ABSTRACT
Yunlin County is located in the southwestern area of Taiwan, of which partial orwhole areas of 13 out of 20 townships have serious land subsidence. This
research uses the data of rainfall stations, groundwater monitor wells, and land
subsidence monitor wells in Yunlin County to investigate whether climate change
has affected Yunlin County’s hydrological environment and its corresponding
land subsidence. According to the land subsidence monitoring data of 2002, thegreatest subsidence rates in the area which the HSR passes through was over 10
cm/yr. In order to reduce the extent of land subsidence along the HSR route, in2005 the government chose specific areas to carry out a well sealing plan, which
was to seal dozens of official wells at a distance of 1.5 kms on each side of thehigh speed rail (HSR) route. The plan was completed in 2008. From the actual
land subsidence monitoring data of 2009, the greatest subsidence rates in thearea which the HSR passes through was decreased from 10.6 cm/yr to 7.0 cm/yr.
Thus limiting over pumping of groundwater has improved the land subsidence
problem.
Keywords: climate change, land subsidence

1. INTRODUTION
The Taiwan High Speed Rail (HSR) is the most important transportation
construction in recent years. HSR passes through the most part of western Taiwan
including Taipei, Taoyuan, Hsinchu, Miaoli, Taichung, Changhua, Yunlin, Chiayi,

0ctober 2010, Kobe, Japan

Tainan, and Kaohsiung counties. The total length of HSR is 330 km and its
highest speed is 300 km/hr. Figure 1 shows the HSR train entering into the stationin Taichung.

Figure 1: HSR train and station
Because the speed of HSR is higher than a general train and the highway, thesmoothness and stability of the HSR tracks are extremely important for safety.
Any deformation of the HSR tracks must be controlled within an allowance range.
HSR passes through the Chou-Shui Alluvial Fan, including Changhua County and
Yunlin County. The soil layers of Chou-Shui Alluvial Fan have a highcompression or consolidation potential. Groundwater is the primary water
resource for irrigation, industry and urban demands. Land subsidence caused bycontinuance groundwater over pumping has been occurring in this region from1970 to now. Unfortunately, HSR passes through the serious land subsidence area,
including Huwei, Tuku, and Yuanchang in Yunlin County as shown in Figure 2.
The differential settlement of the HSR tracks caused by land subsidence may
impact the driving safety of HSR. This is a serious issue of utmost concern by the
Taiwan government.
Climate change is an important factor of water resource management in thesouthwestern part of Taiwan including Yunlin County. The change ofprecipitation has confused the operation of the water supply systems in Yunlin
County in recent years. The gap of water resources has always been satisfied withgroundwater pumping. The demand of groundwater will be expectantly larger inthe future, making the prevention of land subsidence even more difficult. A
mitigation strategy is needed for the water resource management of Yunlin
County to protect the driving safety of the HSR. Therefore, the Water Resources
Agency (WRA) carried out a groundwater pumping reduction project from 2005
to 2007. The purpose of this project was to reduce yields of groundwater pumping
in a banned region within a 3-km width along the HSR tracks in Yunlin County.
As a result, several deep wells belonging to government agencies were
decommissioned and sealed. The remaining wells are still being monitored to

New Technologies for Urban Safety of Mega Cities in Asia

avoid groundwater over pumping. According to the land subsidence monitoring
results from 2006, the improvement of preventing land subsidence was significant
and showed that reduction of groundwater pumping was an effective strategy forconserving the safety of HSR.

Figure 2: HSR route in Yunlin County

2. CLIMATE CHANGE IN YUNLIN COUNTY
The climate change phenomenon is discussed in this research using rainfall
monitoring data from the Yunlin Irrigation Association. The period of rainfall
records consists of 48 years, from 1961 to 2007. Those data can help us know thehydrology differences in Yunlin County of recent years. Figure 3 shows theaccumulated rainfall per year at the Huwei and Huili rainfall monitoring stations.
The linear regression shows accumulated rainfall per year has increased from1961. The increased rates are 4.9 mm/year and 3.0 mm/year at the Huwei stationand Huili station, respectively. In addition to the accumulated rainfall increase,
Figure 3 also shows that the period between the wet years and dry years became
shorter. For example, the time interval between the significant wet years of 1981
and 1990 was, in the past, nine years. But recently, the time interval has shorten to
only four years between that of 2001 and 2005. The rainfall during the dry years
was less than before, an evidence of climate change in Yunlin County. During the
29 years from 1961 to 1990, there were only two years, 1964 and 1980, where theaccumulated rainfall per year was less than 1000 mm. But during the 17 years
from 1990 to 2007, there were three significant dry years. Those phenomena show
from the accumulated rainfall that rainfall will expectantly and dramaticallychange in Yunlin County in the future.
Figure 4 shows raining days per year from 1961 to 2007. According to the linear
regression result of the data, the raining days per year did not increase
The mitigation strategy for Taiwan HSR passing through the land subsidence area of
Yunlin County

0ctober 2010, Kobe, Japansignificantly. The raining days per year did not reflect the increase of accumulated
rainfall per year, which means that the rainfall intensity has increased. Therefore,
there was higher rainfall intensity. The maximum average rainfall intensities were
24.8 mm/day and 25.18 mm/day at the Huwei station and Huili station,
respectively. In recent years, the average rainfall intensities were higher than
before, which means rainfall has become more concentrated in fewer days. Thissituation has impacted the water supply systems which essentially need a stablewater resource.
2250

2000

Accumulated Rainfall (mm)

1750

1500

1250

1000

750
Hu Wei
Hui Li
500
1960

1965

1970

1975

1980

1985
Year

1990

1995

2000

2005

2010

Figure 3: Rainfall per year in Yunlin County (1961-2007)

New Technologies for Urban Safety of Mega Cities in Asia

120

110

Rainfall Day (days)

100

90

80

70

60

50

40
1960

Hu Wei
Hui Li

1965

1970

1975

1980

1985
Year

1990

1995

2000

2005

2010

Figure 4: Raining days per year in Yunlin County (1961-2007)30

Rainfall Intensity (mm/day)

25

20

15

10
Hu Wei
Hui Li

5
1960

1965

1970

1975

1980

1985
Year

1990

1995

2000

2005

2010

Figure 5: Rainfall intensity each year in Yunlin County (1961-2007)

The mitigation strategy for Taiwan HSR passing through the land subsidence area of
Yunlin County

0ctober 2010, Kobe, Japan

3. WATER SUPPLY AND DEMANDS IN YUNLIN COUNTY
The major water supply systems in Yunlin County are the Taiwan Water
Corporation and Yunlin Irrigation Association. The Taiwan Water Corporation
usually supplies urban and industrial waters. The Yunlin Irrigation Association
supplies irrigation water for farming. In addition to the Taiwan Water Corporation
and Yunlin Irrigation Association, there are a large number of private wells in
Yunlin County. According to the result of the general survey on wells, Yunlin
County has over 11,000 wells. Figure 6 shows the water supply and demands
from 2002 to 2021. The water supply and demands from 2002 to 2007 were actual
records collected by the Taiwan Water Corporation, Yunlin Irrigation Association,and Water Resources Agency. According to these actual records from 2002 to2007 and with the possible water resource exploitation in the future, the watersupply and demands were estimated for 2011, 2016, and 2021. The actual records
show that the water supply was less than the water demands from 2002 to 2007.
The average gap of water resources in Yunlin County is 0.24 billion cubic meters.
Even with expectations that the Hushan Reservoir will operate from 2014, the gapof water resources still will exceed 0.1 billion cubic meters in 2016 and 2021. Itshould be emphasized that the records of the water demands did not contain theyield of groundwater by all the private wells. The gap is larger than what therecords show if groundwater pumping ceases in order to prevent land subsidence(WRA, 2009).
25

22.5

20

Water Resource (10 8m3)

17.5

15

12.5

10

7.5

Water Supply
Water Demand
Gap

5

2.5
2.4

2.7 2.9

2.3 2.3

1.9

1.6

1.3

1

0
2002

2004

2006

2008

2010

2012
Year

2014

2016

2018

2020

2022

Figure 6: Water supply and demands in Yunlin County

New Technologies for Urban Safety of Mega Cities in Asia

4. Groundwater level variation
Groundwater level variation can reflect the groundwater over pumping effect. The
decline of groundwater level of a region means the groundwater is continuously
being over pumped. Figure 7 shows the groundwater level variation of four
aquifer layers at the Husi groundwater level monitoring station near HSR. Before
2005, the groundwater declined significantly. During this period, groundwater
was over pumped in this region. Not only was the groundwater level in decline for
one aquifer layer, but also for all four aquifer layers, indicating that each aquifer
layer was over pumped. The situation was really serious and land subsidence most
likely occurred during this period. It also means that disequilibrium existed
between the water supply and demands. But from 2005, the groundwater levelnear HSR increased and became stable. This means actions taken to prevent land
subsidence were effective. Land subsidence has remarkably slowed down (Water
Resources Agency, Consumptive Water Statistics Database).
36
Aquifer 1
Aquifer 2
Aquifer 3
Aquifer 4

34
32
30

Groundwater Level (m)

28
26
24
22
20
18
16
14
12
1992

1997

2002
Date(day)

2007

2012

Figure 7: Groundwater level variation (Husi station)

5. LAND SUBSIDENCE ALONG HSR
The most serious areas of land subsidence are Tuku, Yuanchang, and Huwei. The
route of HSR crosses these three villages. According to historical records, themaximum land subsidence rate was 12.2 cm/year in this region in 2002. However,the land subsidence rate has retarded in recent years. Figures 8, 9 and 10 show thesubsidence rate of Yunlin County from 2006 to 2007, from 2007 to 2008, andfrom 2008 to 2009, respectively. The maximum subsidence rates were 8.2
cm/year, 7.1cm/year, and 7.4 cm/year during these three periods. It shows that the
The mitigation strategy for Taiwan HSR passing through the land subsidence area of
Yunlin County

0ctober 2010, Kobe, Japanland subsidence of the regions along HSR has improved and the effort of reducing
groundwater pumping may be the major reason for the improvement (Water
Resources Agency, Land Subsidence Database).

Mailiao

Erlun

Lunbei

Siluo

Linnei

Cihtong

Tais

Huwei

Baojhong
Tuku

Douliou

Dongshih
DounanHSR

Yuanchang
Sihhu

Gukeng

Dapi

BeigangKouhu

Shueilin

Figure 8: Land subsidence rate (2006-2007)

HSR
Mailiao

Erlun

Lunbei

Siluo

Cihtong

Linnei

Huwei
Tais

Baojhong
Douliou
Dongshih

Tuku
Yuanchang

Sihhu
Dapi

DounanGukengBeigangKouhu

Shueilin

Figure 9: Land subsidence rate (2007-2008)

New Technologies for Urban Safety of Mega Cities in Asia

Mailiao

Erlun
Siluo
Lunbei

Cihtong

Linnei

Huwei
Baojhong

Tais
Dongshih

Douliou

HSR

Tuku
Yuanchang
Dapi

Sihhu

DounanGukengShueilin

Beigang

Kouhu

Figure 10: Land subsidence rate (2008-2009)

6. MITIGATION STRATEGY
In order to protect the driving safety of HSR, WRA carried out the “Project for
Filling or Moving Wells of Government Agencies in Banned Regions within a 3km Width along HSR in Yunlin County”. The project dealt with 69 wells of
Yunlin Irrigation Association, 16 wells of Taiwan Water Corporation, and 2 wellsof Taiwan Sugar Corporation. There were 29 wells filled, 39 wells that ceased
pumping, and 19 wells monitored. Figure 11 shows the distribution of the wells
that have been dealt with in this project. The reduction of the yield of groundwater
was 400 million cubic meters per year in this project. The gap of water resource of
this project was satisfied by allocating surface water from other vicinities. The
land subsidence rate along HSR declined from 10.6 cm/year to 7.0 cm/year after
this project. Also after this project, the threat from land subsidence for the safetyof HSR was reduced. In order to respond to the climate change in Yunlin County,
the Taiwan government must consider carrying out similar projects of reducing
groundwater pumping (WRA, 2009).

The mitigation strategy for Taiwan HSR passing through the land subsidence area of
Yunlin County

0ctober 2010, Kobe, Japan

Fig. 11 Well distribution of the project

4. CONCLUSION
Climate change is happening in Yunlin County. The situation of water resourcesmanagement will become sterner. In order to protect the driving safety of HSR,
prevention of land subsidence in Yunlin County is urgent. How to reducegroundwater pumping is the most important issue for the government agencies. A
rational strategy of surface water allocation should be generated and operated. The
only way to decrease the rate of subsidence in Yunlin County is through reductionof groundwater pumping. The experiment, involving the well plugging projects of2005, also confirms this opinion.

REFERENCES
Water Resources Agency, 2010. Hydrological Year Book of Taiwan Republic ofChina 2009 Total Report, Taiwan.
Water Resources Agency, 2009. The feasibility study of multiple water resource
development demands in Yunlin County, Taiwan.
Water Resources Agency, 2009. The monitoring report of “Project for Filling orMoving Wells of Government Agencies in Banned Regions within a 3-km Widthalong HSR in Yunlin County”, Taiwan.
Water Resources Agency, Consumptive Water Statistics Database.
(http://wuss.wra.gov.tw/index.html. August 21, 2010 this site was reviewed.)
Water Resources Agency, Land Subsidence Database.
(http://www.subsidence.org.tw/index2.aspx. August 21, 2010 this site wasreviewed.)
New Technologies for Urban Safety of Mega Cities in Asia

Identifying Shape Characteristics ofHydrograph Components Based on Flood
Disaster Mitigation
Shin-jen Cheng
Associate Professor, Department of Environment and Resources Engineering
Diwan University, Taiwan
sjcheng@dwu.edu.tw
ABSTRACTThis study investigates the characteristics of hydrograph components Based onflood disaster mitigation. Component hydrographs were modelled by a model ofthree serial tanks with one parallel tank. Mean rainfall was calculated using theblock Kriging method. The seven parameters were calibrated using the shuffledcomplex evolution optimal algorithm and 38 events. Based on the analyticalresults, the findings were obtained: (1) For single-peak events, times to peak ofhydrograph components are an increasing power correlation corresponding topeak time of rainfall; (2) The peak discharges of hydrograph components arelinearly proportional to that of total runoff; the ratio for quick runoff isapproximately 83% and 17% for the slow runoff; and (3) Relationships of total
discharges also have direct ratios between hydrograph components and observed
total runoffs; a quick runoff is 52% and 27% for a slow runoff. The remaining
discharge is baseflow.
Keywords: block Kriging; linear cascade reservoir; streamflow components;hydrograph shape; runoff characteristic

1. INTRODUCTION
In the past, many hydrologists were interested in developments of rainfall-runoff
conceptual models. Generally, approximations of the convolution integral areconveniently used to derive conceptual rainfall-runoff models and to generate
outlet-runoffs of a watershed. These models derived from the convolution integral
are generally known as UH-based modelling. These derivations with specificparameters are the Nash model (Nash, 1957), mathematical models (Clarke, 1973;
Ahmad et al., 2009), geomorphologic IUH (Jin, 1992; Franchini & O’Connell,
1996; Nourani et al., 2009), the distributed parallel model (Hsieh & Wang, 1999),and subwatershed divisions (Agirre et al., 2005). Rainfall-runoff processes(O’Connell & Todini, 1996; Melone et al., 1998; Bhadra et al., 2010) have beenmodelled with IUH. Furthermore, changes of hydrograph characteristics on an
urbanized watershed were also evaluated by identifying the relationships between
IUH parameters and urbanization variables (Cheng & Wang, 2002; Cheng et al.,2008b; Huang et al., 2008a; Huang et al., 2008b; Kliment & Matoušková, 2009;
Cheng et al., 2010).
Basically, essential materials of the UH-based models (e.g. Nash model) usuallyare recordings of rainfall and streamflow. Applying these models based on the0ctober 2010, Kobe, JapanIUH theory involves determining both the effective rainfall and the baseflow of arainfall-runoff event in advance. The baseflow, which is computed separatelyfrom the direct runoff, is a streamflow component and is frequently considered aconstant in a rainfall-runoff event. Effective rainfall is the total rainfall deductingfrom the rainfall lost to depression storage, interception, evaporation andinfiltration. Various works have addressed the effects of different methods for
estimating rainfall excess and baseflow on the accuracy of modelling surface
runoff (Mays & Taur, 1982; Cheng & Wang, 2002). Prior to IHACRES (Jakeman
et al., 1990; Jakeman & Hornberger, 1993) and TANK (Sugawara, 1979;
Sugawara, 1995; Madsen, 2000; Yue & Hashino, 2000; Hashino et al., 2002;
Chen et al., 2003; Lee & Singh, 2005), hydrological modelling was not togenerate total streamflow by a linear convolution with the specific input-output
structures.
The assumptions of IUH like Nash's type linear reservoirs were preserved for themodel used in this study, i.e., a uniform spatial distribution of rainfall and theprinciple of linear superposition. The model structure is serial cascades of threelinear reservoirs and with one in parallel. Each linear reservoir has a kernel
function with an exponential expression derived from the equation of continuity
and convolution integral. These exponential expressions were used to illustratestorage statuses of the linear reservoirs during rainfall-runoff processes.
Generating hydrograph components in a specific river during a storm is the first
application of the proposed model with hydrological serial and parallel cascades.
Then, the causal relationships among rainfall, total runoff observations, andgenerated runoff components were also discussed. The block Kriging method wasused to estimate the mean rainfall as input for the model. Magnitudes of each
open hole in the three serial reservoirs with one in parallel were defined as
specific parameters and were acquired through an optimization approach. In the
optimization processes, three evaluated criteria and an objective function wereused to compare simulations and observations of total runoff hydrographs. The
representative parameters are proportional to the magnitudes of the open holes
and were used to determine surface, rapid subsurface, delayed subsurface andgroundwater runoffs. Finally, hydrograph components (quick and slow flows) of
the research watershed-outlet and their characteristics relating to observations ofrainfall and total runoff were discussed and completed.

2. THE BLOCK KRIGING METHOD
The block Kriging method was used to estimate hourly spatially uniform rainfall
over the whole watershed. The Kriging method is theoretically better than theThiessen method because Kriging has a spatial structure (i.e., semivariogram),
while Thiessen has a lesser ability to represent the spatial structure of rainfall.
2.1 Climatological Mean Semivariogram
A basic semivariogram called the scaled climatological mean semivariogram was
proposed (Bastin et al., 1984) and established through dimensionless rainfall dataon a project basin (Cheng et al., 2007). The relationship between the experimental
New Technologies for Urban Safety of Mega Cities in Asia

semivariogram and the scaled climatological mean semivariogram is shown
below:

 (t , hij )   (t ) d* (hij , a )  s 2 (t ) d* hij , a (1)where  (t ) denotes the sill of the semivariogram for time period t (mm2) and istime-variant; a represents the range of the scaled climatological mean
semivariogram (m) and is time-invariant; and s (t ) denotes the standard deviationof rainfall of all raingauges for time period t (mm). The basic semivariogram isexpressed as2
1 T  p t , xi   p t , x j   hij , a   s t 
2T t 1 
 

*
d

(2)

The basic experimental semivariogram can be calculated by using equation 6.
Because this semivariogram is derived from discontinuous point-observations, it
is not spatially continuous. A realistic application for a block Kriging method is touse a popular semivariogram model, named the power model, to obtain spatial
continuity of rainfall variations in Taiwan. The equation for the power model isexpressed as d* (hij , a )  0 hija ,

a2

(3)

where 0 denotes the sill of the scaled climatological mean semivariogram( mm2 ) and is a constant of approximately one except for the power model.
2.2 Block Kriging System
The block Kriging method obtains optimal weights that are obtained from the
Kriging system by assuming a given spatial structure of rainfall. The system isderived by applying Lagrange’s multipliers. The estimated area V must be
divided into M grids before calculating the hourly mean rainfall of storm events
over the watershed by applying equation 4
1 M
n  j ( xi , x j )    M   Vm , xi , i  1, 2, , n
 j 1m 1n  1
i

i 1
n

 K2   i (V , xi )  

(4)

(5)

i 1

where  ( xi , x j ) is the semivariogram of raingauge xi and raingauge x j (mm2);

Vm is the m-th grid in the estimated area;  (Vm , xi ) represents the average
semivariogram of estimated area V and raingauge xi (mm2); i is the weighting ofeach raingauge;  K2 is the Kriging estimated variance (mm2); and  denotes the
Lagrange’s multipliers (mm2). The estimator Z K* of the hourly mean rainfall is aYour paper title

0ctober 2010, Kobe, Japan

linear combination of n available point-rainfall recordings Z ( xi ) located at xi andwith weightings i . The Kriging estimator can be expressed asn

Z K*   i Z ( xi )

(6)

i 1

3. THE MODEL OF LINEAR CASCADE RESERVOIRSThe model in this study is constructed from three linear serial reservoirs with one
in parallel. These reservoirs are individually viewed as independent systems byfollowing the hydrological cycle. The inputs and outputs of linear systems areanalogous to natural flows as runoff components and infiltration. The convolution
integral was used to describe the interior transformations of independent systems
for the inputs and outputs.

Figure 1: The model structure of three serial reservoirs with one in parallel
3.1 Structure and Flow Mechanism within the Model

The proposed model is a lumped rainfall-runoff model for single-input andmultiple-outputs. Average rainfall is the single input for the whole model system,
while the outputs are surface, subsurface and groundwater runoffs at thewatershed outlet. Subsurface runoff is divided into rapid and delayed subsurface
runoffs. This model (Figure 2) has one horizontal open hole and a vertical opening
in the upper and middle reservoirs in serial (Tank 1 and Tank 2), while the parallel
reservoir (Tank 0) and the lowest serial reservoir (Tank 3) only have a horizontal
opening. The rates at which water moves through the opening for the horizontal
holes of one parallel and three serial reservoirs are denoted as a0, a1, a2 and a3,
while b1 and b2 are for the vertical holes of the upper and middle reservoirs in

New Technologies for Urban Safety of Mega Cities in Asia

serial, respectively. Flow discharges, q1 , q2 and q3 , of the horizontal holes at thebottom of the three serial reservoirs are modelled as rapid subsurface, delayed
subsurface and groundwater runoffs. The analogous meaning of surface runoff isindicated by flow q0 of a horizontal opening of the parallel reservoir whenstorage in the upper reservoir in serial is higher than the height Sc itself. Height Sc
can describe the soil antecedent moisture before rainfall. Infiltration amount f1
flows from a vertical hole in the upper reservoir to the middle reservoir in serial.
Discharge f 2 represents the amount of percolation coming from the deep soil
aquifer, flowing from the middle reservoir to the lowest reservoir in serial.
Rainfall r first falls into the upper reservoir in serial (Tank 1), which begins
storing this rainwater (i.e., S1  0 ). The rapid subsurface runoff q1 and infiltration
f1 are simultaneously produced and flow out of the upper reservoir in serial.
When the storage height of the upper reservoir in serial exceeds height Sc (Tank 1
is full), overflow occurs from the upper reservoir in serial (Tank 1) to the parallel
reservoir (Tank 0) and surface runoff q0 is generated, i.e., S1  Sc . Infiltration f1
enters the middle reservoir in serial (Tank 2) and is stored, and the delayed
subsurface runoff q2 and percolation f 2 then start flowing ( S 2  0 ). Finally,
percolation f 2 flows into the lowest reservoir in serial (Tank 3), and its storage
status is the same as that in the middle reservoir in serial; and groundwater q3
flows away from the lowest reservoir in serial.
3.2 Storage Functions over Time

According to the flow mechanism of the model, runoff components q1 , q2 , q3 ,infiltration f1 and percolation f 2 are storage functions of three reservoirs in serial,
whereas surface runoff q0 is the amount which overflows from the upper
reservoir in serial into and out of the parallel reservoir. These outflows, except
surface runoff q0, are expressed as follows:qi (t )  ai Si (t ), i  1, 2, 3 (mm/hr)(7)f i (t )  bi Si (t ), i  1, 2 (mm/hr)(8)

By combining the equation of continuity and the convolution integral, the storage
functions can be obtained from specific inputs of three serial reservoirs with aparallel reservoir. That is, the IUH for one input unit. The input unit of the upper
reservoir in serial is the rainfall that occurred between 0 and t (the value of tdepends on the recording interval for the rainfall data; in this study, it is 1 hour)
and that of the other time periods is zero. Hence, instantaneous input I1 (t ) equals
1 t , and C1  a1  b1 ; thus, storage height S1 (t ) , which is less than Sc, of the unit
input for the upper reservoir in serial can be derived as follows:
S1 (t ) 



1 1  e C1t
, 0  t  tt
C1Your paper title(9)0ctober 2010, Kobe, JapanS1 (t ) 

1 eC1t  1 e C1t
, t  t
t
C1

(10)

Similarly, unit input I 2 (t ) of the middle reservoir in serial is the infiltration output
f1 (t ) of the upper reservoir in serial, i.e., I 2 (t )  f1 (t )  b1S1 (t ) , and C 2  a 2  b2 ;thus, storage height S 2 (t ) of the unit input for the middle reservoir in serial is asfollows:
S 2 (t ) 
1 b1 C2
C1
e C1t e C2t , 0  t  t
1 
t C1C2  C1  C2
C1  C2S 2 (t ) 

1 b1   C2 eC1t  1 C1t C1 eC2t  1 C2t e e , t  t
t C1C2  C1  C2
C1  C2










(11)

(12)

Finally, the unit input of the lowest reservoir in serial is I 3 (t )  f 2 (t )  b2 S 2 (t ) ,and C3  a3 ; thus, the mathematical expression of storage height S3 (t ) of thelowest reservoir in serial is expressed as
S3 (t ) 

1 b1b2 
C2 a3
C1a3
e C1t e C2t1  
C1  C2 C2  a3 t C1C2 a3 
C1  C2 C1  a3 C1C2e a3t , 0  t  Δt
C1  a3 C2  a3  S3 (t ) 









C1a3 eC2t  1
1 b1b2  C2 a3 eC1t  1
C1t
ee C2t
C1  C2 C2  a3 t C1C2 a3  C1  C2 C1  a3 C1C2 e  1
e a3t , t  t
C1  a3 C2  a3  
a3t

(13)

(14)

Similar to the upper reservoir in serial (Tank1), for the unit input ( I 0  1 ) in
duration t , the unit pulse response function of the parallel reservoir, which isused to generate surface runoff q0, can be obtained asu0 (t ) 1  e a0t, 0  t  tt

u0 (t ) 

1 a0 te  1 e  a0 t , t  t
t





(15)
(16)

3.3 Parameter limitations

Based on physical significances of the principles of the hydrological cycle, soil
infiltration and runoff generation, the model parameters should be confined to thefollowing seven limitations:

New Technologies for Urban Safety of Mega Cities in Asia

1. a0  a1 , rate coefficient of surface runoff q0 should be larger than that of rapid
subsurface runoff q1;
2. a1  a2 , rate coefficient of rapid subsurface runoff q1 is larger than that ofdelayed subsurface runoff q2;
3. a2  a3 , rate coefficient of delayed subsurface runoff q2 is larger thangroundwater amount q3;
4. b1  b2 , rate coefficient of infiltration f1 resulting from the upper reservoir
should be larger than that of percolation f 2 coming from the middle reservoir;
5. 1  (a1  b1 )  0 , sum of two opening ratios in the upper reservoir in serial
shouldbe less than or equal to 1;
6. 1  (a2  b2 )  0 , sum of two opening ratios in the middle reservoir in serial isless than or equal to 1;
7. 1  a3  0 , the opening ratio of the lowest reservoir in serial is less than or equal
to 1, and8. 1  a0  0 , the opening ratio of the parallel reservoir is less than or equal to 1.
4. EVALUATION CRITERIAThis study utilized three criteria to evaluate the suitability of the rainfall-runoff
model for the basin of interest. These three criteria are as follows:
1. Coefficient of efficiency, CE , is defined asT Q (t )  Q (t )

2CE  1  tT1

est

obs

 Q (t )  Q (t )
t 1

(17)

2

obs

obs

where Qest (t ) denotes the discharge of the simulated hydrograph for time period t,
Qobs (t ) is the discharge of the observed hydrograph for time period t, and Qobs (t )is the average discharge of the observed hydrograph for time period t. The betterthe fit, the closer CE is to one. A negative value for CE means that model
predictions are worse than predictions using a constant that is equal to the averageobserved value.
2. The error of peak discharge, EQ p (%) , is defined as
EQ p (%) 

Qest , p  Qobs , p
Qobs , p

 100%(18)

where Qest , p is the peak discharge of the simulated hydrograph and Qobs , p is thepeak discharge of the observed hydrograph.
3. The error of the time for peak to arrive, ETp , is defined as
ETp  Test , p  Tobs , pYour paper title(19)0ctober 2010, Kobe, Japan

where Test , p is the time for the simulated hydrograph peak to arrive and Tobs , p is
the time required for the observed hydrograph peak to arrive.
5. WATERSHED DESCRIPTION
5.1 Geographical feature

The upstream area of the Wu-Tu Watershed was chosen to explore thecharacteristics of runoff components resulting from the model of three serialcascade reservoirs with a parallel reservoir in the research area. The watershedsurrounds Taipei city in the northern part of Taiwan (Figure 2). The Wu-Tu
Watershed covers about 204 km2, and the mean annual precipitation and runoff
depth are 2865 mm and 2177 mm, respectively. Due to the rugged topography of
the watershed, runoff pathlines are short and steep, and rainfall is not uniform interms of both time and space. Large floods arrive rapidly in the middle-todownstream reaches of the watershed, causing serious damage during summers.

Figure 2: Location maps of the Tamshui River Basin and the Wu-Tu watershed
5.2 Rainfall-runoff material

There are three raingauges (Jui-Fang, Wu-Tu and Huo-Shao-Liao) and one
discharge site (Wu-Tu) on the upstream portion of the Wu-Tu Watershed. The
recorded 38 rainfall-runoff events of 1966-2008 were used as the study sample.
The sample of events includes 5 multi-peak events, whereas the remaining ones
are single-peak events. In total, 38 cases were selected for parameter calibration.
The spatial variations of rainfall (i.e., semivariogram in the block Kriging method)were analyzed using the data from the 14 raingauges (including those at Jui-Fang,
Wu-Tu and Huo-Shao-Liao) (Figure 2) located in and around the upstream
portion of the Wu-Tu Watershed. Hourly inputs of mean rainfall for the model
were estimated using the analyzed semivariogram, Kriging system and threeraingauges (i.e., Jui-Fang, Wu-Tu and Huo-Shao-Liao) located in the Wu-Tu
watershed.

New Technologies for Urban Safety of Mega Cities in Asia

6. Results and Discussions

This study initially attempts to generate runoff components on a watershed outlet.
Translating single-input (rainfall) into multi-output (streamflow components)
depends on the lumped model of three serial reservoirs and one in parallel.
Streamflow components during a rainfall-runoff event are generally divided into
surface, subsurface and groundwater runoffs. Subsurface runoff can be further
divided into rapid and delayed subsurface runoffs. This section evaluates model
applicability based on calibration results and generation of streamflow
components. This study also analyzes the characteristics of outlet-hydrographcomponents of the Wu-Tu watershed during rainfall-runoff processes. The quick
runoff (surface runoff) and slow runoff (a sum of the subsurface and groundwaterrunoff) are discussed herein. Restated, this section examines the characteristics ofquick and slow flows related to observations of rainfall and total runoffhydrographs. Runoff characteristics that are compared include the time to peak,
peak discharge and total discharge.
6.1 Model calibration

The hourly semivariogram is a function of time t , isotropy, and a time averageform with a nonzero and T time interval. The analytical results of the scaled
climatological mean semivariogram for the 38 rainfall events recorded by 14
raingauges in or around the watershed were completed. The power form was thenapplied for fitting as follows: d* hij , a   0 h a  0.093h 0.243 , R 2  0.906(20)

where ω0 denotes the scaled parameter of the scaled climatological mean
semivariogram ( mm2 ). Variance s 2 (t ) of a realization  (t ) for each time period t
can be easily calculated from the hourly rainfall measurements. Hourly
semivariograms of rainfall events can then be directly calculated using equations
1 and 20.
The estimated area must be divided into M grids before calculating the hourlymean rainfall during storm events over the watershed by applying equation 8. The
estimated area was divided into 26651- km 2 grids. This study used observations
from three raingauges located in the Wu-Tu watershed to estimate the hourlymean rainfall for applying to the calibrated and verified events.
The simulated runoff components were exported from the model system. In theprocesses of translating the rainfall runoff, the model parameters for each event
were determined by using the shuffled complex evolution (SCE) optimalalgorithm (Duan et al., 1993). These calibrated parameters reflect the complex
rainfall-runoff processes resulting from the watershed and meteorologicalcharacteristics of each case at that time. They also reflect errors in the rainfall
estimates, initial conditions and observed flow. Table 1 shows the comparisons of
the simulated and observed runoff hydrographs using the three criteria ( CE , EQ p ,and ETp ).

Your paper title

0ctober 2010, Kobe, Japan

Table 1: Calibration results for the model of three serial reservoirs with one
parallel reservoir.
Event names (times)
CORA (1966-09-06)
BETTY (1972-08-16)
BILLIE (1976-08-09)
VERA (1977-07-31)
ORA (1978-10-12)
IRVING (1979-08-14)
Storm (1980-11-19)
ANDY (1982-07-29)
CECIL (1982-08-09)
Storm (1983-10-12)
Storm (1983-10-14)
Storm (1984-06-02)
Storm (1984-11-18)
NELSON (1985-08-22)
ALEX (1987-07-27)
ABE (1990-08-30)
Storm (1990-09-01)
Storm (1990-09-02)
Storm (1994-06-18)
FRED (1994-08-20)
GLADYS (1994-09-01)
HERB (1996-07-31)
WINNIE (1997-08-17)
AMBER (1997-08-29)
Storm (1999-09-26)
BEBINCA (2000-11-08)
RANANIM (2004-08-12)
Storm (2004-08-17)
Storm (2004-10-01)
Storm (2005-05-09)
Storm (2005-09-10)
Storm (2005-12-04)
Storm (2005-12-11)
Storm (2006-06-06)
Storm (2007-06-15)
Storm (2007-09-04)
Storm (2008-05-30)
Storm (2008-10-10)
Mean

CE
0.95
0.97
0.98
0.81
0.79
0.94
0.87
0.77
0.80
0.96
0.99
0.94
0.85
0.91
0.88
0.76
0.92
0.92
0.85
0.93
0.91
0.95
0.79
0.75
0.82
0.68
0.61
0.87
0.79
0.78
0.76
0.88
0.70
0.85
0.94
0.94
0.72
0.87
0.85

EQp (%)
15.47
-0.88
-9.01
33.86
23.08
18.97
18.61
15.90
17.71
7.54
-5.74
-29.21
13.01
-2.56
-5.92
11.36
-4.66
-16.23-16.6715.31-17.05
6.23
-2.12
26.26
-11.5612.79-8.16-13.36
12.78
26.76
-4.62
1.44
17.90
10.57
-28.79-18.36-13.628.55
2.78

ETp (hrs)
0
-1
1
0
-2
0
0
0
0
1
0
0
2
0
2
-1
0
2
0
2
2
1
0
1
4
0
1
2
2
1
3
3
5
4
1
1
1
1
1.03

Shape
S
S
S
S
M
S
S
S
M
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
M
M
S
S
S
S
S
S
M
S
S
S
S

* The S notation represents a single-peak rainfall event, and the M notation represents a multi-peak rainfall
event.

Regarding CE for model calibration, 25 calibrated events exceed 0.8, 11 cases arewithin the intervals of 0.7-0.8, and only one is below 0.7 (Table 1). With regard to

New Technologies for Urban Safety of Mega Cities in Asia

EQ p , all samples are smaller than 20% except for six typhoons/storms. The ETp
values are all less than or equal to 3 hours; three are longer than 3 hours. The
average values of the three criteria CE , EQ p and ETp are 0.85, 2.78% and 1.03
hours, respectively. This comparison also exhibits that the calibration issatisfactory for regenerating rainfall-runoff processes. Model calibration using thethree evaluation criteria demonstrates that the calibrated parameters are able toillustrate the situation of the studied watershed during rainfall-runoff processes.
6.2 Simulations of hydrograph components

In this study for hydrological modelling, four hydrograph components are defined,
but five components are necessary to be determined. Those components are
surface runoff, rapid subsurface runoff, delayed subsurface runoff, groundwaterrunoff and baseflow, respectively. The surface runoff, rapid subsurface runoff,delayed subsurface runoff and groundwater runoff are produced from a rainfall
event and they are called “new discharge”. The baseflow is a groundwater flow
before rainfall starts and then the lowest discharge of a rising limb in a total flowhydrograph if it is considered as a constant. Therefore, baseflow can be called“old discharge” and is not a newly-generated flow in a rainfall-runoff event.
The model parameters were determined from rainfall and runoff data by applying
the structure of the proposed model and its exponential derivations. In reality,
various components of excessive streamflow yield from a typhoon event are hard
to be correctly measured and divided. An alternative solution was applied herein
to generate hydrograph components by using the proposed model. Horizontal
outflows of the three linear serial reservoirs with a reservoir in parallel, which
simulate surface runoffs, rapid and delayed subsurface runoffs, and groundwaterrunoff, were obtained based on the calibrated parameters. Figure 3 plots thehydrographs of the quick and slow runoffs for two sets of simulation results in 38
calibrated rainfall-runoff events.
30
Rainfall (mm/hr)

Rainfall (mm/hr)

20

10

0
12

24

36

48

60

72

1000

VERA (1977-07-31)
Duarion: 22 hrs
Rainfall total: 163.7 mm
Basetime: 71 hrs
Total discharge: 8876.50 m3/s

1000
900
800
Runoff hydrographs (m3/s)

10

0
0

600

12

24

36

48

Calibration
Observed Hydrograph
Simulated Hydrograph
Quick Flow
Slow Flow
Baseflow

CECIL (1982-08-09)
Duarion: 34 hrs
Rainfall total: 235.7 mm
Basetime: 48 hrs
Total discharge: 13196.50 m3/s

800

Calibration
Observed Hydrograph
Simulated Hydrograph
Quick Flow
Slow Flow
Baseflow

700

0

900

700
Runoff hydrographs(m3/s)

1100

20

500
400

600

500

400

300
300
200

200

100

100
0

0
0

12

24

36
Time (hrs)
(a)

48

60

72

0

12

24
Time (hrs)
(b)

36

48

Figure 3: Calibrations of runoff hydrographs for rainfall-runoff events
6.3 Times to peak of hydrograph components

Your paper title

0ctober 2010, Kobe, Japan

60

60

50

50

Time to peak of slow runoff (hrs)Time to peak of quick runoff (hrs)Clarifying times to peak of runoff components is vital to determine the timerequired to produce maximum discharge of a runoff hydrograph. Thus, this study
first addresses the characteristic for time to peak. An attempt is made to identify
the relationships between peak time of rainfall and time to peak of runoff
components. Figures 4a and b plot the correlations between peak times ofhyetographs and both hydrograph components, respectively. These positive
correlations, excluding multi-peak rainfall-runoff events, are between peak
rainfall for slow runoffs and peak rainfall for quick runoffs. These figures also
reveals that the power relationship for peak time between rainfall and quick runoff( R 2  0.63 ) is more obvious than between rainfall and slow runoff ( R 2  0.47 ).
The established relationship of rainfall to quick runoff is markedly higher thanthat of rainfall to slow runoff. This is because slow water flowing beneath land
surface is influenced not only by infiltration resulting from rainfall, but also by
porosity, soil moisture and hydraulic conductivity of the soil layers. The above
analytical results demonstrate that time to peak of a quick flow is highly
correlated with peak time of a hyetograph and a slow flow has also a visualcorrelation with rainfall.

40

30

20

Relationship of peak time
Simulated component to rainfall observation
Quick flow for single-peak cases
Quick flow for multi-peak cases
Power regression, R2=0.63 for single-peak cases

10

40

30

20

Relationship of peak time
Simulated component to rainfall observation
Slow flow for single-peak cases
Slow flow for multi-peak cases
Power regression, R2=0.47 for single-peak cases

10

0

0
0

10

20
30
40
Peak time of rainfall (hrs)
(a)

50

60

0

10

20
30
40
Peak time of rainfall (hrs)
(b)

50

60

Figure 4: The relationships of peak times between simulated hydrographcomponents and rainfall observation
Based on the above results, this study concludes that time to peak of a slow runoff
is later than that of a quick runoff. Moreover, the times to peak of both componenthydrographs are related to peak time of rainfall, and their relationships are power
form excluding for the multi-peak events.
6.4 Peak discharges of hydrograph components

The characteristic of the peak discharge of a hydrograph is essential for designing
hydraulic structures. Hence, this study also analyzes the relationships betweenhydrograph components and observed total runoffs in terms of peak discharges.
The above analytical findings indicate that a large total runoff hydrograph (a sumof quick, slow runoffs and baseflow) has a large peak for quick runoff, and islarger than that of a slow runoff.

New Technologies for Urban Safety of Mega Cities in Asia

2000
Ratio of peak discharges: 0.83
Simulated component to streamflow observation
Quick flow for single-peak cases
Quick flow for multi-peak cases
Linear regression, R2=0.93 for all cases

Peak discharge of simulated slow runoff hydrograph (m3/s)

Peak discharge of simulated quick runoff hydrograph (m3/s)

2000

1500

1000

500

0

Ratio of peak discharges: 0.17
Simulated component to streamflow observation
Slow flow for single-peak cases
Slow flow for multi-peak cases
Linear regression, R2=0.58 for all cases
1500

1000

500

0
0

500
1000
1500
Peak discharge of observed total runoff hydrograph (m3/s)
(a)

2000

0

500
1000
1500
Peak discharge of observed total runoff hydrograph (m3/s)
(b)

2000

Figure 5: The relationships of peak discharges between simulated hydrographcomponents and observed total runoffs.
Figure 5 plots the obvious relationships for peak discharges between componenthydrographs and observations of total runoffs. Two linear relationships areevident according to R2 values, i.e. R 2  0.93 and R 2  0.58 for simulated quick
and slow runoffs to total runoff observations, respectively. The extent ofcorrelation for quick runoff with total runoff is stronger than that of slow runoff
with total runoff because slow runoff movements in an aquifer are more complex
than surface runoff (quick runoff) that runs on the ground surface. Figure 5 further
indicates that, while peak discharges of quick runoffs are slightly smaller thanthose of observed total runoff, peaks of slow runoffs are significantly smaller thanthose of observed total runoffs. With respect to multi-peak and single-peak cases,
the ratios are 1-0.83 for observed total runoffs to surface (quick) runoffs and 10.17 for observed total runoffs to slow runoffs.
6.5 Total discharges of hydrograph components

Finally, this study discusses the final characteristic of hydrograph components.
Theoretically, a surface (quick) runoff discharge should be larger than a slow
runoff discharge during a rainfall-runoff episode.
50000
Ratio of total discharges: 0.52
Simulated component to streamflow observation
Quick flow for single-peak cases
Quick flow for multi-peak cases
Linear regression, R2=0.96 for all cases

40000

Total discharge of simulated slow runoff hydrograph (m3/s)

Total discharge of simulated quick runoff hydrograph (m3/s)

50000

30000

20000

10000

Ratio of total discharges: 0.27
Simulated component to streamflow observation
Slow flow for single-peak cases
Slow flow for multi-peak cases
Linear regression, R2=0.75 for all cases

40000

30000

20000

10000

0

0
0

10000
20000
30000
40000
Total discharge of observed total runoff hydrograph (m3/s)
(a)

50000

0

10000
20000
30000
40000
Total discharge of observed total runoff hydrograph (m3/s)
(b)

50000

Figure 6: The relationships of total discharges between simulated hydrographcomponents and observed total runoffs.
Figure 6 plots the comparison results of individual components to observed total
runoff for further identifying the ratio percentages of component flows during

Your paper title

0ctober 2010, Kobe, Japan

rainfall-runoff episodes. For the same events, the points representing specificvalues for total discharges of surface (quick) runoffs to those of total runoffs(Figure 6a) are above those resulting from ratios of slow runoffs to total runoffs(Figure 6b). According to Figures 6a and b, volume of quick flows is larger thanthat of slow flows in rainfall-runoff generations. Both variations of roughly
straight lines can be found for percentages of quick flows to total flows( R 2  0.96 ) and slow flows to total flows ( R 2  0.75 ). Regardless of multi-peakor single-peak rainfall-runoff events, the volume of a surface runoff is 52%
volume of the total runoff and 27% for that of a slow runoff; whereas theremainder is baseflow components.
7. CONCLUSIONSThis study used a model of three serial reservoirs with one parallel reservoir andlimited seven significant parameters to simulate runoff components in a river
outlet. The use of the block Kriging method can help to acquire the bestparameters to represent the hydrological and geomorphic conditions. Based on theanalytical results of the calibrations, the parameters were established and offer
effective assistance on observing runoff components in streamflows of awatershed outlet. The regenerated results show this model is suitable to evaluatehydrological conditions in this and other watersheds and to apply it further towatershed management in Taiwan.
The quick and slow runoffs regenerated from the proposed model reveal
satisfactory characteristics of runoff components, i.e. hydrographs of quick flows
have large peak discharges, whereas slow flows have small peak discharges.
Based on the results of this study, the following significant findings are described:(1) The times to peak for both hydrograph components of single-peak events is anincreasing power correlation corresponding to peak time of a hyetograph. The
relationship resulting from quick runoff is markedly stronger than that from slow
runoff;(2) The peak discharges of hydrograph components for all events are directly andlinearly proportional to observations of a total runoff. The linear correlation
resulting from quick runoffs is higher than that from slow runoffs. The ratio of aquick runoff to the observed total runoff is approximately 83% and 17% for aslow flow to observations of the same total runoff; and(3) The relationships of total discharges for all events also have direct ratios
between hydrograph components and observations of total runoffs; total dischargeof a quick runoff component is 52% that of a total runoff and 27% of that for aslow runoff. The remainder is baseflow in the same total flow. When given
rainfall conditions and total runoff hydrographs, analytical results of this study
significantly contribute to efforts to evaluate hydrograph characteristics of quick
and slow runoffs and, thus provide a valuable reference for watershedmanagement in Taiwan.

New Technologies for Urban Safety of Mega Cities in Asia

REFERENCES

Agirre, U., Goñi, M., López, J. J., and Gimena, F.N., 2005. Application of a unithydrograph based on subwatershed division and comparison with Nash’s
instantaneous unit hydrograph. Catena 64, 321-332.
Ahmad, M. M., Ghumman, A. R., and Ahmad, S., 2009. Estimation of Clark’s
instantaneous unit hydrograph parameters and development of direct surface
runoff hydrograph. Water Resources Management 23, 2417-2435.
Bastin, G., Lorent, B., Duque, C., and Gevers, M., 1984. Optimal estimation of
the average rainfall and optimal selection of raingauge locations. Water Resources
Research 20, 463-470.
Bhadra, A., Bandyopadhyay, A., Singh, R., and Raghuwanshi, N. S., 2010.
Rainfall-Runoff Modeling: Comparison of Two Approaches with Different Data
Requirements. Water Resources Management 24, 37-62.
Chen, R. S., Pi, L. C., and Huang, Y. H., 2003. Analysis of rainfall-runoff relationin paddy fields by diffusive tank model. Hydrological Processes 17, 2541-2553.
Cheng, S. J., and Wang, R. Y., 2002. An approach for evaluating the hydrologicaleffects of urbanization and its application. Hydrological Processes 16, 1403-1418.
Cheng, S. J., Hsieh, H. H., and Wang, Y. M., 2007. Geostatistical interpolation of
space-time rainfall on Tamshui River Basin, Taiwan. Hydrological Processes 21,
3136-3145.
Cheng, S. J., Hsieh, H. H., Lee, C. F., and Wang, Y. M., 2008b. The storage
potential of different surface coverings for various scale storms on Wu-Tu
watershed, Taiwan. Natural Hazards 44, 129-146.
Cheng, S. J., Lee, C. F., and Lee, J. H., 2010. Effects of Urbanization Factors on
Model Parameters. Water Resources Management 24,775-794.
Clarke, R. T., 1973. A review of some mathematical models used in hydrology,
with observations on their calibration and use. Journal of Hydrology 19, 1-20.
Duan, Q., Gupta, V. K., and Sorooshian, S., 1993. Shuffled complex evolution
approach for effective and efficient global minimization. Journal of Optimization
Theory Application 76, 501-521.
Franchini, M., and O’Connell, P. E., 1996. An analysis of the dynamic componentof the geomorphologic instantaneous unit hydrograph. Journal of Hydrology 175,
407-428.
Hashino, M., Yao, H., and Yoshida, H., 2002. Studies and evaluations on
interception processes during rainfall based on a tank model. Journal of
Hydrology 255, 1-11.
Hsieh, L. S., and Wang, R. Y., 1999. A semi-distributed parallel-type linear
reservoir rainfall-runoff model and its application in Taiwan. Hydrological
Processes 13, 1247-1268.
Huang, H. J., Cheng, S. J., Wen, J. C., and Lee, J. H., 2008a. Effect of growing
watershed imperviousness on hydrograph parameters and peak discharge.
Hydrological Processes 22, 2075-2085.

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Huang, S. Y., Cheng, S. J., Wen, J. C., and Lee, J. H., 2008b. Identifying peakimperviousness-recurrence relationships on a growing-impervious watershed,
Taiwan. Journal of Hydrology 362, 320-336.
Jakeman, A. J., Littlewood, I. G., and Whitehead, P. G., 1990. Computation of theinstantaneous unit hydrograph and identifiable component flows with application
to two upland catchments. Journal of Hydrology 117, 275-300.
Jakeman, A. J., and Hornberger, G. M., 1993. How much complexity is warranted
in a rainfall-runoff model? Water Resources Research 29, 2637-2649.
Jin, C. X., 1992. A deterministic gamma-type geomorphologic instantaneous unithydrograph based on path types. Water Resources Research 28, 479-486.
Kliment, Z., and Matoušková, M., 2009. Runoff changes in the Šumava
Mountains (Black Forest) and the Foothill Regions: extent of influence by humanimpact and climate Change. Water Resources Management 23, 1813-1834.
Lee, Y. H., and Singh, V. P., 2005. Tank model for sediment yield. Water
Resources Management 19, 349-362.
Madsen, H., 2000. Automatic calibration of a conceptual rainfall–runoff modelusing multiple objectives. Journal of Hydrology 235, 276-288.
Mays, L. W., and Taur, C. K., 1982. Unit hydrographs via nonlinear programming.
Water Resources Research 18, 744-752.
Melone, F., Corradini, C., and Singh, V. P., 1998. Simulation of the direct runoffhydrograph at basin outlet. Hydrological Processes 12, 769-779.
Nash, J. E., 1957. The form of the instantaneous unit hydrograph. IAHS
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Nourani, V., Singh, V. P., and Delafrouz, H., 2009. Three geomorphologicalrainfall-runoff models based on the linear reservoir concept. Catena 76, 206-214.
O’Connell, P. E., and Todini, E., 1996. Modelling of rainfall, flow and masstransport in hydrological systems: an overview. Journal of Hydrology 175, 3-16.
Sugawara, M., 1979. Automatic calibration of the tank model. Hydrological
Science Bulletin 24, 375-388.
Sugawara, M., 1995. ‘Tank model’, in Singh, V. P. (ed.), Computer Models of
Watershed Hydrology, Water Resources Publications, Littleton, Colorado.
Yue, S., and Hashino, M., 2000. Unit hydrographs to model quick and slow runoff
components of streamflow. Journal of Hydrology 227, 195-206.

New Technologies for Urban Safety of Mega Cities in Asia

A Study on the Planning Regulations ofShin-Hu-Wei Creek Basin, Taiwan
Chiung-Ling Liu1, Shao-Yang Huang2, Cheng-Mau Wu3
and Jet-Chau Wen4
1
Research Assistant, Research Center for Soil & Water Resources and Natural
Disaster Prevention, National Yunlin University of Science & Technology,
Taiwan, R.O.C.
laura@yuntech.edu.tw
2
Research Assistant & Chief, Research Center for Soil & Water Resources andNatural Disaster Prevention, National Yunlin University of Science & Technology,
Taiwan, R.O.C.
3
Executive Secretary, Research Center for Soil & Water Resources and Natural
Disaster Prevention, National Yunlin University of Science & Technology,
Taiwan, R.O.C.
4
Director, Research Center for Soil & Water Resources and Natural Disaster
Prevention, National Yunlin University of Science & Technology,
Taiwan, R.O.C.

ABSTRACT
Yuan-Chang and Tuku Townships, center of the land subsidence area of Yunlin
County in Taiwan, belongs to Shin-Hu-Wei Creek Drainage System. Highly potential
occurrences of floods exist in these areas because of difficult drainage. To mitigate
the inundation problem and protect the resident’s life and property, this study
develops an appropriate comprehensive flood control solution to reduce flood
disasters by considering ecological conservation and environmental landscape. The
major inundation areas were evaluated by a topographical survey, hydrologicalanalysis, and hydraulic modeling. Sobek was used as a tool for creating flood
simulations. Results show three main flood regions occurred at (1) the estuary ofShin-Hu-Wei Creek from Wen-Kang Bridge to West-Mailiao Tributary surrounding
the river catchment area, (2) the downstream area close to the inlet of the
Hsin-Zhuang-Zi Tributary, and (3) the section from Pu-Tzu Bridge to Ho-Ping Bridge.
The flood control measures and improvement plan include (1) heightening the riverdike, (2) widening the entrance of the regional drainage system, and (3) regulating
the main channel. Additionally, a retention pond is proposed to be installed at theupper stream of Ho-Ping Bridge. The benefit-cost ratio is 1.1. The feasibility of the
project is positive for flood mitigation and public safety.
Keywords: hydrological analysis, hydraulic modeling, flood mitigation

1. INTRODUCTION
Flowing into the Taiwan Strait, the Shin-Hu-Wei Creek is located between
Zhuoshuixi River and the Old Hu-Wei River and passes through Cihtong, Siluo, Erlun,
Tuku, Lunbei, Baojhong, Dongshih, Taisi, and Mailiao villages (Figure 1). The total
length of this flood control plan is approximately 45 km from the Qiong-Jiao Control
Gate to the estuary of the Shin-Hu-Wei Creek. The major watershed area covered by
the plan is 107.12 km2. This study is based on hydrological conditions, land use,drainage characteristics, environmental characteristics, topographical surveys andflooding disasters, and an appropriate comprehensive flood control solution to reduce
flood disasters by considering ecological conservation and environmental landscapes.
We can propose effective solid solutions and management strategies to the related
authorities for future river regulations, management, and environmental developments
to be used as a reference.

Regulated area
downstream

Starting point ofestuary

upstream

Lu-Chang Bridge

Figure 1: Shin-Hu-Wei Basin Map

Terminal point
Qiong-Jiao
Control Gate

2. RESEARCH PROJECT
The content of this project are as follows:（1）Investigation of basic information（2）Hydrological analysis（3）Creek characteristics and hydraulic analysis（4）Flood control measures and improvement plan（5）Environmental planning（6）Engineering solutions and evaluation

3. RESEARCH RESULTS
3.1 Investigation of basic information
After the investigation, the basic information of the Shin-Hu-Wei catchment issummarized as follows:（1）The average temperature is around 23 degrees Celsius, the average annual
rainfall of about 1,400 mm, and the relative humidity of about 82.5 percent.
（2）The territorial regions of this river were divided into specialized agriculturalareas of about 57.64% followed by generalized agricultural areas in theproximity of 12.62%. In addition, the remaining classifications were industrial
zones, urban planning districts, specialized areas, and rural areas.
（3）The Water Conservancy Bureau is responsible for operating the irrigation of
farmland. There are three major water outtakes from upstream to downstream:
the You-Che discharge channel, the first discharge channel, and the second
discharge channel. There are two water intakes which deliver water to thesurrounding irrigation area: a branch of Shin-Hu-Wei and the already existing
Lu-Chang Ke channel.
（4）Three villages, Chitong, Lunbei, and Mailiao, had constructed stormwater sewer
systems. The stormwater sewer systems were planned by the Bureau of
Residential and Urban Development and were finished in 1976 and 1982.
（5）Twenty four kinds of birds, three kinds of fish, eight kinds of mammals, and fivekinds of reptiles were found in the Shin-Hu-Wei catchment.
（6）The water quality according to the monitoring stations for pollution indicators
generally showed moderate pollution. The reason is that the main water sourceof the Shin-Hu-Wei comes from the interflow of Chou-Shui River whichcontains high concentrations of suspended solids.
3.2 Hydrological analysis
The hydrological analysis of the Shin-Hu-Wei was based on historical one-day andtwo-day rain storm records. Computation of the areal average rainfall was performedby the Thiessen polygon method based on the rainfall records from 1961 to 2006. For

the frequency analysis of rainstorms, five theoretical distribution models were used,
namely lognormal distribution with two parameters, lognormal distribution with threeparameters, Pearson type Ⅲ distribution, Log-Pearson Ⅲ distribution, and extreme
value distribution. The Horner rainfall pattern of Hu-Wei station was selected as thedesign rainfall pattern. Three methods were used to estimate peak flow, which were
the rational formula, triangle hydrograph and dimensionless unit hydrograph. The
peak flow with a return period of 50 years was used as the design flood flow for
making further analysis of the hydraulic model and the use of engineering plans.
3.3 Creek characteristics and hydraulic analysis(1) Qualitative analysis
A. Slope and pattern
The average decline gradient of the Shin-Hu-Wei is 1/747; generally the creek
gradient changes moderately. The main channel gradient ascends
progressively. According to the creek characteristics, the creek flow is slow
and has little erosion impact on the creekbed.
B. Changes of longitudinal section
The main channel bed generally contains fine particle sizes. The reason is thatthe creek passes through a non-mountainous valley. Therefore, no supply
source of sand and gravel is provided.
C. Comparison of river erosion and deposition
From the segment of the new Lu-Chang Bridge to the sea, channel
cross-sections were rectified by the Planning and Design Division of theWater Conservancy Bureau in 1986. These channel sections are regulated.
However, subsidence has caused the elevation of the main channel to be lower
than the mean sea level. In addition, although planning for the upper reaches
has been performed by the Yunlin County Government in 1990, the practicalengineering projects have not yet been implemented. Therefore, the averageheight has created no significant changes in the creekbed.
(2) Hydraulic analysis of current status
A. Roughness coefficients
The Shin-Hu-Wei Creek was divided into 189 sections. The roughness
coefficients for these sections of the Shin-Hu-Wei were referred to according
to the planning reports of 1986 and 1990 and the manual of river management
and environmental planning. The roughness coefficients used for Sections 1 to
29 was 0.028; from Sections 30 to 140 was 0.03, and from 140.2 to 189 was
0.015.

B. Start water level
In this study the start water level 3.32 m was used as a basis for creating
further simulations.
C. Flood capacity evaluation
Besides Po-Tzu Bridge and Ho-Ping Bridge, the existing dikes were mostly
capable of withstanding a 50-year flood return period (Figure 2).

Figure 2: River Profile Diagram
D. Safety evaluation for cross-river structures
There are totally 56 cross-river structures on the Shin-Hu-Wei Creek from the
Lu-Chang Bridge to the estuary of the Shin-Hu-Wei. According to thehydraulic analysis based on the peak flow of a 50-year return period with afreeboard margin of 1.5 meters, safety for most of the cross-river structures arebearable except for the Xin-Zhuang Bridge. Suggestions have been made toraise the bridge abutments of the upstream bridges from the Lu-Chang Bridgeto the Qiong-Jiao Controlling Gate; the flow section is insufficient owing to
the depth of the main beam which obstructs the flow from passing through.
E. Inundation simulation and analysis
The SOBEK model was used which combines the function of aone-dimensional channel flow and a two-dimensional overland flow toanalyze the flood potential of the Shin-Hu-Wei Creek basin in Taiwan. The
river watershed conceptual model was created by overlapping a 1/5000 site
surveyed topographic map onto the digital terrain model (DTM) prepared by

the Ministry of the Interior. Simulations based on design storms of different
return periods were then carried out. Results show that the flood zones in thecatchment occurred at three major locations (Figure 3): from the estuary ofShin-Hu-Wei Creek to the West-Mailiao Tributary surrounding the rivercatchment area, the confluence of the Shin-Hu-Wei Creek, and theHsin-Zhuang-Zi Tributary, and the area from the cross-section of Pu-Tzu
Bridge to the cross-section of Ho-Ping Bridge.

Figure 3: Major flooding regions in catchment area
3.4 Flood control measures and improvement plan
An appropriate comprehensive flood control program for inundation zones were
designed according to the local conditions and overall consideration of the rivercatchment, which is primarily for reducing flood disasters and secondarily for
improving ecological conservation and the environmental landscape. Three solutions
were proposed according to the inundation simulation and analysis:(1) Downstream (Wen-Kang Bridge) 0 k + 239 ~ 2 k + 698
Simulation results show that the dike heights in most sections are sufficient tohandle flooding except for the area from the cross-section of Wen-Kang Bridgeto the estuary of the Shin-Hu-Wei Creek. The reason is because of the serious
subsidence along the coastal area. There is about 20 ~ 90 cm shortage of height
regarding the embankment. Suggestions were proposed to prevent overflow
and reduce damages by heightening the river dikes, and by pumping in advanceabout 30~90 cm of water in depth from the fish ponds before a torrential raincomes (Figure 4).

Reduce by 65%
Flood area

The status of flood situation

Improved flood situation

Figure 4: The improved results of downstream (Wen-Kang Bridge)(2) The confluence of the Shin-Hu-Wei Creek and the Hsin-Zhuang-Zi Tributary
The original gate size was enlarged to 6 m * 2 m instead of 6 m * 1.5 m.
Therefore, the water trapped at the confluence of the Shin-Hu-Wei and theHsin-Zhuang-Zi Tributary was avoided (Figure 5).

Hsin-Zhuang-Zi
The status of flood situation

Hsin-Zhuang-Zi
Improved flood situation

Improved flood situation

Figure 5: The improved results of downstream area close to the inlet of the
Hsin-Zhuang-Zi Tributary(3) The area from the cross-section of Pu-Tzu Bridge to the cross-section of Ho-Ping
BridgeA suggestion to install a detention pond with a capacity of 370,800 cubic meters
was proposed. The detention pond will be about 15.14 hectares with a 3.5 meter
depth and 1:3 gentle slope, which may reduce flooding in 103 hectares of theflood area (Figure 6).

Improved region

Figure 6: The improved results of the section from Pu-Tzu Bridge to Ho-Ping Bridge
3.5 Environmental planning
Environmental planning within the region needs to take into account the irrigation
drainage, ecological protection, recreational functions, and so on throughout theplanning process to develop a sustainable environment for Shin-Hu-Wei Creek. Basedon environmental characteristics of the river as well as the local geographical andcultural characteristics of the river environment for effective management, the plan
proposes to divide the Shin-Hu-Wei Creek basin into eight regional segments
according to their environmental characteristics. In the future, these segments will be
adjusted according to their socio-economic development, the characteristics of theirlocal disasters, and the local residents’ opinions.

4. CONCLUSION
The planned engineering solutions include heightening the river dike (from 0 k + 239
to 2 k + 689), widening the entrance of the regional drainage system, and regulating
the main channel. Additionally, a detention pond is under consideration to be installed
upstream of Ho-Ping Bridge at the 34 k + 900 to 38 k + 220 river distance. Functionsof the detention pond are to attenuate the peak flow and retard the time of peak flow.

REFERENCES
Water Resources Planning Institute, Water Resource Agency, 2006. The Planning ofRegulation of River Management and Environment, Taiwan.
Water Resources Planning Institute, Water Resource Agency, 2006. The Planning ofRegulation of Southern Yunlin Coast, Taiwan.

Water Resources Agency, Regulation Project of Flood-prone Areas(Website: http://fcp.wra.gov.tw/default.asp?mp=11)

Developing Technology for
Multiple-Hazards Protection
Tso-Chien PAN
Professor, Dean, College of Engineering
Director, Protective Technology Research Centre
Nanyang Technological University, Singapore
cpan@ntu.edu.sg
ABSTRACTThis paper outlines the development of the Protective Technology ResearchCentre (PTRC) at Nanyang Technological University (NTU). The paper also
describes PTRC’s core R&D capabilities, which have over time evolved into thefoundation of technologies that can be employed for protection against multiple
hazards. The multiple hazards described here include the effects of natural forces
such as earthquakes as well as those of manmade ones from underground
explosion or surface explosion events which may be related to homeland security.

Keywords: multiple-hazards protection, earthquakes, explosions, homeland
security

1. INTRODUCTION
The Protective Technology Research Centre (PTRC) is an inter-disciplinary
research centre, established on 29 September 1998 via a Memorandum ofUnderstanding (MOU) signed between the Ministry of Defence (MINDEF) andthe Nanyang Technological University (NTU) in Singapore. PTRC is hosted in
the School of Civil and Environmental Engineering (CEE) at NTU, and isprimarily funded by NTU and MINDEF. On 9 September 2008, NTU and
MINDEF signed its second renewal of MOU for PTRC via the Defence Scienceand Technology Agency (DSTA) for another 5 years.
The Centre provides a platform for synergistic R&D programmes which involve
NTU’s schools in science and engineering colleges. The three-fold mission of
PTRC is:•••To spearhead research efforts in developing advanced protective
technology and homeland security
To provide professional education/training and technology transfer
To provide specialised advisory services to government ministries andlocal industry

October 2010, Kobe, Japan

Most of the joint R&D projects in PTRC have been supported by DSTA,MINDEF. PTRC’s R&D project with DSTA on the development of undergroundspace for civilian and military uses represents one of the most successful
examples of joint R&D projects with the industry or government agencies. The
project supports the national effort in constructing caverns and tunnels within
granite, as well as sedimentary rocks for the storage of strategic materials.
As part of the Underground Technology and Rock Engineering (UTRE)
programme, DSTA and PTRC, together with geologists of Building andConstruction Authority (BCA), studied soil samples over the past 2 years tocompile the Geology of Singapore. The second edition of Geology of Singapore
was launched in 2009 at the Inaugural Defence Construction Seminar. It will be auseful reference for construction and urban planning professionals, who are
constantly looking for space to develop in the land-scarce Singapore.
The Straits Times article on the Construction of Jurong Rock Cavern (dated 16
April 2009) shows the successful transfer of PTRC technology which had started
for military usage with DSTA has transformed itself successfully to civilian usage,
in which PTRC and DSTA act as consultants to JTC Corp. The Jurong RockCavern, which is an excellent example of dual-use technology applicable to bothmilitary and civilian domains, will be the first underground oil storage facility in
Singapore and Southeast Asia.
2. PTRC CORE R&D CAPABILITIESPTRC has carried out many joint R&D projects with various agencies. Some ofthe projects have been on the effects of dynamic, explosion or blast loading on
blast doors, foundations of civil defence shelters, underground facilities andaboveground structures. These research projects involve both numericalsimulations and experimental investigations on the effects of high-intensity
transient dynamic loading on soil and rock media, as well as on structuralcomponents and structural systems. The core R&D capabilities of PTRC can thus
be broadly grouped into three areas as follows:•

Soil and Rock Dynamics– Underground cavern development– Tropical soil engineering•

Structural Dynamics– Structural damage under ground shocks– Blast and fire response of building components and systems•

Computational Mechanics– Constitutive models for concrete perforation and break-up– Dynamic properties of rock materials

New Technologies for Urban Safety of Mega Cities in Asia

3. LEADERSHIP IN PROTECTIVE TECHNOLOGY DEVELOPMENT
AND PTRC CONTRIBUTION TO DEFENCE
PTRC’s growth and development over the last 12 years has spearheaded thefollowing major R&D projects which have made significant impact on advancing
protective technology in Singapore’s defence capabilities:
3.1 Underground Technology & Rock Engineering (UTRE) R&D
Programme and Underground Ammunition Facilities (UAF) Project
PTRC has provided the effective management and crucial leadership for the
success of initial R&D projects on Rock Cavern Engineering and Ground ShockEffects on Buildings. These two projects provided the direct technical support andinput to the engineering and construction of UAF inside granite formation. The
outstanding outcomes of these two initial R&D projects of PTRC did not only
lead to the establishment of a long-term R&D programme in Underground
Technology & Rock Engineering (UTRE), but also the winning of an Outstanding
Engineering Achievement Award by the Institution of Engineers Singapore (IES),
besides upgrading the North Atlantic Treaty Organisation (NATO) codes toenhance the safety of underground ammunition storages as well as to reduce theinhabited building distance (IBD) for surface structures.
What is even more worth noting is the extension of technologies resulting fromthe UTRE R&D programme to the engineering and construction of Jurong RockCavern (JRC). The success of extending UTRE R&D results for UAF to the JRC
construction, the first in Southeast Asia for petroleum storage underground,demonstrates the combined capability of PTRC & DSTA in developing dual-use
technology which can be used for both defence and civilian applications.
3.2 Concrete Penetration and Breakup Simulation R&D Projects
PTRC has worked with Swedish defence research organisation in starting an R&D
project on perforation of concrete targets which involved both numericalsimulations and experimental validations. Resulting from these initialinvestigations, a multi-surface stress-state model, which is a dynamic plastic
damage material model developed to simulate the response of concrete targets.
When compared with experimental data, the model simulated very well theperforation of a rigid steel projectile through concrete panels at 30 degrees
obliquity.
This model has attracted much interest from the Klauz group for further work. It
was thus further developed in a subsequent project to simulate the structural
breakup modeling of both uncovered and earth-covered reinforced concretemagazines under internal high loading-density detonation up to 30 kg/m3. Thiswas complemented with an in-house program developed to determine the debris
dispersion patterns and the hazard zone.

Developing Technology for Multiple-Hazards Protection

October 2010, Kobe, Japan

4. PIONEERING R&D WORK IN BUILDING SECURITY FORHOMEFRONT SECURITY
Before the 911 incidents in the USA, PTRC had pioneered the R&D work
together with DSTA in understanding the progressive collapse of non-hardenedbuilding structures. The R&D work was then quickly evolved into a core projectwith Ministry of Home Affairs, Homefront Security Division (HSD), toinvestigate the blast performances of high-rise commercial buildings, governmentbuildings, and high-risk private buildings. This set of extensive initial R&D workforms the basis of the subsequent development at PTRC in Building Protection for
homefront security.
4.1 Leadership in Building Security Research
In carrying out the above R&D work before and after the 911 incidents in theUSA, PTRC has demonstrated the vision and leadership in providing technologies
to support the homefront security needs. This close collaboration with MHA HSD
on the disproportional collapse of buildings has resulted in the production of
MHA’s book of guidelines for the building industry on building security in
Singapore. The success of PTRC’s pioneering efforts in this domain is clearlyreflected by the recent signing of MOU between NTU and MHA to collaborate
via PTRC with NTU for the Building Security Research Programme which
focuses not only on R&D in progressive collapse of building structures, but also
on education and ad-hoc consultancy services.
5. INNOVATIVE CONTRIBUTIONS TO NATIONAL SECURITY VIA
EARTHQUAKE ENGINEERING
5.1 Pioneer Earthquake Engineering work for Singapore and the Region via
Sumatra Studies
PTRC has pioneered NTU’s R&D work on several aspects of earthquake threat to
Singapore’s built environment, starting from the earthquake source to the building
performance. On earthquake source, PTRC has investigated the potential
devastating earthquakes in Sumatra that could occur in the future. The researchteam has derived a set of attenuation relationships to predict the rates of decay ofseismic waves travelling from the source to Singapore. In addition, PTRC has also
started the investigation of response of soft soil site which is a critical aspect ofground motion intensity in Singapore as demonstrated by the past experience ofbuilding responses to Sumatra tremors.
PTRC has also pioneered a research programme on real-time building response
measurement system to better understand the effects of the Sumatra tremors on
Singapore’s high-rise buildings. This research programme is now supported byboth Ministry of Home Affairs (via HSD) and Ministry of National Development(via BCA and Housing Development Board) to establish a National Data Centreof Seismic Building Response. It started with instrumentation of 81 residential
and commercial buildings in Singapore, which provide the real-time response data
New Technologies for Urban Safety of Mega Cities in Asia

for analysis and display of results on a geographical information system (GIS)
platform that can be shared among several government agencies to decide on thenecessary post-tremor actions.
With PTRC’s national leadership in understanding the effects of Sumatra tremors
on Singapore buildings, it now leads a national committee which is looking into
the establishment of Singapore's earthquake loading requirements as part ofbuilding code upgrading. In the international arena, PTRC provides the leadershipof Southeast Asia region via Prof Pan’s role on the Governing Board of Global
Earthquake Model (GEM) Foundation of Organisation for Economic Cooperation and Development (OECD). PTRC’s leadership is demonstrated in the
recent call of a GEM-SEAsia Regional Workshop at NTU which attracted theattendance of senior researchers and government agencies from around ASEAN,
plus Australia and New Zealand.

Developing Technology for Multiple-Hazards Protection

Development of simulation exercise
for emergency response headquarters
focused on management by objectives
Shinya KONDO1, Shingo NAGAMATSU2, Masaru KAWANISHI3
and Makoto YASUTOMI4
1
Project Researcher, ICUS, IIS, The University of Tokyo, Japankondos@iis.u-tokyo.ac.jp
2
Associate Professor, Faculty of Safety Science, Kansai University, Japan
3
Science Department, Osaka Head Office, The Yomiuri Shimbun, Japan
4
Department Manager, Osaka Yomiuri Service, Japan
ABSTRACTDisaster Reduction and Human Renovation Institution (DRI) developed asimulation exercise for emergency response headquarters, management by
objectives (SEMO), based on the result of several years of experience. The
purpose of SEMO is to perform and learn how to manage an emergency response
headquarters based on management by objectives. Participants of SEMO follow
the whole situation of the crisis event from fragmented information, develop an
action plan based on the strong objectives of the organization, and conduct
strategic public relations to realize objectives. Management by objectives is one
type of management thinking. The authors adapt this thinking to the style ofdisaster response as an organization based on disaster occurrences. Management
by objectives consists of three principles: sharing the common operational picturewith all concerned, developing action plan with strong objectives, and conducting
strategic public relations. The basic model of SEMO consists of five stages;
orientation, team meeting, exercise, simulated press conference, and evaluation.
Exercise means the field participants practice management of emergency
response headquarters according to management by objectives. To design a real
exercise, the basic model is customized based on constrained conditions,characteristics of participants, the object of exercise, and time for exercise. In thiscase, a training course based on SEMO is conducted at DRI. As a result,participant satisfaction is improved, and participants can understandmanagement by objectives. SEMO is an effective exercise for emergency response
officials to learn how to manage an emergency response headquarters.
Keywords: simulation exercise, management by objectives, public relations,common operational picture, incident action plan

1. INTRODUCTION
Disaster Reduction and Human Renovation Institution (DRI) developed asimulation exercise for emergency response headquarters, management by
objectives (SEMO), based on the result of several years experience (Kondo, 2009).

October 2010, Kobe, Japan

The purpose of SEMO is to perform and learn how to manage an emergency
response headquarters based on management by objectives. Participants of SEMO
follow the whole situation of the crisis event from fragmented information,
develop an action plan based on the strong objectives of the organization, andconduct strategic public relations to realize objectives.
Management by objectives is one type of management thinking. The authors
adapted this thinking to the style of disaster response as an organization based on
disaster occurrences such as the Mid-Niigata Prefecture Earthquake (Kondo,
2006) and Hurricane Katrina (Kondo, 2007). Management by objectives consistsof three principles: “sharing the common operational picture with all concerned”,“developing action plan with strong objectives”, and “conducting strategic public
relations”.
The basic model of SEMO consists of five stages (Figure 1): “operation”, “teammeeting”, “exercise”, “simulated press conference”, and “evaluation”. To design areal exercise, the basic model is customized based on constrained conditions,characteristics of participants, the object of exercise, and time for exercise.
“Exercise” means the field participants practice management of emergency
response headquarters according to management by objectives.
In this paper, outlines of three principles of management by objectives and an
exercise based on SEMO are introduced.
Orientation(10-30min.)•Sharing the purpose of exercise with projector
and participants.
•Checking setting and rule of exercise.

Teammeeting(15min.-1hr.)•Defining how to manage information and thedivision of roles between participants.

(1-2hrs.)•Organization of information for the wholesituation of disaster-affected area.
•Developing an action plan.
•Interviewed about the objects of organization andconducting public relations.

Simulatedpress
conference(10-30min.)•Explaining condition of disaster-affected area,
objects and policies of organization.
•Delivering messages to affected people andrelevant players.

Evaluation(10min.-1hr.)•Looking back response of exercise andsimulated press conference and evaluating.

Exercise

Figure 1: The basic model of SEMONew Technologies for Urban Safety of Mega Cities in Asia

2. MANAGEMENT BY OBJECTIVES
2.1 Sharing the common operational picture with all concerned“Information sharing” and “Sharing the common operational picture” are different
concepts. “Sharing the common operational picture” is one of the main functionsof emergency response headquarters. However, in reality quantified details of
disaster affected area are only reported from relevant players. These reports are
given to the emergency response headquarters for information sharing, butconditions of the affected area and emergency response information suggestions
are more important. Therefore the headquarters should follow the whole situationfrom fragmented information such as the number of evacuees, staffing in shelters,
and the damage level of hospitals.
Figure 2 shows the process for sharing the common operational picture. This
process is modeled on disaster response on some local governments in Japan.
Headquarters’ officers derive internal environment such as “Food and drinking
water are stored for only capacity of shelters” and “There is no system to connect
shelters with emergency response headquarter”, and external environment such as“It is highly possible that some affected people could not live in a shelter” and “Itwill be high temperature” from the combination of information. Combining
internal environment and external environment, “Situation of shelters could not becompletely figured out” is recognized by the lack of connection between sheltersand emergency response headquarters, and it is easy to estimate that “There are
not enough relief supplies at some shelters” because some affected people are notliving in shelter and food and drinking water are stored for only the capacity ofshelters. Also, because of high temperatures, “Enough drinking water should beobtained” and “There is high risk for food poisoning” become an assignment.
There are notenough stockpile forcapacity of shelters.

Half of officers can
not come shelters
for liaison.

Some shelter
overflow theircapacity.

Some people arewithout water.
From tomorrow,people will have
“Summer day”.

Information
Information

Information
Information

Internal environment

External environment•Food and drinking water are
stored for only capacity of shelters.
•There is no systems to connect
shelters with emergency response
headquarter.

•It is highly possible thatsome affected people can notlive in a shelter.
•It will be high temperature.

Common operational picture•Situation of shelters can not be completely figured out.
•There are not enough relief supplies at some shelters.
•Especially, enough drinking water should be obtained.
•There are highly risk for food poisoning.

Figure 2: The process for sharing common operational picture

Development of simulation exercise for emergency response headquarters focused on
management by objectives

October 2010, Kobe, Japan

There are three reasons for sharing the common operational picture instead of thefragmented information. First, it is possible to make decisions from the point ofview of all affected areas. Second, it is possible to respond proactively with futureforecast. Third, it is easy to set objects and to gain understanding of the relevant
players. This point will be covered in detail later.
2.2 Developing action plan with strong objectives
It is necessary that emergency response headquarters make an action plan withstrong objectives. The action plan is composed of hierarchical attainableobjectives and action policies for achieving objectives. “Objectives” makes clear
the desired situation for the community with “by when”, “who / where”, and “howfar emergency response headquarters improve”. “Action policies” makes clear the
direction the organization should go and promote relevant players for achieving
objectives. According to the action plan, divisions within the organization should
respond and coordinate with other divisions. Figure 3 shows an example of action
plan. At first, operations divisions and field sites should consider strong objectives
with future forecast from a global point of view, and following that action policies
for achieving the objectives are decided.

【Future forecast】
・Hygienic conditions become worse.
【Objective】
All refugees keep healthy life.
【Action policy】
1. Setting temporary toilet to all shelters
2. Sending public health nurses to shelters for healthconsultation
3. Encouraging people going in and out of shelters towear a mask and wash their hands【Operation】
Storing temporary toilet and antiseptic available
Structure and route for heals consultation○

×( Unnecessary: divisions and field site should consider.)Figure 3: An example of action plan
For making the action plan, there are three points to pay attention to. Firstly,
objects are measurable. Objects are clear by when and how far to do, not abstractsuch as “Quick recovery and reconstruction”. Secondly, objects give operations
for achieving objectives flexibility. Decision of operations is left to field site.
Thirdly, expression of objects is short and to the point. This way, all members
easily respond with discipline.
There are four advantages of making an action plan with strong objectives. First,
affected people’s reliability is improved because they can have a clear vision for
New Technologies for Urban Safety of Mega Cities in Asia

the future. Second, action policies are made in top-down style, so staff members
understand the position of operations and become a highly-motivated team. Third,
it is possible to respond depending on the time and situation because operational
decisions for achieving objectives are left to the field site. Forth, emergency
response headquarters can get support from relevant organization such as public
institution, press, volunteer, and companies because it is easy to understand thecontents of action.
2.3 Conducting strategic public relations
A lot of press visit affected area in emergency situations, and emergency response
headquarters of local governments become one of the places for press coverage.
The more massive and highly concerned the crisis, the more difficult it is to do
operations for achieving objectives under the public relations. For example, TV
camera comes into the operations place, and the head of division who should lead
operations is very busy with press coverage. Almost all local governments do not
clearly position public relations as emergency operations and, as a result there is
no professional public relations officer at emergency response headquarters inemergency situations.
“Strategic public relations” means putting out the information to citizens
aggressively using press for achievement of objectives. This is different frompassively answering questions from the press. For instance, when a fire breaks out
in a factory due to earthquake, giving only the fact of notice to the press makes it
difficult for recipients such as the press and audience to recognize the content andto understand and take actions. Therefore, the press asks about “What will people
living around the fire do?” and “What will emergency response headquarter
operate in the situation?” The answers for them depend on action plan with strong
objectives. For example, it is necessary to know whether the fire on the factoryspreads or hazardous materials catch fire for sharing common operational pictures.
In the former case, no risk of burst and fire spread is delivered and the message ofacting in a level-headed manner is put out. In the latter case, emergency response
headquarters delivers a risk of second accident and puts out a message for
evacuate procedures. Therefore, the contents of public relations are decided
according to action plan and the public relations division and emergency response
headquarter should respond together.
3. EXAMPLE OF TRAINING COURSE BASED ON SEMOTo evaluate the effectiveness of SEMO an exercise based on SEMO wasconducted at DRI. The main target of this course was the disaster response officer
of local government, the purpose was to learn management by objectives.
Participants consisted of 13 people from prefectural governments and 26 people
from municipality. Operators consisted of 3 people as designers of course andexercise, 5 people as the role of journalist, 3 people as the role of chief, and 3
people as logistic supporters. The length of this course was two days and optional
orientation was conducted for applicants to understand the background fordesigning this course.
Development of simulation exercise for emergency response headquarters focused on
management by objectives

October 2010, Kobe, JapanDay 1（10:00～10:15） Opening ceremony（10:15～10:30） オリエンテーション

Day 2

Day 3

（9:00～9:30）作戦会議
Team meeting

第２回演習の進め方、役割分担の再確認（9:30～11:30）第２回図上訓練

Orientation（10:30～10:45）講義１：目標管理型災害対応（10:45～11:00）講義２：災害時における自治体の戦略的な広報とは（11:10～12:00） ルール説明 .
（12:00～13:00） Lunch time

Team meeting（13:00～14:30）作戦会議

１週間後までの災害対応計画の策定
Exercise「目標管理型災害対応」の体感（11:30～12:00）本部長レク
共通の状況認識と１週間後までの災害対応計画を本部長に進言（12:00～12:15）記者会見資料の作成

Press conference（12:15～13:15） 休 憩（13:15～14:45）記者会見シュミレーション

３日後までの災害対応計画の策定
訓練の段取りと役割分担の理解（15:00～16:00）振り返り

Press conference（16:30～17:00）本部長レク

共通の状況認識と３日後までの災害対応計画を本部長に進言（17:00～17:30）振り返り
第１回演習内容の振り返り、第２回演習の解決策のEvaluation
検討

Orientation

記者会見シミュレーションで配布・使用する資料の作成

第１回演習の進め方、役割分担の確認

Exercise（14:30～16:30）第1回演習（地震発生当日）（10:00～12:00）
Option lecture

共通の状況認識、１週間後までの災害対応計画の発表と市民への協力の呼びかけ
第２回演習内容の振り返り（16:15～16:45）振り返りの発表
振り返り成果の全体での共有Evaluation（16:45～17:45）講評
演習全体の評価（17:30～18:00）講評
演習全体の視点から受講者にアドバイス（17:45～18:00） Closing ceremony（18:00～18:30）作戦会議

第２回演習の進め方、役割分担の確認
Team meeting

Figure 4: Curriculum of the training course at DRI
Three constrained conditions to design a curriculum are given as follows. First,
participants come from all over the country because their area characteristics,
frameworks of emergency response headquarter, and working method are
different. Second, the rules of the exercise take time to understand. Third, twodays are ensured for this training course.
Four concepts to design a curriculum according to constrained conditions are
given as follows. First, forming three groups (one prefecture and two
municipalities), a participant respond with other participants whose area
characteristics, frameworks of emergency response headquarter, and their working
method are similar. Second, participants are provided orientation to understandthe settings and rules of exercise. Third, participants have time to decidearrangements for response in exercise with team meeting. Forth, the scenario forthe exercise is a huge earthquake disaster and the exercise is conducted twice. The
purpose of the first try for participants is to get used to the rules of the exercise.
For the first exercise, the scenario assumes four hours have passed since theearthquake happened, and participants make an action plan with objectives forthree days after the earthquake happened. For the second exercise, the purpose isfor participants to realize management by objectives, and the scenario assumes
three days have passed since the earthquake happened. Participants make anaction plan with objectives for one week after earthquake happened. Figure 4
shows a curriculum of this training course based on these concepts to design.
Participants repeat the sequence; “team meeting” “exercise” “simulated press
conference” and “evaluation”, twice after first orientation.
In the training course, participants learned the purpose of this course and rules ofthe exercise with concentration through first team meeting, exercise, and
New Technologies for Urban Safety of Mega Cities in Asiaevaluation. In the second exercise, participants respond according to management
by objects based on this experience. For example, participants shared common
operational pictures such as writing a situation on a post-it and putting the post-it
on a whiteboard (Figure 5). They organized action policies according to problems
in the affected area for making action plan with objectives (Figure 6), and they
conducted strategic public relations using maps with journalists (Figure 7). If
some participants had not yet understood the purpose of this training course, thenthe exercise designers coached them. During the simulated press conference,
participants announced their own action plan with objectives one week after
earthquake happened to journalists (Figure 8). After the simulated press
conference, each group looked back at their response and made a presentation
summarizing the content of their self-view according to the three principles ofmanagement by objectives. Finally, the roles of journalist and designers of
exercise evaluated and commented on the response and presentation ofparticipants.

Figure 5: Scene of exercise (Sharing common operational picture)

Figure 6: Scene of exercise (Developing action plan with strong objectives)
Development of simulation exercise for emergency response headquarters focused on
management by objectives

October 2010, Kobe, Japan

Figure 7: Scene of exercise (Strategic public relations)Figure 7: Scene of simulated press conference
From the investigation on participant satisfaction, the average score was 90 out of
100 (quantity of response was 37 people). This shows that the participants weresatisfied with the training course at DRI based on the trend that participants had
lower satisfaction even when they failed but they were still satisfied with thetraining course.
The authors also surveyed awareness of management by objectives for achieving
the purpose of SEMO. As a result, almost all participants answered they benefited
greatly from this training course. Some participant replied that they understand theimportance of management by objectives and will try to apply SEMO to theirdisaster training course of local government.

New Technologies for Urban Safety of Mega Cities in Asia

4. CONCLUSION
DRI developed a simulation exercise for emergency response headquarters,
management by objectives (SEMO). In this paper, an outline of three principles ofmanagement by objectives and an exercise conducted at DRI based on SEMO
were introduced. As a result, participant satisfaction was improved andparticipants could understand management by objectives. SEMO is an effective
exercise for emergency response officials to learn how to manage an emergency
response headquarters.

REFERENCES
Kondo, S., Hiruma, Y., Meguro K., and Kawata, Y., 2009. Analysis oforganizational disaster response of the local government at the operation-based
exercise. JSCE Journal of Earthquake Engineering Vol. 30, 710-716.
Kondo, T., Koshiyama, K., Hayashi H., Fukutome K., and Kawata, Y., 2006.
Emergency Management and Common Operational Picture of Emergency
Operation Center in Niigata Prefecture in the 2004 Mid-Niigata Prefecture
Earthquake : Analysis from Management by Objective perspective. Journal ofsocial safety science (8), 183-190.
Kondo, T., and Nagamatsu, S., 2007. Emergency Response applying Incident
Command System by Local Government : A case study on 2005 Hurricane
Katrina Disaster. Journal of social safety science (9), 253-260.

Development of simulation exercise for emergency response headquarters focused on
management by objectives

The Study of the Residents’ Demands for Fire
Escape--Illustrated by Two Senior Citizen HomesChin-Hsing HUANG1, Ching-Yuan LIN2
1. Assistant Professor, Nanya Institute of Technology, Taiwan
sas2007@nanya.edu.tw
2. Professor, National Taiwan University of Science and Technology, Taiwan

ABSTRACTThe study aims to investigate fire escape behaviors derived from residents insenior citizen homes and then to analyze the demands for fire escape. Taipei Mucha Self-paid residential home and Taipei Municipal Haoran Senior Citizen
Home were chosen as study sites. The results find that over 50% of seniorresidents considered the current fire alarm system sufficient for their needs while
25% of senior residents expected to install a fire alarm with a louder horn towake them up on each floor. The greatest number of senior residents chose to taketheir nearest stairs as the best method to come to fire safety. Meanwhile, they alsochose their nearest elevators or stairs for safe evacuation. When asked todetermine the measures to help residents escape from a fire, the majority of seniorresidents chose adding interval horizontal platforms, followed by strengthening
the function of elevators to meet the requirements of emergency elevators. These
two options can be further studied and then served as the guidelines for fire safety
in order to secure senior citizens from a fire emergency.
Key words: senior citizens, senior citizen home, fire escape, escape behavior,

1. INTRODUCTION
Any disaster that might occur at any time or place is undoubted. How to reduce
the personnel casualty and the belonging loss in a disaster becomes a major
problem, but preventing the personnel casualty is primarily important. The designof the facility and advanced equipment for fire safety would help alter the situation. Furthermore, the facility design can be improved by the assessment of safety
evacuation theories. Senior citizens and their housing such as senior homes orhealth care facilities have been inseparable since an aging society approached. All
in the society should pay close attention to safety issue.
The increase of senior citizens results in an aged society in Japanese. This urges
many researchers or professionals to pay great efforts and concerns for the study
or investigation of evacuation plan for senior population. The topics are various.
The study of installation of horizontal zone concludes that occupants might only
take half of evacuation time to reach a safe zone in an emergency, which slightly
affect occupants who are able to walk independently. At the same time it decreases half number of occupants who are in danger and surely creates a spacious
waiting zone. Since the capacity of fire zone become smaller, It’s important that

October 2010, Kobe, Japanventing equipment and bedroom zoning should be carefully planned(矢代嘉郎,掛川秀史,海老原學,大槻明 & 岩城英朗,1993).
To investigate the building types, ways of evacuation, interior design for fire
safety and fire alarm system is another focus among the studies(室崎益輝、大西一嘉、久次米真美子、多田純治 & 伊場圭司, 1988). 376 eldercare facilities
specializing in extended care or assisted living and 491 health care organizations
on disability were included. The mailed questionnaires were completed by those
who are responsible for evacuation in the event of a fire or other emergency. The
results conclude that buildings used by the majority of senior own three characteristics in common. First, the building layout caused users themselves not to be able
to evacuate for fire safety. Secondly, it ‘s difficult for building staff members tohave a priority over to try to put off at the first stage of fire, to call fire department,or to help those who are supposed to be taken care of. Thirdly, it’s difficult for
staff members quickly to know the occurrence of a fire and to notify users of thefire, especially in the evening. .
The simulation test was designed to measure staff member reaction toward a fireat its early stage(室崎益輝,大西一嘉,久次米真美子,多田純治 & 伊場圭司,
1988). If these organizations determined only one position in charge of fire safety
program, they concluded that it might take 2-3 minutes to put off a fire at its earlystage while one minute for notification and two minutes for passing the message.
After a total of 4-5 minutes past, the staff member started to take a further step tolead the users to evacuate. As for the evacuation ability in disadvantages groups,
what users with or without the independent or the dependent waking ability
experienced in the drill was taped to quantify their evacuation ability(室崎益輝,
大西一嘉,久次米真美子,多田純治&伊場圭司, 1988). Users’ evacuation speed
and time consumed for preparation and setting up fire safety equipment provided
by helpers were concluded to assess the overall evacuation ability. Obviously,accessibility and capability of equipment for fire safety became more important toboth staff members and building users.
Many authors in Taiwan has been engaged in the pace and cluster density theory
study for over 10 years. The results tried to establish the local evacuation data
based on general population, and the study sites contained hospitals, auditorium
for concert, train station and MRT main station(Yang & Lin, 1999；Ho & Jian,
1999；Ho& Cheng, 1999; Lai,2001). As for senior residents in disadvantagegroups such as seniors, the first study of evaluation of the evacuation safety
design for five senior rest homes in Taipei metropolitan area was found. The
residents were divided elders into healthy, walking stick users, and wheelchairusers. The results concluded the average of horizontal and vertical walking speedof seniors (Tsai, 2001). The other study also focused on the three different kindsof mobility users in 10 senior citizens homes of central and southern part of
Taiwan. The results provided with basic evacuation data (Lin, Hsu &Cheng 2001).
Not only horizontal and vertical walking speed but also the Neff value was derived
from the residents in there senior citizens homes sponsored by Taipei Municipal
Government.(Huang, 2002, 2007).

New Technologies for Urban Safety of Mega Cities in Asia

Based on the idea of respecting each human life, the fire protection design in abuilding is ultimately to help all the occupants or users escape to safe areas.
However, current acts or regulations relevant to building design and fire
protection design are mainly enacted for the interests of general public. Since nostudies of fire escape specializing in disadvantages groups have been found, there
is an intensive need to collect what they require or how they behave for safe
escape. The results expect to indicate the weaknesses in current building acts andfire acts, which inspire the public pt pay close attention to these groups andprovide designers with guideline for designing their living and activity
environments. Eventually, it’s also believed that the results will help amend
relevant acts or regulations in the future. The purpose of the study is to identify
what seniors need for fire escape.

2. RESEARCH METHODS
The research is designed to investigate senior fire escape behavior and seniorprofiles in two senior homes of Taipei. The study subjects were occupants in
Taipei Mu-cha Self-paid residential home and Taipei Municipal Haoran Senior
Citizen Home. The questionnaire was in three parts. The first part of thequestionnaire focused on items of horizontal and vertical moving ability andcapability of using the extinguisher. The second part was to investigate behavior
patterns concerning moving types, awareness of fire, reaction toward the earlystage of a fire and a large fire and the demands for safe evacuation. The final partcontained questions regarding a respondent’s gender, age, education, occupation
before retirement, exercise hours per day and moving ability. From June 1 to July
31 of 2009, a total of 246 questionnaires were distributed to the residents in these
two senior homes. The data were transferred from the questionnaire andcalculated by the SPSS statistic computer package. The frequency and Chi-square
test were used in the study.

3. RESULTS AND DISCUSSIONS
Response rate was 85% in Taipei Mu-cha Self-paid residential home while91%
in Taipei Municipal Haoran Senior Citizen Home.
3.1 Senior resident profiles
Of the 225 senior residents, 47.6 percent were male and 52.4 percent were female.
The majority of them were between at the age of 81 and 90 (45.3%), followed bythose at the age of 71-80 (34.7%). Residents at senior high school level (24%),
illiterate (18.2%) and elementary level (18.2% ) were major groups in education
classification. As for the occupation before retirement, the major groups wereresidents without working experience (18.7%), professional (17.8%) and serviceman (13.6%). Over 60.4percent of them spent less than 1 hour doing exercise,followed by 31.1 percent with 1-2 hours within. Based on the mobility levels of
the residents, 56 percent of them were able to walk independently only, followed

The Study of the Residents’ Demands for Fire EscapeOctober 2010, Kobe, Japanby 19.1 percent of them were able to walk and run independently, 18.2 percent
with walking sticks and 6.7 percent with wheelchairs
Table 3-1 Senior Resident Profiles

GenderMale
FemaleAge
Under 70 years old
71-80 years old
81-90 years old
Over 91 years old
Education level
Illiteracy
Self-study
Elementary graduate
Junior high school graduate
Senior high school graduate
2-year-college graduate
College or University graduate
Graduate
Occupation before retirement
Public opinion representative/Manager
Professional
Employee work for professional
Fisherman /Farmer
Technician
Serviceman
Employee in service industry
Non-technician
Without working experience
Length of daily Exercise
Within 1 hour
1-2 hours within
2-3 hours within
3-4hours within
Over 4 hourslevels of mobility
To walk and run independently
To walk independently only
Auxiliary aids such as walking sticks
Wheelchairs

N=225

%

114
111

47.6%
52.4%

23
78
102
22

10.2%
34.7%
45.3%
9.8%

41
19
41
24
54
13
31
2

18.2%
8.4%
18.2%
10.7%
24.0%
5.8%
13.8%
0.9%

7
40
25
5
24
31
25
26
42

3.1%
17.8%
11.1%
2.2%
10.7%
13.6%
11.2%
11.6%
18.7%

136
70
13
4
2

60.4%
31.1%
5.8%
1.8%
0.9%

43
126
41
15

19.1%
56.0%
18.2%
6.7%

New Technologies for Urban Safety of Mega Cities in Asia

3.2 Resident mobility in senior homes
When asked the place where they took a break if they went downstairs, Table 3-2
shows two major groups were those who reached to the 6th floor (40.9%) and to
the 1st floor (28.9%). Residents took 1-2 minutes within for a break (41.38%) was
the major group while the second major group with a break of 2-3minutes within(23.1%).As for hand-held portable extinguishers, 44.4% of the residents were able
to hold smaller than a 10-pound extinguisher, and the following were24.4% withholding a 10-pound extinguisher, 19.1% with holding larger than a 20-pound
extinguisher, and 12% with holding a 20-pound extinguisher.
Table 3-2 Resident Mobility in Senior Homes
N=225%
A break needed to take while
going down the stairs from 7th
floor
to the 6th floor
92
40.9%
to the 5th floor
36
16.0%
to the 4th floor
6
2.7%
to the 3rd floor
23
10.2%
to the 2nd floor3
1.3%
to the 1st floor
65
28.9%Time for the break
1-2 minutes within
94
41.8%
2-3 minutes within
52
23.1%
3-4 minutes within
15
6.7%
4-5 minutes within
19
8.4%
5-6 minutes within
13
5.8%
over 6 minutes
32
14.2%
The fire extinguisher weightthe senior residents can holdOver 20 pounds
43
19.1%
20 pounds27
12.0%
10 pounds
55
24.4%
Below 10 pounds
100
44.4%
3.3 Senior residents’ behavior and fire safety
When asked how to move vertically in their senior homes, Table 3-3 indicates that74.2 percent of the residents took elevator in both directions, followed by 13.8
percent with using stairs in both directions, which were two groups representing
the majority of senior residents. 72.4 percent of the residents thought they werecapable of putting off a small fire, while 51.1 percent would go to the staff
members in the nearest service station to ask for help as they encountered a large
fire. Another option is 34.2 percent of them would push down the nearest PBL togive a signal. When the residents reviewed fire alarms, 50.2 percent of themthought that current equipment was adequate. The rest of them expect a fire alarmwith horn installed on each floor and its volume enlarged (24.2%), followed bystaff members knocking doors to give warnings (20.4%).

The Study of the Residents’ Demands for Fire EscapeOctober 2010, Kobe, JapanThe best way they chose to evacuate in a event of fire was self-approach to thenearest stairs ( 55.6 %). For other options, 18.7 percent of the residents chose to
take elevators. The places for safe evacuation they chose were the nearest stairs orelevators (22.2%) and public areas (18.2%). These two groups represented the
majority of senior residents. Only 18.2 percent of the residents were unable toevacuate by themselves and 10.2 percent of the residents were unsure to haveevacuation ability. This distribution indicates that over 60% of the residents werecapable of evacuating. As for the facilities benefiting their evacuation for fire
safety, to add interval horizontal platforms chosen by 115 residents and allelevators to meet the requirements of emergency elevators chosen by 98 residents
represented what the majority of them would like to have.
Table 3-3 Senior Residents’ Behavior and Fire Safety

Vertical moving types
To use the stairs in both directions
To take elevator up and go down the stairs
To go up the stairs and take elevator down
To take elevators in both directions
Ability to put off a small fire
Be able to do it
To ask someone for help
To cry loudly for help
To inform the service station of getting a help
In an event of a large fire
To Inform service station of a fire and ask for help
To push down PBL
To stay right there and wait for rescue
OthersFire alarm / improvement
A fire alarm with horn and its volume can beenlargedTo ensure fire alarm heard in the room and to add
the installation of visual notification appliances
A fire alarm with visual notification appliances
installed on the top of nightstand in the room
Current equipment adequate
Staff members to notify by knocking doors
The best way to evacuate
To take elevators
Self-approach to the nearest stairs
To stay in balcony for rescue
Self-approach to a service station on each floor
Someone come to help lead the way out expected
Places for safe evacuation
Toward public areas

N=22
5

%

31
23
4
167

13.8%
10.2%
1.8%
74.2%

163
31
19
12

72.4%
13.8%
8.4%
5.3%

115
77
28
5

51.1%
34.2%
12.4%
2.2%

55

24.2%

7

31.0%

4

1.8%

113
46

50.2%
20.4%

42
125
15
19
24

18.7%
55.6%
6.7%
8.4%
10.7%

50

22.2%

New Technologies for Urban Safety of Mega Cities in Asia

Toward the nearest elevators or stairs
To wait in the balcony for rescue
To wait in the bathroom for rescue
To wait for staff members to take a lead
To follow the other residents
Ability to evacuate
Yes.
“No, need someone guided”“I don’t know, It depends”
The improvement of facility and equipment for
fire safety
To strength the elevator function to meet therequirements of emergency elevators
To add a safety zone in the building
To sponsor training program of fire safety for staff
members.
To add interval horizontal platforms
To add spaces for refuge and escape in balconies
Cell phone with GPS system and special service
for emergency
Others

110
6
1
40
18

48.9%
2.7%
0.4%
17.8%
8.0%

161
41
23

71.6%
18.2%
10.2%

98
52
85
115
67
7
4

3.4 Chi-square test of independenceChi-square test of independence was applied to examine whether each of the resident profile variables with each of behavior pattern variables were related. The
results indicated gender classification and the weight classification of portable
extinguishers were associated (Tab3-4). It also indicates age classification andeach of the following classifications—vertical moving types, the demand foralarm equipment and evacuation area were associated.
As the cross table is examined, Table 3-5 shows that the greatest number of theresidents (44.4%) were capable of holding smaller than a10-pound extinguisher.
Among them, 70 percent were female and 30 percent are male. It might infer thatthe female residents were unable to hold larger than a 10-pound extinguishers
because of their physical conditions.
As the cross table is examined, Table 3-6 demonstrates that the greatest number ofthe residents (74.2%) took elevators to move vertically. It consisted of 81.5
percent of residents above the age of 80 and 65.3 percent of the residents below orat the age of 80. It’s found that the older the residents took elevators the more.
Table3-7 shows the distribution of fire alarm/ and its improvement and genderClassifications. For the group below or at the age of 80, the greatest number of theresidents (53.5%) considered that the equipment was adequate, followed by those
who needed to enlarge its volume (28.7%). For the group above the age of 80,
most of the residents (47.6%) also considered that the equipment was adequate,
followed by knocking doors expected (27.4%).

The Study of the Residents’ Demands for Fire EscapeOctober 2010, Kobe, JapanAs the cross table is examined, Table 3-8 indicates that places for safe evacuation,
the greatest number of the residents in both age groups approached the nearest
elevators or stairs with 52.5% and 46%, respectively. The second major group in
age classification also demonstrated the same result. 24.8 percent of the residents
above the age of 80 and 20.2 percent of the residents below or at the age of 80
went to public areas.
Table 3-4 Chi-square Test of Independence

Variable 1

Variable 2

PearsonChi-squarevalue
35.847
5.802
3.980
(×)
0.310
7.386
0.530
1.117
4.287
9.019
1.067
(×)
8.738
5.221
10.3680.775

Degreeoffreedom
3
2
3
(×)
3
4
4
2
3
2
3
(×)
3
4
4
2

ρ
value
0.000
0.055
0.264
(×)
0.958
0.117
0.970
0.572
0.232
0.011
0.785
(×)
0.033
0.265
0.035
0.679

SignificanceThe weight of portable Extinguisher＊
G
Vertical moving types
E
Ability of putting off a small fireN
In an event of a large Fire
D
Fire alarm/ Improvement
E
The best way for Evacuation
R
Places for safe evacuation
Ability of evacuating
The weight of portable Extinguisher
Vertical moving types＊
A
Ability of putting off a small fireG
In an event of a large Fire
E
Fire alarm/ Improvement＊
The best way for evacuation
Places for safe evacuation＊
Ability of evacuating* Statistically significant at ρ<0.05 level.
× Represents that more than 20% of the expected values may be less than 5
Table3-5 Cross Table for the distribution of Fire Extinguisher Weight and Gender Classifications
Variable 2
Variable 1
G
E
N
D
E
R

Male

FemaleTotal

Frequency

Over 20lb.
34Fire Extinguisher Weight
20 lb.
10 lb.
Below 10
lb.
19
31
30

R%
C%
Frequency
R%
C%
Frequency
R%
C%

29.8%
79.1%
9
8.1%
20.9%
43
19.1%
100.0%

16.7%
70.4%
8
7.2%
29.6%
27
12.0%
100.0%

27.2%
56.4%
24
21.6%
43.6%
55
24.4%
100.0%

26.3%
30.0%
70
63.1%
70.0%
100
44.4%
100.0%

Total
114

100.0%
50.7%
111
100.0%
49.3%
225
100.0%
100.0%New Technologies for Urban Safety of Mega Cities in Asia

Table3-6 Cross Table for the Distribution of Vertical Moving Types and Gender Classifications
Variable 2
Variable 1
A
G
E

≦ 80
＞80

Total

Frequency
R%
C%
Frequency
R%
C%
Frequency
R%C%

To use thestairs only
21
20.6%
67.7%
10
8.1%
32.3%
31
13.8%
100%1

Vertical Moving Types
Either the stairs
To takeor elevators
elevators only
14
66
13.9%
65.3%
51.9%
39.5%
13
101
10.5%
81.5%
48.1%
60.5%
27
167
12.0%
74.2%
100%
100%

Total
101
100.0%
44.9%
124
100%
55.1
225
100%
100%

Table3-7 Cross Table for the Distribution of Fire Alarm /improvement and Gender Classifications
Variable 2

Fire Alarm /Improvement
1.

Variable1

2

3

4.

Total

Frequency
29
6
54
12
101
R%
28.7%
5.9%
53.5%
11.9%
100.0%
≦ 80
C%
52.7%
54.5%
47.8%
26.1%
44.9%
Frequency
26
5
59
34
124
R%
21.0%
4.0%
47.6%
27.4%
100%
＞80
C%
47.3%
45.5%
52.2%
73.9%
55.1%
Frequency
55
11
113
46
225
Total
R%
24.4%
4.9%
50.2%
20.4%
100%
C%
100%
100%
100%
100%
100%
1 representing a fire alarm with horn installed on each floor and its volume enlarged
2 representing to ensure fire alarm heard in the room and also install visual notification appliances
3 representing current equipment adequate
4 representing that staff members to notify by knocking doors
A
GE

Table3-8 Cross Table for the Distribution of Places for Safe Evacuation and Gender classifications
Variable2
Variable1

1
25
24.8%
50.0%
25
20.2%
50.0%
50
22.2%
100%

Places for Safe Evacuation
2
3
4
53
4
9
52.5%
4.0%
8.9%
48.2%
57.1%
22.5%
57
3
31
46.0%
2.4%
25.0%
51.8%
42.9%
77.5%
110
7
40
48.9%
3.1%
17.8%
100%
100%
100%

FrequencyA ≦ 80
R%
G
C%
E ＞80
Frequency
R%
C%
Frequency
Total
R%
C%
1 to representing the public areas
2 representing to approach the location of the nearest elevators or stairs
3 representing to wait in the room for rescue
4 representing to wait for staff members to take a lead
5 representing to follow the other residents

The Study of the Residents’ Demands for Fire Escape

5
10
9.9%
55.6%
8
6.5%
6.5%
18
8.0%
100%

Total
101
100.0%
44.9%
124
100%
55.1%
225
100%
100%

October 2010, Kobe, Japan

4. CONCLUSIONS
1. The research indicate that 72 percent of senior residents were capable ofputting off a small fire while 51 percent would go to the nearest service station
for help as a large fire occurred.
2. When asked for the demand of fire alarm, over 50 % of senior residents
thought that current equipment was adequate and 25 percent expected a fire
alarm installed on each floor and its volume enlarged.
3. As for the usage of fire extinguisher, the Chi-square test demonstrates that theweight of fire extinguisher and three respective variables--gender, length ofdaily Exercise and levels of mobility were not independent. As the cross table
is examined, it shows that 84.7 percent of female senior residents were unable
to carry larger than a 10-pound extinguisher because of the limitation of their
physical condition.
4. When asked how to evacuate properly to safe areas, the majority of seniorresidents were capable of approaching to the nearest stairs by themselves.
Those who chose to take elevators become the second major group. Similarly,
around 71.6% of senior residents considered that they were able to evacuate,
and most of them chose the location of the nearest elevators or stairs.
5. As for the measures of enhancing safety level of fire protection, the majority
of senior resident considered to add interval horizontal platforms, followed by
to strengthen the function of elevators to meet the requirements of emergency
elevators.. The results are expected to provide the information to amend theacts or regulations relevant to building design for fire protection.

REFERENCES
Chen, C. C. & Jian, S.W., 2008.Handbook of Performance-based Design Method
for Fire Safety Design Code of Building. Architecture & Building ResearchInstitute, Ministry of Interior.
Ho, M. J.,& Chang. C.C., 1999. A Preliminary Research of Disaster Aversion on
Building Types and User Behaviors—Taking Department Stories as an Example,
Architecture & Building Research Institute Case Study Report
Ho, M. J. & Jian, S.W. , 1999. An Investigation on the Mass Evacuation Characteristics of Earthquake Disasters in Taiwan, Architecture & Building ResearchInstitute Case Study Report
Huang, C.H. , 2002. Research on the Horizontal Escape Speed of the Aged －－illustrated by three senior nursing homes in Taipei－－, Master Thesis, Dept. ofArch., National Taiwan University of Science and Technology.
Huagn, C.H., 2007. The Study of Senior Moving Ability Applied to Evacuation
Plan Verification, Doctoral Dissertation, Dept. of Arch., National Taiwan
University of Science and Technology.
Lai, Y. S., 2001.General and Emergency Evacuation in Pedestrian Flow Analysis
and Mode Establishment for Passage and Stairway, Doctoral Dissertation, Dept.
of Civil Engineering, National Taiwan University
Lin, C.Y., Hsu, M. H., & Cheng, S. T., 2001. Survey for the Evacuation Data in
Senior Welfare Institute , Proceedings of the 13th Taiwan Architect Association

New Technologies for Urban Safety of Mega Cities in Asia

Architecture Study Conference Report.
Tsai, S. F. , 2001. Study for the Evacuation Safety Design in the Senior Rest
Home, Master Thesis , Department of Architecture, Tan-Kang University
Yang, I.Y. & Lin, C.Y., 1999. The Study on the Design and Plan for the Hospital
Facilities of Disaster Evacuation, Architecture & Building Research Institute Case
Study Report
矢代,嘉郎; 掛川,秀史; 海老原,学; 大槻,明; 岩城,英朗,1993.高齢者施設における水平避難方式の効果 : 災害弱者施設の火災安全対策(その 4)学術講演梗
概集. A, 材料施工,防火,海洋,情報システム技術 1993,1341-1342,19930725 (社団法人日本建築学会)
室崎,益輝; 大西,一嘉; 久次米,真実子; 多田,純治; 伊場,圭司, 1988.老人, 身障者福祉施設の避難計画に関する研究 : その 1 アンケート調査にみる防災体
制の実態学術講演梗概集. E, 建築計画, 農村計画 ,567-568,19880901 (社団法人日本建築学会)
室崎,益輝; 大西,一嘉; 久次米,真実子; 多田,純治; 伊場,圭司, 1988.老人, 身障者福祉施設の避難計画に関する研究 : その 2 管理者の初期対応行動の定量化学術講演梗概集. E, 建築計画, 農村計画 1988,569-570,19880901 (社団法人
日本建築学会)室崎,益輝; 大西,一嘉; 久次米,真実子; 多田,純治; 伊場,圭司, 1988.老人, 身障者福祉施設の避難計画に関する研究 : その 3 弱者の避難行動能力の定量化
学術講演梗概集. E, 建築計画, 農村計画 1988,571-572,19880901 (社団法人日本建築学会)The Study of the Residents’ Demands for Fire EscapeA study on the decrease in tourism
to regions affected by natural disasters
Yu TAKANO1, Kimiro MEGURO2
1
Graduate Student, The University of Tokyo, Japantakano@risk-mg.iis.u-tokyo.ac.jp
2
Professor, Director, ICUS, IIS, The University of Tokyo, Japan
ABSTRACT
When a natural disaster happens within or around tourist spots, the number oftourists decreases even if there is no damage or the region is recovered. In
previous studies, it was said that harmful rumors and restraint are the major
reasons of the decrease, but surveys from the viewpoint of tourists are insufficient.
In this paper, the decrease in tourism to regions affected by natural disasters is
studied by conducting surveys through a case study and by opinion poll. The
survey results show that the main reason for the decrease is the perception that“it seems dangerous,” which is not based on the real situation. Information on thesituation in affected regions should be properly distributed, especially to people
living in other prefectures, but it was found that in reality little information wasdelivered. Experts or local organizations can be reliable as sources of
information. It was found that most tourists are aware that travel would help
support the tourism spots, but they cannot decide whether to go there because oflack of information. Thus, it is vital to provide information on safety and to spread
support for tourism.
Keywords: natural disaster, tourism, avoidance of visit, harmful rumor, opinionpoll
1. INTRODUCTION
In this paper, we propose countermeasures to the decrease in tourism to regions
affected by a natural disaster based on surveys through a case study on the IwateMiyagi Inland Earthquake in 2008 and by opinion poll. When a natural disaster
happens within or around tourist spots, the number of tourists decreases even if
there is no damage or if the region recovers. In this paper, we call this decrease“holding back tourism”. For affected regions and surrounding areas, damage fromthe decrease in tourism is enormous, particularly in addition to the direct damage
such as casualties or collapsed houses. Damage on tourism has great influence onother industries because of its ripple effects. There are some previous reports
about reconstruction of tourism after natural disasters by Ide (2006). In a study on
the decrease in tourism by Sekiya (2003), it was said that harmful rumors andhesitation are the major reasons for the decrease, but surveys of mass media andfrom the viewpoint of tourists are insufficient.

0ctober 2010, Kobe, Japan

2. CASE STUDY ON THE IWATE-MIYAGI INLAND EARTHQUAKE
We conducted a case study on the Iwate-Miyagi Inland Earthquake in 2008, after
which it was said that the damage due to decrease in tourism was tremendous.
2.1 The earthquake information
We assembled information from the report by the cabinet office.
- Date, Time: Saturday, June 14, 2008 at 08:43:46 AM at epicenter- Location: 39.122 degrees N, 140.678 degrees E (southern Iwate Prefecture)- Depth: 8km- Magnitude: 7.2- Maximum seismic intensity: 6+ in Japanese intensity scale- Casualties: 17- Totally collapsed houses: 23
2.2 Newspaper survey
We investigated newspaper articles about the earthquake from the day it happened
to the end of the year. Using “Kikuzo 2 visual”, we counted the number of articlesof the national edition and Miyagi edition of Asahi Shimbun. Articles areclassified into four categories: damage and refuge life, support and administration,
safety and reconstruction, other (Figure 1).
70
damage, refuge life
support, administration
safety, reconstruction
othernumber of article

60
50
40
30
20
10
0
National

Miyagi1～10week

National

Miyagi11～20week

National

Miyagi21～29week

Figure 1: Transition of the number of articles
Just after the earthquake occurred, the number of articles about damage andrefuge life was very large. However, in the national edition, the number of articles
about safety and reconstruction was small, and after 11 weeks, there were few
articles about the earthquake. In the national edition, most articles are aboutdamage and refuge life and provided only within 10 weeks.

New Technologies for Urban Safety of Mega Cities in Asia

2.3 Survey on statistics
Figure 2 shows the transition of the number of tourists to Hanamaki city of 2007
and 2008 classified by origin (from inside or outside of the prefecture). The data
was obtained from tourism statistics of Iwate.

number of tourists[thousand]

1,800
1,600

lodging
1day

1,400
1,200
1,000
800
600
400
200
0
2007

2008

2007

from inside2008

from outside

Figure 2: Transition of the number of tourists to Hanamaki
The number of tourists from outside of the prefecture decreased remarkably
compared with that from inside. Moreover, when classifying tourists from outside
into 1 day and lodging, the decrease of lodging tourists was larger than that of 1
day tourists. The same tendency was observed in other cities. Focusing on thenumber of lodging tourists, based on the Japan Tourist Agency statistics, growth
rates of lodging tourists by prefectures in 2008 (January to December 2008
compared to 2007) spread widely.

25.0

20.0

growth rate [%]

15.0

10.0

5.0
0.0

-5.0

-10.0

Saga

Akita

Iwate

Miyagi

Kyoto

Tottori

Tochigi

Oita

Tokyo

Ibaraki

Aomori

Saitama

Yamaguchi

Gifu

Kumamoto

Ehime

NaganoNagasaki

Aichi

Shiga

Hyogo

Gumma

Tokushima

Shizuoka

Hiroshima

Nara

Chiba

Osaka

MiyazakiFukuoka

Okinawa

Okayama

Hokkaido

Kanagawa

Kochi

Yamagata

Fukushima

Wakayama

Yamanashi

Kagoshima

Mie

KagawaFukui

NiigataToyamaIshikawa

Shimane-15.0

Figure 3: Growth rate of tourists by prefectures (2008 compared with 2007)

A Study on the Decrease in Tourism to Affected Regions after Natural Disasters

0ctober 2010, Kobe, JapanIn Figure 3 it could not be seen that national tourism activities were stagnant. In
the Tohoku area, Yamagata and Fukushima visitor numbers have increased
compared to 2007, but three prefectures (Iwate, Miyagi, Akita) are included in thebottom five. Thus, the trend of decrease in the number of tourists seen in theparticular areas was not the trend of Tohoku area or Japan. In the three prefecturesof Iwate, Miyagi and Akita, there was no event considered to cause decrease of
tourists excepting the Iwate-Miyagi Inland Earthquake. Therefore, the reductionin the number of lodging tourists was caused by holding back of tourism becauseof the earthquake.
2.4 Survey on local organization
We sent questionnaires by email to the department of tourism in the three affected
prefectures (Iwate, Miyagi and Akita) and six cities (Oshu, Hanamaki, Sendai,
Osaki, Senboku and Yuzawa). Responses were obtained from seven organizations.
The first question asked "the causes of the decrease of tourists," and fiveorganizations answered. The most common answer was "a lot of report ofdamage." In addition, many organizations answered "ambiguous recognition oflocation" and "lack of safety information," as factors related to harmful rumors.
"Economic downturn" and "soaring oil prices" were also mentioned as factors.
The second question asked "ideal tourists action at the time." This question was
answered by all and the answer was "after confirming safety, wanted to come totravel." The four organizations said "the usual tourist activities would be
supports," and “there are many safe areas, be calmly and get information."
We also investigated the rate of decrease of tourists and the amount of damage
caused by holding back tourism. However, we couldn’t compare the damage byholding back tourism with that of actual disaster situations because the way of
calculating the amount of damage and counting the number of tourists vary withgovernments. For example, in Hanamaki, the number of cancellations was 1,679
and the amount of damage was 164 million yen, but in Osaki the number ofcancellations was 1,456 and the amount of damage was 69 million yen. Evenconsidering the differences in personal spending, this is too big a difference.
3. OPINION POLL ON THE INTERNET
3.1 Survey overview
We conducted a survey of 800 people living in Tokyo (men and women from 20
to 59) via the Internet (January 2010) on tourist activities around the affectedareas after natural disasters. It was confirmed that a representative sample of theTokyo population was met by chi-square test. The purpose of this survey was toreveal behavioral factors for holding back tourism after natural disasters andrecognition on support activities to the regions suffered from holding backtourism. In this survey, 5% significance level was set. We discuss the results
below, for which significant differences were found by statistical hypothesis
testing.

New Technologies for Urban Safety of Mega Cities in Asia

3.2 Reason of cancellation
To the question of "Have you ever cancelled tourism after natural disasters?" 11.6
percent answered "yes". A third of them cancelled because of "it seems
dangerous" (Figure 4). About one-third said that the reason was that the actual
damage has occurred. On the other hand, "restraint for the affected areas" wasanswered by only 3.2 percent of respondents. “Restraint,” which was cited as afactor in holding back tourism in previous studies, was not a big factor.
0%

20%

40%

3.2

33.3

10.8

restraint
actual damage

60%

80%

100%

32.3

seems dangerous
other

20.4

no reason

Figure 4: Reason of cancellation
Looking in more detail at the answers to this question, it is clear that there are
gender differences in the response (Figure 5). Except "other", all answers showeda significant difference between the sexes. On one hand, women tend to cancel for"it seems dangerous" (41.5%), whereas on the other hand men cancelled due to"real damage" (36.5%). Compared to men, women cancelled because of
dangerous image without the actual damage. Conversely, men tend to judge by theactual damage more than women.
0%male 1.9

20%
26.9

female 4.9
restraint
actual damage

40%

60%

13.5
41.5

80%

36.5
7.3

21.2

26.8

seems dangerous
other

100%

19.5

no reason

Figure 5: Reason of cancellation by genders
In this study, we consider "cancellation of tourism," regardless of whether the
tourist visited other areas instead or canceled the tour itself, as holding backtourism if there was a decrease in tourists who originally planned to visit certain
spots.

A Study on the Decrease in Tourism to Affected Regions after Natural Disasters

0ctober 2010, Kobe, Japan

3.3 Tourism around affected regions
To the question of "Have you ever visit regions suffered by holding back tourism
after natural disasters?" 20.0 percent answered "yes". Those respondents wereasked the reason for the visit and the results are as follows (Figure 6). The
answers are classified into six categories: curiosity, support, after check safety, asscheduled, visit relatives and other.
0%

20%

10.0 12.5 7.5

40%

60%

80%

35.0

23.1

curiosity
after check safety
visit relatives

supportas scheduled
other

100%

11.9

Figure 6: Reason of visiting affected regions
Most answers classified into "as scheduled" contain descriptions that they haveconfirmed safety. The answers "visit relatives" means they visited to support orcheck safety of their relatives, so it may include the purpose of support and theanswers which said the purpose was support to other people are classified into
“support.” In the “other” classification, the response “because thought that there
were less people than usual” stood out. No answer included attractive public
relations such as "enjoyable tourism information". Respondents who answered"after check safety" and "as scheduled" originally scheduled to visit there. On theother hand, respondents who answered "curiosity", "support", "visit relatives,""others" decided to visit there after natural disasters. To increase the visitors
because of their relatives is difficult, but we may suppress holding back tourism toincrease tourists who visit because of "curiosity", "support".
3.4 Reliability of information sources
We examined the reliability of safety information sources (Figure 7). We set six
information sources: disaster response experts, local hotel association, city
government, prefecture government, national government and travel agencies. For
each these organizations, we investigated the reliability as a source of safety
information. Results showed that disaster response experts are most reliable. In
addition, local hotel associations are more reliable than the prefecture or national
government. For tourists, the nearer to the affected region sources are the more
the tourists believe the information is reliable.

New Technologies for Urban Safety of Mega Cities in Asia

0%

20%

expert

40%

22.3

60%

80%

56.9

100%
18.4 2.5

local hotel

14.4

59.6

city

10.4

prefecture

8.8

55.5

31.8

4.0

government

11.4

52.5

29.9

6.3

59.9

travel agency 6.4
quite reliable

42.6
reliable

24.1

1.9

26.4

3.4

43.5
unreliable

7.5

quite unreliable

Figure 7: Reliability as source of information
For answers to this question, we were able to see different trends between genders(Figure 8). Focusing on the comparison of men and women, the answers are
combined into two: "reliable" and "unreliable". For all sources, women consideredthem reliable more than men.

73.8

80%

84.5

local hotel

female

26.3

15.5

male

69.5

30.5

female

78.5

21.5

65.3

34.8

city

male

75.3

femalereliableunreliable

0%

100%

24.8

prefecture

60%

expertmale

40%

government

20%

travel agency

0%

20%

40%

60%

80%

male

60.8

39.3

female

67.8

32.3

male

60.3

39.8

female

67.5

32.5

male

45.5

54.5

female52.5

47.5

reliable100%

unreliable

Figure 8: Reliability as source of information by genders
3.5 Usual tourism activity
To the question "how much do you think the effect of these responses (volunteer
activity and usual tourism) supports the tourist spots harmed by holding backtourism?", usual tourism was considered as support as well as volunteer activities
in the spot (Figure 9).
A Study on the Decrease in Tourism to Affected Regions after Natural Disasters

0ctober 2010, Kobe, Japan

Moreover, when surveying experiences of help for these tourist spots, there were18 people with experiences, 3 of whom were involved in volunteer activities and
15 of whom did usual tourist activities. Among the people whose level ofawareness is high enough to act, their help correspond to the need of tourists spots.
0%

20%

40%

60%

80%

100%

volunteer
activity

25.8

53.5

16.8 4.0

usual tourism

24.1

52.6

19.6 3.6

quite agree

agreedisagreequite disagree

Figure 9: Recognition about support activity
4. PROPOSAL OF COUNTERMEASURE
Preparation of emergency response considering the tourism industry is inadequate.
For example, in regional disaster prevention plans there is no independent heading
about emergency response for tourism. For holding back tourism in particular,
only "damage control" is mentioned and specific measures are not referred to.
Therefore, we propose the following measures based on the above results.
From 3.2, it was shown that the main cause of holding back tourism is therecognition of “it seems dangerous”, even without confirmation of the actual
damage situation. To this cause, information that regions are “not dangerous =safe” is needed. However, we can say from Section 2.2 that safety information
was provided for people inside prefecture but was inadequate for outside people.
However, safety information should be provided particularly for people outside of
the prefecture because the decrease rate of tourists from outside of prefecture washigher than that from inside as seen in Section 2.3. When considering information
provision, we need to keep in mind that women tend to trust information and get
image of danger without checking the real situation more than men, as discussed
in Section 3.4. In addition, the source of this information should be organization
close to the specific region and disaster response experts. For people who alreadyplanned tourism to the area, it would be effective to disseminate information
actively by local hotel association and municipal organizations. On the other hand,for the potential tourists, it is important to report widely by mass media and toindicate the source of information clearly.
According to Ide (2006), in this highly information-oriented modern society,"information not from the suppliers of tourism, but from whom once has been thesame spot would be important." Also, "it would be necessary to rewrite theinformation by tourists." However, among measures discussed in this study, postNew Technologies for Urban Safety of Mega Cities in Asia

disaster information from local “supplier of tourism” is important because local
conditions vary dramatically by the occurrence of disasters. After tourists begin toenter, it is important to create a mechanism to provide information through theeyes of tourists who visited the region after a disaster. Moreover, it was found thatmost tourists are aware that usual travel would support for the regions sufferingfrom holding back tourism. However, they cannot confirm that they can go to theregion because information is inadequate. Therefore, from this aspect, it isessential to inform safety of region.
These proposals are arranged in Figure 10. To the original attraction of tourist
spot, after natural disaster, there would be negative (-) element such as "seems
dangerous" or "restraint" and positive (+) elements such as "tourism for support"
and "curiosity". It is important to provide information that “not dangerous =safety” because the main negative element is "seems dangerous". Also, to spreadtourism for support is important. For both measures, information on clearly
defined conditions is essential from local institutions and experts. In addition,"tourism for support" should be promoted to convey the needs of the local sights.
tuorists spots aroundaffected area
original attraction－

seems
dangerous

clear information
on safety＋

tourismfor support－ restraint

local organization
experts as source＋

curiosity

request from the spot

Figure 10: Proposal concept
5. CONCLUSION
Through a case study including newspaper reports and opinion poll, we clarified
the cause of holding back tourism. We then proposed countermeasures to build
concrete methods to clearly inform safety and to spread tourism for support.
However, it is difficult at present to evaluate damage caused by holding backtourism quantitatively. Thus, it is the next challenge to develop techniques toevaluate damage and to verify the effectiveness of the measures we proposed.

A Study on the Decrease in Tourism to Affected Regions after Natural Disasters

0ctober 2010, Kobe, JapanACKNOWLEDGEMENT
Finally, we really thank to those who answered to our questionnaire despite thebusy schedule.
REFERENCES
Akira IDE, 2006. Categorization and Future Direction of Recoveries by Tourism.
Proceedings of Institute of Social Safety Science 19, 91-94
Naoya SEKIYA, 2003. Social Psychology of “Image Contamination” -The
Fact of “Image Contamination” and its Mechanism-. Journal of Japan Society
for Natural Disaster Science 1, 78-89
Cabinet Office: A Summary of Iwate-Miyaga Inland Earthquake
Website: http://www.bousai.go.jp/kinkyu/iwate2/2008-iwate-cao-033.pdf
Kikuzo 2 Visual, Website: http://database.asahi.com/library2/
Iwate tourism statistics (2008),
Website: http://www.iwatetabi.jp/page/association/statistics2009.html
Japan Tourism Agency, 2009. A Report of tourism statistics (2008), 9
Phuket Reconstruction Committee,
Website: http://www.phuketja.org/fukko/tokei.htm
Yoshio KUMAGAI, Yusuke ONO, Takao NAKANO, 1998. An Analysis of
Emergency Measures for Natural Disaster in Tourist Cities : Case Study ofMunicipalities around the Tokyo Metropolitan Region. Journal of Institute ofSocial Safety Science 8, 414-419
Akira IDE, 2006. The Desirable Direction of Future Tourism Information System.
Journal of Information Processing Society of Japan 128, 99-106

New Technologies for Urban Safety of Mega Cities in Asia

The possibility of involving local wisdom tomitigate substructure construction system
concerning Earthquake hazard(Yogyakarta May 27, 2006 Earthquake case studies )Silvia.F. HERINA
Researcher, Research Institute for Human Settlements,
Public Works Department , Indonesia
silvia_herina@yahoo.com
ABSTRACT
Mitigation of upper structure construction have been developed dramatically,
however only few experts interested with sub-structure’s safety, especially forsimple buildings. As a part of building which is not only supported upper part ofbuilding load, but also should pass that load to the soil underneath besides keepon its balance, consideration of sub-structure safety cannot be neglected.
On May27,2006 Yogyakarta Earthquake , more than 400 thousands simple
building were inflicted massive damage, some of them caused by melting of its soil
support ( liquefaction) or soil settlements.
Yogyakarta people have a strong
cultural heritage, most of their traditional houses designed in considering its
relationship with a natural balanced, the use of timber as the primary material
helped much them when the vibration of earthquake attack those buildings.
Generally the foundation were made of compacted soil, the interesting things is
people used a specific wooden pole with a set of heavy board put on its tip as acompaction tool. The compacted soil can reduces some soil failure such asliquefaction , combine with umpak ( short natural stone or heavy timber which isplace in the base of column) systems which is possible to move in certain
direction, can be one of the tool to support sub structure earthquake resistantconstruction.
Keywords: local wisdom, earthquake hazard, traditional buildings, Joglo, umpak,
soil liquefaction.

1. INTRODUCTION
Mitigation to reduce the impact of the earthquake for building construction islargely done and developed, especially for the safety of upper-structure.
Unfortunately, attention to the sub-structure is still very small because many
people have an opinion that their failure rarely occur or if there was, almost no
impact to the human safety. Though this sub-structure system plays an importantrole in maintaining the stability of buildings on it . If the sub-structures failure’s
triggered the large damage can be occurred.

0ctober 2010, Kobe, JapanOn May 27, 2006 earthquakes with 6.3 Mw scale, in Special Region of
Yogyakarta which is located in the central of Java island, more than 400 thousand
simple buildings were damaged, some of which are caused by the liquefaction andland subsidence.
State of Indonesia consists of many islands and many tribes, each having
different cultures, though sometimes influence each others. Some of thosecultural traditions is still followed by the local population. One of the areas ofthick cultural heritage is Yogyakarta and its surroundings.
In the construction field, the cultural influence policy in determining the type ofbuildings to be constructed until the time of commencement of construction. This
wisdom was inherited by parents orally, and through examples of applications insitu. Even though it’s been mostly done custom modifications of construction inancient times, it turns out the basics are taken in the building are still using thewisdom. As an example of the symmetrical layout of buildings and the open space
between buildings and courtyard. In terms of construction can be seen in is always
a consensus to discuss steps to be taken to start construction.

Figure 1 Consultation on the field when it comes to commencement ofconstruction
Construction of traditional buildings in Yogyakarta and Java in general, the mostwidely applied first and is still there, is Joglo construction, which form theframework of the open, with columns that supported the umpak foundation . Somebuildings do type development with a commitment to adopt the system ofcolumns and install wall coverings made of wood. Supported by a double layer
and the type of connection to the beam above it, the Joglo framework is mostly
more withstand earthquakes than masonry buildings with practical columns.
2.THE PHILOSOPHY OF TRADITIONAL HOUSES IN YOGYAKARTAAND CENTRAL JAVA
Construction of traditional buildings in Yogyakarta and central Java, built on thephilosophy that considered the regulations in building construction, the building is
not only built for residential, but is expected to bring happiness and prosperity forthe residents, this philosophy was handed down orally from parents to future
generations. Merging elements of the macrocosm and microcosm for a house

New Technologies for Urban Safety of Mega Cities in Asia

starting from the selection of the site, building design, and also the day whenconstructionmaybegin.
In the selection of the site, there are four conditions that must be followed(Sumintardja, DJ, 1974), firstly, the conditions on the soil , there are two factors
to be considered in determining the condition of the ground where the building
will be constructed, namely gasik and loh. Gasik means soil ground in the rainyseason should be well drained and not muddy or soggy, and during the dry season
do not have cracks. Loh means that soil should contain enough water and fertile
soil to grow crops, should also be considered that the land does not stink.
Secondly on the environment, provisions must be followed are: jujugan, whichmeans easy access from any direction, close to places of worship, markets, or
station, and rejo meaning lies in the prospects for developing regions, and the lastshall ayem which means the building is safe and not damage the environment.
Two other provisions are about the layout or the buildings, fences and gates.
Javanese beliefs say that the location of buildings on the river or mountain anddirection of its orientation greatly affects the lives of residents, as well as thelocation of the fence gate, gate location selection is based on the distribution ofnine sections (figure2), each section affect the inhabitants of the house, forexample on the north side, the door on the second section will be many invited
guests, but in the ninth section will make its inhabitants into poverty.

Figure 2 Spatial location of fence gates
Building design is based on the selection form that is joglo roof, the pyramid, thevillage and grilled, these roof forms essentially determine the floor plan (figure 3).
regular building form a square or rectangular.

Figure 3 Yogyakarta and Javanese house roof types (source: Sumintardja.Dj)

The possibility of involving local wisdom to mitigate substructure….

0ctober 2010, Kobe, Japan

Building element consists of three parts, the top is the roof and the lid, the middle
part consists of sakaguru (middle column), the column edge, and the wall, thebottom consist of foundations, floors and umpak. (figure 4). Umpak as support ofthe column are located at the foot of columns, the material usually massive stoneor old teak wood old enough, umpak is considered as part of the building
foundation.

Figure 4 Distribution of types of building elements of traditional Javanese house ,a. foundations, floor and umpak, b.column, c. roof and lids (source: Yogyakarta
Heritage Society)
Components of the main building is of wood: teak (Tectona grandis), wood
jackfruit (Artocarpus heterophyluss), glugu (Cocos nucifera), sengon (albizzia sp)
or meranti (Shorea leprosila). Wood used as a column installed in accordance withthe direction of wood growth, the top of the tree represents the top of the column,
so too the bottom of the timber is the bottom of the column. Wood used is thathas no connection intact..
3. TYPICAL FOUNDATION
The part that considered the traditional building foundation is umpak, floor and
sub grade construction. Sub grade material is often a mixture of soil and sand,sand usually used is in situ sand, because of the geological conditions, volcanic
sand covering almost the entire city of Yogyakarta (figure 5). Before construction
foundation system started, the soil compacted manually with a tamping, it iswooden pole whose bottom connected by a thick and heavy board (figure 6). On
soft ground were scattered fragments of red brick (gambar7), some even use abrick building intact (figure 8) put under construction umpak -column (figure 9).

Figure 5 Physiographical conditions of Yogyakarta city and sourrounds (Source:
Geological Engineering, Gadjah Mada University, Yogyakarta)
New Technologies for Urban Safety of Mega Cities in Asia

Figure 6 Sketch of tool manual soil compactor

Figure 7 Fractions of red brick as soil stabilization

Figure 8 The composition of red brick below the foundation

Figure 9 Sketch base of umpak column (source: Public Works
Directorate.General)
The possibility of involving local wisdom to mitigate substructure….

0ctober 2010, Kobe, Japan

There are two system construction of columns to the foundation: the first one ishinge support system, column placed on umpak and put on the ground that has
been stabilized without any bond, which is relied upon umpak mass weight, thejoint between the columns and umpak using tongue and groove system, there isno definitely provision of the length of tongue and groove (figure 10). Saka guru
umpak (center) has a dimension greater than the saka rawa umpak (under thecolumn edge) as shown in Figure 11, this system provides an opportunity tocolumn to move in a limited particular direction. The second system is a semi-fix
support, called ceblokan system, column is directly inserted into the soil, thiscolumn ends smear with tir and wrapped the rope fibers to prevent dry rot (figure
12).

Umpak

Figure 10 Construction of the umpak column

Figure 11, Saka guru umpak in the center of the building, saka rawa umpak atthe edge (source image: Prihatmani, JP)

New Technologies for Urban Safety of Mega Cities in Asia

Figure 12, System ceblokan column
Currently, preservation of old buildings anchored umpak and the foundation
underneath it, stabilization of soil with broken brick is rarely done, the popular
foundation system is the river stone foundation whose made continuous aroundthe building.
4. SIMPLE BUILDING CONDITION AFTER 2006 YOGYAKARTA
EARTHQUAKE
In some parts of the city of Yogyakarta and its surroundings show the occurrenceof liquefaction, figure 13 below shows the sand boil on one of the wells owned byresidents.

Figure 13 Sand boil, in a home residents, the city of Yogyakarta
Liquefaction was also shown by the appearance of sand and soil settlements inurban areas, as in the picture below:

Figure 14 Impact of liquefaction on the building, the city of Yogyakarta
The possibility of involving local wisdom to mitigate substructure….

0ctober 2010, Kobe, Japan

Masonry building without columns have heavy structural damaged, but thestructure did not experience in soil settlements or foundation failure, some part
underneath of the building stabilized by broken stones, this building is located at
500 m from the Opak river.

Figure 15 Damage to the house in Bantul, 500m near Opak river
On the adjacent site, timber framed building construction suffered less damage
than masonry buildings. Figure 16 below shows one of the wooden columns thatexperienced in a slight shear, while the other columns there is no damage, thelocation of this building in jl.Adi Sucipto, close to the airport Adi Sucipto who its
some buildings suffered severe damage.

Figure 16 Meeting Room, Agency of Research and Development, Ministry of
Public Works Yogyakarta

Figure 17 The columns on umpak base

New Technologies for Urban Safety of Mega Cities in Asia

Construction of the Joglo building meeting room at the Sultan Palace still stand up
well when the earthquake struck Yogyakarta. Building form which is as a single
rigid unit seems quite possible to resist lateral forces caused of earthquake..

Figure 18 The four columns supporting the Joglo building in the palace of
Yogyakarta

Figure 19 Construction of a fairly stiff tongue connection of beam of the Joglo
building
The failure of the columns of buildings due to lateral forces do not shift thelocation of the umpak, possibly due to less rigid connection between theconnection of the tongue groove in the beam.

Figure 20 System Joglo the sloping frame building because of earthquake force

The possibility of involving local wisdom to mitigate substructure….

0ctober 2010, Kobe, Japan

Cineas, Garin Nugroho homes in the area Jagalan, Yogyakarta, central part Joglo
appeared intact after the earthquake, in addition to building houses suffered cracks
in the columns and walls. Some wooden column house at Kota Gede also still
beautiful stand when there was an earthquake in Yogyakarta, May 27, 2006a.

b.

Figure 21 a.Joglo’s home Garin Nugroho, was not disturbed and b. one of thebuildings at Kota Gede , no damage during the earthquake Yogyakarta May 27,
2006
5. CONCLUSIONS
Some local wisdom regarding the design and implementation based on theconstruction of local cultural traditions can be appointed as the basis ofconstruction, soil compaction tradition of doing before using it in fact is an effort
to increase the density of the soil to obtain soil stability, especially if the soilliquefaction potential in the shallow surface. Beam and column construction
system which is a single rigid unit, and the use of wooden column umpak system
is one way to absorb the energy due to lateral forces. Safety of the building
structure below can be enhanced by tie umpak and foundation with an anchor thatwill spreading concentrated loads from column to the graoun beneath. Deeper
study is needed to understand the limiting balance of the gravitational force acting
on the column – umpak and lateral earthquake load expected.
REFERENCES
Arsitektur Research Center, Gaja Mada University, 1971. Studi Perumahan
Tradisionil di Yogyakarta dan Sekitarnya. Direktorat Jenderal Cipta Karya,
Ministry of Public Works and Electric Power, Bandung.
Prihatmaji,Y.P, 2003. Perilaku Rumah Tradisional Jawa Terhadap Gempa.
Thesis, Magister Arsitektur, Institut Teknologi Bandung
Sumintardja, DJ. Traditional Housing in Indonesia, Central Java. Masalah
Bangunan, Vol 19, No 2-June 1974, pp 32-38. Ministry of Public Works andElectric Power, Bandung.
Yogya Heritage Society, 2007. Revitalization of Kotagede Heritage District :Homeowner’s Conservation Manual. UNESCO Bangkok, UNESCO Jakarta.

New Technologies for Urban Safety of Mega Cities in Asia

ANALYZING COASTAL COMMUNITYRESILIENCE TO EARTHQUAKE-TSUNAMISWITH FOCUS ON ARRANGEMENT OFEVACUATION ROUTE AND SHELTER BUILDINGRAHMAN HIDAYAT12*, KIMIRO MEGURO1and SRIKANTHA HERATH2
1

Meguro Laboratory,
Institute of Industrial Science, The University of Tokyo, Japan
2
Institute for Sustainability and Peace, United Nations University(UNU-ISP) Tokyo, Japan
E-mail: rahmanh@webmail.bppt.go.id
ABSTRACTThis paper is a report on the study of coastal community resiliencein Cilacap. Cilacap is one among small numbers of regency in Indonesia,
the first in Central Java, which has disaster management office establishedin accordance to Indonesia’s Law Number 24 of 2007 on Disaster
Mitigation. The earthquake with magnitude M7.2 happened in southernJava followed by the tsunami on July 17, 2006 caused some casualties in thearea of Cilacap.
TUNAMI modeling was used to produce the wave run-up andinundation map. The input data used for the modeling was bathymetry andtopography based on the GEBCO and SRTM 90 m respectively, combining
with field survey data. Field survey consists of the bathymetry survey
covering around 60 kilometer squares of Cilacap’s coastal water andground check survey. We used hypothetically earthquake scenarios thatpossibly generating tsunami in the future with several magnitudes, i.e. 7.5,
8.0, and 8.5 Ms scales respectively.
The result of the modeling shows that tsunami run-up will reach theland area with maximum flow depth of 3,8 meters and the inundation will
cover 0,5～2.2 kilometers from coastline. For the decision of evacuationroute and safe area as well as shelter building, the magnitude of 8.5 Ms will
be used as the standard of planning. The choice of the magnitude needs tobe considered; by referring that many buildings and infrastructure damagedby earthquake with magnitude lower than 8 Ms. Padang’s earthquake,
which happened in September 2009 for instance, shows that approximately
one-third of the allocated shelters for tsunami evacuation risk weredamaged.
1. INTRODUCTION
During the period of the last 45 years, in Indonesia tsunami occurred
20 times or in average tsunami occurs every 2.25 years. The tsunami of
Sumatera, which is claimed to be the most casualties in the Province of*On leave from Agency for the Assessment and Application of Technology of Indonesia

Aceh Darussalam and North Sumatra in December 2004, has been followedby some other tsunami events, namely Nias in 2005, South Java in 2006,
Bengkulu in 2007, and Manokwari-Papua in 2008.
During the period
mentioned above, the tsunami disaster caused more than 250 thousandpeople dead or missing and property loss of more than 45 trillion rupiah.
In accordance with efforts to reduce tsunami impact, since 2006
Indonesian government (through several relevant government agencies andinternational aid), has been developing Indonesia’s Tsunami Early Warning
System (INA–TEWS) to enhance preparedness from tsunami. One effort toimprove preparedness is the availability of data predictions on: tsunami
travel time from the source, wave height around the coastline, and area oftsunami inundation. With the data availability, hopefully communities andgovernment are going to be able to create a rescue and evacuation scenario
by considering the threat of tsunami.
This paper is an interim report on the study of coastal community
resilience to earthquake-tsunami. This study is a part of the on-going
research to provide tool at local level in assessing resilience of community,
particularly in a pilot community of coastal area prone to earthquaketsunami disaster. In general, the aim of the study was to develop a reference
tool or guideline to reduce risks of disaster in selected communities to be
adopted in any other vulnerable area to earthquake-tsunamis.

Figure 1 Map of Indonesia and location of the study area of Cilacap Regency

2. METHODOLOGY AND APPROACHESThe study was divided into two stages. The first step was public
perception survey and physical environment survey. During public
perception survey,
questionnaires were distributed, followed by depth
interviews, wherein workshops and focus group discussion (FGD), as wellas consultation with local government were conducted to investigate andconfirm the data collected from questionnaires and depth interviews.
Meanwhile, physical survey was done by collecting physical data field,
including topography, bathymetry, and tidal measurements. Physical field2

data were collected for the purpose of developing numerical modeling oftsunamis. In this study, numerical model was developed based on theearthquake-tsunami potential without considering other coastal disasters.
The second step of the study was constructed to select evacuation route andsafe areas, including potential areas to build shelters, based on numericalmodeling and the results of public perception survey.
2.1 Study area
Cilacap Regency was selected as a pilot study area based on the data
availability, strategic value consideration in term of business and industrial
activities of the region, willingness of local government and communities tocollaborate with, and ease of access. Besides, Cilacap Regency is the firstregency in Central Java that has been implementing the Law No.24/2007 by
the establishment of the Regional Disaster Management Office. The new
Law No.24/2007 on Disaster Management has been legalized to response topolicy on disaster risk reduction and preparedness in Indonesia. Figure 1
shows the location of the study area.
Cilacap Regency is an area with approximately 2138 km2 andconsidered to be the widest regency in Central Java province. The regency is
inhabited by 1,727,607 population spread in 23 sub-districts. Among 23
sub-districts, 11 sub-districts have a coastline immediately adjacent to theIndian Ocean. In general, the coastal area of Cilacap has flat topography
with a height less than 8m up to 5 km distance from the coastline. Based ondata from the last 30 years (1977-2007), a total of 420 earthquakes struck
the region with the epicenter at a depth of less than 40 km with amagnitude>5.0 Mw. During those periods, it was recorded at least two
tsunami events, the tsunami Banyuwangi in1994 and South Java tsunami in2006. The event of the tsunami on July 17, 2006 caused 165 people died anda few dozen were wounded and missing in Cilacap Regency (Wibisono,2008). The number of casualties was mainly caused by the tsunami waves.
Based on field measurements after the tsunami, it was noted that the depthof water (flow-depth) ranges from 1 to 5 meter with the increase of water(run-ups) ranges from 3.6 to 5.4 meter, and the water reaching to themainland (inundation) was 450 meter from shoreline in some villages(Cousins et al., 2006; Kongko et al., 2006; Lavigne et al., 2007).
2.2 Coastal Community Resilience (CCR) Framework
There are several methods to measure the resilience of coastal
communities, including the establishment of existing conditions ofvulnerability of a region based on social systems, natural conditions, andbuilt environment (Cutter, 2006), by assessing and determining the coastal
vulnerability index globally (UNEP, 2005). In collaboration with thecountries in Indian Ocean region, under cooperation program in theframework of the Indian Ocean Tsunami Early Warning System (IOTEWS),
USAID has issued a guidance for evaluating coastal community resilience
to tsunamis and other coastal disasters (earthquakes, storms, erosion,
sedimentation, oil spills, sea level rise, destruction of coastal resources, etc.)that has been collected in a package of Coastal Community Resilience/ CCR
3

(USAID, 2007). In this study, the CCR-IOTEWS framework was used as areference.
Coastal Community Resilience (CCR) is defined as the ability toreceive the impact of coastal disasters (such as tsunamis, floods, storms,
coastal erosion or coastal hazard), to be revived from the event of disaster,and to adapt to ongoing changes in circumstances. Resilience is an
integration and balance of three frameworks that is Community
Development, Coastal Management, and Disaster Management, in which
the implementation of the programs is based on community-based planning.
Community Development framework enables resilience for socio-economic
conditions and culture. Coastal Management framework is intended tocreate an environment and natural resources resilience. Meanwhile, Disaster
Management framework focuses on preparedness, response, recovery andmitigation to reduce casualties and loss of property and infrastructure fromdisaster.
Since the CCR-IOTEWS concept covers a very broad aspect tomeasure the elements of community resilience, particularly in thequestionnaire survey, in this study modifications of the methods and scoring
were done. Modifications were made primarily by giving the score number
on the answer choices, while the original document score value given by thesurveyor. The scores were in the range of 0, 1, 2, 3 and 4 representing thelowest to the highest response. The score was [0] Not know / No / Not ever;[1] Little/ Poor/ Not There; [2] Enough/ Few/ Moderate; [3] Good/ Many/
Large; and [4] Very good/ Very much/ Very big. List of questions wereselected and arranged to meet local needs. This modified method wasassumed to be more objective to reveal the real conditions in the field, andto avoid or at least to reduce the subjectivity of the surveyor. To maintainconsistency and uniformity among surveyors related to data collection
method, at the initial stage calibration was done by executing survey in one
location together.
2.3 Tsunami modeling and map development
The purpose of modeling is to simulate the tsunami wave fromgeneration, propagation, and inundation to know the characteristics andbehavior of the tsunami. Tsunami model used in this study was only
generated by the movement of the seabed by the earthquake. To simulate thepropagation of tsunami waves, two-dimensional hydrodynamic model oflinear long wave equations of motion was used. While for simulating thetsunami run-up, the theory of nonlinear shallow water was used. Tsunami
modeling was done using TUNAMI N3 (for near-field tsunami) developedby Tohoku University of Japan. Numerical equations were developed using
Non-linear shallow water equation (NSWE), i.e. long-wave hydrodynamics
equations with the numerical solution using finite difference method (FDM)
and Leap Frog scheme, based on input parameters of seismic, bathymetry
and topography. The output of the simulation was information about thewave height, run up height, travelling times of waves from sources to thecoast of Cilacap. The data resulted from modeling were then presented in
the form of forecasting inundation map as well as hazard map.

4

3. FIELD OBSERVATIONS AND MODELING
3.1 Measurement of community resilience elements in the field
To identify the community resilience to coastal disasters in Cilacap
Regency, parameters of resilience were measured during the initial step.
Research locations were spread on 4 villages in 4 sub-districts in Cilacap
Regency. The locations were chosen by considering that the areas hadlargest number of casualties and damage in Cilacap Regency when the areas
were attacked by the tsunami of July 17, 2006. In each village 100 copies ofquestionnaires with a total of 85 questions divided into 8 elements/ groups
were distributed. The resilience elements measured in the survey include:[1)] Governance, [2] Social-economy and livelihoods, [3] Coastal resourcesmanagement, [4)] Land use and structural design, [5] Risk knowledge, [6)]Warning and evacuation, [7] Emergency response, and [8] Disaster recovery.
Based on the CCR-IOTEWS standard, value 2 (two) is set as the limitof minimum value (threshold) to measure the resilience of a region. As aconsequence, if there was an element with average scores less than two (<2),
it was then avowed as low-resilience. In this study, to assess the resilienceof coastal communities in Cilacap Regency, a standard score (benchmark
score) was used as follows: [4] Very Good; [3] Good; [2] Fair; [1] Bad; and[0] None. The result of resilience measurement in the survey areas is shownby spider-graph to easily recognize the level of resilience. Field study has
been conducted during the period March to April 2009. Workshops and
FGD were conducted in August 2009. Moreover, the physical survey andfield observations has been previously conducted between the periods ofJuly 2006 until August 2008, and then continued in August 2009.
3.2 Model tsunami and Set-up model
The Southern Java tsunami of July 17, 2006 was not the only
benchmark to identify the risks of tsunami in Cilacap Regency. The
simulation to determine the potential run-up, flow-depth, and the potential
inundation were conducted based on the magnitude and epicenter as asource which allows tsunami generating (hypothetical sources). In thisregard, finer topography and bathymetry data were needed to develop
numerical modeling of tsunami at local scale. In addition, the validated
source/ tsunami scenario was also needed. Earthquake parameters data
(depth, the length and width of the earthquake, the angle of the strike, dip,
slip and dislocation) were obtained from the USGS website (United States
Geological Survey). The bathymetric and topographic data were obtained by
combining primary and secondary data.
Bathymetric and Topographic Data
Bathymetric and topographic data used were GEBCO (General
Bathymetric Chart of the Ocean) and SRTM (Shuttle Radar Topography
Mission) coupled with topographic and bathymetric measurement data at the
local scale obtained within the framework of Indonesian-German
cooperation projects namely German-Indonesian Tsunami Early Warning
System (GITEWS), which produce data with better resolution.
5

Bathymetric data for modeling was based on ocean depth map
GEBCO with 1-minute resolution level (1850 meters) plus a special depth
measurement in coastal water areas (near shore bathymetric) using Multibeam instrument survey. Whereas the coastal topographic data were usedwith SRTM-90 m with the corrections based on ground surveys (groundcheck) by leveling every 100 meters along the study area of Cilacap bywidth 200 meters to inland from coastline. By measuring bathymetry ofcoastal water and topography correction, it was expected that the input data
for modeling would be closer to actual conditions in the field.

Figure 2 Setting-up of domain area for TUNAMI modeling in Cilacap Regency

Designation of Study Area (Domain)
Considering the modeling which covers a wide area, ranging fromseismic source, tsunami generating sources until the run-up area, withconsiderations of time consuming in running the model, a nested grid
system was used. For the purpose of numerical within this nested grid
system, the domain used in the modeling was divided into four domain units
namely domain A, B, C, and D. Domain A was the largest domain in thearea between 105o to 121o longitude and -5o to -12o latitude. Domain B
was the area within the domain A with the boundaries of 108o 21’ 00”to109o 42’ 00” longitude, and 8o 43’ 60” to 24o 00’ 00.2” latitude. Domain C
was the area within the domain B with the boundaries of 108o 52’ 44” to109o 11’ 15.4” longitude, and 7o 56’ 43.4” to 7o 35’ 53.9” latitude. Domain
D was the area within the domain C with the boundaries of 108o 58’ 28.6” to6109o 08’ 16.1” longitude, and 7o 46’ 26” to 7o 36’ 52.2” latitude. Figure 2
shows the setting up of domain areas for this study.
In this model, Manning coefficient was set-up as 0.025, by assumingthat all surface roughness was uniform. Hypothetically earthquake scenariosthat possibly generating tsunami in the future with several magnitudes, i.e.
7.5, 8.0, and 8.5 Ms scales respectively were used. The running time of themodel was determined as 3 hours (10.800 seconds). Inundation map, ideally,
made of some tsunami scenarios that might occur; was developed by doinga superposition of each scenario on each segment of the study area.
4. RESULTS AND DISCUSSION
Figure 3 shows the map of inundation areas based on the simulationof tsunami (hypothetical tsunami) with the scenario as described in Section
3. 2. For a better appearance, hence the simulation results in over-lay using
Google Earth imagery. From the map it is shown that the scope of inundated
area is wider compared with previous study (Mardiatno et al., 2008).

Figure 3 Inundation of study area with three earthquake scenarios, M7.5, M8.0, and
M.8.5 which then over-layed by Google earth images

Explanation of this is as follows: First, the scenario of the tsunami sources isdifferent so the rupture parameters as tsunami’s generating sources also
differ. Second, another significant difference is the level of finer resolution
bathymetric and topographic data for input modeling. The result of themodeling shows that tsunami run-up reaches the land area with maximum
flow depth 3,8 meters and the inundation covers 0,5～2.2 kilometers fromcoastline to inland. The simulation result also shows that South Cilacap subdistrict (Tegal Kamulyan Village) is potential as the region with highest risk
level compared to other regions. These results are consistent compared toprevious research (Wibisono, 2008; Mardiatno et al., 2008). The travel timeof the first wave reaches the shoreline of Cilacap was 36 minutes, based on
the observation point on the tidal station at the port of Cilacap. The resultsof the modeling coupled with data on post- South Java tsunami in 2006 fieldsurvey were used as a reference to choose the location of the questionnaire
survey, and to determine safe area and evacuation route.
4.1 Element of Warning and Evacuation
7

Community perception through questionnaire survey and interview
was needed to get information to determine how far the level of community
preparedness to face the danger of next tsunami event. From the field work,
it is shown that the average resilience rate of all eight elements was less thantwo, which is categorized as below the critical limit of resiliency. This
character was also nearly uniform for all measured elements (Hidayat and
Meguro, 2010). To further know the public perception regarding evacuationroutes and shelter building, it is shown in element no. [4] Land-use andStructural Design and [6] Warning and Evacuation. Figure 4 shows in detailone example of public perception measurement results based on following
questions: Q1. To what extent does the community know about the need foran evacuation route? Q2. To what extent has an evacuation route beensocialized to the community in your area? Q3. To what extent have there
been evacuation simulations undertaken by the community in your area? Q4.
Is there an agreed system for socializing the early warning and evacuation
plan in your village? and, Q5. To what extent does the evacuation plan
involve all members of the community in your area? From the graph, it isclear that the majority of the respondents (>70%) gave answers to the fivequestions with “Not yet, Very Little, Little”, showing that the level ofcommunity preparedness is still low.

Figure 4 Warning and evacuation elements of CCR based on questionnaire survey inCilacap

4.2. Consideration in Designation of Evacuation Route and Shelter
Building
8Knowing the estimated time for arrival of a tsunami and the timeneeded for evacuation is essential for evacuation planning. In Cilacap, it was
assumed that the first wave would reach coastal line in 36 minutes after
earthquake. Inundation map (tsunami inundation forecast map) was
analyzed to determine tsunami hazard map. Evacuation route and safe area
including the area to build shelter were then determined based on tsunami
hazard map. Based on the hazard map, an evacuation capability of the
population was assessed.

Figure 5 Potential locations for evacuation roads and safe area/shelter building in
Cilacap [source: Wibisono (2008), with modification]

The basic principle of the approach was to calculate the time needed
to evacuate to the nearest evacuation building, taking into account theparameters that effect on people’s evacuation speed. A flat road, forexample, allows faster evacuation speed than dense vegetation or paddy
field. The analysis made here was based on limited spatial data only, so theassessment rely more on direct observation in the field. Field observation
was used to identify the conditions of the building, roads including bridges,
both within potentially inundated and surrounding areas. Referring to the
Tsunami Mitigation Guidelines for Evacuation Buildings Book
(Anonymous, 2005) it is noted that there are two options for thedetermination of tsunami evacuation building/ shelter, i.e. to use existing
facilities or new construction. Based on our finding during field observation,
we proposed some locations as a safe area (horizontal evacuation) and asmall number of buildings for vertical evacuation, as shown in Figure 5.
9Special attention is needed to be considered on the selection ofexisting facilities as a designation of evacuation routes and shelter building.
Experience in many seismic events in Indonesia, for example the earthquakein Aceh in 2004, Yogyakarta in 2006, and Padang in 2009 showed thatmany reinforced concrete buildings collapsed due to structural failures.
Recently Padang’s earthquake on September 2009 shows that approximately
one-third of the allocated shelters for tsunami evacuation risk were damaged.
In addition, some roads were covered with ruins of collapsed buildings aswell as roads damaged, so it did not allow to be used as an evacuation route,even if the path was already established as the tsunami evacuation route for
dealing with future tsunami event (Sigit et al. 2010). For the study area of
Cilacap, it was not found yet examples of earthquakes which destroyed
reinforced concrete buildings, as mentioned above. However, whenreferring to the Seismic Hazard Map of Indonesia (SNI-03-1726-2002), it ismentioned that maximum Peak Ground Acceleration (PGA) at bedrock (for
10% in 50 years) for each location is as follows: 0.15g in Yogyakarta,
Padang 0.30g, and Aceh between 0.2 and 0:25g, and Cilacap 0.20g. This
indicates that the potential hazard in Cilacap is as equal as in Aceh andgreater than the potential hazard of Yogyakarta.
5. CONCLUSIONS
Although tsunamis happen quite frequently in Indonesia, mostpeople living in the risk areas have never experienced a tsunami during their
lifetime. To improve preparedness, risk maps, evacuation plans, and shelterbuilding are needed. The production of this reference is not able to bedelegated to the entire communities because necessary knowledge may not
be sufficient locally. Support from experienced experts and scientist areneeded. Having an evacuation plan in place when a tsunami warning comesis crucial for effective preparedness and quick reaction. Evacuation
planning is the task of local authorities.
A numerical simulation is very helpful in the efforts to mitigate coastal
area from tsunami disasters, particularly in the areas where only insufficient
records of tsunami inundation in the past are available. However, it isnecessary to design a numerical simulation carefully to obtain reliable
results, particularly to set-up input data and tsunami’s generating scenario.
With the assistance of the modeling the affected areas of risk (including
wave’s arrival time, wave height, run-up and flow depth in coastal area, andthe penetration of the wave) can be predicted more accurately in eachlocation. However, this supporting instrument might be more credible if it is
supported by accurate data entry and verified by field data.
INA-TEWS is designed with clear vision of national and local level.
However, it is considerably known that at the moment, many local
governments are not aware of their roles within INA-TEWS.

REFERENCES

10

-----------, 2005, Tsunami Mitigation Guidelines for Evacuation Buildings,
Review Committee on Tsunami Mitigation Guidelines for Evacuation
Buildings, Director General for Disaster Management, Cabinet Office,Japan.
Cousins, W. J.; Power, W. L.; Palmer, N. G.; Reese, S.; Tejakusuma, I.;
Nugrahadi, S. 2006. South Java Tsunami of 17th July 2006,
Reconnaissance Report, GNS Science Report 2006/33 p42.
Hidayat, R., and Meguro, K., 2010, Developing parameter for measuring
coastal resilience by using community based perceptions and tsunami
run-up modeling, IOC/WESTPAC, E-Bulletin, May 2010, pp 4-6,
http://www.unescobkk.org/fileadmin/user_upload/westpac/documents/E-bulletin/E_Bulletin_No_6_May_10.pdf.
Kongko, W., Suranto, Chaeroni, Aprijanto, Zikra, Sujantoko, 2006, Rapid
Surveyon
Tsunami
Jawa
17
July
2006.
http://ioc3.unesco.org/itic/files/tsunami-java170706_e.pdf.
Lavigne, F., Gomez, C., Giffo. M., Wassmer, P., Hoebreck, C., Mardiatno,
D., Priyono, J., and Paris, R., 2007, Field Observations of the 17 July
2006 Tsunami in Java, Natural Hazards Earth System Sciences, 7,
pp.177-183 (www.nat-hazards-earth-syst-sci.net/7/177/2007/).
Mardiatno, D., Kongko, W., Lavigne, F., Sunarto, and Stoetter, J, 2008, GIS
Application for Tsunami Risk Assessment in Cilacap, South JavaIndonesia, Proc. International Conference on Tsunami Warning (ICTW),
Bali, Indonesia.
Sigit, S., Murakami, K., Rinaldi, 2010, Evaluation of Tsunami Evacuation
Risk in Padang City-Case Study on 2009 West Sumatera Earthquake-,Kayou Kaihatsu Rombun-shu, No.26, 2010.
Twig, J., 2007, Characteristics of a Disaster-resilient Community: A
Guidance Note, DFID-DRR-ICG, (Bahasa Indonesia version, translatedby Theresia Wuryanti).
USAID, 2007, How Resilient Is Your Coastal Community? A Guide for
Evaluating Coastal Community Resilience to Tsunamis and Other
Hazards; U.S. IOTWS Document No. 27-IOTWS-07
UNEP, 2005, Assessing Coastal Vulnerability: Developing a Global Index
for Measuring Risk, pp.54, ISBN No: 92-807-2577-7, online version :http://www.unep.org/DEWA/products/publications/2006/CVI_PM65_Fi
nal_05.pdf
Wibisono, A.A., 2008, Tsunami Mitigation Study with Determination ofsafe area and the evacuation route in Cilacap Regency, Central Java
Province based on Tsunami Run-up simulation model, UG.Thesis, Dept.
of Environmental Engineering, Faculty of Mineral Technology,
Pembangunan Nasional “Veteran” University, Jogyakarta (in Bahasa
Indonesia, unpublished).

11Modeling the SARS epidemic in China
based on dynamical passenger flow
in railway and airline networks
Weicheng FAN1, Shunjiang NI2
Professor, Director, Center for Public Safety Research,
Tsinghua University, Beijing, China
2
Postdoctoral Research Associate, Center for Public Safety Research,
Tsinghua University, Beijing, China
sjni@tsinghua.edu.cn
1

ABSTRACTThis paper presents a framework for the simulation of large-scale spread of
epidemics in realistic mobility networks, such as railway, civil aviation and othertransport networks. The framework consists of three parts: the population
structure model, the dynamical passenger flow model and the local infection
dynamics model. The population structure model, which is based on themetapopulation network, depicts the heterogeneity of the distribution of personnel
and the way of contact between them. The dynamical passenger flow model, whichconstitutes the mobility network model and the passenger traveling model, hasconsidered three key features of the passenger traveling patterns in thetransportation networks, including the traveling process, waiting process, andreturning process. The local infection dynamics model adopts a stochastic SEIR
(Susceptible-Exposed-Infected-Recovered) model to describe the mechanism of
the spread of infectious diseases in local metapopulations. We have implemented
the model framework and the history data of 2003 SARS (Severe AcuteRespiratory Syndrome) epidemic in China has been used to compare with thesimulation results for verifying the feasibility of our model. Simulation results
show that our model can well reproduce the main characteristics of the process of
SARS transmission. These results and their analyses can not only be used togenerate insights into understanding the dynamic processes of epidemic
spreading, but also support the emergency management sectors to make more
effective and efficient prevention and control strategy of epidemic spreading.
Keywords: epidemic modeling, traveling patterns, mobility network, SARS
1. INTRODUCTION
The spread of epidemics in human populations is a typical public health incident,
and has also become one of the major public safety issues that humanity is facingin the 21st century. Traditional epidemiological research has focused on the use of
rate-based differential-equations to establish the mathematical models of the
spread of infectious diseases, such as SIR and SIS compartment models (Hethcote,2000). Although successful in explaining certain phenomena of epidemic
spreading, the traditional approach is unable to deal with epidemic spreading inrealistic large-scale social contact networks with significant heterogeneity due toits assumption of uniformly mixing populations. Therefore, the approach based on

0ctober 2010, Kobe, Japana combination of complex network theory and epidemiology has become an
important trend in modeling of transmission of infectious disease.
Meyers et al. (2005) applied the methods of contact network epidemiology toillustrate that for a single value of the basic reproduction number R0 —the numberof new cases of infected individuals resulting from a single initial case, any twooutbreaks, even in the same setting, may have very different epidemiologicaloutcomes, which cannot be explained by the traditional compartmental models.
Yang et al. (2004) proposed a simple contact network model to study the
immunity mechanism of the network during the spreading of SARS: the SARS
spreading will destruct the network, and in turn the destructed network can halt
the SARS spreading effectively. Watts et al. (2005) introduced a class of
metapopulation models in which they assume that local contexts are embedded ina nested hierarchy of successively larger domains and homogeneous mixing holds
within these local contexts. The individuals are allowed to move between contexts
via simple transport parameters. Their model suggests that when epidemics do
occur the basic reproduction number R0 may bear little relation to their final size,and exhibits some important stylized features of real epidemics, including extreme
size variation and temporal heterogeneity, which are all difficult to characterizewith traditional compartmental models.
However, previous studies on network-based epidemic models have remained
mostly theoretical, practical application-oriented research is relatively few.
Moreover, the passenger travel process which is an important factor in globallytransmission of the infectious diseases are usually oversimplified due to the lackof quantitative knowledge of human traveling statistics. Recently, Brockmann etal. (2006) analyzed the dispersal of bank notes in the United States and extracted
the scaling laws of human travel; i.e., the human travel distance r and the rest
 1 btime tw between displacements obey the heavy tailed distributions p  r  ~ r  and p  tw  ~ tw1 a  , respectively, where they predicted a  b  0.6 . Gonzalez et al.
(2008) studied the human mobility patterns by analyzing the trajectory of 100,000
anonymized mobile phone users whose position is tracked for a six-month period,and find that the distribution of displacements over all users is well approximatedbby a truncated power-law: p  r    r  r0  exp  r /   with b  1.75  0.15 , andthey also find that the traveling individuals have a significant probability to return
to a few highly frequented locations. These new findings have greatly help
researchers understand how the human mobility patterns affect the virus spread(Colizza and Vespignani, 2007; Ni and Weng, 2009).
In modern life, passengers can do frequently long-distance travel by the railway
and civil aviation transportation networks, which are two of most important wayof human travel that are responsible for large-scale epidemic spread. Therefore,
recent studies on epidemic modeling have paid attention on the role of the railway
and civil aviation networks in the spreading of infectious diseases (Hufnagel et al.,
2004; Bowen et al., 2006). However, the scaling laws of human mobility
mentioned above were still not considered in these studies. In this paper, we

New Technologies for Urban Safety of Mega Cities in Asia

proposed a framework for the simulation and analysis of large-scale spread of
epidemics in realistic mobility networks, such as railway and civil aviation, in
which the passenger travel patterns, including the travel process, waiting process,and returning process have been implemented in detail. We have implemented themodel framework and the history data of 2003 SARS (Severe Acute Respiratory
Syndrome) epidemic in China has been used to compare with the simulation
results for verifying the feasibility of our model. Preliminary simulation results
show that our model can well reproduce the main characteristics of the process of
SARS transmission.
2. POPULATION STRUCTURE

In our model, the study population consists of 1,211,030,000 people, which is
divided into 314 prefecture-level cities located in China’s 31 provinces,autonomous regions and municipalities in accordance with the existing
administrative divisions. Within each city, the population is further divided into a
number of metapopulations (subpopulations that represent communities, schools,
workplaces, hospitals, etc.) according to the following metapopulation network
algorithm (Ni and Weng, 2009). Consider a city i that has a population of N i
individuals. The population N i is randomly partitioned into M i metapopulations

Ni, j j  1, 2,..., M i  , each of which is represented by a node of themetapopulation network and the initial size of N i , j is drawn from a power-law
distributionp  N i , j  ~ N i, j

where

 is

an

exponent

parameterandN min  N i , j  N max . In this way, these metapopulations (nodes) are connected by a
network and individuals in one node can diffuse along the network links to othernodes in their daily travel activities.
In order to incorporate the scaling law of human travel into our model, we define
the network substrate on a two-dimensional square space of unitary length on thex  y plane with periodic boundary conditions. Specifically, each node j j  1, 2,..., M i  is randomly assigned a pair of values  xi , yi  to represent its
coordinates on the geographical plane. We assume that each coordinate is anindependent and identically distributed random number drawn within the interval
0.0,1.0  . Initially, m fully connected nodes, labeled by 1, 2,..., m respectively,
are randomly distributed in the square, and then at each time step t t  m  1, m  2,..., M i  , a new node labeled by t is added to the network andconnected to m preexisting nodes according to the attachment probability that thenode j  j  1, 2,..., t  1 would be chosen to connect to the newly added node t : j  t  ~ k j  t  / d jt(1)where d jt is the Euclidean distance between the nodes t and j , which ismeasured using periodic boundary conditions, and  and  are two tuning
parameters governing the degree distribution and link length distribution
respectively.

Modeling the SARS epidemic in China based on dynamical passenger flow in railway andairline networks

0ctober 2010, Kobe, Japan

As Ni and Weng (2009) pointed, the resulting network shows two striking
features: (i) the network have a skewed degree distribution, which is consistent
with the actual situation; (ii) the link length that is defined as the probability that arandomly selected link has the length r follows a power-law distributionp  r  ~ r   1 for proper configurations of  and  , which is a convenient feature
for modeling the scaling law of travel distance. For more information about theabove metapopulation network, please see the reference (Ni and Weng, 2009).
3. THE DYNAMICAL PASSENGER FLOW MODEL
3.1 The Definition of Train and Airline Networks

The main objective of establishing the metapopulation network in the previous
section is to simulate the urban travel process because we are lack of specificmobility data of personnel’s daily travel within the city. However, in reality,
individuals can not only move inside the city, but also move to other cities
through the railway and civil aviation transportation networks that connect thecities to each other. Therefore, in this section, we will describe the construction
method of the train and airline networks.
The train network is defined as a weighted, directed network based on 4877 train
stations and 2622 trains in China. Specifically, each train station is regarded as anode in terms of the network terminology. If there is a train bound for train station
j from train station i , then a directed edge eij from node i to node j will beestablished. If there are n trains from station i to j , then we will define the value
wij  n as the edge weight for eij , and the value si   ii  wij will be defined as
the node weight for node i , where   i  represents the set of neighboring nodes
of node i . In Fig. 1(a), we depict the train network where each node represents
one of 314 prefecture-level cities and the edge means there are one or more trainsconnect these two cities. Here, most of the city node contains more than one train
stations while a few of cities have no train stations.

Figure 1: China’s train network (a) and civil airline network (b).
The airline network is made up of 134 civil airports and 8299 flights, and theconstruction method is the same as that of the train network as described above.
New Technologies for Urban Safety of Mega Cities in Asia

Fig. 1(b) shows how the 314 prefecture-level cities in China are connected to eachother by the airline network, where the isolated nodes (represent prefecture-level
cities) indicate there are none of airports in these cities.
It should be noted that the train network and the airline network load a large
portion of long-distance (between 50km~1500km) traffic flow and another part oflong-distance (~100km) traffic flow are handled by the inter-city highways androads, which are not considered by our model for the current study.
3.2 The Passenger Traveling Model

The passengers’ daily travel that including the local travel within the city and theglobal travel between cities is responsible for the large-scale spread of theinfectious diseases. However, the actual process of passenger travel is toocomplex to be directly considered, so that we can only take the simulation method
to describe it. Therefore, whether the simulated passenger flow can capture thecharacteristics of the actual one is critical for the modeling of epidemic spreading.
In this paper, we model the passenger traveling process as follows.
(1) Traveling.
(1.1) Choice of travel distance. For each infected individual h that initiallylocated in node i , at each time step, it will leave the node i withprobability pi ,travel and then go to step (1.2); otherwise, it will go to step(1.3). The parameter pi ,travel is the probability that any individual in cityi will travel by train or air, and can be evaluated by the following
equation:dpi ,travel  eff Ti / N i(2)365
where Ti is the annual traffic by train and airline in the city i , N i is the
population size of city i , and d eff is an empirical coefficient.
(1.2) Global travel.
(1.2.1) Choice of transport mode. The infected individual h will travel
through the railway network with probability pi ,train , and through the civil
aviation network with probability 1  pi ,train  . The value of pi ,train can be

determined by Eq. (3):pi ,train  Ti ,train / Ti

(3)where Ti ,train is the annual traffic by train. If there is no railway station in cityi , pi ,train will be set to 0. Similarly, if there is no airport in the city, pi ,train
will be set to 1.
(1.2.2) Choice of travel route. Because there are usually multiple railway
stations or airports in a prefecture-level city, the infected individual h needs
to choose the departure and arrival sites before its traveling. Taking as an
example, when the individual choose to travel through the railway network,
the selection process of the travel route can be described as follows. Firstly,
the individual will select one of railway stations in the city as a departure sitewith a probability proportional to the node weight of the site. Then, one ofModeling the SARS epidemic in China based on dynamical passenger flow in railway andairline networks

0ctober 2010, Kobe, Japanedges that emanate from the departure node will be selected as a travel routewith a probability proportional to the edge weight. The individual will enter
into the city containing the arrival site that is connected by this edge.
(1.2.3) Choice of target metapopulation. Finally, the individual will enter into
the target metapopulation which is randomly selected from all
metapopulations in the arrival city and go to step (2).
(1.3) Local travel. The infected individual h will jump into a neighboring
metapopulation node with probability pi , jump and go to step (2);otherwise, it will continue to stay in the original metapopulation node.
The parameter pi , jump is given by Eq. (4):i   min p jump ,min (4)p max   min jump ,max
where i is the population density of city i ,  min and  max represent
pi , jump  p jump ,min 

the minimum and maximum population density of all cities, andp jump ,min and p jump ,max are two empirical lower and upper boundary
values of i .
(2) Waiting. When the infected individual h enters into a node j thatdifferent from its original node i , it will be assigned a waiting time twthat is drawn from a heavy-tailed distribution p  tw  ~ tw1  , where  0 and 1  tw  Tmax ; then the individual h will wait for tw time
steps in node j before going to step (3).
(3) Returning. After waiting for time steps in node j , the infected individual
h will return back to its original node i with probability pback and then
go to step (1); otherwise, it will turn to step (1.3) to try to do local travelwith probability p j , jump . If the trial fails, it will turn to step (1.2) to do
the global travel.
In order to reduce the usage of computer memory, the passenger travelingmodel described above only track the traveling process of the infected individuals(including the exposed individuals), while the traveling process of the susceptible
and the recovered individuals are ignored.
4. THE LOCAL INFECTION DYNAMICS

In our model, direct contacts between individuals that can potentially lead to
infection are only allowed to occur within the metapopulations. The outbreakamong humans would then spread globally via the railway and civil aviationtransportation networks. The local infection dynamics within each node ormetapopulation can be described by a stochastic Susceptible-Exposed-InfectedRecovered (SEIR) model, which is given as follows.
pi ,seSi , j  I i , j  Ei , j  I i , j
(5.1)
i ,ei
Ei , j 
Ii, j

(5.2)

i ,ir
I i , j 
Ri , j

(5.3)

p

p

New Technologies for Urban Safety of Mega Cities in Asia

where Si , j , Ei , j , I i , j , Ri , j represents the susceptible, exposed, infected, andrecovered individuals of the metapopulation N i , j respectively. According to themodel, at each time step, i) a susceptible individual will become an exposed(infected but does not develop infectivity yet) one with probability pi , se for its
each contact with an infected individual in the same metapopulation N i , j ; ii) the
exposed individual will become infected individual with probability pi ,ei ; iii) the
infected individual will be recovered with probability pi ,ir .
The local infection dynamics described by Eqs. (5.1)-(5.3) are so-called
individual-based simulation model. However, as mentioned in section 3.2, ourmodel does not track the susceptible individuals, so that the Eq. (5.1) cannot be
implemented at individual level. To solve this problem, we approximate the Eq.
(5.1) by a stochastic equation reads
dSi , jII ki pi , se i , j Si , j  ki pi , se i , j Si , j   t (6)dt
Ni , jNi , jwhere   t  is an independent Gaussian white noise function (Watts et al., 2005),
and ki is the number of neighbors each node can contact at every time step and isgiven by Eq. (7):   minki  kmin  i(7)k  k  max   min max min
where kmin and kmax are the lower and upper boundary values of ki respectively.
This hybrid model consisting of Eqs. (5.2)-(5.3) and Eq. (6) allow us to achieve abalance between the efficiency and accuracy.
The actual process of SARS transmission will be intervened by the public healthagencies inevitably and many prevention and control measures will be
implemented. We have built up a simple model as given in Eq. (8) to describe theoverall impact of these factors on the SARS transmission. Here, we assumed thatthe transmission process will be going on without any exogenous interventions
and the transmission probability pi , se will take a constant value when t  t free ,while the transmission probability pi , se will decreased exponentially if t  t free .
t  t free0.25,pi , se  t   
0.002  0.25exp 0.13  t  t free  , t  t free





(8)

5. RESULTS AND DISCUSSIONS

The model implementation is shown in Fig. 2, in which the height of the red bar
represents the epidemic size of the prefecture-level city. It can be seen that themodel is very suitable for simulating the geographical spread of infectious
diseases. Moreover, by adjusting the model parameters, the model can apply formany different infectious diseases, such as SARS and H1N1 influenza et al., aslong as the disease is transmitted through direct physical contacts between
Modeling the SARS epidemic in China based on dynamical passenger flow in railway andairline networks

0ctober 2010, Kobe, Japan

individuals. In the following discussion, we will use the model to simulate the2003 SARS spread in China, and some preliminary results will be given andcompared with the history data.

Figure 2: Model implementation.
SARS is a kind of respiratory illness that firstly occurred in Guangdong provinceof China in November 2002 and spread to rapidly infect individuals in some 37
countries around the world within a matter of weeks in early 2003 (Smith, 2006).
There has been one near pandemic to date, between the months of November
2002 and July 2003, with 8096 known infected cases and 774 confirmed humandeaths worldwide according to the World Health Organization’s (WHO) 21 April
2004 concluding report (WHO, 2008). China is one of the most serious infected
regions. Fig. 3(a) shows the time series of the daily new cases of SARS in China,
from which we can see that there are two waves of outbreaks—the first wave iscaused by the outbreaks mainly in Guangdong province and after a period ofregression the disease spread to new susceptible individuals in Beijing area tomake the second wave occur. The Chinese government introduced a series ofpowerful control measures on April 18, 2003, after which the SARS epidemic was
fully contained quickly.
140
200

(a)

120
Daily new cases

Daily new cases

250

Second wave of outbreak

150
100

First wave of outbreak

50
0

(b)

100
80
60
40
20
0

0 20 40 60 80 100120140160
Time of onset

0 20 40 60 80 100120140160
Time of onset

Figure 3: Time series of the daily new cases. (a) Actual data; (b) Simulated data.
The simulation was started with a single initial infection that randomly selectedfrom Guangdong province and the result has been averaged over 5000
New Technologies for Urban Safety of Mega Cities in Asia

independent simulations. The configuration of model parameters are as follows:  3.0 , N min  5 103 , N max  5 105 , m  3 ,   1.0 ,   2.6 ,   0.6 , Tmax  365 ,pi ,ei  0.2 , pi ,ir  0.3 , p jump ,min  106 , p jump ,max  105 , pback  0.85 , kmin  4 ,kmax  12 , d eff  5 102 , and t free  120 . In Fig. 3(b), we plot the simulated curve

6000
(a)

5000
4000
3000
2000
1000
0 20 40 60 80 100120140160

Number of cumulative cases

Number of cumulative casesof the daily new cases versus the time of onset. It can be noted that the simulated
curve exhibits two peaks around time 50 and 120 respectively, and after abouttime 120, the SARS epidemic died quickly due to powerful intervention measures
were initially involved in the model, which accords well with the actual data. One
obvious deficiency is that the platform period after the first peak is not well
reproduced by our model.
6000 (b)
5000
4000
3000
2000
1000
0
0 20 40 60 80 100120140160

Time of onset

Time of onset

Figure 4: Time series of the cumulative cases. (a) Actual data; (b) Simulated data.
The final epidemic size of the whole country is about 5318 cases, which can beseen from Fig. 4(a)—the evolution of the number of cumulative cases as time.
The corresponding simulation curve is provided in Fig. 4(b), in which the total
infected cases are about 5800, slightly larger than the actual value.

3

(a)

10

2

10

slope = -2.5
1

10

0

10

0

1

10

10
Provinces

Number of cumulative cases

Number of cumulative cases

4

10

(b)
3

10

2

10

slope = -2.1

1

10

0

10

0

10

1

10
Provinces

Figure 5: Final epidemic size in different provinces/autonomous
regions/municipalities in China. (a) Actual data; (b) Simulated data.
Fig. 5(a) shows the geographical distribution of the number of cumulative SARS
cases for different provinces (autonomous regions, municipalities) in China. Eachdata point in the figure is for a specific province. The slope of the solid line
obtained by linear fitting is -2.5, indicating a power law behavior. In Fig. 5(b), thecorresponding curve is given and the slope of the linear fitting line is -2.1, slightly
less than the actual data.

Modeling the SARS epidemic in China based on dynamical passenger flow in railway andairline networks

250
(a)

Daily new cases

200

tfree=60
tfree=90150

tfree=120
tfree=150

100
50
0
0

40

80

120 160 200 240

Time of onset

Number of cumulative cases

0ctober 2010, Kobe, Japan

12000
10500 (b)tfree=60
9000
tfree=907500
tfree=120
6000
tfree=150
4500
3000
1500
0
0
40 80 120 160 200 240
Time of onset

Figure 6: Influence of different intervention time on the SARS spreading. (a)Daily new cases; (b) Cumulative cases.
Finally, we studied the effects of different intervention time of prevention andcontrol measures on the SARS spreading. Fig. 6(a) and Fig. 6(b) show the timeseries of daily new cases and cumulative cases respectively for different
intervention time. It can be seen that the earlier the control measures take place,the better the effect of mitigating the SARS transmission. However, in reality, theprevention and control measures can inflict significant negative impact on socialand economic systems if they have been taken too early, especially for a novel
infectious disease. Therefore, the more reasonable strategy is to monitor the
epidemic for a period of time and collect enough infected cases in the early stage
to predict the trend of its propagation before taking appropriate control measures.
6. CONCLUSIONSThe objective of this research is to set up a practical framework to explore thespatiotemporal dynamics of large-scale spread of infectious diseases based onrealistic mobility networks, such as railway, civil aviation and other transport
networks. The population is divided into a number of metapopulations and form athree-level nested structure, i.e., the population structure of each prefecture-levelcity is modeled by a spatial metapopulation network and the cities are connectedwith each other by the railway and civil aviation networks. The dynamic
passenger flow is simulated by a passenger traveling model in which the travel
process, waiting process, and returning process have been described in detail.
We then introduced a hybrid stochastic Susceptible-Exposed-Infected-Recovered(SEIR) model into the framework to study the case of SARS spreading in 2003 in
China. Preliminary results, including the time series of the daily new cases, thetime series of cumulative cases, and the geographical distribution of the final
epidemic size for different provinces indicate that our model can well reproduce
the main characteristics of the SARS transmission. We also explored the impact
of different intervention time of prevention and control measures on the SARStransmission and suggested that it is very important to implement appropriate
control measures at right time.
It should be noted that the current model is still imperfect in following aspects.
Firstly, the individuals’ local travel process is subjectively approximated by the
movement of individuals in the simulated spatial metapopulation networks due to
New Technologies for Urban Safety of Mega Cities in Asia

the lack of statistical data of human travel within the city. Secondly, the railway
network and the civil aviation network are built up on the static statistical data ofthe trains and the flights respectively and assume that each train or flight takes thesame amount of passengers, while the real scheduling data of the trains and flights
as well as the daily passengers are both dynamically changed over time. Last but
not least, the effects of many measures for mitigating the SARS transmission,
such as case isolation, household quarantine, exit and entry screening, contact
tracing and travel restrictions, are all reflected by the same parameter oftransmission probability pi , se , which may be inconsistent with the actual situation.
The future directions of improvements should be focused on the above aspects.
ACKNOWLEDGMENT

The authors deeply appreciate the financial support for this paper from National
Natural Science Foundation of China (Grant No. 91024018) and China
Postdoctoral Science Foundation (Grant No. 20090460290).
REFERENCES

Hethcote, H. W., 2000. The mathematics of infectious diseases. Siam Review
42(4): 599-653.
Meyers, L. A., B. Pourbohloul, et al., 2005. Network theory and SARS: predicting
outbreak diversity. Journal of Theoretical Biology 232(1): 71-81.
Yang, H. J., F. C. Zhao, et al., 2004. Modeling SARS spreading on complex
networks. International Journal of Modern Physics B 18(17-19): 2734-2739.
Watts, D. J., R. Muhamad, et al., 2005. Multiscale, resurgent epidemics in ahierarchical metapopulation model. Proceedings of the National Academy of
Sciences of the United States of America 102(32): 11157-11162.
Brockmann, D., L. Hufnagel, et al., 2006. The scaling laws of human travel.
Nature 439(7075): 462-465.
Gonzalez, M. C., C. A. Hidalgo, et al., 2008. Understanding individual humanmobility patterns. Nature 453(7196): 779-782.
Colizza, V. and A. Vespignani, 2007. Invasion threshold in heterogeneous
metapopulation networks. Physical Review Letters 99(14): 148701.
Ni, S. J. and W. G. Weng, 2009. Impact of travel patterns on epidemic dynamics
in heterogeneous spatial metapopulation networks. Physical Review E 79(1):016111.
Hufnagel, L., D. Brockmann, et al., 2004. Forecast and control of epidemics in a
globalized world. Proceedings of the National Academy of Sciences of the UnitedStates of America 101(42): 15124-15129.
Bowen, J. T. and C. Laroe, 2006. Airline networks and the international diffusionof severe acute respiratory syndrome (SARS). Geographical Journal 172: 130144.
Smith, R. D., 2006. Responding to global infectious disease outbreaks, Lessons
from SARS on the role of risk perception, communication and management.
Journal of Social Science and Medicine, 63, 3113-3123
WHO. Retrieved 2008-10-31. Summary of probable SARS cases with onset of
illness from 1 November 2002 to 31 July 2003.

Modeling the SARS epidemic in China based on dynamical passenger flow in railway andairline networks

An Event-Driven Routing Algorithm
Applied for Urban Safety in WirelessHeterogeneous Networks
Hsing-Chung CHEN 1, Jyh-Horng Wen2, and Sheg-Hao FANG3
1
Assistant Professor, The Asia University, Taiwan
shin8409@ms6.hinet.net also cdma2000@asia.edu.tw
2
Professor, The Thonghai University, Taichung County, Taiwan
3
Master Student, The Asia University, Taiwan

ABSTRACTIn recent years, on the researches in various routing protocols, applied towireless heterogeneous networks, become more and more important. In this paper,
we propose an event-driven routing protocol applied for urban safety in wirelessheterogeneous networks based on a selected knowledge discovery agent withmaintaining an n-bits map table. The routing protocol can be applied to digital
home wireless heterogeneous networks. It is an event-oriented routing protocol
which can get more flexible and achieve fault tolerant for packet routing inwireless heterogeneous networks.
Keywords: wireless heterogeneous networks; knowledge discovery agent; bitmap; digital home networks; event-oriented

1. INTRODUCTION
Due to Internet has been development rapidly, various routing protocols, inwireless heterogeneous networks (WHNs), were proposed by researchers (Yasser
et al., 2008, and Senner et al., 2008). There are various routing protocols forrouting packet data in Internet. The routing protocols can be categorized into two
types; one is the Global Routing (GR) algorithm, and the other one is the
Decentralized Routing (DR) algorithm (Kurose et al., 2007).
By way of GR algorithm, the routing path of minimum cost will be calculated
between source node and destination node by gathering the topology informationfrom global network, such as the knowledge discovery (KD) agent for topology
bit-map) algorithm (Lee et al., 2008). Both RIP (Routing Information Protocol)
algorithm (Malkin G., 1998) and AODV (Ad hoc On-Demand Distance Vector
Routing) algorithm (Perkins et al., 2003) are typical DR algorithms, in which eachnode only knows the costs which directly connect to other neighbor nodes. And
when all nodes exchange the topology information, it will calculate its shortest
path from each source node to destination node.
In this paper, we propose an event-driven (also called event-oriented, in thispaper) routing protocol based on KD agent with maintaining n-bits map routing
table (n-bits map KD-ED routing protocol, for short), which is suitable for WHNs
urban safety environment. It is an event-oriented routing protocol which can get

0ctober 2010, Kobe, Japan

more flexible and achieve fault tolerant for packet routing in WHNs. In addition,
the proposed routing protocol is suitable to the environment of Digital Home
Wireless Heterogeneous Networks (DHWHNs).
The rest of the paper is organized as below. In Sec. II, we introduce therelated works. Our scheme is proposed in Sec. III. In Sec. IV, discuss and analyze
for fault tolerant for packet routing and control packet overheads. Finally, ourconclusions are presented in Sec. V.

2. REVIEW OF KDATB ROUTING PROTOCOL IN (LEE ET AL., 2008)
In 2008, Lee et al. proposed a KDATB routing protocol, in which selected agent
node will gather all network topology information, and then distribute a
constructing bit-map routing table (BRT) to all other nodes. In BRT, a connecting
state between two neighboring nodes is expressed as a binary bit. Through with
the BRT, each node can decrease the overheads for maintaining its routing table(Lee et al., 2008). For example, a network topology is shown as Figure 1, we
suppose the node 1 is an agent node which directly connects node 2 and node 3.
The other nodes are nodes 4, 5, 6, 7 and 8. In Figure 1, all nodes will send aperiodic ‘Hello message’ (Chakeres et al., 2002 and Lee et al., 2008) in order toconfirm the existence of neighboring nodes. After receiving a ‘Hello message’from neighboring nodes, the node will add into its neighbor information table(Lee et al., 2008) which consist the gathered information from all neighboring
nodes. To construct the network topology, the agent node will broadcast a
topology query message to all neighboring nodes. By this way, it creates a selfcentered topology tree (Lee et al., 2008). The node, which has received the
topology query message, will assign the node which has sent the message to it as
the parent-node, and all other neighboring nodes are assigned to be its child-nodes.
After receiving a topology query message (Lee et al., 2008), the node will gather
all information from sub-tree or said child-nodes and send a topology reply
message (Lee et al., 2008) to its parent-node. The topology query message
consists of the node’s ID, battery life-time and connectivity information (Lee etal., 2008). When receiving topology reply messages from other nodes, the KD
agent node will collect the topology information for all nodes.

Figure 1: A network topology
After collecting all topology information, the KD agent node will create a
BRT, for example, Table 1 shows a bit-map that expresses the network topology

New Technologies for Urban Safety of Mega Cities in Asia

shown on Figure 1, where “1” is expressed as “one-hop distance connection” and“0” is expressed as “non one-hop distance connection”.
Table 1: The corresponding BRT for network topology shown on Figure 1

Finally, the KD agent node uses the topology advertisement message (Lee etal., 2008) in which the bit-map table is carried and sent to other nodes. When anode needs to deliver a packet to other node, it will check the routing path byusing the bit-map table. It can quickly establish multiple routing paths which
include the shortest path from source node to destination node. The bit-map table
represents a graph which is shown as the connected link state for all nodes in the
network.

3. OUR SCHEME
In this paper, we first propose an n-bits map KD-ED routing protocol for WHNs
urban safety environment. There are m exiting nodes in WHNs. A node c or r is
one of m nodes and c≠ r . Within the n-bits map routing table (n-bits MRT, forshort), a connecting state si corresponding to an event ei between two neighboring
nodes c and r , which is expressed as a binary bit si ∈{0,1} , where “1” is expressed as“one-hop distance connection for the event ei ” and “0” is expressed as “non onehop distance connection for the event ei ”. In order to create the event-oriented
routing protocol with n-bits MRT, we suppose there are n pre-defined events,
which are expressed as an event set E c , r = {e1 ,e 2 ,...,e i ,...e n −1 ,e n } , where ei is an
event and i is the index number of the i-th event, i ∈ {0 ,1, 2 ,..., n − 1} and ei ∈ Ec, r .
Thus, the n pre-defined events E c , r are corresponding to n binary bits
S c , r = {s1 ,s 2 ,...,s i ,...s n −1 ,s n } in n-bits MRT. When an event ei is happened, if anode is as the intermediate node for routing the event packets, its corresponding
bit will be set as si =1 for node c and r , i.e. S c , r = {s1 ,s 2 ,...,s i = 1,...s n −1 ,s n } , in its
n-bits MRT. Otherwise, its corresponding bit will be set as si = 0 for node c and r ,i.e. S c , r = {s1 , s 2 ,...,s i = 0 ,...s n −1 ,s n } , in its n-bits MRT. For example, we

suppose Ec, r is an event set, E c , r = {e1 ,e 2 ,e 3 ,e 4 , e5 , e 6 , e 7 , e8 } = S c , r = {01011001 } ,which there eight digital bits are corresponding to eight pre-defined events. Whena node states two connections for two events ei and ej individually, the n-bits
An Event-Driven Routing Algorithm Applied for Urban Safety in Wireless Heterogeneous
Networks

0ctober 2010, Kobe, Japan

MRT will be marked both two routes via setting the directly connection states
between itself and the next-hop neighboring node for the two events, individually.
In our protocol, one border router acts as an elected KD agent for the i-th
event, which is used to gather information and deliver the knowledge data formed
into a network topology as the form of an n-bits MRT to all nodes. The main roleof the KD agent is to gather, calculate and distribute n-events network topology
knowledge. All nodes periodically broadcast a ‘Hello message’ in order todiscover neighboring nodes for each event. The format of this ‘Hello message’ isshown in Figure 2.
Node's IP Address
The i-th event identity
Node's Sequence NumberLife time
Figure 2: ‘Hello message’ format
After receiving a ‘Hello message’ from neighboring nodes for the event e1 , anode generates the neighbor information and gathers them into n-events neighbor
information table. For example, an n-events neighbor information table is shownin Figure 3, which shows the table collecting by an intermediate node n1 based on
Figure 6. In Figure 6, node b1 is the KD agent and node n1 has the following steps
for gathering neighbor information:(1) Receive topology query from nodes b1 and n4 .
(2) Assigns node b1 as the parent-node, and nodes l2 and n4 as child-nodes.
(3) Broadcasts a topology query message to child-nodes l2 and n4 .
Node ID

Neighboring
nodes

n1

b1 , l2 (0), n4 (0)Number ofneighboring
nodes
3

The i-th event
identity

Agent(Yes/No)e1

No

Figure 3: The i-th event neighbor information table for node n1
Then, the KD agent node b1 broadcasts a query message to all neighboring
nodes to collect information for constructing network topology of the i-th event,i.e. e1 . The node transmitting the topology query message becomes the parentnode, and the receivers become the child-nodes for constructing network topologyof the i-th event. Figure 4 shows the format of the query message. By this means it
constructs the i-th event self-centered topology tree. The node which has received
the topology query message assigns the node which has sent the message to be theparent-node, and all other neighboring nodes are assigned to be child-nodes.
Type

Query ID
Event identity (the i-th event)Reserved
The elected KD Agent’s IP address for the i-th event
The elected KD Agent’s sequence Number for the i-th event
Figure 4: The i-th event topology query message format

New Technologies for Urban Safety of Mega Cities in Asia

After receiving all topology reply messages from its child-nodes, a parent
node records all information in the topology information table and transmits theinformation to its parent-node for the i-th event. Figure 5 shows the format of thei-th event topology reply message.
Type

Reply ID
Event identity (the i-th event)Reserved
Node IP address for the i-th event
Neighboring node's IP address for the i-th event
The elected KD Agent’s IP address for the i-th event
The elected KD Agent’s sequence number for the i-th event
Figure 5: The i-th event topology query message format

e1
e2

n

l
b1

n4

l
n2

l2
b2

n5

n3

l5

l3
b3

.
.
.
en

nq −1
nq

bp

lr

b1 ~ bp : Border routers (Knowledge discovery agents)
n1 ~ nq : The 1st network nodes
l1 ~ l p : The 2nd network nodes
e1 ~ en : Event identities

Figure 6: A topology of heterogeneous network
After receiving topology information, the agent node constructs the n-bits MRT,
shown in Table 2, for n-bits map KD-ED routing protocol. Based on the n-bits
MRT, the elected KD agent can be changed according to the following rules:(1) The intermediate node is the preferred agent node.
(2) The agent node should have the longest battery life-time.
(3) The agent node should have as many neighboring nodes as possible.
An Event-Driven Routing Algorithm Applied for Urban Safety in Wireless Heterogeneous
Networks

0ctober 2010, Kobe, Japan

Table 2: The n-bits MRT for n-bits map KD-ED routing protocol
Node ID (c)… nq−1 lp−1
nq
n1
l1
n2
l2

lp

Node ID (r)n1s1s2...sn

s1s2...sn

s1s2...sn

.

.

.

.

s1s2...sn

s1s2...snl1

s1s2...sn

s1s2...sn

.

.

.

.

.

.

s1s2...snn2

s1s2...sn

.

.

.

.

.

.

.

.

l2

s1s2...sn

.

.

.

.

.

.

.

.

.
.
.
nq−1

.
.
.
.

.
.
.
.

.
.
.
.

.
.
.
.

.
.
.
.

.
.
.
.

.
.
.
.

.
.
.
.

.
.
.
.

lp−1

.

.

.

.

.

.

.

.

.

nq

s1s2...sn

.

.

.

.

.

.

.

s1s2...snlp

s1s2...sn

s1s2...sn

.

.

.

.

.

s1s2...sn

s1s2...sn

} {

}

{

Note: E c , r = e1 ,e 2 ,..., e n = s1 s 2 ... s n .

The elected KD agent will send the n-bits MRT information to all nodes in
the heterogeneous network via using a topology advertisement message. Figure 7
shows the topology advertisement message format for each i-th event. After eachnode has received the topology advertisement messages, it will check whether
there are any differences between this and previous topology information in order
to update the n-bits MRT.
Type

Reply ID
Event identity (the i-th event)The elected KD Agent ID
1-st candidate-agent node ID
2-th candidate-agent node ID.
.
.
(p-1)-th candidate-agent node ID
The n-bits MRT
Figure 7: Advertisement message format

Reserved

When a node needs to transmit data to another node, it checks a routing pathto the destination node by using the n-bits MRT. It can quickly establish theconnection. The n-bits MRT represents a graph which shows the network
topology. The pseudo algorithm for the path search process is illustrated below.

New Technologies for Urban Safety of Mega Cities in Asia

The path search algorithm for the i-th event-driven routing protocol:
Step 1: Perform “AND” operation with source node and destination node for thei-th event.
1a. if there is a path for the i-th event to the destination node, then go to step 3
1b. if there is no path for the i-th event, then go to Step 2.
Step 2: Find neighboring node for the i-th event.
2a. Select an unchecked neighboring node for the i-th event, perform “AND”
operation with destination.
(1) find a path for the i-th event to destination, and then go to Step 3.
(2) if there is no path for the i-th event, go to Step 2a.
2b. when all neighbors assigning for the i-th event are checked, then select aneighbor and perform Step 2, recursively.
Step 3: Use searched nodes assigning for the i-th event for the path, and finish.
□

DISCUSSIONS AND ANALYZE
In this subsection, our proposed protocol is compared with both of traditional
AODV and R-AODV (Reverse RAODV), see (Kim et al., 2006), in the number ofcontrol packets, shown in Table 3. We define the relevant parameters as below:(1) t: number of nodes in WHNs relied on route reply message(2) p+q: number of nodes in WHNs
(3) n: number of events in WHNs
Table 3: The numbers of control packet
routing protocol # of control packets
AODV(p+q)-1+t
R-AODV2(p+q)-2
Our protocol((p+q)/n)-1+t
We compare the number of control packets among AODV, R-AODV with our
protocol as shown in Table 3. AODV needs to transmit the (p+q)-1+t control
packets. And R-AODV needs to transmit the 2(p+q)-2 control packets. Becauseof dividing the WHNs into n event groups, our protocol only need ((p+q)/n)-1+t
control packets. Therefore, our propose protocol can reduce the number of control
packets. In other words, the proposed protocol can save the power of nodes in
WHNs.
If one path has interrupted, the intermediate node can easy choose a new path byusing the path search algorithm for the i-th event-oriented routing protocol
algorithm via the n-bits MRT. Therefore, our propose protocol can achieve fault
tolerant mechanism.

CONCLUSIONSIn this paper, we first propose an n-bits map KD-ED routing protocol for WHNs
urban safety environment. It is an event-oriented routing protocol which can
An Event-Driven Routing Algorithm Applied for Urban Safety in Wireless Heterogeneous
Networks

0ctober 2010, Kobe, Japan

reduce the number of control packets and achieve fault tolerant for packet routing
in WHNs.

ACKNOWLEDGMENTS
This work was supported by National Science Council, Taiwan, Republic ofChina, under Grant NSC 98-2218-E-029 -004 and NSC99-2221-E-468-011.

REFERENCES
Kim C., Talipov E. and Ahn B., 2006, A reverse AODV routing protocol in ad hoc
mobile networks, in Proceedings of Embedded and Ubiquitous Computing, vol.
4097, 522-531.
Perkins C. and Belding-Royer E., 2003, Ad hoc On-Demand Distance Vector(AODV) Routing, RFC 3561.
Malkin G., 1998, RIP Version 2, RFC 2453.
Yasser G. and Hadeel E. K., 2008, A WSN/MANET hybrid protocol for routing
data in heterogeneous wireless sensor networks, in Proceedings of WirelessCommunications and Mobile Computing, 523 - 528.
Chakeres I. D. and Belding-Royer E. M., 2002, The utility of hello messages fordetermining link connectivity, International Symposium on Wireless Personal
Multimedia Communications, vol. 2, 504-508.
Kurose J. K. and Rose K. W., 2007, Computer Networking: A Top-Down
Approach, 4th ed., New York: PEARSON.
Lee S. S., Kim H. K. and Kim C. G., 2008, A knowledge discovery agent for a
topology bit-map in ad hoc mobile networks, Journal of Universal Computer
Science, vol. 14, no. 7, 1105-1117.
Senner T., Karnapke R., Lagemann A. and Nolte J., 2008, A combined routing
layer for wireless sensor networks and mobile ad-hoc networks, in Proceedings of
Sensor Technologies and Applications, 147-153.

New Technologies for Urban Safety of Mega Cities in Asia

The Performances Study of IEEE 802.11e
EDCF with TXOP in Disaster Prevention
Networks
Jyh-Horng WEN1, Chien-Erh WENG2
1
Professor, Department of Electrical Engineering, Tunghai University
Taichung, Taiwan. ROC
jhwen@thu.edu.tw
2
Assistant Professor, Department of Electronic Communication Engineering,
National Kaohsiung Marine University
Kaohsiung, Taiwan. ROC
ceweng@mail.nkmu.edu.tw
ABSTRACTIEEE 802.11e Enhanced Distributed Coordination Function (EDCF) is a newwireless technology in disaster prevention networks. It defines a new supplement
to the existing IEEE 802.11 MAC protocol. In IEEE 802.11e EDCF, the aim isproviding a QoS support in WLANs. While the system services different Access
categories (ACs), IEEE 802.11e EDCF does not perform well under high loadconditions. In order to improve the efficiency, we pay attention to the EDCF ofIEEE 802.11e with TXOP mechanism. We first proposed a new markov chain
model and studied the behavior. We extend the model to support IEEE 802.11e
EDCF in wireless disaster prevention networks, and presented a more accurate
analysis of the IEEE 802.11e EDCF under a non-ideal channel environment.
Keywords: WLANs, QoS, EDCF, TXOP, Block ACK

1. INTRODUCTION
In recent years, the wireless local area networks (WLANs) market is
experiencing an explosive growth. The medium access control (MAC) protocol is
the key element that provides the efficiency in accessing the channel, whilesatisfying the quality of service (QoS) requirements. IEEE 802.11e EDCF is a
new wireless technology which is an enhanced version of IEEE 802.11 distributed
coordination function (DCF). The IEEE 802.11e EDCF aims at improving thecapabilities and efficiency of the IEEE 802.11 MAC protocol by defining a newmechanism to support the QoS services. While the system services different ACs,
EDCF does not perform well under high load conditions. In order to improve theefficiency, EDCF provides two mechanisms named as transmission opportunity(TXOP) and Block ACK. These two mechanisms are allowed to offer new datatransmission services that include the multiple frame delivery. There have been
many performance analyses of the IEEE 802.11e EDCF. Deng and Chang
proposed a priority scheme by differentiating the backoff window. Aad andCastelluccia proposed a priority scheme by differentiating inter-frame spaces(IFS’s), in which a higher priority class uses IFS, whereas a lower priority class0ctober 2010, Kobe, Japan

uses a space that equals the sum of IFS and the maximum window size. Veres andCampbell et al. proposed priority schemes by differentiating the minimum backoff
window size and the maximum window size. These performance studies
neglected that high load situation. They can not truly reflect the real operation of
EDCF with priority schemes. In order to improve the efficiency, IEEE 802.11e
EDCF provides two mechanisms named as TXOP and Block ACK mechanisms.
In this paper, we pay attention to the EDCF of IEEE 802.11e with TXOP
mechanism. We proposed a new markov chain model and studied the behavior.
We extend the model to support IEEE 802.11e EDCF in wireless disasterprevention networks, and present a more accurate analysis of the IEEE 802.11e
EDCF under a non-ideal channel environment.
The rest of this paper is organized as follows. In section II, a generaldescription of our proposed model with TXOP mechanism is presented.
Analytical performance deviations of proposed model with RTS/CTS and basic
access mechanisms including throughput analysis under a non-ideal channel
scenario are presented in section III. The numerical results are given withdiscussion in section IV. Finally, conclusions are drawn in section V.

2. OVERVIEW OF IEEE 802.11E EDCF MODEL
2.1 The System ModelIEEE 802.11e is a feasible scheme for different QoS requirements. In IEEE
802.11e, the contention-based access mechanism is called an enhanced DCF(EDCF). EDCF specifies four default access categories, which are shown in Table
1.
Table 1: Priority to AC mappings

Each STA contends for the channel access and independently starts its backoff
depending on its associated AC. Each AC uses AIFS[AC], CWmin[AC] andNew Technologies for Urban Safety of Mega Cities in Asia

CWmax[AC] instead of DIFS, CWmin and CWmax of the DCF. The contention
method of EDCF is the same as that in DCF. Each STA having a frame totransmit has to wait for the channel to be idle without interruption for a period
AIFS[AC], and then it should start a random backoff process with its own
CW[AC]. For each time slot interval, during which the channel stays idle, therandom backoff value is decremented. When the backoff counter reaches zero, theframe is transmitted. AIFS[AC] is calculated as follows:
AIFS[AC] =AIFSN[AC] ∗ aSlotTime + aSIFSTime,(1)where AIFSN[AC] is shown in Table 2 and the backoff time is calculated asfollows:
backoff time = random_integer * aSlotTime,(2)where random_integer is uniformly and randomly chosen in the range[0,CW(AC)], instead of [0,W-1] in the DCF. CW of each AC is equal to
CWmin[AC]. After each collision, CW is doubled up to:
CWmax [AC] = 2 m * (CWmin [AC] ),(3)
where m is called the maximum backoff stage. Once it reaches CWmax[AC].
Table 2: AIFSN for each ACs
AC
AIFSN

AC_BK
7

AC_BE
3

AC_VI
2

AC_VO
2

The timing diagram of the EDCF is shown in Figure 1

Figure 1: The timing diagram of the EDCF
We assume in the following that for a given station in the priority i class, b(i, t ) isdefined as a random process representing the value of backoff counter at time t,
and s(i,t) is defined as the random process representing the backoff stage j , where
0 ≤ j ≤ m and m is the maximum backoff stage. The value of the backoff counter
is uniformly chosen in the range (0,1,......Wi , j − 1) , where Wi , j = 2 j Wi ,0 and

Wi ,0 = CWmin [i ] . Let pi denote the probability that a transmitted frame collides in
The Performances Study of IEEE 802.11e EDCF with TXOP in Disaster Prevention
Networks

0ctober 2010, Kobe, Japanthe priority i class. A Markov chain {s(i, t ), b(i, t )} can be established to analyze
the contention process. Therefore, the state of each station in the priority i class is
described by {i, j, k}, where i is just an index standing for the priority i class, jstands for the backoff stage and takes values (0,1,...,m), and k stands for the
backoff delay and takes values (0,1,......,Wi , j − 1) in time slots. The proposed
Markov chain model is shown in Figure 2(1 − pi )(1 − pei )Qii, −1, 0(1 − pi )(1 − pei )1 − pii , 0, 0

1 − pii , 0,1

Wi ,0

pi

1
Wi ,0

Qi

Qi
1 − pi1 − pi

i , j ,1i , m, 0

1 − pipi

1 − pii, j, 2iii

1 − pii , 0, W i ,0 − 1pii, j,W i, j − 2

1 − pii, j,Wi, j − 1

pi

pi

pi

Wi , j +1
Qi(1 − pi )(1 − pei )i , 0, W i ,0 − 2

Wi , jpi

Qi

1 − pipi + (1 − pi ) pei = Qi

Wi ,1i , j − 1, 0

i, j , 0iiipi(1 − pi )(1 − pei )(1 − pi )(1 − pei )1 − pii , 0, 2

1 − pi1 − pii, m,1pi

Wi ,m
1 − pi

i , m, 2iii

1 − pii, m,Wi ,m − 2pi

1 − pii, m, Wi ,m − 1pipi

Figure 2 : Markov chain model for the priority i with the backoff window size
under channel error scenario
The contention window size at the backoff stage j in the priority i class is definedas Wi , j . For convenience, Wi , j = 2 j Wi .0 , where j ∈ [0, m ] is called the backoff
stage, Wi ,0 is the initial contention window size in the priority i class, and m is the
maximum backoff stage. For each STA, the backoff window size at the backoff
stage j in the priority i class can be shown asj⎪⎧2 W , j ≤ m
Wi , j = ⎨ m i ,0(4)⎪⎩ 2 Wi ,0 , j >mWhere 2m Wi ,0 − 1 = CWmax . Let pi denote the probability that a transmitted
frame collides in the priority i class:
i −1

N −1

h =0

h = i +1

pi = 1 − (∏ (1 − τ h ) nh )(1 − τ i ) ni −1 ( ∏ (1 − τ h ) nh ).

(5)

New Technologies for Urban Safety of Mega Cities in Asia

Let ps ,i denote the probability that a successful transmission occurs in a timeslot for the priority i class. We then have
N −1

ps ,i = niτ i (1 − τ i ) ni −1 ∏ (1 − τ h ) nh .

(6)

h = 0, h ≠ iFrom the state transition diagram for the priority i class as shown in Fig. 2. The
transmission probabilities of the Markov chain model are listed as follows:
1. The backoff counter decrements when the STA senses that the channel is idle
at the beginning of each slot time in the priority i class:P{i, j , k i, j, k + 1} = 1 − pi , 0 ≤ k ≤ Wi , j − 2, 0 ≤ j ≤ m.
(7)
2. The backoff counter freezes when the STA senses that the channel is busy inthe priority i class:.
P{i, j , k i, j , k} = pi , 0 ≤ k ≤ Wi , j − 1, 0 ≤ j ≤ m.
(8)
3. The STA enters the {i, -1, 0}state if it verifies a successful transmission
without any channel errors:
P{i, −1, 0 i, j , 0} = (1 − pi )(1 − pe,i ), 0 ≤ j ≤ m.

(9)

Where Pe,i is the packet error rate for the priority i class.
4.

The STA transmits it frame without entering the backoff process if it detectsthat its previous transmitted frame was successfully received, the channel isidle, and has no channel errors:
P{i, −1, 0 i, −1, 0} = (1 − pi )(1 − pe,i ), 0 ≤ j ≤ m.
(10)

5. If the STA finds a collision has occurred or has any channel errors, the STA
defers to transmit a new frame and enters stage 0 to start the backoff process:p + (1 − pi ) pe ,i(11)
P{i, 0, k i, −1, 0} = i, 0 ≤ k ≤ Wi ,0 − 1.
Wi ,0
6. The STA chooses a backoff time slot of the next stage j after an unsuccessfultransmission at stage j-1 in the priority i class:p + (1 − pi ) pe ,iP{i, j , k i, j − 1, 0} = i, 1 ≤ j ≤ m, 0 ≤ k ≤ Wi , j − 1, (12)Wi , j
7. At the maximum backoff stage, the contention window will be reset to theinitial value due to discarding the frame caused by too many retransmissions:1(13).
P{i, 0, k i, m, 0} =Wi ,02.2 TXOP Mechanism
In IEEE 802.11e, the TXOP is a time period when a particular station (STA) thatwins the channel access has the right to initiate transmission along with the EDCF
parameters of AIFS[AC], CWmin[AC], and CWmax[AC]. During the TXOP, STA isallowed to transmit more than one frame with a short inter-frame (SIFS) time gap
between an ACK and the subsequent frame transmission without the backoff
process Since SIFS is used for frame separations, the other STAs cannot gain
channel access because they must wait at least a DIFS interval. The TXOP frame
structure is shown in Fig. 3.

The Performances Study of IEEE 802.11e EDCF with TXOP in Disaster Prevention
Networks

0ctober 2010, Kobe, Japan

SIFS

SIFS
A
C
K

Frame

SIFS

SIFS
A
C
K

Frame

Frame

A
C
K

TXOP

Backoff

AIFS[AC]

Figure 3 : TXOP frame structure
3. PERFORMANCE ANALYSIS OF EDCF WITH TXOP MECHANISM
3.1 Saturation Throughput and Delay Analysis of EDCF with TXOP
Mechanism

From the analysis that was depicted in the previous section II, the transmission
probability is related to CW size and AIFS[AC]. When deriving the saturation
throughput with different TXOP durations, the collision probability and thetransmission probability of a STA are the same as those derived in section II.
However, the equations relating to the transmission time of each successfulcontention will be different for the different ACs, i.e., different ACs are assigned
different TXOP durations. We assume that the system is under an environment ofchannel error and having the RTS/CTS CSMA/CA mechanism. Thus, we canobtainSi =ps ,i * E [TLi ]

N −1

N −1

RTS
CTS
ACK
(1 − pi )σ + ∑ ps ,i (1 − Pe,i ) TS ,i + [ pi − ps ,i ]TC ,i + ∑ ps ,i ( PeRTS
TeDATA+ PeCTS+ PeDATA+ PeACK),i Te ,i,i Te ,i,i,i,i Te ,i
i =0

i =0

(14)
Ki −1

∧

∧

∧

E[TLi ] = { ∑ l *((1 − Pe,i )(1 − P e,i )l −1 P e,i ) + K i *(1 − Pe,i )(1 − P e,i ) Ki −1}* TLi . (15)l =1

TS ,i = TRTS + TCTS + 2TSIFS + ki ∗ (TLi + TACK + 2TSIFS ) + AIFS (i ),(16)where TS ,i is the TXOP duration which equals the time needed to successivelytransmit ki frames. When the system is under the environment of a channel error,
there are three kinds of transmission error frames: 1) The RTS/CTS framestransmission error. When the RTS/CTS frames transmit an error, the STA cannot
determine whether the error is caused by a collision or channel error. 2) The data
frames transmission error. 3) The ACK frames transmission error. The
probabilities of an unsuccessful transmission can be written as:
L +L +L +L
Pe,i = 1 − (1 − Pb ) RTS CTS i ACK .
(17)∧

P e,i = 1 − (1 − Pb ) i .

(18)

PeRTS
= 1 − (1 − Pb ) RTS .
,i

(19)

L

L

(

)

PeCTS
= (1 − Pb ) RTS 1 − (1 − Pb ) CTS .
,i
L

PeDATA= (1 − Pb ) RTS,i
L+ LCTSL(1 − (1 − P ) ) .
Li

b

(20)
(21)

New Technologies for Urban Safety of Mega Cities in Asia

PeACK= (1 − Pb ) RTS,i
L+ LCTS + Li

(1 − (1 − P ) ) .
LACK

b

(22)

Where Pb is the bit error rate, and Lxxx is the length of different types of frames.
Pexxx,i is the frame error rate of the frame type xxx for the priority i class.

4. NUMERICAL RESULTS

In this section we assume that the DBPSK (Differential Binary Phase Shift
Keying) modulation scheme is used in the simulation. Then, we can calculate therequired SNR at the receiver by using the following equation:
SNR = 2*(erfc −1 (2 Pb )) 2 .
(23)
1
SNR
(24)
erfc(
).
2
2
We finished the analysis the TXOP mechanism with the RTS/CTS CSMA/CA
access scheme under the channel error scenarios and compared it with the modelthat is without the TXOP mechanism. Fig. 4 shows the saturation throughput
performance of the TXOP mechanism with the RTS/CTS CSMA/CA access
scheme for different priority STAs under channel error scenario. Figure 5 depicts
the saturation throughput performance of different priority STAs using the
RTS/CTS CSMA/CA access scheme without the TXOP mechanism underchannel error scenario. From the results, we can conclude that the model with the
TXOP mechanism under channel error scenario can achieve higher performance
than the model that is without the TXOP mechanism because the model with the
TXOP mechanism is allowed to transmit more than one frame with a short interframe (SIFS) time gap between an ACK and the subsequent frame transmission
without the backoff process.
Pb =The Performances Study of IEEE 802.11e EDCF with TXOP in Disaster Prevention
Networks

0ctober 2010, Kobe, Japan

RTS/CTS machanism in error channel,SNR=13 dB, Ki=[ 1,1,1,6 ]0.9
0.8

Saturation Throughput

0.7
0.6
0.5

Priority 0
Priority 1
Priority 2
Priority 3
Total throughput

0.4
0.3
0.2
0.1
0

5

10

15

20
25
Number of Stations

30

35

40

Figure 4 : Saturation throughput of the different priority STAs with the TXOP
mechanism under a channel error scenario, Ki=[1,1,1,6].
RTS/CTS machanism in error channel,SNR=13 dB, Ki=[ 1,1,1,1 ]0.9
Priority 0
Priority 1
Priority 2
Priority 3
Total throughput

0.8

Saturation Throughput

0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
5

10

15

20
25
Number of Stations

30

35

40

Figure 5 : Saturation throughput of the different priority STAs with the TXOP
mechanism under a channel error scenario, Ki=[1,1,1,1].

New Technologies for Urban Safety of Mega Cities in Asia

5. Conclusions

In this paper, an improved analytical model was proposed to study the behaviorsof the backoff process in terms of saturation throughput. In order to be suitable for
the QoS requirements, we extended the model to support the multi-priority
schemes under non-ideal channel scenarios. In order to improve the efficiency, we
integrate the TXOP mechanism in a non-ideal channel scenario.The model with
the TXOP mechanism under a channel error scenario can achieve a higher
performance than that without the TXOP mechanism due to fact that the proposedmodel with the TXOP mechanism is allowed to transmit multiple frames during
the TXOP duration.

Acknowledgments
The authors would like to thank the National Science Council of Taiwan, R.O.C.
for financially supporting this research under Contract Nos. NSC 98-2218-E-029 004
REFERENCES

D. J. Deng and R. S. Chang, “A priority Scheme for IEEE 802.11 DCF Access
Method,” IEICE Trans. Communications., Vol. E82-B, No.1, Jan. 1999, pp.96102.
I. Aad and C. Castelluccia, “Differentiation Mechanisms for IEEE
802.11,” IEEE INFOCOM 2001.
A. Veres, A. T. Campbell, M. Barry, and L.-H. Sun, “Supporting Differentiationin Wireless Packet Networks Using Distributed Control,” IEEE J-SAC, Vol. 19.
No. 10, Oct. 2001, pp. 2081-2093.
Y Xiao, “QoS guarantee and provisioning at the contention-based wireless MAC
layer in the IEEE 802.11e wireless LANs,” IEEE Wireless Communications
Magazine, vol. 13, pp. 14-21, Feb. 2006.
Daqing Gu and Jinyun Zhang, “QoS enhancement in IEEE 802.11 wireless local
area networks,” IEEE Communications Magazine, vol. 41, pp. 120-124, June
2003
S. Choi, J. del Prado, S. Shankar N, and S. Mangold, “IEEE 802.11e contentionbased channel access (EDCF) performance evaluation,” Proceedings of the IEEE
International Conference on Communications, May 2003.

The Performances Study of IEEE 802.11e EDCF with TXOP in Disaster Prevention
Networks

The Development of Disaster Prevention andResponse Information Platform in Yunlin,
TaiwanJih-Shih HSU1, Tzung-Tai TANG1, Chi-meei YANG2
Associate Prof., Department of Information Management,
National Yunlin University of Science and Technology, Taiwan
hsujs@yuntech.edu.tw
2
Lecture, Department of Information Management,
National Yunlin University of Science and Technology, Taiwan
1

ABSTRACTDue to the occurrence of natural disasters is on an upward trend in Taiwan,
Yunlin County Government promotes 5-year Disaster Prevention and Response
Operation Plan that follows the experience of previous similar activities. The
government chooses the high risk disaster hotspots – Gukeng Township, Taixi
Township, Dapi Township, Kouhu Township, and Douliu City as the targets ofthis plan. Hereby, we select Gukeng and Taixi Townships which are areas ofhigher risk disaster as examples to explain the details.
There are many problems with disaster recovery in those five townships before thedeployment of this plan. For example, the lack of equipments and the difficulty incollecting real time information have delayed the rescue of disasters. To improve
the abilities of disaster recovery for these local governments, the main purpose ofthis project is to help them enhance Disaster Emergency Operation Center (DEO
Center) and implement Disaster Prevention and Response Information Platform（DPRIP）. The existing DEO Centers in above-mentioned local governments
lack for information and communication equipment, and the staffs havedifficulties in receiving the disaster messages to handle the disaster in time. In
addition, lots of paper works in the disaster prevention and relief workflow havemade the processes inefficient. To solve the problems, this project intends toprovide suitable space and needed hardware and software equipment to enhanced
DEO Centers. DPRIP is a web-based platform to replace the existing paper-based
workflow for staff to receive information in time. With enhanced DEO Centers
and DPRIP, the local governments can handle the disaster relief work more
efficiently and increase the capacity and quality of disaster prevention and relief.
Keywords: disaster emergency operation center, web-based platform

0ctober 2010, Kobe, Japan

1. INTRODUCTION
With global climate change, the frequency of disaster in Taiwan is increasing. The
921 earthquake in 1999 and the 88 flood in 2009 had brought a great loss to thesociety. To prevent the similar disaster, Taiwan’s regional governments have beenplanning for disaster prevention policy, so that they can take the relief action
immediately when the disaster occurs. Besides, most of the cities in Taiwan are
either near coastline or mountains. Taixi Township (台西鄉) is a typical coastal
township and Gukeng Township (古坑鄉) is a hill township, and both of them are
the most serious disaster townships in Yunlin county (雲林縣) Therefore, wechoose Taixi and Gukeng as according examples to demonstrate how to enhancetheir Disaster Emergency Operation Centers (DEO Center) and implement
Disaster Prevention and Response Information Platform (DPRIP) for them.
1.1 The Terrain And The Conceivable Disasters Of Taixi TownshipTaixi is located at the western coastal areas of Yunlin, and it faces the Taiwan
Strait (Figure 1). The most area of Taixi is dominated by flat plains that coverabout 75% of the whole land with the land elevation of about five meters. There
are three drainages – Cailiao ( 才 寮 ), Huoshaoniuchou ( 火 燒 牛 稠 ), andChenghaicuo (程海厝), which intersect with Taixi from east to west and flow into
Taiwan Strait. In regard to the climate, the mostly rainy season is during summer,
southwest monsoon is during spring, and northeast monsoon is during fall andwinter; high temperature is in summer and fall, and cold temperature is in winterand spring. The conceivable disasters of Taixi are classified into several different
categories, such as typhoon, earthquake, and others. From July to September insummer, the typhoon forms on Western Pacific, and brings abundant rainfall tothe local area. Additionally, Taixi has serious problem with land subsidence. Oncetyphoon or torrential rain comes, it will cause flood and make great loss toagricultural and fishing industries. The earthquake did not cause too much damage
in Taixi. But to prevent the loss from the possible earthquake, we still made theearthquake as a part of the disaster prevention plan. In addition, because of being
close to No.6 Naphtha Cracker Industrial park, it might cause some kinds ofdisasters like chemistry, fire, and traffic disaster.
1.2 The Terrain And The Conceivable Disasters Of Gukeng TownshipIn contrast to Taixi, Gukeng is located at the eastern mountain area of Yunlin(Figure 1). The region of Gukeng is dominated by hills and mountains, and theland elevation is between 60 to 1750 meters. The possible disasters here areclassified into several different categories: typhoon, slope, earthquake, and others.
In regard to typhoon, even though Gukeng do not have the problem with land
subsidence, but flood is still formed at rural village where near the drainages when
typhoon or torrential rain comes. And because Gukeng is slopeland area, it evenmight occurs debris flow and landslide. For example, KALMAEGI (卡玫基颱風)

New Technologies for Urban Safety of Mega Cities in Asia

and SINLAKU (辛樂克颱風) in 2008 cause many debris flows in Gukeng and thelandslide in Caoling (草嶺). The earthquake is also an important part of disasterprevention plan in Gukeng. The 921 earthquake in 1999 had caused the collapseof building and Caoling landslide on Jhuo-Shuei River (清水溪) that led to“quakelake”. Yunlin County Government has been promoting the tourism industry in
Gukeng, so the famous Janfusun Fancyworld, Janfusun Prince Hotel, and
HuaShan (華山) Coffee attract many tourists on holidays. We consider that thetraffic accidents may be included in the disaster prevention plan because of theheavy traffic.

Figure 1: Maps of Yunlin County and Taixi and Gukeng Townships

2. PROBLEMS TO BE SETTLED
The problems of the existing Disaster Emergency Operation Center (DEO Center)are that they need more professionals of disaster prevention and response thanthey have. Due to the shortage of the finance and human resource, the staffs
seldom have enough drill for disaster prevention and relief. So they lack ofautonomy and capabilities for disaster prevention and relief. The workflow of the

The Development of Disaster Prevention and Response Information Platform in Yunlin,
Taiwan0ctober 2010, Kobe, Japandisaster prevention and response is also inefficient because a lot of paperwork
needed to be filled up. Therefore, we plan to design the Disaster Prevention andResponse Information Platform (DPRIP) to relieve the staffs from the inefficientpaperwork to enhance their capacity and quality of disaster prevention andresponse.
2.1 The Present Situation Of Disaster Management In Gukeng TownshipThe chief and deputy commander of the DEO center are taken by the mayor andchief secretary respectively. The task forces consist of relevant officials andadministrators according to the necessity of the disaster prevention and response.
The debris flow occurs frequently in this township, and some areas are easy tohave the mountain torrents and flood disaster situation. Therefore, the townshipaggressively pushes the disaster prevention works. They usually hold a Disaster
Prevention and Response Council. When the disaster occurs, the DEO center will
be set up in the briefing room on the second floor of the town hall. However, thelocal government still suffers from lacking good capacity and quality of disasterprevention staffs, and lots of paper works in the disaster prevention and relief
workflow have made the processes inefficient. Due to the shortage of sufficient
funds and human resources, the local government doesn’t have related experienceand self-governing ability. There is still room for improvement about disasterprevention.
2.2 The Present Situation Of Disaster Management In Taixi Township
As Gukeng Township, the town mayor and chief secretary of Taixi Township are
the chief and assistant commander of DEO center. The task forces also consist of
relevant officials and administrators according to the necessity of the disasterprevention and response. When the disaster occurs, the DEO center will be set up
to resolve everything about disaster relief. However, because of insufficient spacein the Taixi town hall, the local government doesn’t allocate an exclusive spacefor DEO center. However, the staffs appointed for the disaster prevention arerotated very often, so the experience and knowledge of disaster prevention cannot
pass down. This makes them not able to react to the urgent event correctly andmight make a wrong decision. They usually have to wait for the instructions fromthe superiors when the disaster occurs. This local government needs moreassistance from county government and the relevant experts to enhance theirdisaster prevention skills.

3. IMPLEMENTATION
In order to enhance the capabilities of disaster recovery for these five townships in
Yunlin, such as Gukeng Township, Taixi Township, Dapi Township, Kouhu
Township, and Douliu City, we interviewed the relevant officials of the fivetownships to understand the current processes and guidelines of operating in thefield and make appropriate recommendations accordingly. During the interview
with the officials, we want to know that what kind of features the local
governments want for the DPRIP, how many software and hardware equipments

New Technologies for Urban Safety of Mega Cities in Asia

they already have, and whether the five townships have established the DEO
Center or not. If they haven’t established the DEO Center, we will counsel withthem about their requirements and expectations for the DEO center.
3.1 The Deployment For DPRIPThe purpose of DPRIP is for local officials to exchange related documents, shareresults of the latest disaster information, integrate geographic information, andoffer expert experience and potential analysis. The home page of DPRIP is shownin Figure 2. In this section, the functions and content of DPRIP were introduced as
the following: the front-end processing functions, the back-end processing
functions and the system use case diagram.

Figure 2: The home page of DPRIP
3.1.1 Front-End Processing Functions
The front-end functions of DPRIP are cataloged into two major parts: information
search and data register. The features of the functions are discussed as following:(1) DPRIP follows the framework of Web 2.0 to provide information service toresidents and relevant officials. DPRIP is a web application which can beaccessed through the internet. It provides dynamic HTML web pages createdfrom continuously updated database. Therefore, DPRIP can provide residents
and relevant officials continuously updated information as long as theirlinking to DPRIP website.
(2) DPRIP intends to offer citizens complete disaster prevention and response
information. Ordinary people can browse the following web pages such as:organization introduction, disaster prevention, publicity, disaster list, history
The Development of Disaster Prevention and Response Information Platform in Yunlin,
Taiwan0ctober 2010, Kobe, Japan

records, related websites, and so forth (Figure 3). The contents of these pages
are listed as following:a. Organization Introduction: Organization Chart, Disaster Prevention andResponse Act, Disaster Prevention and Response Plan, and Standard
Operating Procedure (SOP).
b. Disaster Prevention Information: News, Weather Report, Rainfall
Forecasting, Earthquakes, Evacuation Shelters, Debris Flow Alert Areas.
c. Publicity: Report and Multimedia Demonstration.
d. Disaster List: List for Flooded Area, Debris Flow Area, Landslide Area,
Rural Villages In Danger.
e. History Records: Serious Disaster Cases, Reports, and Image Database.
f. Related Websites: Workshops and Related Links.
g. File Download: Related Files For Visitors To Download.
h. Volunteer: Volunteer Registration Form
i. Donation: Donation Registration Form

Figure 3: Front-end processing functions
3.1.2 Back-End Processing Functions
The back-end processing functions of DPRIP are for system administrators tomanage the web site. The features of the functions are discussed as following:(1) Files management system: DPRIP provides on-line files management system
for administrators to upload related documents to information platform.
Ordinary people can get what they need quickly according to theclassification of files.
(2) Electronic administrative system: In addition to files management system,
DPRIP also provides disaster notification system, human resource system,
and goods and materials system for DEO Center to deal quickly with theinformation of rescuers, volunteers, goods and materials, and disaster
notification records (Figure 4). These features are explained as following:a. Website Management: Website management allows web administrators
to insert, update, and delete web page.
b. Access Control Management: Access control management is used to
grants different users, such as visitors, officials, and administrators,
different levels of authority. Different users are allowed to accessdifferent information as long as permissible.
c. Donation Management: Web administrators can use this function toinsert, delete, update, and query data for donated goods and materials.

New Technologies for Urban Safety of Mega Cities in Asia

d.

e.

The announcement of needed goods and materials is made for people todonate needs voluntarily.
Disaster Management: Through this function, web administrators caninsert, delete, update, and query disaster information according to thecurrent situation of disaster.
Human Resource Management: This function is for web administrators toinsert, delete, update, query human resources information, and makeannouncements for human resources requirement. The administrator canalso search, group, and adjust task force according to the requirementfrom each township.

Figure 4: Back-end processing functions
3.1.3 System Use Case Diagram
There are three kind of actors in DPRIP, such as visitor, official and administrator(Figure 5). DPRIP consists of two processors: one is front end processor and theother one is back end processor. All processing functions can be used by officials
and administrators, but visitors can only use front-end processing functions. The
front end processor has two major functions: information search and data register.
The information search provides all actors as many functions as shown in figure 3.
The functions provided by back-end processor are shown in figure 4.

The Development of Disaster Prevention and Response Information Platform in Yunlin,
Taiwan0ctober 2010, Kobe, Japan

Figure 5: Use case diagram of DPRIP
3.2 The Deployments Of Hardware Equipment And DEO Center(1) Gukeng Township
Gukeng Township has settled their DEO center in the briefing room on the second
floor of the town hall. There are projector, network and broadcasting equipment in
the room. In addition, we suggest them to have a liquid crystal display TV for
acquiring information from television news. Regarding the mobility of notebooks,
we recommend that each task unit to have their own notebook in order to collectinformation and make crossing comparison as needed. Moreover, the notebook
has not only an advantage of working in the power failure but also a webcam tosupport video conference. Since there is only one network line now, we will add
both the wired and wireless network to support the network connection. We alsosuggest that each unit at least has a telephone respectively to communicate witheach other as needed for exchanging information of disaster. Furthermore, theregional government has a satellite phone, but the regional government is notafforded to use it. And only few people know how to operate it. We recommended
that every village have their own radio set. Thus, the disaster information can betransferred immediately when other communication devices are down. If it is
impossible to make every village have their own wireless device, we can deploy
wireless devices to the villages in alert area first.
(2) Taixi Township
The DEO center of Taixi Township is not in the town hall but in a conference
room on the second floor of the next building for Mediation Committee. There are

New Technologies for Urban Safety of Mega Cities in Asia

not any network, projector, and broadcasting equipment in that room. Firstly, theconference room must be set up the network and the telephone line, and then a setof a liquid crystal display TV, a projector, and the network and broadcasting
equipments. Besides, there is no disposition of safeguard. In consideration of
security and mobility, we recommended that each unit of the task force to havetheir own notebook for video conferencing with the superiors, collecting
information and making crossing comparison. Since, there is no network line, wewill deploy wired and wireless network as soon as possible. We also suggested
that each task unit has a telephone respectively. Furthermore, the regional
government has a satellite phone, but it is too expensive for them to use. We
recommended that every village has a radio set in case of all other communication
devices are broken. If it is not afforded to make every village have radio sets,
those villages in alert area must have high priority. Regarding peripheral
equipment, we suggest them to use all-in-one printer for paper processing.
According to the previous disaster, we find that the continual supply of electric
power is the most important factor while disaster happens. So we suggest that
there should be Uninterruptible Power Supply (UPS) or electronic storage devices.
Additionally, there are not any security systems, so we suggested that there should
be a security system to keep the equipments from being stolen in the DEO center.

4. CONCLUSION
This project is for deploying DPRIP and DEO Centers in five townships in Yunlin
County, so that township officials can exchange related documents, share thelatest disaster information, get message in real time and make the right decisions.
As the result of rapid decision making and information acquiring, they improved
the efficiency of disaster response and reduced the decision error rate and cost ofdecision making. In addition, there are future plans for this project which are
discussed as the following.
(1) Training workshop for disaster prevention and response are going to be held toenhance the ability of collecting and reporting disaster-related information invillage and township offices, so DPRIP and DEO Centers can really work out
and reach their goal.
(2) Make the DPRIP to have overall resources about disaster prevention andresponse, historical disaster data, disaster prevention and response act,
standard operating procedure, and prevention method.
In order to make this project be implemented and promoted successfully, theinteraction with the township officials is very important. The discussion between
project developers and township officials will be held continually to ensure thatevery requirement can be heard during the period of project execution. And
according to the requirements, an appropriate platform will be established to makethe disaster prevention and response work successfully. Moreover, it can increase
the ability of disaster prevention and response and reduce the damage fromdisasters.

The Development of Disaster Prevention and Response Information Platform in Yunlin,
Taiwan0ctober 2010, Kobe, JapanACKNOWLEDGEMENTS
We would like to thanks Yu-Ting YI, Chun-hui LIAO, Fang-Cheng HUANG,
Hsiang-Lin YANG, and Ya-Chunat Hung at Graduate School of Information
Management, National Yunlin University of Science and Technology, Taiwan for
their help in preparing this article.

REFERENCES
National Disaster Prevention and Protection Commission, R.O.C, 2003.5.
Three-year medium-term plan of enhancement of disaster prevention and rescue
ability in regions, Taiwan.
National Disaster Prevention and Protection Commission, R.O.C, 2008.1.
Five-year medium-term plan of disaster prevention and rescue, Taiwan.
National Fire Agency, Ministry of the Interior,Website: http://www.nfa.gov.tw/
National Disaster Prevention and Protection Commission, R.O.C,
Website: http://www.ndppc.nat.gov.tw/
National Yunlin University of Science and Technology, 2004.11. Detailed plan
application of united Institute plan subsidized by National Disaster Prevention andProtection Technology Center, Taiwan.
National Yunlin University of Science and Technology, 2005.12. The 94th annual
year plan of enhancement of disaster prevention and rescue ability in Yunlin
County, Taiwan.
National Yunlin University of Science and Technology, 2006.12. The 95th annual
year plan of enhancement of disaster prevention and rescue ability in Yunlin
County, Taiwan.
National Yunlin University of Science and Technology, 2007.7. Plan ofenhancement of disaster prevention and rescue ability in Yunlin County, Taiwan.
National Yunlin University of Science and Technology, 2010.4. Final report on
long-term disaster prevention and rescue plan, Taiwan.
Taipei City Disaster Prevention and Rescue Information,
Website: http://tdprc2.tfd.gov.tw/TaipeiCityEms1_public/
Taipei County Disaster Prevention and Rescue Information,
Website: http://www.dsc.tpc.gov.tw/home.asp?Pager=Link.asp&Kind=00173
Yunlin Fire-Fighting Department,
Website: http://www.ylfire.gov.tw/

New Technologies for Urban Safety of Mega Cities in Asia

MISSIONS AND PARTICULAR ACTIVITIESOF THE CENTER FOR ADVANCED ENGINEERING STRUCTURAL ASSESSMENT
AND RESERACH, CAESAR
ATSUSHI YOSHIOKA
Director of Bridge and Structure Research Group,Center for Advanced Engineering Structural Assessment and Research,
Public Works Research Institute, JAPANyoshioka@pwri.go.jp

ABSTRACTWith recent rapid increase in demand for structural conditionassessment and rehabilitation of existing highway bridges the Center for
Advanced Engineering Structural Assessment and Research, CAESAR, wasestablished in April 2008, as one of four Research Institutes and Centers of
the Public Works Research Institute, Tsukuba, Japan. This paper presents a
review of the background, mission, organization, and research areas of
CAESAR, in addition to their expected impacts on highway bridge
administration practices.

1. INTRODUCTION
Public Works Research Institute, which is one of the Japanese incorporated
administrative agencies, established the Center for Advanced Engineering
Structural Assessment and Research (CAESAR) as of April 1st, 2008,
recognizing increased social needs for appropriate maintenance of existing
structures. As a core research center in Japan, it accumulates findings
related to maintenance technology of the structures. This paper describes the
background of establishment of CAESAR, organization and system, mission,and new activities.

2. BACKGROUND
The majority of highway bridges in Japan were constructed during the1950s–1970s, which coincides with Japan’s high-growth period.
Accordingly, bridges older than 50 years will increase drastically in the
coming years (Figure 1). Moreover, highway bridges in Japan are exposed
to severe automobile traffic and natural environment; it is highly probablethat the deterioration and damage will increase rapidly. Consequently, undertight financial circumstances, technologies related to inspection, assessment,

0ctoberr 2010, Kobe, Japandiagnosis, repair, and reinforcement should be established urgently for thesake of preventive maintenance.
However, many instances of damage such as fatigue of floor slabs, fatigue
of steel girders and beams, and salt corrosion and alkali-silica reaction of
concrete members have already been recognized as the national major
defects, which strongly influence bridge load-bearing characteristics (Figure2). For example, such trouble was reported in 2006 that a fatigue crack
exceeding 1 m in length developed in a main girder of a steel girder bridgearound a part welded to a cross beam (Yamazoe Bridge, National Route 25).
In 2007, a tension diagonal bracing of a steel truss bridge (Kiso River
Greater Bridge, National Route 23, Honjyo Ohashi, National Route 7)
fractured because of corrosion. In all these cases, traffic restrictions were
enforced temporarily for repair, resulting in a considerable social impact.
Regarding overseas trouble, the I-35W Bridge (Minneapolis, Minnesota,U.S.) collapsed in August 2007 despite the fact that detailed inspections,actual bridge measurements, and status assessments had been carried out
annually.
In Japan, infrastructure was heavily damaged by the Hyogo-ken Nanbu(Kobe) Earthquake in 1995. In recent years, large-scale earthquakes haveoccurred successively: the Niigata Chuetsu Earthquake in 2004, the Noto
Peninsula Earthquake and Niigata Chuetsu-Oki Earthquake in 2007, in
addition to the Iwate-Miyagi Inland Earthquake in 2008. Improvement ofdisaster prevention and mitigation technologies has been requested to copewith the increasing sophistication of socioeconomic activities.

3. ORGANIZATION AND SYSTEMCAESAR is one of four research organizations constituting the Public
Works Research Institute. The research teams of bridge engineering,foundation engineering, management, and earthquake engineering wererestructured, with staff at the establishment of CAESAR of 22 (as of Sept2010). In addition, five researchers from the Tsukuba Central ResearchInstitute and Civil Engineering Research Institute for Cold Region are also
on call so that construction material and severe cold environment effect canbe also covered.
CAESAR tackles every research need in a flexible fashion, covering a wider
range of the bridge engineering field. It does not employ a conventional
research organization system of PWRI to create organizations and systems.
While the PWRI’s former highway bridge-related research teams wereorganized in terms of major highway bridge components and materials(such as metal superstructures, concrete superstructures, substructures, andseismic design), CAESAR adopted a radically different approach, -- one
where interdisciplinary communication and support are stressed. The
rehabilitation and seismic reinforcement of older bridges involve a much

New Technologies for Urban Safety of Mega Cities in Asia

more multifaceted and complicated series of issues than those encounteredduring conventional design/construction efforts. For older bridges, acomprehensive structural assessment of the entire structure is often required.
For example, when designing a seismic reinforcement of an existing steel
bridge, the structure’s overall state of deterioration and the possible negativeside effects of the planned reinforcement method on the fatigue
vulnerability must be taken into account. Therefore, in CAESAR, now
researchers are assigned on a project-by-project basis to ensureinterdisciplinary collaboration across all disciplines.
As shown in Figure 3, respective specialists of superstructure, substructure,earthquake engineering, fundamental materials, and cold region construction
technology promote research and technical development. This group also isintended to be an organization with abundant comprehensive strength fordesign and construction, disaster mitigation, inspection, diagnosis andprognosis, rehabilitation and reinforcement, and management systems.
Areas of the superstructure to substructure of the bridge are considered as a
total system.
Research coordinator for earthquake engineering is responsible fororganizing individual research projects related to earthquake engineering
including bridges and other road and river structures covered by all PWRI’s
research institutes and centers. When a large-scale earthquake occurs, thecoordinator urgently summons researchers from CAESAR, Tsukuba Central
Research Institute, and Civil Engineering Research Institute for Cold
Region to send an emergency survey team. When required by the regional
development bureau and local public authorities after the earthquake, thecoordinator also directs technical assistance activities.

4. ROLES AND ACTIVITIESCAESAR provides technical supports to highway administrators andconducts research with a much closer relationship with them, as shown in
Figure 4. CAESAR especially covers highly sophisticated issues for which
relevant diagnosis and prognosis technique, assessment method, or
corrective method has not been generally understood. While highway
administrators need information to judge how serious that damage is, howsoon it should be treated, and what remedial method should be chosen orwhat, CAESAR provides technical assistance using cutting-edge technology
even though it is in the middle of development. For example, Figure 5
shows an example of an on-site test of the on-going project of a fatigue
prevention technique for steel deck plates utilizing SFRC (steel fiber
reinforced concrete) pavement. In addition, CAESAR continues follow-up
activities after an assessment was conducted or a corrective measure wastaken. While CAESAR accumulates findings from the site, it develops andimproves cutting-edge technology to resolve such an issue. That’s what
CAESAR calls scientific trials. CAESAR pursues this kind of win-win cycle
between highway administrators and the CAESAR’s research activities.

MISSIONS AND PARTICULAR ACTIVITIES OF THE CENTER FOR ADVANCED ENGINEERINGSTRUCTURAL ASSESSMENT AND RESERACH, CAESAR

0ctoberr 2010, Kobe, JapanCAESAR also intends to be the meeting ground of highway administrators,
academic sector, and private sector to shear and exchange state-of-the-art
information and yield collaborations.
Then CAESAR’s know-how based on the findings obtained through thescientific trial and meeting ground are presented by technical guidelines andreports as well as a knowledge database for engineers that will be developed.
CAESAR also continues to contribute to developing national technicalstandards as the Tsukuba Research Institute done before. It is crucial thatexperiences and findings obtained through scientific trials be fed backsuccessively to the design and construction of new bridges and be fed backto the rehabilitation of existing bridges to make bridges easier to maintainand have a longer service life.

5. RESEARCH AND DEVELOPMENT BASED ON SCIENTIFIC
TRIALS AND AN AUTOPSY APPROACH
CAESAR keeps many basic research projects going in the laboratory tounderstand the mechanism of deterioration and repair. However, CAESAR
will keep going not only as the way we did in the laboratory but also
promote a scientific trial approach in the field much more. Structural
conditions, construction status (initial construction quality, etc.), andenvironmental and traffic conditions are different bridge by bridge.
Therefore, CAESAR assigns greater importance to a scientific trial
approach to resolve technical issues for maintaining individual bridges
rather than laboratory study with prescribed conditions.
5.1 Inspection
The development of non-destructive test (NDT) tools is highly
expected. NDT tools in the market are supposed to work based ontheoretical background and laboratory tests but they sometimes do not work
well in the field. Accordingly, we have started a project in cooperation of
highway administrators. In 2009, we applied NDT tools such asmeasurement of ultrasonic propagation velocity for a 45yrs-old bridge
damaged by ASR to evaluate the accuracy and feasibility of the tools interms of physical characteristics of damaged concrete (Figure 6). Moreover
we plan to give opportunities to industry to test many kinds ofnondestructive testing tools. The result on accuracy and feasibility will beshared with highway administrators and developers. We expect that thiseffort will show developers the clear needs of improvement and highway
administrators the potentials of newer technology.
5.2 Autopsy and scientific trials using decommissioned bridges

New Technologies for Urban Safety of Mega Cities in Asia

When any damage is noticed for a certain structural member or
portion of the bridge, the urgency, priority, and required level of corrective
action depends on how much that damage can affect the bridge system
structural performance. Because each bridge has the uncertainty ofstructural conditions, it is difficult to assess the precise degree of structuralsoundness. Now CAESAR and highway administrators cooperatively
conduct several projects in autopsy survey using bridges that will be
decommissioned. Figure 11 illustrates a concept of the autopsy research
approach for structural safety assessment.
For example, as for concrete bridges, we conduct load tests using
bridges that will be decommissioned or members that were replaced while
we also disassemble them to survey the corrosion of reinforcement,
deterioration of concrete, and so on. Using this approach, we will associate
the actual load bearing capacity of older or damaged bridges with the degreeand condition of damage and develop a methodology to identify relevant
numerical parameters for calculation, resulting in the assessment of theremaining load bearing capacity and deterioration rate of older or damaged
bridges. This research also may lead to set replacement criteria for older
bridges in the future.
The on-going project that should be highly intriguing is using a largespan steel truss and girder bridge of Choushi Oh-hashi bridge whichsuffered severe corrosion damage (Figure 7). After the decommission,
several components of the bridge were sampled to transport to the CAESAR
large-scale structural test laboratories. CAESAR researchers will scrutinize
many issues to improve the inspection technique for finding structural
deficiencies and the prediction technique for estimating the remaining
strength of deteriorated critical structural components. For example, thestrength of those members is also going to be tested and compared withnumerical predictions. As of Sept 2010, the researchers already haveconducted a visual-based bridge inspection, truck loading test on site,measurement of remaining steel thickness of corroded components, andvibration test. In addition, they also have looked over the history of earlier
rehabilitation works and started furnishing finite element models.
5.3 Follow-up investigation of repair/rehabilitation case histories
CAESAR conducts a three-year project to design the follow-up
database for the effectiveness and durability of earlier repair andrehabilitation work in actual bridges in real environments. Most corrective
measures/chemicals/materials come to the market via laboratory tests andtheoretical research. However, they often do not have sufficient data in thefield to see if those are effective and durable in any conditions. We
acknowledged that sometimes they work well and sometimes they do notwork well for bridge by bridge. Accordingly, the follow-up database will
give highway administrators the direction of relevant choice of repair andrehabilitation methods considering the surrounded environment, age, bridge
structural type, position and type of structural members, level ofdeterioration and damage, traffic volume etc.

MISSIONS AND PARTICULAR ACTIVITIES OF THE CENTER FOR ADVANCED ENGINEERINGSTRUCTURAL ASSESSMENT AND RESERACH, CAESAR

0ctoberr 2010, Kobe, Japan

So far, as stated above, seeds of industry and needs of highway
administrators are somewhat different. The follow-up database also will
give strong directions to industry what is needed, what should be improved,
and what should be tested before hitting the market.
5.4 Long-term bridge monitoring of deterioration
Long-term bridge monitoring is also a key to model the deteriorationof bridges and verify design technology for durability. However, long-termand reliable observation results in the field are rare. It is therefore necessary
to accumulate findings associating continuous monitoring data, periodical
thorough inspection results, and the change in the load-bearing
characteristic of the structure with each other. CAESAR and Okinawa
Prefecture have started a 100-year collaborative project to obtain the longterm observation data for chloride-induced deterioration of concrete bridges.
Okinawa islands are the southern part of Japan and designated in the code as
the region at which a special treatment is required for preventing chlorideinduced deterioration. Many bridges in the islands suffer from chlorideinduced deterioration and there are many long span bridges between islands.
Accordingly, the effective data acquisition is a keen strategy to conduct
preventive maintenance at the right time with the right method. Irabu Ohhashi Bridge, which is a prestressed concrete bridge, is designed under thelatest codes of practice in terms of the durability against chloride-induced
deterioration. It is now under construction and will be completed in 2012. In
some parts, the cover concrete of the piers is designed to have an additional
thickness so that samples can be obtained to monitor the time evolution in
the chloride penetration into concrete during 100 years after the completion.
When the sampling will be conducted, many NDT tools also will be tested
for comparison. In addition, many sample specimens are also going to bemade when the concrete is cast at piers and will be delivered to exposure
tests. We will see the differences in the deterioration condition of the piers
for a long time because of the deference in the fresh concrete quality,
cement quality, and environmental conditions. On top of that, other 10
bridges with longer spans also will be inspected to model the time evolutionof the on-site chloride penetration and strength of concrete. This project isvery beneficial for both parties to establish reasonable behavior curves, sothat they will be able to make the bridges’ lives longer than 100 years.
We expect that this kind of long-term observation, follow-up
investigation of earlier corrective measures, and autopsy survey of heavily
damaged bridges will strongly improve the micromanagement technology ofindividual bridges such as behavior curves, reasonable structural safety
evaluation algorithms, and the right choice and timing of method to repair.
6. EARTHQUAKE ENGINEERING
Earthquake engineering is another key technology in CAESAR, and thescientific trial approach is also adopted. For example, CAESAR supports
highway administrators when they reinforced older bridges against strong

New Technologies for Urban Safety of Mega Cities in Asia

earthquakes, and the bridges that were reinforced based on a PWRI research
result had no serious damage in recent strong earthquakes. Now CAESAR
keeps improving post-earthquake strengthening methods for RC piers,
testing very rapid repair work methods that are simple, easy, and fast, andwhich utilize materials that are easy to obtain, such as carbon-fiber sheet
and polyester bands (Figure 8).
Moreover CAESAR dedicates to international cooperation activities for theseismic damage investigation and the technical supports of the repair andretrofit after an earthquake. On February 27, 2010, an intensive earthquakeof the magnitude 8.8 occurred in Chile. With the request from Japan Societyof Civil Engineering (JSCE), CAESAR dispatched Chief Researcher toChile with the schedule from March 27 to April 7, 2010 as thereconnaissance investigation group member of JSCE. Investigation results
and unseating mechanism of the damaged bridge were immediately reported
to bridge administrators in Chile. The seismic design technique developed inJapan was also introduced to them with the traffic serviceability judgment
based on the damage in bridge and technical information for improving theseismic performance of Chilean bridges. Those activities conducted in Chile
have affected the new Chilean seismic design manual established in July
2010, in which the seismic design recommendations of the unseating
prevention system in Japan were introduced.

7. STANDARDIZATION OF VERIFICATION MEASURESCAESAR will address standardization of rehabilitation technologies. The
point is that it will also include a verification measure to confirm whether a
proposed repair or a rehabilitation/reinforcement technique meets theperformance requirements under given various conditions and to clarify thelimitation of application. For example, the PWRI's standard tests for thefatigue durability of deck plates and the seismic ductility for piers have been
gaining wide acceptance.
CAESAR takes over the mission to develop the Japanese Specifications for
Highway Bridges and other design directions and guidance that wereoriginally undertaken by the Tsukuba Central Research Institute, because itis very important that findings obtained through corrective actions anddisaster mitigations have to be fed back sequentially to the design andconstruction of new bridges. For example, problems are often related to theinitial construction and design qualities. CAESAR has been preparing forthe next revision of the Japanese Specifications for Highway Bridges, which
will be based on a performance-based specification concept, involving a
reliability design concept.

8. REMARKSCAESAR is organized especially to be able to respond precisely and timely
to needs of society and highway administrators in a flexible manner beyond

MISSIONS AND PARTICULAR ACTIVITIES OF THE CENTER FOR ADVANCED ENGINEERINGSTRUCTURAL ASSESSMENT AND RESERACH, CAESAR

0ctoberr 2010, Kobe, Japanthe framework of typical studies in the laboratory. The scientific trail
approach is considered to be crucial while basic research also runs. The
acronym CAESAR was inspired by Julius Caesar of the Roman Empire,
who established and maintained the infrastructure of long empire-wide
highway network -- parts of which are still in use more than 2000 years later.
We hope our new CAESAR research center will forge ahead with anequally strong will, and thus ensure we can complete our missions.
Collaborative work with related research organizations will be highly
appreciated.

REFERENCES
Road Bureau, MLIT, 2007–2008. Data presented to the Expert Meeting on
Preventive Maintenance of Highway Bridges, Data for press appeared on
the Road Bureau website.
MLIT Technical Investigation Team for the 2007 Minneapolis bridge
collapse, 2007. Technical investigation report on the 2007 Minneapolis
bridge collapse.

FY2006FY2026FY2016

6%

20%

47%

8,900

8,900

66,300(Total # of bridges in 2006 ~ 140,000)

Figure 1: Percentage of bridges of ages 50 and older(No shorter than 15 m)(A1)

Fatigue fracture at
welding parts of UU-rib anddeck plate(A2)

Fatigue fracture in a steel main girder,
Yamazoe Bridge, R25, constructed in
1971.

(B)

Anatomic survey for Kuretsubo
overpass, R7, constructed in 1965, that
suffered from salt attack.

(C)

ASR

New Technologies for Urban Safety of Mega Cities in Asia

Figure 2: Three major types of distress that severely impact bridge strength
capacity: A = fatigue fracture in steel members, B = chlorideinduced deterioration of concrete structures, and C = alkali silica
reaction of concrete structures.

CAESARPWRI

Concrete construction

Earthquake Engineering

Substructure

Superstructure

Cold region construction

Superstructure

Substructure

Inspection technology

Earthquake
Engineering

Structural Assessment

Concreteconstruction

Rehabilitation
Managementtmaterials

Cold region
Construction* Group as a whole studies inspection technology, prediction
assessment technology, repair and reinforcement technology,

Figure 3: Difference between conventional organization and CAESAR
related to bridges in the Public Works Research Institute

MISSIONS AND PARTICULAR ACTIVITIES OF THE CENTER FOR ADVANCED ENGINEERINGSTRUCTURAL ASSESSMENT AND RESERACH, CAESAR

0ctoberr 2010, Kobe, Japan

Highway

CAESAR

Detection of dangerous
damage(s)Findings from on-site

Critical damage

scientific trials

Recovery after disaster
Presentation of investigation(Diagnosis and corrective action of individual

What measures should betaken for particular bridges,
and whenPresentation of findings(Systematization to be useful for otherbridges)through manuals

Data accumulation for

Judgment of causes forprediction and assessment

damageAssessment of load-bearing(Acquisition of data from
(Prediction and assessment method)characteristics
Prediction of deterioration

Measures for longer
operating life of new
bridges

Conditions forlonger service life ofbridges

Receiving of site engineers
Know-how that can be
expressed only slightly through

Maintenance and(Training etc.)

improvement of site

Figure 4: Scientific trials: a cycle of a technical assistance for highway
administrators and the corresponding research activities of
CAESAR

SFRC 舗pavement
CFRP材
Deck
material デッキプレ
plate
U-rib

Ｕリ

Asphalt pavement
Local deformation
and

Stud

スタ
SFRC pavement
Local deformationand stress are small

Figure 5: Fatigue durability improvement technology of existing steel floorslab using steel fiber reinforcement concrete (SFRC)

New Technologies for Urban Safety of Mega Cities in Asia

Crack at a pier by ASR

Measuring ultrasonic propagation velocity

Figure 6: Measuring ultrasonic propagation velocity for a ASR-damaged
bridgeLoss of section due tocorrosion

Re-deterioration of repaired part

Figure 7: Choshi Oh-hashi Bridge and deterioration of the members

Damage identified

Filled with quick
setting mortar

Braced with CFS or polyester bands

Figure 8: Easy-to-apply emergency recovery technology for RC bridge
columns after an earthquake

MISSIONS AND PARTICULAR ACTIVITIES OF THE CENTER FOR ADVANCED ENGINEERINGSTRUCTURAL ASSESSMENT AND RESERACH, CAESAR

Introduction to possible natural disaster andproblems of urban development in Mongolia
B. Ganzorig1, S. Jargalan2, D. Erdenebileg3, Yasuyoshi Ichihashi
1Cabinet Office of Mongolian Government, Mongolia
2
Mongolian University of Science and Technology, Mongolia
3
Police Academy of Mongolia, Mongolia
４
ICUS, IIS, The University of Tokyo, Japan

ABSTRACT
Mongolia is a country where various natural disasters occur frequently: blizzard;
heavy snow “ZUD”; dust storm; rain water flood; dibaish flow; snow melt flow;earthquake; and others such as wildfire; drought; and desertification. Blizzards
occur generally between September and May. Duration may be short, just a few
hours, or up to 10 days, but it can be extremely dangerous with heavy snow and
up to 35 m/s wind. Heavy snow fall disasters differ from blizzards in that persons
are not so much at risk. Damage is primarily caused by livestock being
immobilized on the range or in shelters and unable to reach grazing. Extreme
snow falls are up to 1.5 m in mountain areas. Transport becomes difficult withsnow falls greater than 40 cm. Earthquakes are quite frequent in some parts ofMongolia. The consequences in villages are generally destruction of housing,roads and bridges. The traditional “GER” houses are very resistant toearthquake damage. According to the statistical report, biggest earthquake wasoccurred in the Gobi Altai mountain on 1957 and killed 1200 person; wind storm
on 2001, killed 16 person and flood occurred on 2003, killed 15 person. The
Government of Mongolia is responsible for all activities related to prevention andmitigation of all types of natural disaster. In 1990, the Government of Mongolia
established the State Permanent Emergency Commission (SPEC) in order tocoordinate activities among the government agencies against any type of natural
disaster. Mongolia still does not have reliable earthquake-resistant construction
technology. In Mongolia, there are very few buildings equipped with earthquakeresistant facilities and means. However, “GER” houses are more resistant toearthquake they can be damaged, but to a lesser extent than conventionalbuildings. Since 1990, a decentralization policy for people and industry has beeneffected in urban development planning and regional development. Due toaccelerated urbanization in the last three decades, the demand for house building
has increased greatly. In this connection, a large number of 5-12 storey
apartments have been built in the cities. The government is taking measures toimprove the system for natural disaster preventing and reduce losses anddamages that may affect social, economic, and ecological values, and reduce thevulnerability situations, protecting human life and national riches. Here, wewould like to introduce natural disasters occurring in Mongolia, and government
preventing policies and as well as problems related to urban development.
Keywords: disasters, earthquake resistance, urban development, loss reduction

0ctober 2010, Kobe, Japan

1. INTRODUCTION
Mongolia is situated in Central Asia with continental climate, hot summers andcold winters. About 40 % of the country is mountainous, 40 % hills (1000-1500m)
and the remainder denotation plain. The main agricultural production is animalhusbandry, with herds of cattle, sheep, horses, camels, and goats. The populationof Mongolia was estimated to be 2.6 million in 2009, with almost 40% of the
population in the capital. The most densely populated rural areas are the rivervalleys in the forest steppe zone. The least populated are the semi desert, desert
and mountain taiga zones.
Mongolia has an extreme continental climate. The winter continues long with cold
temperature but summer is hot and short. The average summer temperature is+20°C, ranging from +20°С to +36°C. The average winter temperature is 20°C, ranging from -18°C to -40°C. The wind is 1.5-4.5m/s and the average
rainfall 200-220 mm in a year.
However, agriculture is a dominant part of the economy, recently mining sector
develops rapidly and it makes almost 30% of GDP, 65% of Industrial product and
80% of export product.

2. NATURAL DISASTER IN MONGOLIA
There are several natural disasters in Mongolia as following: meteorological suchas blizzard; heavy snow; dust storm “zud”; rain water flood; dibaish flow;snow
melt flow; and others such as earthquake; wildfire; drought; and desertification.
Top ten Natural disasters which occurred in Mongolia are presented in Table 1.
Table 1 Top ten disaster occurred in Mongolia
Disaster

Date

KilledDisaster

Date

Affected

Earthquake

2.Dec.1957

1 200

Wind storm

Dec.2000

571 000

Flood

11.Jul.1966

57

Wind storm

Jan.2000

500 000

Wind storm

21.Apr.1990

36

Famine1990

500 000

Wild fireApr.1996

25

Drought

Sep.2000

450 000

Flood

8.Aug.1996

24

Flood

11.Jul.1966

270 000

Wind storm

Dec.2000

19Wind storm

7.Apr.2001

175 000

Wind storm

7.Apr.2001

16

Wind storm

14.Mar.1993

100 000

Epidemic

Aug.1996

8

Wild fireApr.1996

5 061

Wind storm

17.Mar.1993

7

Flood

Dec.2001

4 000

Wind storm

21.Apr.1991

6

Epidemic

Aug.1996

108

New Technologies for Urban Safety of Mega Cities in Asia

Table 2 Natural Disasters from 1982-2008 (UN Report)
Overview
No of events:
No of people killed:
Average killed per year:
No of people affected:
Average affected per year:
Economic Damage (US$ X 1,000):
Economic Damage per year (US$ X 1,000):

21
237
9
2,474,446
91,646
1,913,070
70,8542.1Blizzards
Blizzards occur in Mongolia generally between September and May. Duration
may be short, just a few hours, or up to 10 days. Number of blizzard days varies
between less than two days in the west of the country to between 2 and 8 days in
the eastern part of the country and 8-10 days in some mountainous areas.
Blizzards can be extremely dangerous with heavy snow and up to 35 m/s wind.
Table 3 Recent blizzard disaster in Mongolia
Year

Place

Fatalities

Livestock lost

Other

Sept.1995
May1993
Sept.1993
Oct.1992
1988

Eastern Mongolia
Central Mongolia
Central and East
Central and West
Dornod, Hentii,
Sukhbaatar,Dornogobi

8
17
11
4
8

48,000100,000
5,000
500,000
10,00020% potato crop lost
Property damage

The sequence of events in a blizzard disaster begins with the weather turning badand terminates with harmful events to persons, livestock and crops.
2.2 Heavy snow fall
Heavy snow fall disasters differ from blizzards in that persons are not so much atrisk. Damage is primarily caused by livestock being immobilized on the range orin shelters and unable to reach grazing. There are two major aspects of the
problem, that of people obtaining supplies if snow lasts a long time, and that ofproviding fodder for animals which cannot reach pasture due to snow.
On farms there is unlikely to be a large shortage of food. The primary problem isin villages, where direct access to food may not be available if transport is halted
for a long time. This is a question of the amount of snow falling, and the length oftime it remains. The mean depth for heavy snow falls is typically 10-15 cm, in
mountain areas 20-25 cm. Extreme snow falls are up to 1.5 m in mountain areas.
Transport becomes difficult with snow falls greater than 40 cm.
When snow is heavy and the snow remains for longer periods, animals begin to
weaken and die. Delays in feeding of one day are unlikely to cause significant
Introduction to possible natural disasters and problems of urban development in
Mongolia

0ctober 2010, Kobe, Japan

damage. But following two days without fodder, mortality begins to increase. In
winter of 2010, there was heavy snow in whole country and 8 million live stocks
could not survive and died
2.3 Earthquake
Earthquakes are quite frequent in some parts of Mongolia. The consequences invillages are generally destruction of housing, roads and bridges. On farms the
traditional “GER” houses are very resistant to earthquake damage. During the20th century, western Mongolia experienced three earthquakes of approximately
magnitude 8, and another six events of about magnitude 7. Figure 1 shows
locations of these events.

Figure 1 Earthquake locations occurred during the 20th century

3. NATURAL DISASTER REDUCTION
The Government of Mongolia is responsible for all activities related to prevention
and mitigation of all types of natural disaster. In 1990, the Government ofMongolia established the State Permanent Emergency Commission (SPEC) inorder to coordinate activities among the government agencies against any type ofnatural disaster.
SPEC has the following functions: Preparation of a National Disaster and Calamities Preparedness Plan Organization of disaster coordinating down to the ministerial and local
government level Coordination of relief activities and measures to reduce consequences

New Technologies for Urban Safety of Mega Cities in Asia



Organization of reconstruction or rehabilitation measures (SPEC has abranch in each aimag and in the large cities).

3.1 State Civil Defence Board
The State Civil Defence Board operates under SPEC in emergency and has thefollowing flmctions:
 duties of civil defence in peace-time
 quick dissemination of information on natural disaster warning and alarm
operations
 civil defence education and Training: The Civil Defence Board has a central organization u~ Ulaanbaatar, withunits at the aimag (province) and sum (district) levels.
3.2 Ministries
Ministries have duties and responsibilities in accordance with their functions toprevent, mitigate and relieve natural hazards, and to educate and build national
capacity to combat them. Ministry of Nature and Environment: natural disasterrelated data collection and processing, forecasting and warning; dissemination ofother operational information to public community, investigation of pollution
levels after nuclear and chemical accident.
Ministry of Development disaster-resistance measures: reconstruction or
rehabilitation of transport supply.
Ministry of Finance: financing reconstruction and relief measures.
Ministry of Fuel and Energy: fuel and energy supply in emergency.
Ministry of Food and Agriculture: food reserve to meet natural hazards.
Ministry of Health: medical equipment supply; organization of medical service
and aid.
3.3 Legislation and natural disasterIn 1990 the Government established the State Permanent Emergency Commission
and approved its regulations. In 1993 the Government adopted a resolution on
natural disaster prevention measures, coordinating the duties and activities ofCentral and a local government agencies, and approving the system oftransmission for meteorological warnings.
The legislative basis for environmental protection in Mongolia including,emergency and disaster actions, is the MONGOLIAN LAW ONENVIRONMENTAL PROTECTION, approved on March 30 1995. The
following paragraphs are most directly related to emergencies and disasters:
Article 22 Areas of Natural Disasters and Emergencies.
1. The term “areas of natural disasters and emergencies” means an area which isaffected by adverse impacts or hazardous changes of the environment resulting
from human activities or natural evolution, which may have detrimental impacts
on the environment, human, animals, wildlife, plants, and their genefunds.
Introduction to possible natural disasters and problems of urban development in
Mongolia

0ctober 2010, Kobe, Japan

2. The Government shall establish boundaries for areas of natural disaster andemergencies upon consultation with the Central State Administrative Organizationin charge of nature and environment.
3. The Central State Administrative Organization in charge of nature andenvironment, Civil Defence Board, Governors of all levels and other concernedorganizations shall jointly take measures on prevention and mitigation of natural
disasters and emergency, elimination of adverse impacts, rehabilitation of natureand environment, and restoration of natural resources.
4. All costs for mitigating natural disasters and emergencies shall be allocatedfrom the State budget. After the investigation of real cause the guilty party or
citizens shall be assessed for the full compensation of any damages and losses.
Article 23. Environmental Protection in State of Emergency
Any measures with respect to mitigation of natural disaster, elimination of adverse
impacts, and preservation of the environment and its natural resources undertaken
within an area affected by State emergency shall be carried out pursuant to therationale for, and procedures stipulated by the State Emergency Laws as provided
by the Constitution of Mongolia.
The Civil Defence Law, approved in May 1995, officially included set ofmeasures aimed at preventing, and safeguarding the people from natural disaster,
eradicating the damage hitherto incurred by the population, and training in these
aspects.

4. CONCLUSIONS
1. Natural disasters are very sensitive issues for Mongolia, especially from theeconomic point of view. Losses to herds, flocks and crops annually affect avery significant part of the country.
2. The high frequency of natural disasters and their extent presents a serious
constraint which delays development of the country.
3. Natural disasters cause significant loss of life, and of property.
4. The sheep flocks, cattle and horse herds of Mongolia represent a large portionof the wealth of the nation, and are an essential part of the livelihood of mostmongolians.
5. The disasters contributing to losses of herds and flocks are heavy snow,
blizzards, dust storms, drought, and floods.

New Technologies for Urban Safety of Mega Cities in Asia

EVALUATION OF FIRE FIGHTING SYSTEM AT
HIGH-RISE BUILDINGS IN DHAKA CITY
Mehedi Ahmed ANSARY
Professor, Department of Civil Engineering &Director, BUET-JIDPUS, BUET, Dhaka, Bangladesh
ansary@ce.buet.ac.bd
Sharmin ARA
Research Planner, BNUS, Dhaka, Bangladesh
Tanjina AFRIN
Research Engineer, BNUS, Dhaka, Bangladesh

ABSTRACT
Incident associated with fire is a common phenomenon in Bangladesh especiallyat densely populated Dhaka city. Being the hub of all economic activities this city
provokes people to live here and compels to construct high rise building. Fire isbecoming an unmanageable threat particularly in high rise buildings mostly
constructed violating the national building code of Bangladesh. In Dhaka,buildings are closely spaced such that if one building accidentally catches fire, it
is obvious that building beside the affected one may also catch fire. Recently somegrievous fire incidence has been experienced and fire engulfed lot of lives andproperties. The main causes behind the colossal losses were inadequate firefighting equipments in buildings and lack of awareness about fire safety. These
stimulate to conduct a detailed study on fire fighting system in high rise buildingsof Dhaka city. For this study a questionnaire survey has been conducted to checkthe existing condition of fire fighting system, awareness level and residents’evacuation plan. To have overall scenario regarding fire safety, 2.5% buildingsout of 2150 high rise buildings in Dhaka city have been surveyed from 9 zones(Department of Fire Service and Civil Defense divided Dhaka City into 12 zones)
and most of them are above 8 storied. This paper have examined the existing
condition of fire fighting system including protection and detection system,
precautionary arrangement in and around high rise buildings, occupants’awareness level and evacuation plan during fire break out and assessment ofthese systems with Bangladesh National Building Code (BNBC) rules in terms of
Total Score (TS). This paper also has studied how far high-rise buildings arepracticing these systems, main causes of fire hazard, obstacles to evacuation,
rescue operation and fire control.
Keywords: fire, high-rise buildings, fire fighting system, awareness level,
evacuation plan0ctober 2010, Kobe, Japan

1. BACKGROUND
A fire hazard is any situation in which there is a greater than normal risk of harmto people or property due to fire. Urban fires have devastating impact oncommunities. Unplanned urbanization and rapid industrialization are the major
causes of huge number of fire related accidents in Dhaka city and increase thevulnerability of the country’s major population and economic centers. Densebuilding concentrations, narrow roads, flammable building materials and electricalsystem as well as the lack of resources to raise awareness and response skills haveresulted in a growing risk of large scale, multiple structure fires.
Fire incidents are very common in Dhaka city, especially in relatively densely
populated areas. The damage of property and loss of human life are intensified bydifferent factors. The extent of loss due to fire incidents has an increasing trend and
it is shown in Figure 1.

Figure 1: Extent of losses due to fire hazards in different years
A developing country like Bangladesh cannot afford the huge amount of loss
caused by fire accidents every year. Moreover, fire incidents in shops, industrial
and commercial buildings cause heavy toll of life and property. The fire incidents
are on an increase due to lack of awareness, almost no feeling for following safetymeasures and practicing fire fighting drills, violation of building codes and noncompliance with the Fire fighting and Extinguishing Law (BFSCD, 2003).
Some recent flagitious fire incidents in Dhaka city have stimulated a detailed
study on high rise buildings about fire safety and awareness. This study depicts an
overview on overall condition of existing fire fighting system and on awarenesslevel among the occupants of high rise buildings in Dhaka city.

2. MAJOR CAUSES OF FIRE INCIDENT IN BANGLADESH
Common Causes of fire are smoking, welding or cutting operation and use ofblow lamps, sparks from power unit, short circuit and over loading of electrical
New Technologies for Urban Safety of Mega Cities in Asia

current, children playing with crackers, ignition by chemical action/spontaneous
combustion, gross carelessness, malicious, deliberate during riot or strike,lightening, earthquake etc (see Figure 2). Fire at garments is very common in
Bangladesh, major fire incidents take place due to unplanned construction ofbuildings being used by garment factory owners. Most of the buildings did not
follow the building code and lacked arrangements for alternative staircases andemergency exits and firefighting equipment. Keeping collapsible gates under lockand key in the name of security is the main cause of increases casualties in theincidents. According to the statistics, the major accidents occurred due to electric
shot circuits. The highest 3334 accidents took place in 2006, 2787 in 2005 and2522 in 2004 ( The New Age, February 10, 2009) (see Figure 3).
High-rise buildings now being constructed in different parts of the city is in lackof the minimum safety features and endangers both adjoining structures andpublic thoroughfares. Many of the high-rises have been constructed without
proper planning, ensuring adequate structural strength, without taking the proper
safety measures and considering environmental factors.

Figure 2: Causes of fire incident in Bangladesh

Figure 3: Trends of fire incident in Bangladesh (The New Age, 2009)

Evaluation of fire fighting system at high-rise buildings in Dhaka city

0ctober 2010, Kobe, Japan

3. RECENT SEVERE FIRE INCIDENTS IN BANGLADESH
In Bangladesh, especially in Dhaka and Chittagong city, fire is becoming an
unmanageable threat particularly in high rise buildings mostly constructedviolating the national building code. Various incidences of major occurrence offires in different type buildings are given below.
Fire in BSEC Bhaban
A devastating fire broke out at the Bangladesh Steel and Engineering Corporation(BSEC) Bhaban in the capital on 26 February 2007. Several witnesses said the fire
originated from electric oven; while some others said it was sourced from electric
short-circuit. There were fire extinguishers on almost all the floors but none daredto use them. This building’s neither has any emergency exits nor a sufficientnumber of fire-fighting equipment and operators to use them during fire. There
was also no fire lift but a switched off lift. Acute shortage of water and inadequate
equipment hampered the rescue operation. Three persons were killed and morethan 100 injured in this incidence. NTV, RTV offices totally burnt and went off
air. (www.thedaily star.net)

Photograph 1: Smoke billows out of the BSEC building and victims trapped in thefire that caught the building come down a ladder
Bashundhara FireOn 13 March 2009, Friday at about 1:45pm, a hell fire engulfed the upper levelsof 20 storey office cum shopping centre known as Bashundhara City Complex at
Panthopath, Dhaka killing 7 and injured 20 people. Though the building was
equipped with sufficient fire detecting, suppressing, and evacuating systems but
they were useless during the fire. From the fire Brigade sources it was known thatcomplex's water reservoir remained empty, the hydrants were useless as there was
no water in the tank. Due to faulty fire fighting system, the fighters of the building
didn't care about those warnings though the fire alarm on the 18th floor, where thefire broke out first, gave false alarm 18 times during the same period.
Terrible fire incident in Nimtoli at Old Dhaka
An overwhelming fire broke out in the densely-populated part of Old Dhaka city
at Nimtoli. Fire devoured at least 117 people and causing injury about hundreds ofpeople at 3rd June, 2010. Most of the affected peoples were women and children.
Initially it was thought that explosion of two transformers at Nimtoli started the

New Technologies for Urban Safety of Mega Cities in Asia

fire but later it has been known the fire originated from an oil stove and spread tothe chemical warehouses nearby and resulted high casualty figures and damages.
It is common scenario in Old Dhaka that most of the buildings have small
factories i.e. chemical, plastic, rubber etc., and ware house and food shops up tosecond floor of the residential building. In Old Dhaka no house is equipped withfire fighting equipments like extinguisher, hose pipe etc. They don’t havesufficient width of staircase let alone the emergency exit (www.thedaily star.net).

Photograph 2: Fire engulfing the Bashundhara City market

Photograph 3: Fire engulfing the Nimtoli area
Fire in KTS textile mills
Ninety one people were killed in a fire in KTS textile mill, Chittagong, February
23, 2006. At least 500 workers were inside the mill when the fire broke out. Mostof the survivors had to jump from windows as the only exit from the factory wasreportedly locked when the fire broke out late on a Thursday night. Most of thevictims were women, trapped by the flames or suffocated from smoke inhalation.
The fire might have been caused by an electrical short circuit. The explosion of aboiler escalated the blaze (www.thedaily star.net).
After analyzing the past incidents and accidents, some terrible facts are revealed.
In most cases imperfect arrangements and training of the safety equipments suchas fire alarm, smoke alarm, fire extinguishers, water supply system etc., lack ofproper exit route to reach the place of safety ,routes are blocked by different
materials ,lack of signage for escape route and emergency lighting, adequate doors
as well as adequate staircases are not provided to aid quick exit , fire exit or
emergency staircase lacks proper maintenance , lack of proper exit route to reachthe place of safety and most importantly lack of awareness among the residents,
workers and the owners are the main causes of heavy toll of life and property.

Evaluation of fire fighting system at high-rise buildings in Dhaka city

0ctober 2010, Kobe, Japan

4. EXISTING CONDITION OF FIRE FIGHTING SYSTEM IN DHAKA
CITY
For the evaluation of fire fighting system in Dhaka city a questionnaire survey
was conducted to assess the existing condition of total fire fighting system,
awareness level of the respondent and their evacuation plan during fire catch up.
To have overall scenario regarding fire safety, 2.5% buildings (includes residential,commercial, garments and institutional etc.) of 2150 (according to Dhaka City
Corporation, total no. of high rise building) has been surveyed from 9 zones(Department of Fire Service and Civil Defense divided Dhaka City into 12 zones)
and most of them are above 8 storied (see Map1). Figure 4 and Figure 5 show
number of study buildings and existing use of the buildings in percentage
respectively. Another objective of this study was to determine the awareness levelof occupants of the surveyed buildings. 64% and 80% of total respondents know
about earthquake and fire respectively but only a little number of respondents has
any evacuation plan about fire incidents.

Figure 4: Number of study buildings by storey (in %)Figure 5: Use type of high rise building
For covering the all details, fire fighting equipments are divided into four parts i.e.
fire fighting and fire protection system which includes water-based system anddry system, precautionary arrangement, detection and alarm system, and

New Technologies for Urban Safety of Mega Cities in Asiaevacuation, rescue and salvation system. All of these four parts comprise of
several components.
4.1 Evaluation of fire fighting and protection system
Fire fighting and fire protection system consists two sub-system i.e. water –based
system and dry system. Water-based system of fire fighting and fire protection
include availability of standpipe and hose system, sprinkler system, water supply
sources to standpipe, capacity of underground and roof gravity tank, details of firepump and jockey pump, and availability of Siamese connection. Buildings shouldhave underground reservoir of 50000 gallons and overhead reservoir of 25000
gallons (BNBC, 1993).

1

2
6

17

15
5
8

3
7
4
18

14
12

13
16

9

10

19

11
20

41
43

21

38
42
40

45

22

37

44
39

46

26

55
23

54
47
48

49

51
50

35
53
57

48

28
33

56
36
59

63
64
65

N

67
66

68 72

29
30

69 70
71

31

32

62
61
60

25
27

36

52

58

24
34

74

75
76

84

78

73
79

80 81

86
87

82

88

83
90

2000

0

2000

Legend85

774000 Feet

89

Surveyed Zones
Polashi Zone
Tejgaon Zone
Baridhara Zone
Mohammadpur Zone
Siddique Bazar Zone
Mirpur Zone
Postagola Zone
Khilgaon Zone
Rail line
Water body
Ward Boundary

Map 1: Study Area within Dhaka City

Evaluation of fire fighting system at high-rise buildings in Dhaka city

0ctober 2010, Kobe, JapanThe survey has shown that 74% and 96 % of total buildings are undersized forunderground and overhead reservoir respectively. From questionnaire survey it
has been found that out of 53 buildings, 24 have standpipe connection but not allof them were in work. After a detail investigation about standpipe which includes
number, diameters of standpipe, class of standpipe (class I, class II, class III), only
7 buildings reflected a good condition whereas 15 buildings showed very bad
condition. Among 24 buildings having standpipe, only 10 buildings have firepumps and only 5 of these are in good condition i.e. number and pressure of pump
are adequate. Only 2 commercial buildings have water sprinkler system. In BNBC
(1993), sprinklers, hose reel and hose pipe are strongly recommended to install inhigh-rise buildings as safety measure. Photograph 4, 5 and 6 show fire pump,jockey pump and hose reel with standpipe in a commercial building respectively.

Photograph 4: Fire pump Photograph 5: Jockey
in commercial
pump in commercial
buildingbuilding

Photograph 6: Hose reel withstand pipe in commercial
building

Dry system includes fire lift and portable fire extinguisher in floor and basement.
Fire extinguisher system with combination of carbon-dioxide extinguisher, dry
chemical extinguisher is available in 53% buildings. However, it has been
observed that most of the buildings’ fire extinguishers are not in required quantity
and they are out of date. As the surveyed buildings are high rise structures, it ismandatory to set up fire extinguisher system to control the fire incidents initially.
Most of the buildings have no hose pipe or hose reel system.
Hose reel

Extinguisher

Photograph 7: Blocked hose pipe

Photograph 8: Perfect position ofhose reel with fire extinguisher

New Technologies for Urban Safety of Mega Cities in Asia

4.2 Evaluation of precautionary arrangements
Precautionary arrangement is very important for minimizing the loss of lives andproperties. It comprises heat and smoke vent, four hours rated door of substationand 2 hours rated wall of substation. From the questionnaire survey it has foundthat only 10 buildings have 4 hours rated door and 2 hours rated wall of substation.
Number of building having smoke and heat vent is only one.
4.3 Evaluation of fire detection and alarm system
Detection and alarm system includes availability of fire alarm (automatic or
manual), smoke and heat detector, Public Address (PA) system and existence of
emergency light in stair case and corridor. Among the studied buildings none ofthem have flame detector. On the other hand, it has been observed that 25%
buildings and only 4% buildings have smoke detector and heat detector
respectively. In addition, 36% buildings have alarm system and among them 30%
have public address (PA) system (see Figure 6).
From observation, it is evident that fire fighting detectors and equipments are
seldom tested and checked as routine work.

Figure 6: Overall scenario of fire fighting system in Dhaka City

Photograph 9: Fire alarm and firebell

Photograph 10: Smoke detector

Evaluation of fire fighting system at high-rise buildings in Dhaka city

0ctober 2010, Kobe, Japan

4.4 Evaluation of evacuation, rescue and salvation system
Evacuation, rescue and salvation system consists of total number of stair andemergency staircase, width of normal and emergency stair, availability of fire
refuge area, trained personnel, width of front road, evacuation plan of the inmatesof the buildings and practice of fire drill. According to Bangladesh Fire Service
and Civil Defense (BFSCD, 2003), Minimum width of frontal road should be 30 ft
for free moving of fire vehicle. Survey shows that a considerably large number ofbuildings i.e. 27.5% of surveyed building have inadequate width of approach road(less than 30ft) for fire engines to reach the building (see Figure 7).

Figure 7: Width of approach road

New Technologies for Urban Safety of Mega Cities in Asia

Photograph 11: Narrow

Photograph 12: Blocked emergency stair case in aMorethanstair
49%casebuildings
don’tcommercial
have any building
emergency exit stair. In addition, exit
emergency
in asignals
forbuilding
escape route are provided improperly and inadequately which poses a
residential
threat to the evacuation. In most of the cases escape routes remain blocked (seePhotographs 11 and 12).
Among all the surveyed buildings, only 11 buildings have trained personnel andonly 16 buildings which include garments and commercial building perform fire
drill regularly. Most surveyed garments workers were trained by Bangladesh
Garment Manufacturers and Exporters Association (BGMEA). Usually they
provide lectures, taken exam and lastly done evacuation drill in the premises ofgarments. In the surveyed commercial buildings which have trained personnel got
training related to operation of hose reel and fire extinguisher and evacuation drill
from Bangladesh Fire Service and Civil Defense (BFSCD, 2003). Mainly security
guard and few care takers of the building have this training. The respondents wereasked about their evacuation plan during the fire incidence but only few people
have their evacuation plan. Evacuation plan consists use of firefighting equipment
what they have, escape from the building through emergency exit and taking
shelter in ground floor or any available open space adjacent to the building.
5. SCORING OF THE SURVEYED BUILDINGSOne of the main purposes of this study was to provide score to the surveyedbuilding based on their existing fire fighting equipments. For providing score, datacollected from field survey were compared to the provision of Bangladesh
National Building Code (BNBC, 1993) and that of Bangladesh Fire Service andCivil Defense (BFSCD, 2003). 0-10 scale was selected to provide an initial rank
to the different components of fire fighting equipments. Then from case studies
and experts opinion, weights were assigned to each of the four parts of firefighting
equipment. The process of obtaining the score is given below:
Total Score (TS) = weight for water-based system *(acquired number in scale of0-10) + weight for dry system *(acquired number in scale of 0-10) + weight forprecautionary arrangement *(acquired number in scale of 0-10) + weight for
detection and alarm system *(acquired number in scale of 0-10) + weight forevacuation, rescue and salvation system *(acquired number in scale of 0-10).
According to the experts, the weight assigned for water-based system is 12, fordry system is 8, for precautionary arrangement is 25, for detection and alarmsystem is 30 and for evacuation, rescue and alarm system is 25. For evaluating thecondition of Buildings, all buildings are divided into 5 category based on their inbuilt fire fighting system. These categories are given below,
Table1: Building Condition Based on Total Score
Building Condition
Low
Moderately Low
Moderate
Moderately HighHigh

Total Score(TS)Below 20
21-40
41-60
61-75
75-100Evaluation of fire fighting system at high-rise buildings in Dhaka city

0ctober 2010, Kobe, Japan

Figure 8: Quantitative diagram of present condition of building at Dhaka city
The pie chart portrays that most of the buildings (62%) lacks in-built fire fighting
equipments whereas the number of buildings which are highly equipped with inbuilt fire fighting system are significantly low.
6. CONCLUSIONS
After analyzing a considerable amount of highrise building information in Dhaka
city, it can be said that the overall condition of buildings are not suitable for firefighting. Only a small number of buildings have moderate to good status for firefighting. This study was not conducted on a large number of building samples.
Although the sample size was small, it represents the miserable condition of
Dhaka city buildings to fire hazards. For improving the condition, all buildings
should follow the provision provided by Bangladesh National Building Code andBangladesh Fire Service and Civil Defense during construction of building. To
ensure that, authority should be strict and need to take action against thoseviolating the concerned laws. The good practices of fire hazard prevention in thebuilding codes of other countries need to be studied and adopted according to
Bangladesh’s context. In addition to law enforcement, to create public awareness,workshops and seminars may be arranged. Electronic and printing media can play
an important role for increasing awareness. A pragmatic fire safety plan may be
developed for all the buildings with the help of Bangladesh Fire Service
department.
REFERENCES
Bangladesh National Building Code (BNBC), 1993, published by HBRI-BIDS.
Bangladesh Fire Service and Civil Defense (BFSCD), 2003, Fire Fighting &Extinguishing Law.
www.thedaily star.net accessed on June 2, 2010.
New Technologies for Urban Safety of Mega Cities in Asia

The New Age (2009) accessed on June 2, 2010.

Evaluation of fire fighting system at high-rise buildings in Dhaka cityExperimental study on the turbulent
characteristics in thermal buoyant plume ofurban fireHong HUANG1,2
1
Professor, Center for Public Safety Research,
Tsinghua University, Beijing, China
2
Professor, Department of Engineering Physics,
Tsinghua University, Beijing, China
hhong@tsinghua.edu.cn

ABSTRACT
It is very important to investigate the turbulent characteristics in the thermal
buoyant plume of urban fire in the present of wind to understand the urban fire
spread risk. In this study, the thermal buoyant plume of urban fire is presented byhelium, and turbulent physical statistics parameters have been measured in awind tunnel in windy conditions. Hazard gas is presented by ethylene which ismixed in the helium. The turbulent physical statistics parameters including
average velocity, turbulent fluctuation of velocity, Reynolds stress, turbulent
kinetic energy, average pollutant concentration and turbulent fluctuation ofpollutant concentration are measured. The characteristics of these turbulent
physical statistics parameters are investigated and the effects of buoyancy onthese parameters are analyzed.
Keywords: thermal buoyant plume, urban fire, turbulent characteristics, helium

1. INTRODUCTION
In the present of wind, the thermal buoyant plume induced by urban fire will givelarge heat flux to the neighboring buildings and increase the risk of fire spread.
Furthermore, firebrands and hazard gases generated from the fire will be spreadby the thermal buoyant plume and enlarge the fire spread and pollutant areas.
Therefore, it is very important to investigate the turbulent characteristics in thethermal buoyant plume of urban fire in the present of wind.
There are many studies on the measurement of temperature of thermal flow
(Hayashi et al, 2002; Imamura et al, 2003), however, few study has been done on
the measurement of the turbulent characteristics in the present of wind. In thisstudy, the thermal buoyant plume of urban fire is presented by helium, andturbulent physical statistics parameters have been measured in a wind tunnel inwindy conditions. Hazard gas is presented by ethylene which is mixed in thehelium. The Froude number is adjusted by the inflow wind speed, and two Froudenumber cases have been conducted. The turbulent physical statistics parameters
include average velocity, turbulent fluctuation of velocity, Reynolds stress,

0ctober 2010, Kobe, Japanturbulent kinetic energy, average pollutant concentration and turbulent fluctuationof pollutant concentration. The characteristics of these turbulent physical statistics
parameters are investigated and the effects of buoyancy on these parameters areanalyzed.
2. EXPERIMENT OVERVIEW(1) Wind Tunnel
The used wind tunnel is a boundary layer wind tunnel. The wind tunnel has 13- m
long, 2.2- m wide, and 1.8- m high test section. A schematic diagram illustrationof the wind tunnel is illustrated in Figure 1. The simulated boundary layer was
generated with the aid of homogeneously distributed roughness elements mounted
on the tunnel floor and by vortex generators installed at the test section inlet (ACE,1999). The spires as well as the size and arrangement of the roughness elements
controlled the properties of the induced boundary layer.

Windroughness(909090) mm

1.8 m

3‐D auto‐traverse systemvortexgenerator

concentration sampling probe or LDV
roughness(606060) mm

roughness(303030) mm
the model

0.3 m

2.8 m

6.0 m

1.6 m

2.0 m

12.7 mFigure 1 Schematic diagram illustration of the wind tunnel(2) Urban model
Figure 2 shows the urban model. And the scale is 1:200. A modeled urban area is
set here. A building is assumed to be on fire. The thermal plume is presented byhelium which is emitted from the roof of the building. Ethylene is mixed inhelium to present hazard gases in the fire.
(3) Experimental cases
Table 1 shows the test case. Two actual situations, that the average wind speed at
the height of 10m (building height) from the ground are 4m / s and 8m / s, areassumed. The fire plume temperature is 800℃, and the outdoor temperature is
20℃. Froude number ( Fr  ( /  ) Dg / U 2 ) of the wind tunnel test is arranged tomatch the actual Froude number. In order to simulate the buoyant plume,
according to the reference (Mell et al, 1996), the emission rate of the gas mixtureof helium and ethylene is set to be W = 0.15m / s and the gas mixture iscompletely exhausted from the building roof. Then, considering that the explosion
limit of ethylene, the ratio is set to be 0.34%.

New Technologies for Urban Safety of Mega Cities in Asia

50 50
50

50

100

50
100

1 2
Wind
The gas is emitted fromthe building roof

4

5

・8
・
・・
・・7 ・9 ・10
・ ・6
3
・11

・12

30
45

Centerline

75
Flow development section

Y

X

20
25
30

25

50

50

Figure 2: The city model and measurement points
Table 1: Experimental cases
Experimental
cases
Case 1Case 2Wind speed at 10m
height(actual situation)
4m/s
8m/s

Wind speed at 5cm
height(model)
0.31m/s
0.62m/s

Froudenumber
4.37
1.09(4) Measurement item
The average velocity, turbulent fluctuation of velocity, Reynolds stress, turbulent
kinetic energy, average pollutant concentration and turbulent fluctuation ofpollutant concentration have been measured.
(5) Measuring instrument
The wind speed is measured by 3D Laser Doppler Velocimetry (LDV).
Measurement time is set to 120 seconds. FID (Flame Ionization Detector)hydrocarbon concentration meter (Cambustion, THC-2A) which has highresponse is used to measure the pollutant concentration. The response of theconcentration sensor of FID is 100Hz, approximately.
(6) Measurement points
Measurement points are shown in Figure 2. In the vertical direction, the points
were set at an interval of 10mm or 20mm over the ground or building roof.
(7) Approaching wind flow
To reproduce the natural wind, vortex generator and the roughness are arranged in
the inlet part of the wind tunnel. Figure 3 shows the average velocity andturbulence intensity of the wind flow. The approaching wind flow profile is
U Z1/3 approximately.

Your paper title

0ctober 2010, Kobe, Japan

Z(mm)
1000

case 1case 210

100(m/s, %)

100

10

I

U

1
0.1

1

Figure 3: Approaching wind profile
3. EXPERIMENT RESULTS
The figures (Fig.4-11) show experimental results. The velocity has beenstandardized by UH which is the velocity of the inflow at the building height.
3.1 Vertical distribution of U andu2(Figure 4, 5)

Looking at the vertical distribution of U, there was no significant difference of thenon-dimensional U in Case 1 and Case 2. It is understood that the buoyancy has
no large effect on U. The velocity U in the canyons between buildings (point 7, 10)
is almost zero. The distribution of u is slightly larger.
2

4

2

Z/ZH

Z/ZH

1.5
1

2
1

case 1case 2

0.5

Z/ZH

3

0

0
0

1
point 32

0

1
point 7

2

6

6

5

5

4

4
Z/ZH

2.5

3

3

2

2

1

1

0

0

0

1
point 92

-1

0
1
point 102

Figure 4: Vertical distribution of U (U/UH)

New Technologies for Urban Safety of Mega Cities in Asia

4

2

Z/ZH

Z/ZH

1.5

Z/ZH

3
2

1

1

0.5

0

0
0

0.5
point 301

0.5
point 7

6

6

5

5

4

4
Z/ZH

2.5

3
2

2

1

1

0

0
0

1

0.5
point 9Figure 5: Vertical distribution of

3.2 Vertical distribution of W and

W 2

3

u2

0

1

0.5
point 101

( u /UH)
2(Figure 6, 7)

It is found that upward flow occurs at each point which shows the buoyancy effect.
In Case 1 there is a stronger upward flow. In case 2, it should be considered that
because of the strong wind inflow, the upward flow is suppressed. There are peaks
in Case 1. In Case 2 there is upward flow near the outlet, and the upward flow
decreases to almost zero after point 7. It is shown that the fluctuation of velocity ismore significant in Case 1 and W shows a peak approximately at the same heightas the peak of the concentration (shown in Figure 10). This is considered to be dueto the positive contribution of the buoyancy production termtransport equation of W .

2g wc

in the242.5case 1

0
-0.5

5

5

4

4

2

3

3

2

2

1

1

1

case 20 0.5
point 3

Z/ZH

1

Z/ZH

1.5

0.5

6

3
Z/ZH

Z/ZH

2

6

1

0
-0.5 0 0.5
point 71

0-0.5 0 0.5
point 91

0-0.5 0 0.5
point 10Figure 6: Vertical distribution of W (W /UH)Your paper title10ctober 2010, Kobe, Japan

2

Z/ZH

Z/Z H

1.5

Z/Z H

3
2

1

0.5

1

0

0
0

0.5
point 3

1

0

0.5

6

6

5

5

4

4
Z/Z H

4

2.5

3

3

2

2

1

1

0

0
0

1

0.5
point 9point 7

Figure 7: Vertical distribution of

W 2

0

1

0.5
point 101

( W /UH)2

3.3 Vertical distribution of u ' w ' and k (Figure 8, 9)At point 7 and 10, the Reynolds stress is positive, while near the roof surface(point 9 and 3), it shows a negative value. This is due to the effect of separation at
the building roof. The Reynolds stress decreases along the downwind direction.
Peaks are shown for the turbulent kinetic energy, which are consistent well withthe distribution of u and W . The large fluctuation in Case 1 is considered to be
due to the large buoyancy production.
2

2

2

Z/ZH

Z/ZH

1.5
1

Z/ZH

3
2
1

0.5
0
-0.2 -0.1 0
point 3

0.1

0
-0.1

0 0.1 0.2
point 7

6

6

5

5

4

4
Z/ZH

4

2.5

3

3

2

2

1

1

0
-0.2 -0.1 0 0.1 0.2
point 90-0.1

0 0.05 0.1
point 10Figure 8: Vertical distribution of u ' w ' ( u ' w ' /UH2)

2

Z/ZH

Z/ZH

1.5
1

2

0.5

1

0

0
0

0.2 0.4 0.6
point 3

Z/ZH

3

6

6

5

5

4

4
Z/ZH

4

2.5

3

2

2

1

1

0

0

0

0.2 0.4
point 70.6

3

0

0.2 0.4
point 90.6

0

0.2 0.4
point 100.6

Figure 9: Vertical distribution of k (k /UH2)
New Technologies for Urban Safety of Mega Cities in Asia

3.4 Vertical distribution of concentration and turbulent fluctuation ofconcentration (Figure 10, 11)
Urban air pollution and gas are transported (advection and diffusion) by thebuoyancy flow and urban wind in the downwind direction. The pollutant
concentration is high near the roof surface, while the concentration decreases
along the downwind direction. Away from the outlet, peaks are clearly shown.
The faster the approaching wind flow, the lower the peak height is. Above thepeak position, Case 1 shows a higher concentration, while below the peak, theconcentration in Case 2 is higher. This means that the advection and diffusion of
the gas are suppressed. Along the downwind direction, the height of the peak rises.
The distribution of the average concentration and the distribution of concentration
fluctuation are well consistent. It is shown that at the position with high average
concentration and high concentration gradient, the concentration fluctuation
increases. The average concentration and the concentration fluctuation are
consistent with the maximum height, which is considered to be reasonable due to

4

2

3

1.5
1

1

0.5

0
0.00

0
0.00

2

0.50
point 31.00

0.20
point 7

6

6

5

5

4

4

3

3

2

2

1

1

0
0.00

0.40

Z/ZH

2.5

in the transport equation of c2 .

Z/ZH

2 uic ( c / x i )

Z/ZH

Z/ZH

the production term

0.10
point 900.20 0.00

0.10
0.20
point 10

2

3

1.5
1

0
0.00

5.00
10.00
point 3

0
0.00

6

5

5

4

4

3

2
1

0.5

6

Z/ZH

4

Z/ZH

2.5

Z/ZH

Z/ZH

Figure 10: Vertical distribution of concentration (c/cmax)

5.00 10.00
point 7

3

2

2

1

1

0
0.00

0
0.00

2.00
point 9

4.00

2.00
4.00
point 10Figure 11: Vertical distribution of fluctuation of concentration ( c /cmax)
2

Your paper title

0ctober 2010, Kobe, Japan

4. SUMMARY
The thermal buoyant plume induced by urban fire were simulated using a gas
mixture of helium and ethylene. The average velocity, turbulent fluctuation ofvelocity, Reynolds stress, turbulent kinetic energy, average concentration andturbulent fluctuation of concentration were measured in a boundary layer windtunnel in detail. These turbulent properties confirm the effect of buoyancy. In our
future work, LES will be used to validate the experimental data. And we plan toinvestigate more turbulent properties of the thermal buoyant plume of turbulencemodel from urban fire in detail.
REFERENCES
American Society of Civil Engineering, Wind tunnel studies of buildings andstructures, ASCE Manuals and Reports on Engineering Practice No. 67, 1999.
Hayashi, Y., Omiya, Y., Saga T., Ohsaki T. and Wakamatsu, T., Study on flames
and thermal plumes induced by fires under windy conditions, Proceeding of 17th
National Symposium on Wind Engineering, 173-178. 2002.
Imamura, et al, Proceeding of Japan Association for Fire Science and Technology,380-383, 2003.
Mell, W. E., McGranttan, K. B. and Baum, H., Numerical simulation of
combustion in fire plumes, Twenty-sixth symposium (International) on combustion,
1523-1530, 1996.

New Technologies for Urban Safety of Mega Cities in Asia

Seismic Behavior of ¼ Scale
Unreinforced Masonry House Models
Retrofitted by PP-band Meshes
Navaratnarajah SATHIPARAN
Postdoctoral Fellow, IIS, The University of Tokyo, Japansakthi@iis.u-tokyo.ac.jp
Kimiro MEGURO
Professor/Director, ICUS, IIS, The University of Tokyo, Japanmeguro@iis.u-tokyo.ac.jp

ABSTRACTThis paper introduces a technically feasible and economically affordable PP-band(polypropylene bands) retrofitting for low earthquake resistant masonry structuresin developing countries. Results of the basic material tests and shaking table tests
on building models show that the PP-band retrofitting technique can enhancesafety of both existing and new masonry buildings even in worst case scenario ofearthquake ground motion like JMA 7 seismic intensity. Therefore, proposed
method can be one of the optimum solutions for promoting safer building
construction in developing countries and can contribute earthquake disastermitigation in the future.
Keywords: unreinforced masonry, polypropylene bands, pp-band mesh retrofitting,shaking table test, arias intensity

1. INTRODUCTION
The collapse of non-engineering masonry is one of the major causes of humancasualties during recent earthquakes in developing countries.
Therefore,
retrofitting of low earthquake-resistant masonry structures is the key issue forearthquake disaster mitigation in developing countries to reduce the casualties
significantly. When we propose the retrofitting in developing countries,
retrofitting method should respond to the structural demand on strength and/or
deformability as well as to availability of material with low cost including
manufacturing and delivery, practicability of construction method and durability
in each region. Considering these points, PP-band (polypropylene bands, which isworldwide available and cheap material, commonly used for packing) retrofitting
technique has been developed and many different aspects have been studied by
Meguro Laboratory, Institute of Industrial Science, The University of Tokyo.
In order to understand the dynamic response of masonry houses with and without
PP-band mesh retrofitting, crack patterns, failure behavior, and overall
effectiveness of the retrofitting technique, shaking table tests were carried out. In
this experimental program, ¼ scale single box shape room structure with wooden

0ctober 2010, Kobe, Japan

roof models were used. Addition to that, effect of surface plaster on PP-band
retrofitted house model also studied.
From the experimental results, it was found that a scaled dwelling modelwith PP-band mesh retrofitting was able to withstand larger and more repeatableshaking than that without PP band retrofitting, which all verified to reconfirm
high earthquake resistant performance. When surface finishing applied above
house model, due to improve bond connection between PP-band and brick wall,
surface plaster kept well with wall.
2. DESIGN AND CONSTRUCTIONG THE MODELS
2.1 Design of the models
According to the shaking table size and allowable loading condition, the model
scaling factor is 1:4 as shown in Figure 1. The model material, we use the unburnt
bricks as masonry units and cement, lime and sand (1:2.8:8.5) mixture as mortar
with cement/water ratio of 33%, to simulated to the replica of adobe masonrybuildings in developing countries.
All the building models dimensions were 933mmx933mmx720mm with
50mm thick walls. The sizes of door and window in opposite walls were
243x485mm2 and 325x245mm2 respectively.

Figure 1: House model for shaking table tests (dimensions in mm)
2.2 Model types
All four models are represented one-storey box-like building with timber roof;
two models are non-retrofitted and other two models are retrofitted with PP-bandmesh after construction. In each case, one specimen; i.e. one non-retrofitted and
one retrofitted, were applied by surface finishing. The mortar thickness covering
the inside and outside of walls is 7.5mm. For surface finishing material mixing
ratio as follows; Water: Cement: Sand: Lime = 1.00: 0.14: 2.80: 1.11. This simple
geometry and boundary conditions were considered as the data generated will be

New Technologies for Urban Safety of Mega Cities in Asia

used for numerical modeling in future. Physical characteristic of the models are
showed in Table 1.
Table 1: Model types
Model no.

Model name

Brick unit

Roofcondition

1

A-NR-X

Adobe



2

A-RE-X

Adobe



3

A-NR-P

Adobe



4

A-RE-P

Adobe

Retrofitted
condition

Surfacefinishing







2.3 Making of Models
All specimens consisted of 18 rows of 44 bricks in each layer except openings.
Construction process takes place in two days, first 11 rows in first day andremaining rows construct in following day. The geometry, construction materials
and mix proportion, construction process and technique and other conditions that
may affect the strength of the building models were kept identical for better
comparison. The cross-section of the band used was 6mm×0.32mm and the pitchof the mesh was 40mm. The retrofitted procedure presented in Figure 2 isillustrated with photos taken during the experimental program.

Seismic Behavior of ¼ Scale Unreinforced Masonry House Models
Retrofitted by PP-band Meshes

0ctober 2010, Kobe, Japan

Figure 2: PP-band mesh retrofitting procedure for masonry house











PP-bands are arranged in meshes and connected at their intersection points
using a portable plastic welder.
Structure walls are cleaned and any loose pieces of brick should be removed.
Straw, which placed in holes are removed. (In this experiment, during
construction of the model house, we put the straw in the place atapproximately 160mm pitch where we required holes.) In case of existing
structures, holes can be prepared by drilling through the wall.
Walls are wrapped by meshes around the corners and wall edges. The
overlapping length should be long enough to accommodate sufficient wire
connectors as this is the only system used to connect meshes to the structure.
Wires are passed through wall holes and used to connect the meshes on bothwall sides. In order to prevent the wires from cutting the PP-band meshes, aplastic piece or any other stiff element is placed between the band and the wire.
It is desirable to have connectors as close as possible to the wall intersections
and corners.
The top/bottom mesh edges are connected with steel wires. The bottom edge
should be connected to the structure foundation as much as possible. In
installing the PP-band mesh on existing houses, it was considered that it
would be hard to excavate the ground to bury and fix the mesh bottom to thefoundation of the house. The result of treatment only at above ground willsave operational cost as well as its workload. Similarly, for existing houses,
PP-band mesh attachment on the roof level, the top edges of PP-band meshneed not wrapped the roof.
Fixed connectors around the openings after the mesh was cut and overlappedon the other side.

3. INPUT MOTION
Simple easy-to-use sinusoidal motions of frequencies ranging from 2Hz to 35 Hz
and amplitudes ranging from 0.05g to 1.4g were applied to obtain the dynamic
response of both retrofitted and non-retrofitted structures. This simple input
motion was applied because of its adequacy for later use in the numericalmodeling. Figure 3 shows the typical shape of the applied sinusoidal wave.

Figure 3: Typical Shape of Input Sinusoidal Motion
Loading was started with a sweep motion of amplitude 0.05g with all
frequencies of 2Hz to 35Hz for identifying the dynamic properties of the models.

New Technologies for Urban Safety of Mega Cities in Asia

The numbers in Table 2 indicate the run numbers. General trend of loading wasfrom high frequency to low frequency and from lower amplitude to higher
amplitude. Higher frequencies motions were skipped towards the end of the runs.
Table 2: Loading Sequence
Amplitude
1.4g
1.2g
1.0g
0.8g
0.6g
0.4g
0.2g
0.1g
0.05g
sweep

2Hz
54
53
52
51
46
18
10

5Hz
50
49
48
47
45
44
25
17
09

10Hz

Frequency
15Hz 20Hz

25Hz

30Hz

35Hz

43
42
41
24
16
08

40
39
38
23
15
07

34
33
32
21
13
05

31
30
29
20
12
04

28
27
26
19
11
03

37
36
35
22
14
06
01,02

4. ANALYSIS OF THE TEST RESULTS
In order to analyze the test results, the Japan Meteorological Agency intensity andArias intensity of the input motion as a function of time was calculated.
4.1 Perfomance evaluation based on JMA scale
The Japan Meteorological Agency seismic intensity scale (JMA) is a measureused in Japan to indicate the strength of earthquakes. Unlike the Richtermagnitude scale (which measures the total magnitude of the earthquake, andrepresents the size of the earthquake with a single number) the JMA scale
describes the degree of shaking at a point on the Earth's surface.
Table 3: Damage categories
Category

Damage extension

D0: No damage

No damage to structure

D1: Light structural
damageHair line cracks in very few walls. The structural resistance capacity did
not decrease noticeably.

D2: Moderate
structural damage

Small cracks were observed on masonry walls. The structure resistancecapacity decreased partially.

D3: Heavy structural
damageLarge and deep cracks were observed on masonry walls. Some bricks
are fallen down. Failure in connection between two walls.

D4: Partially collapse

Serious failure and Partial structural failure was observed on walls androofs, respectively. The building was in dangerous condition.

D5: Collapse

Structure is totally or partially collapsed.

The performances of the models were assessed based on the damage levelof the buildings at different levels of shaking. Performances were evaluated inreference to three levels of performances: light structural damage, moderate
structural damage, heavy structural damage, partially collapse and collapse ondamage levels described in “European Macroseismic Scale 1998”.
Seismic Behavior of ¼ Scale Unreinforced Masonry House Models
Retrofitted by PP-band Meshes

0ctober 2010, Kobe, Japan

Figure 4 shows the damage evaluation based on JMA intensity for all fourmodels. In case of house models without surface finishing, until Run 26 bothmodels showed the light structural damage levels. From this point, model A-NRX performed moderate damage level up to Run 40 and after that it’s shown rapid
degradation and partially collapsed after Run 44. This input motion corresponded
to JMA intensity 5-.

Figure 4: Performance evaluation based on JMA Scale
Model A-RE-X damage, on the other hand, progressed gradually.
Although the structure was subjected to four shakes intensity JMAI 6-, it did notcollapse. The specimen is cracked, however, no permanent deformations or partial
collapse were observed until Run 50. In the field, a structure with this degree ofdamage can be readily repaired and used. Figure 16(right) depicts A-RE-X afterRun 52, which correspond to JMA intensity 6+. It can be seen that even at thisstage, the permanent deformations of the structure were limited. Furthermore,
escape routes such as doors and windows were secured.

New Technologies for Urban Safety of Mega Cities in Asia

Figure 5: Retrofitted model A-RE-X after Run 50 (left) and Run 52 (right)
In case of house models with surface finishing (A-NR-P & A-RE-P), totalcollapse of the non-retrofitted building was occurred at the 47th run at intensity
JMA 5+. The retrofitted building performed moderate structural damage level at
47th run at which the non-retrofitted building was totally collapsed. Moreover,moderate structural damage level of performance was maintained until 48th run,leading to intensity JMA 5+. It should be noted again that this model survived 7
more shakings in which many runs were with higher intensities than JMA 5+ at
which the non-retrofitted building was collapsed before reaching to the final stage
at the 54th run.
From this it can be concluded that a structure retrofitted with PP-bandmeshes would be able to resist strong aftershocks. Moreover, it proves that eventhough a house retrofitted with PP-band is cracked after a strong earthquake, it
can be repaired and be expected to withstand subsequent strong shakes.
4.2 Performance evaluation based on arias intensity
The Arias intensity was initially defined (Arias, 1970) as
Ia 

 t

a (t )dt
2g 
2

(1)
and was called scalar intensity. It is directly quantifiable through the acceleration
record a(t), integrating it over the total duration of the earthquake. The arias
intensity is claimed to be measure of the total seismic energy absorbed by theground. Arias intensity gave cumulative effect of seismic input motion.
Figure 6 and Figure 7 show the performance level of each specimen
against the dynamic motion. Form results, it clearly showed that; retrofitted model
damage level performance at least 3 times better than that of the non-retrofitted
model.
0

Figure 6: Performance evaluation
for models A-NR-X & A-RE-X

Figure 7: Performance evaluation
for models A-NR-P & A-RE-P

4.3 Lateral drift
In design, drift (i.e. story drift/story height) limits can be used to control the extent
of structural and nonstructural damage in the building. Hence, the drift levels that
correspond to the onset of a major damage in the teat models were summarized inTable 4. These can be used as approximate guidelines for design.
As we can be observed from Table 4, in all the models tested, themoderate structural damage occurred at a drift between 0.14mm and 0.20mm,
Seismic Behavior of ¼ Scale Unreinforced Masonry House Models
Retrofitted by PP-band Meshes

0ctober 2010, Kobe, Japan

except A-RE-P. For both non retrofitted models very heavy structural
damage/partially collapse occurred at a drift around 3mm. However, in case ofretrofitted models, it went up to 29mm and 50mm for A-RE-X and A-RE-P,
respectively. It indicates the retrofitted house could withstand at least lateral drift
level 10 times larger than the non-retrofitted house, even without any surface
finishing applied.
Table 4: Drift levels in mm at various damage levels
Damage level
Model name.

Light Structural
damageModerate structural
damageHeavy structural
damageA-NR-X
A-RE-X
A-NR-P
A-RE-P~ 0.14
~0.20
~0.17
~0.96

0.14-1.47
0.20-7.00
0.17-0.61
0.96-17.86

1.47-3.39
7.00-28.90
0.61-2.62
17.86-49.93

Considering the predominant first vibration mode shape of vibration, andassuming that the observed mode shape is stable during the shaking, andneglecting the damping, base shear and story lateral force can be determined.
Lateral shear force is determined as a sum of inertia forces acting on walls:n

SS   mi ai(2)
Where SS is the lateral shear force, mi pertinent mass at each location, ai theacceleration and n the number of location considers for calculation. Figure 8 and
Figure 9 shows the lateral shear force variation with lateral drift for models
without surface finishing and models with surface finishing, respectively. In bothcases, before major cracking observed in specimens; different in lateral shear
force between non-retrofitted and retrofitted models was not observed.
However, after cracking, both retrofitted specimens were shown the higher
story lateral force; even lateral drift more than 20mm. It indicates after cracking,the mesh presence positively influenced the lateral resistance of the specimen.
1

Figure 8: comparison of lateral shear
force between A-NR-X and A-RE-X

Figure 9: Comparison of lateral shear
force between A-NR-X and A-RE-X

4.4 Stiffness degradation
Masonry is an inelastic structural material, which doesn’t behave elastically evenin the range of small deformation. However, for a practical reason, effective

New Technologies for Urban Safety of Mega Cities in Asia

stiffness of the wall, defining the slope of the hysteresis curves, is determined as
the ratio between lateral force and deformation in the house model. Calculated
values after each run are shown in Figure 10.

Figure 10: Stiffness degradation for each house models

Seismic Behavior of ¼ Scale Unreinforced Masonry House Models
Retrofitted by PP-band Meshes

0ctober 2010, Kobe, Japan

Figure 11: Energy dissipation for each house models
4.5 Energy dissipation
The comparison among the values of energies related to different severities of thebase excitation is meaningful. However, in some instances it is useful tonormalize cumulated energy time histories with respect to the impedance of theexcitation. The energy dissipated in each cycle is the area enclosed by thehysteresis loop corresponding to that cycle. The energy dissipated by whole housemodel corresponds to total house model force and the horizontal displacement of
the top of the house model.
To assess the overall performance of the structures, energy dissipation interms of input runs is shown in Figure 11. Generally, energy dissipation capacityof the retrofitted house specimen was much larger than non-retrofitted house
specimens.
5. CONCLUSIONSThe shaking table experiments showed that; scaled dwelling model with PP-bandmesh retrofitting can withstand larger and more repeatable shaking than thatwithout PP band retrofitting. Which all verified to reconfirm that, the PP-band
retrofitting technique significantly enhanced the structural seismic performance.
When we applied the surface finishing to above house model, due to improvebond connection between PP-band and brick wall, surface plaster kept well withwall. This is not observed in the non-retrofitted model. Addition to this, covering
the mesh with mortar is very important to fill up any gaps between mesh andmasonry thus improving the structural performance. The mortar also protects themesh against UV radiation and sharp temperature variations as well as provides asmooth finishing to the retrofitted structure.
From all the experimental results, it was found that this retrofitting
technique can enhance safety of both existing and new masonry buildings even in
worst case scenario of earthquake ground motion like JMA 7 intensity. Therefore,
PP-band retrofitting method can be one of the optimum solutions for promoting
safer building construction in developing countries and can contribute earthquake
disaster in the future.
REFERENCES

New Technologies for Urban Safety of Mega Cities in Asia

Yoshimura, M. and Meguro, K., 2004. Proposal of Retrofitting Promotion System
for Low Earthquake-Resistant Structures in Earthquake Prone Countries, Proc. of
the 13th World Conference on Earthquake Engineering, Vancouver, Canada.
Meguro, K., Mayorca, P., Sathiparan, N., Guragain, R., and Nesheli, N., 2005.
Shaking Table Tests of 1/4 Scaled Masonry Models Retrofitted with PP-band
Meshes, Proc. of the Third International Symposium on New Technologies for
Urban Safety of Mega Cities in Asia, Singapore, pp. 9-18.
European Macroseismic Scale 1998 (EMS-98), 1998. Grunthal, G. (ed.),European Seismological Commission, GeoForschungsZentrum Potsdam,
Germany.
Coburn, A. and Spence, R., 2002. Earthquake Protection. John Wiley & Sons Ltd,West Sussex.
Travasarou, Thaleia., Bray, J.D., and Abrahamson, N.A., 2003, Empiricalattenuation relationship for Arias Intensity, Earthquake engineering & structuraldynamics, vol. 32, pp 1133-1155.

Seismic Behavior of ¼ Scale Unreinforced Masonry House Models
Retrofitted by PP-band Meshes

Assessment of fire loss in building
based on fire statistic data
1

Zhanhui SUN1, Guofeng SU2, Hongyong YUAN3Engineering Researcher, CPSR, DEP, Tsinghua University, China
zhsun@mail.tsinghua.edu.cn
2
Associate Prof., CPSR, DEP, Tsinghua University, China
sugf@mail.tsinghua.edu.cn
3Prof., CPSR, DEP, Tsinghua University, China
hy-yuan@mail.tsinghua.edu.cn

ABSTRACTIn this paper, taking the fire occurrence reasons as the classification criteria forthe building fire statistics data, a detailed analysis and evaluation was conductedto obtain the correlation between the causes of the fire and the building fire loss.
The analysis results using the Gray Correlation Analysis to the sub-loss statistics
data showed that the fire numbers and fire loss caused by the electric, illegal
operation, careless use of fire, smoking and spontaneous combustion reasons are
the mainly factors which influence the overall fire numbers and the fire loss in
China. These kinds of fire causes should be treated as the focus of fire prevention.
Persons’ unsafe behavior such as illegal operation, careless use of fire, smoking,as well as the combustible which may cause the spontaneous combustion being in
unsafe conditions should be paid great attention to.
Based on the statistical data of the fire cases, probability analysis was used to
study the fire frequency distribution, loss expectation, the maximal risk sub-loss,
fire frequency and loss expectation of the maximal risk sub-loss aroused byvarious fire causes. The results showed that under the current social andeconomical development conditions in China, the occurrence of electrical fire andthe above 100,000 fire sub-loss had the greatest risk.
Through the analysis, the focus and the weak point can be found out, which will
support the adjustment for fire safety regulations and measures, to find the main
disaster-reducing direction, and to carry out the fire prevention work with more
pertinency.
Keywords: fire loss, fire cause, fire statistics, Gray Correlation Analysis
1. INTRODUCTION
As a kind of disaster, the occurrence and the development of fire appears bothrandomicity and certainty. A single fire will not show any probabilistic law, yetlarge numbers of fires arises during a period of time often present some obvious
probatilistic rules, which is the theoretical basis of fire statistics. Through the firestatistics analysis, the fire hazard rating of a region can be summarized,
furthermore a more detailed analysis and evaluation will support the adjustment
for fire safety regulations and measures, to find the main disaster-reducing
direction, and to carry out the fire prevention work with more pertinency. The firestatistics is one of the important basis for the fire department to understand the fire

0ctober 2010, Kobe, Japandevelopment laws, to judge the fire situation, to establish the fire prevention plan,
to make the fire emergency response plan, etc. (Liu, et al.,2005). In China, the firestatistics mainly aims at the direct property loss caused by the building fires,
which included the fire loss caused by burning, smudging, radiation, collision
during the fire and the extinguishment, waterlogging, the pollutions caused by thefire, etc. (Ministry of Public Security of PRC, 1999).
Many researches on the fire statistic methods have been done, various of firestatistic and evaluation models were advanced. Most of the models are based on
the fire mechanism researches, using the computer numerical simulation
technology, statistical probability theory, fuzzy mathematical theory to evaluate
the fire loss. Li, et al.(1997) educed the calculation formula of the building fire
safety levels, via comparing the fire risk factors and the building safety factors.
Wang, et al.(2002) established a neural network model to predict the annual fireloss in China in 1994, using the 1971-1993 annual fire loss statistic data. Chu, etal.(2004) established a evaluation method for the direct fire property loss based on
the prediction of fire-burned area using event tree analysis method and statisticalprobability theory. Jiang, et al.(2005) drew a conclusion that the fire loss in China
present a ascending trend and predicted the intending annual fire loss in thefollowing years, which was acquired using the time-trend analysis based on thefire statistic data of China. Chen, et al.(2007) estimated the regional fire loss in
China using the cluster analysis, and the relationship between the regional
economic level, the fire prevention investment and the fire loss were discussed.
Fire loss were considered as a kind of disaster loss in the above-mentioned
researches, the main purpose is to predict the future fire loss using the statistic
significance. In this paper, the main purpose is to study the influence of the firecaused to the fire numbers and fire loss using the Gray Correlation Analysis basedon the 1999-2007 fire statistic data, main factors which influence the overall fire
numbers and the fire loss in China are found out through the analysis. The results
will support the adjustment for fire safety regulations and measures, to find themain disaster-reducing direction, and to carry out the fire prevention work withmore pertinency.
2. FIRE SUB-LOSS
Based on the fire statistic data, the fire loss can be divided into five sub-loss level:
0-1,000, 1,000-10,000, 10,000-50,000, 50,000-100,000, above 100,000. Using the
sub-loss, the 1999-2007 statistic data of fire numbers and fire loss are showed inTable 1.
Table 1: 1999-2007 fire number and fire loss of sub-loss
Sub-loss
0-1,000
1,00010,000
10,00050,000

Fire
numbers
20,764
9,145

Rates of fire
numbers0.63650.2803

Fire loss

Average loss

6,757,123
25,537,299

325.422,792.49

Rates of fireloss
0.03960.14952,011

0.0616

41,156,115

20,465.50

0.2409

New Technologies for Urban Safety of Mega Cities in Asia

50,000100,000
Above
100,000
SUM

379

0.011625,040,892

66,070.96

0.1466324

0.010072,351,095

223,305.85

0.423432,623

1

170,842,524-

11) The majority of fire loss caused by a single fire lies in the 0-1,000 sub-loss, thepercentage is 63.6%, however, the total fire loss of these fires is less than 4% of
all fire loss; 28% of the fire loss caused by a sing fire lies in the 1,000-10,000 subloss, yet the total fire loss of these fires is less than 15% of all fire loss. This resultshows that most of the fire can be put out effectively at the initial stage, and thefire loss can be controlled at a relatively low level.
2) Nearly 6.2% of the fire loss caused by a sing fire lies in the 10,000-50,000 subloss, whereas the total fire loss of these fires is more than 24% of all fire loss; lessthan 1.2% of the fire loss the fire loss caused by a sing fire lies in the 50,000100,000 sub-loss, while the total fire loss of these fires is more than 14% of all
fire loss. The result shows that the fire whose loss lies in the 10,000-100,000 subloss, especially the 10,000-50,000 sub-loss is the important target of the fire
prevention t job which should be given significant attention.
3) A very few of fire loss caused by a single fire lies in the above 100,000 subloss, the percentage is only 1%, however, the total fire loss of these fires is morethan 42% of all fire loss. This result shows that the fires whose fire loss lies in theabove 100,000 sub-loss is the most important factor which influence the high fireloss in China, this kind of fire is also the chief target of the fire prevention job.
3. FIRE CAUSES GRAY CORRELATION ANALYSIS OF SUB-LOSS
The occurrence of fire is a random process, the fire causes can be divided into ten
categories of reasons in China (Fire Department of Ministry of Public Security of
PRC, 1999): incendiarism, electric, illegal operation, careless use of fire, smoking,fire play, spontaneous combustion, lightning stroke, unknown and others. The fire
numbers and fire loss of different kinds of reasons are different, Gray Correlation
Analysis is used to analysis the fire statistic data of every sub-loss, the influence
degree of different fire causes to fire numbers and fire loss is derived.
3.1 Gray Correlation Analysis theory
The relational degree is used to analyze the fire statistic data, the absolute
relational degree is calculated out using the nearness degree of the changing trendof the influence factors' time series. As for the discrete data series, the nearness
degree of two curves is determined by the nearness of the gradient of the timeseries curves at the corresponding time interval, the less of the differentials of thecurves' gradient, the more relational degree of the two factors is, vice versa. The
absolute relational degree can be calculated as follows:
The original data series is:

Assessment of fire loss in building based on fire statistic data

0ctober 2010, Kobe, JapanX  xi  xi 1，x i 2，，x i n，i  0，1，，m 

Suppose,yi k   xi k  / xi 1，i  0，1，，my0i k   y0 k   yi k ，i  0，1，，myi k   yi k   yi k  1，i  0，1，，mthen the calculation formula of the absolute relational degree is (equation 1):
r0i 

1 n
1

n  1 k  2 1  y 0i k   y i k 

(1)

3.2 Gray Correlation Analysis of fire causes and fire numbers
Using Gray Correlation Analysis method to analysis the fire numbers and the firecauses statistic data lies in 0-1,000 sub-loss, Table 2 is obtained as follows.
Table 2: fire causes and fire numbers lies in 0-1,000 sub-loss
Year

Total

Fire causes
1
2
3
4
5
6
7
8
9
10
1999
850
27
228
64
165
29
63
4
2
184
84
2000
1228
41
460
72
291
56
61
14
4
158
71
2001
1336
35
575
88
357
46
50
27
1
84
73
2002
744
29
293
58
188
44
46
7
2
51
26
2003
705
32
273
71
161
37
31
9
0
50
41
2004
540
20
183
43
155
40
30
9
1
47
12
2005
615
27
231
33
168
26
21
15
1
58
35
2006
6603
173 2905 224 1404 426
291
93
7
566
514
2007
8143
124 3355 230 1676 744
527
145
16
360
966
1.Incendiarism, 2.Electric, 3.Illegal operation, 4.Careless use of fire, 5.Smoking, 6.Fire play,
7.Spontaneous combustion, 8.Lightning stroke, 9.Unknown, 10.Others

And the correlation degree of fire causes and fire numbers obtained from the firestatistic data lies in 0-1,000 sub-loss is listed in Table 3.
Table 3: Correlation of fire causes and fire numbers of 0-1,000 sub-loss
Fire causes
Incendiarism
Electric
Illegal operation
Careless use of fire
Smoking
Fire play
Spontaneous combustion
Lightning stroke
Unknown
OthersCorrelation degree
0.511460.758133
0.511856
0.622782
0.543832
0.5169780.511460.500502
0.500026
0.533032

New Technologies for Urban Safety of Mega Cities in Asia

Table 3 shows that the influence sequence of fire causes to the fire numbers, fromhigh to low, is electric, careless use of fire, smoking, others, fire play, illegal
operation, incendiarism, spontaneous combustion, lightning stroke, unknown.
The same analysis is conducted to the fire statistic data lies in the 1,000-10,000,
10,000-50,000, 50,000-100,000, and above 100,000 sub-loss. The influence
sequence of fire causes to the fire numbers of different sub-loss differs, too, as
follows:
1,000-10,000 sub-loss, from high to low: electric, careless use of fire, spontaneous
combustion, illegal operation, smoking, incendiarism, fire play, unknown,lightning stroke, others.
10,000-50,000 sub-loss, from high to low: electric, unknown, illegal operation,others, fire play, incendiarism, careless use of fire, smoking, lightning stroke,spontaneous combustion.
50,000-100,000 sub-loss, from high to low: electric, illegal operation, careless useof fire, smoking, incendiarism, unknown, fire play, lightning stroke, spontaneous
combustion, others.
Above 100,000 sub-loss, from high to low: illegal operation, smoking,incendiarism, unknown, careless use of fire, fire play, lightning stroke, electric,
others, spontaneous combustion.
3.3 Gray Correlation Analysis of fire causes and fire loss
Using Gray Correlation Analysis method to analysis the fire loss and the firecauses statistic data lies in 0-1,000 sub-loss, Table 4 is obtained as follows.
Table 4: fire causes and fire loss of 0-1000 sub-loss
Year

Total

1999
2000
2001
2002
2003
2004
2005
2006
2007

29.4655
44.5906
38.6898
24.2647
25.4904
21.4780
26.1337198.7504
266.8492

Fire causes
1
2
0.82671.57701.13690.7406
0.95200.7246
0.98755.10314.15468.239716.8677
16.5725
1.308110.0438
7.5147
10.3318
92.9962118.4587

32.30102.66002.65951.72382.23081.8631
1.19587.55028.080645.753510.1720
10.0092
5.85675.99806.16157.665444.0567
55.36945

0.96802.16951.35611.41001.32501.25300.911010.8116
23.186762.40502.46701.6144
1.61101.17001.22000.6735
7.693215.386570.12000.61000.67350.27100.36000.42000.54822.46545.465080.90000.17620.05000.035000.05000.07000.25000.501095.80665.34722.4462
1.44501.9003
1.91302.270015.3258
9.0523102.95502.54402.17150.86351.51050.35811.480512.4982
27.1944

1.Incendiarism, 2.Electric, 3.Illegal operation, 4.Careless use of fire, 5.Smoking, 6.Fire play,
7.Spontaneous combustion, 8.Lightning stroke, 9.Unknown, 10.Others

And the correlation degree of fire causes and fire loss obtained from the firestatistic data lies in 0-1,000 sub-loss is listed in Table 5.
Table 5: Correlation of fire causes and fire loss of 0-1,000 sub-loss
Fire causes
Incendiarism
Electric
Illegal operation

Correlation degree
0.512997
0.778052
0.512257

Assessment of fire loss in building based on fire statistic data

0ctober 2010, Kobe, Japan

Careless use of fire
Smoking
Fire play
Spontaneous combustion
Lightning stroke
Unknown
Others

0.628199
0.541168
0.511297
0.513137
0.5012090.500831
0.522853

Table 5 shows that the influence sequence of fire causes to the fire numbers, fromhigh to low, is electric, careless use of fire, smoking, others, spontaneous
combustion, incendiarism, illegal operation, fire play, lightning stroke, unknown.
The same analysis is conducted to the fire statistic data lies in the 1,000-10,000,
10,000-50,000, 50,000-100,000, and above 100,000 sub-loss. The influence
sequence of fire causes to the fire numbers of different sub-loss differs, too, as
follows:
1,000-10,000 sub-loss, from high to low: electric, careless use of fire, spontaneous
combustion, smoking, unknown, incendiarism, fire play, lightning stroke, illegal
operation, others.
10,000-50,000 sub-loss, from high to low: unknown, electric, illegal operation,others, careless use of fire, fire play, incendiarism, smoking, lightning stroke,spontaneous combustion.
50,000-100,000 sub-loss, from high to low: electric, illegal operation, careless useof fire, smoking, incendiarism, unknown, fire play, lightning stroke, spontaneous
combustion, others.
Above 100,000 sub-loss, from high to low: spontaneous combustion, electric,
lightning stroke, unknown, fire play, incendiarism, others, smoking, careless useof fire, illegal operation.
3.4 Conclusion of the Gray Correlation Analysis of sub-loss
The analysis results using the Gray Correlation Analysis to the sub-loss statistics
data showed that the fire numbers and fire loss caused by the electric, illegal
operation, careless use of fire, smoking and spontaneous combustion reasons are
the mainly factors which influence the overall fire numbers and the fire loss under
the current social and economical development conditions in China. These kindsof fire causes should be treated as the focus of fire prevention. Persons’ unsafe
behavior such as illegal operation, careless use of fire, smoking, as well as the
combustible which may cause the spontaneous combustion being in unsafe
conditions should be paid great attention to.
4. PROBABILITY ANALYSIS OF SUB-LOSS
Based on the statistical data of the fire cases, probability analysis is used to study
the fire frequency distribution, loss expectation, the maximal risk sub-loss, fire
frequency and loss expectation of the maximal risk sub-loss aroused by various
fire causes.

New Technologies for Urban Safety of Mega Cities in Asia

4.1 Fire risk
The basic formula of fire risk can be expressed as follows (equation 2):
R   Pi  Ci 

(2)i

Pi is the probability of occurrence of a single fire event, Ci is the anticipatedconsequence of this fire event. In this paper, the Pi is replaced by the occurrence
frequency of fire, and Ci is replaced by the average loss.
4.2 Risk analysis of sub-loss and fire causes
The fire occurrence frequency, the average loss and the fire risk of different subloss is calculated out, as listed in Table 6.
Table 6: Risk analysis of sub-loss
Sub-loss
0-1,000
1,000-10,000
10,000-50,000
50,000-100,000
Above 100,000
SUM

Fire
numbers
20,764
9,145
2,011
379
324
32,623Frequency

Fire loss

0.63650.28030.06160.01160.01001

6,757,123
25,537,299
41,156,115
25,040,892
72,351,095
170,842,524

Averageloss
325.422,792.49
20,465.50
66,070.96
223,305.85-

Fire risk
207.13782.801261.57
767.582233.06-

Table 6 shows that the fire risk of different sub-loss, from high to low, is above
100,000 sub-loss, 10,000-50,000 sub-loss, 1,000-10,000 sub-loss, 50,000-100,000
sub-loss, 0-1,000 sub-loss.
The fire occurrence frequency, the average loss and the fire risk of different firecaused is calculated out, as listed in Table 7.
Table 7: Risk analysis of sub-loss
Fire cause
Incendiarism
Electric
Illegal operation
Careless use of fire
Smoking
Fire play
Spontaneous combustion
Lightning stroke
Unknown
Others
SUM

Fire
numbers
1156
13737
1838
6544
1857
1542
685
80
2634
2550
32623

Frequency

Fire loss

0.03540.4211
0.05630.2006
0.05690.04730.02100.00250.08070.0782
112010234
66609496
21689008
17421325
37581784987632
5709546277649221982926
13897687
170842524

Assessment of fire loss in building based on fire statistic data

Averageloss
10389.48
4848.91
11800.33
2662.18
2023.79
3234.528335.1034706.15
8345.83
5450.07-

Fire risk
368.152041.80664.84534.02115.20152.89175.0285.11
673.85426.01-

0ctober 2010, Kobe, Japan

Table 7 shows that the fire risk of different fire causes, from high to low, iselectric, unknown, illegal operation, careless use of fire, others, incendiarism,
spontaneous combustion, fire play, smoking, lightning stroke.
The results showed that under the current social and economical development
conditions in China, the occurrence of electrical fire and the above 100,000 fire
sub-loss had the greatest risk.
5. CONCLUSIONTaking the fire occurrence reasons as the classification criteria for the building
fire statistics data, a detailed analysis and evaluation was conducted to obtain thecorrelation between the causes of the fire and the building fire loss. Through theanalysis, the focus and the weak point is found out, which will support theadjustment for fire safety regulations and measures, to find the main disasterreducing direction, and to carry out the fire prevention work with more pertinency.
ACKNOWLEDGEMENTS
This paper was supported by NSFC of China (No. 70701019).
The authors deeply appreciate the supports, and thanks for the works of Center for
Public Safety Research, Tsinghua University.
REFERENCES
Liu, D. H., Ji, T., Gao, J. T., Bai, F. L., 2005. Discussions on the fire statistics.
Fire Technique and Products Information 2, 35-37.
Ministry of Public Security of PRC, 1999. GA185-1998 Statistic method for thefire direct property loss. Standards Press of China, Beijing.
Yang, L. Z., Zhou, X. D., Deng, Z. H., Fan, W. C., Wang, Q. A., 2002. Firesituation and fire characteristic analysis based on fire statistics of China. Fire
Safety Journal 37(8), 785-802.
Li, Y. Q., Ji, G. Q., Li, S. H., Liang, S. M., Deng, Z. X., 1997. The research ofstatistical fire loss calculated method. Fire Safety Science 6(2), 24-32.
Wang, C., Li, C., 2002. Application of BP network in fire forecasting. Journal of
the Chinese People's Armed Police Force Academy 18(2), 25-27.
Chu, G. Q., Sun, J. H., 2004. Building fire direct loss evaluation based on fire
dynamics and probability statistics theory. Engineering Science 6(8), 64-68.
Jiang, X. P., Xu, Z. S., 2005. Analysis and prediction on the time trend of fire costin China. Fire Science and Technology 24(4), 412-414.
Chen, Z. J., Wang, F. L., Lu, S. X., Fang, Z. B., 2007. Cluster analysis of fire datain china. Engineering Science 9(1), 86-94.
Fire Department of Ministry of Public Security of PRC, 1999. Fire accident
investigation. Jilin Science and Technology Press, Changchun.
Liu, S. F., Dang, Y. G., Fang, Z. G., Xie, N. M., 2004. Gray system theory andapplication. Science Press, Beijing.

New Technologies for Urban Safety of Mega Cities in Asia

PEOPLE’S SEISMIC RISK RECOGNITIONIN DHAKA AND BANGLADESH NATIONAL
BUILDING CODE (BNBC) 1993
MD. FAIZ SHAH
Doctoral Student, Department of Risk Engineering, Graduate School of
Systems and Information Engineering, University of Tsukuba, Japan
mdfaizshah@yahoo.com
OSAMU MURAOAssociate Professor, Department of Risk Engineering, Graduate School of
Systems and Information Engineering, University of Tsukuba, Japanmurao@risk.tsukuba.ac.jp

ABSTRACT
Dhaka, the fastest growing megacity in Asia, is prone to natural
disasters including earthquake. The present generation have neverwitnessed big earthquake since the last one in 1897 that destroyed 60%
masonry structures with mass casualty. According to shaking intensity data,
the same earthquake may recur at any time, which requires good level ofknowledge and earthquake resistant infrastructure to mitigate loss.
However, rapid urbanization of Dhaka did not concentrate much on
earthquake risk; buildings are constructed in an unregulated mannerwithout earthquake consideration, which questions people’s risk recognition.
In order to examine inhabitant’s risk recognition and intention forresidential safety measures, the authors conducted questionnaire survey ineighteen selected wards of Dhaka. The questionnaire content house
construction year, type, disaster experience, recognition of emergency,
anticipated large disaster, risk recognition, acceptable risk, safety measures,cause of destroyed house, willingness to pay, and knowledge on Bangladesh
National Building Code (BNBC). Based on the obtained data, major resultshows that inhabitants anticipate earthquake as the most catastrophic
disaster for Dhaka, which may occur in 5-10 years; and cost cut, lack of
information, and not following proper design will be the main cause ofdestroyed houses. Result shows only 2.4% respondent heard about the
BNBC, but they do not know the contents. Then the authors checked thepresent status of BNBC with construction practice and conducted interview
with BRAC University, Bangladesh University of Science and Technology(BUET), Rajdhani Unnayan Kartipakkha (RAJUK), and Housing andBuilding Research Institute (HBRI). In conclusion, the paper shows– (1)inhabitants construct buildings without following approved design, (2)BNBC is not followed in constructing new buildings, (3) BNBC is included
under law, but no building legally follow it, (4) a big number of buildings,
constructed before and after 1993, may perform poorly in big earthquake.

October 2010, Kobe, Japan

1. INTRODUCTION
Dhaka is considered the fastest growing megacity in Asia for its
rapid urbanization, population growth and incensing geographic area. Dueto the concentration of both domestic and foreign investment, Dhaka has
experienced massive migration from the rural population in recent decades(Hossain 2008). The city is prone to natural disaster including earthquake.
The present generation never have witnessed large earthquake since the last
one in 1897 that destroyed about 60% of masonry structures with muchcasualty (Al-Hussaini 2003). Bilham and England (2001) cited that thisearthquake would recur and affect Dhaka at anytime, which requires goodlevel of knowledge and earthquake resistant infrastructure to mitigate loss.
However, the city did not concentrate much on earthquake risk. Buildings
are constructed in an unregulated manner without earthquake consideration,
which questions people’s risk recognition. In order to examine inhabitant’s
risk recognition and intention for residential safety measures, the authors
conducted a questionnaire survey in eighteen selected wards of Dhaka. The
objective of the paper is to clarify the survey outcomes, which might beuseful for adopting residential safety measures in Dhaka city.
2. METHODOLOGYThis study applied literature review, questionnaire survey andinterview methods to achieve the objective. The steps are explained below.
2.1 Literature review:

Figure-1: Analysis of reviewed literatures and status of this study
Figure-1 shows the reviewed literature flow. Total four types ofliteratures were identified and collected on Dhaka’s earthquake vulnerability(Kamal 2004, Ansary 2000, Al-Hussaini 2003, Ansary 2004), which havebeen shown in the first four columns of first row in Figure-1. The second
row shows the major findings of those literatures and the third row shows
the results. The fifth column of the figure and consequent rows explains thescope of this study, probable findings and expected results. The authors

New Technologies for Urban Safety of Mega Cities in Asiafound that present study is new in its type and no previous research focusedon people’s risk recognition. This study will contribute to reconstruction
phase of typical disaster management cycle, which has been shown at thebottom of the figure.
2.2 Cluster analysis of wards:
The authors collected Dhaka’s ninety wards’ characteristics datafrom Dhaka City Corporation (DCC), Bangladesh Bureau of Statistics(BSS) and Bangladesh University of Engineering and Technology (BUET).
This included population, density, building number and density, number ofblock, open space and earthquake intensity (done by BUET). Threevariables of population density, building density, and probable earthquake
intensity were selected for cluster analysis in statistical software STATA
and result was derived in three clusters like less vulnerable, most vulnerable,
and moderate vulnerable. Taking six wards from each cluster, total eighteen
wards were selected for the questionnaire survey.
2.3 Contents of the questionnaire:
The questionnaire mainly contained the house construction year,
type, major structure, disaster experience, recognition of emergency,
anticipated large disaster, risk recognition, acceptable risk, safety measures,cause of destroyed house, willingness to pay, and knowledge on Bangladesh
National Building Code (BNBC). Total 720 sample were collected i.e. 40
from each ward. The next chapter shows the major results of thequestionnaire survey based on the obtained data.
3. MAJOR RESULTS
3.1 Basic information of the respondents:
First, we analyze the basic information of the respondents and theirresidence, which we explain in following figures.

Figure-2: Type of buildings

Figure-3: Major structure of buildings

People’s Seismic Risk Recognition in Dhaka and Bangladesh National Building Code (BNBC) 1993

October 2010, Kobe, Japan

Figure-4: Building construction trend in percentage
Figure-2 shows three types of residential buildings in Dhaka. They
are detached houses (65.4%), government houses (9.2%) and apartment
houses (25.4%). Figure-3 shows the major structure of buildings. About
42.5% are full RC structure, 31.3% are brick and RC, and 16% are masonry
structure. Most of the buildings in Dhaka are RC structure, which arestronger than wooden houses. However, as shown in Figure-14, they arevulnerable as they do not followed building code properly. Figure-4
demonstrated the building construction trend. We observed a risingtendency in building construction. From 1800 to 1971, buildings wereincreasing in a long interval. From 1972 to 1992, it became upward. And
from 1993 to 2010, the tendency became liner and straight upward.
3.2 Disaster experience and recognition of emergency:

Figure-5: Disaster experience

Figure-6: Experienced disaster list

Figure-7: Anticipation of large earthquake

Figure-8: Anticipated time

New Technologies for Urban Safety of Mega Cities in Asia

Here we analyze the disaster experience and recognition of
emergency of the respondents. As shown in Figure-5, we observed that
67.1% respondents have disaster experience in their lifetime in Dhaka.
Figure-6 shows the consequent disaster list. About 50.1% respondents
experienced flood. Only 1.1% people have experienced earthquake. Figure7 shows that 91.9% respondents recognize the emergency of earthquake
occurrence in Dhaka in near future. Figure-8 shows the anticipated time.
Most of the respondents (45.8%) anticipate in 5 years time.
3.3 Risk Recognition (RR) and Acceptable Risk (AR):Then we check the risk recognition of the respondents. Figure-9
shows the level of anticipated damage to the buildings in Moholla (adjacentlocal area). Figure-10 shows the same in Ward and Figure-11 shows in own
house. For Moholla and Ward, we found that people fear for complete
destruction, 45.6% for Moholla and 39.6% for Ward. The bar chart shows
upward tendency for this two variables. But for the case of destruction levelof own house, respondent increased more for ‘no damage’ (5.3%) or ‘little
damage’ (20.1%), though complete destruction stands for 36.7%. In case of
acceptable damage to own house, we found no extreme response. About
16.7% respondents expects ‘no damage’, 20.0% anticipated partial damage,which they can repair by themselves. On the other hand, 26.4% respondent
fears for complete destruction and 21.1% respondents were not sure howmuch damage they can accept.

Figure-9: Damage in Moholla (%) (RR) Figure-10: Damage in Ward (%) (RR)

Figure-11: Damage in own house (%) (RR) Figure-12: Acceptable damage (%) (AR)

3.4 Intention for safety measures:
In this section, we analyze resident’s intention for safety measures.
The proposition we made here is that if acceptable risk is lower thanrecognition of risk, then residents will intend for different alternative safetymeasures for their residence (Kato 2002). Figure-13 shows the result ofintention, 36.9% respondent expressed their aim for retrofitting, and 34.2%

People’s Seismic Risk Recognition in Dhaka and Bangladesh National Building Code (BNBC) 1993

October 2010, Kobe, Japanfor repair. Though restoration is expensive, 18.5% people wish to adopt it.
However, earthquake insurance is not that much popular in the context of
Bangladesh, only 8.6% respondents expressed their desire for it. Figure-14
shows the causes for damaged house in big earthquake. Mainly threereasons are identified, which are responded in an upward trend. For example,
24.0% respondent thinks that cost cut or use of low cost materials will be
the main cause while 28.6% thinks for lack of information i.e. informationof earthquake vulnerability or following earthquake resistant design as
specified in Bangladesh National Building Code (BNBC) 1993, and 32.6%
think for built without following proper design or without engineeringsupervision. The two bar charts at the bottom show the willingness for pay
for the intention of safety measures. Figure-15 shows that 58.9% respondent
were not interested to pay for any safety measures, only 41.1% wereintended. Then we informed them some specific earthquake disaster and risk
information of Dhaka and some idea of expenses for safety measures. Afterthat we repeated the same question of willingness to pay. This time wefound change in their intention, which have been shown in Figure-16. About
50.8% respondent expressed their aim to pay for safety measures while
49.2% were still in negative position. Among them most of the respondents
were tenants. The survey covered 49.6% of landlord and 49.6% of tenants.
Tenants were not interested to pay for rent house’s safety measures.

Figure-13: Intention for safety measures

Figure-14: Cause of damaged house

Figure-15: Willingness to pay (without info) Figure-16: Willingness to pay (with info)

3.5 Knowledge on the BNBC 1993:
Here we explain respondents’ knowledge on BNBC-1993. Figure-17
shows the result. Only 2.4% respondents know about the BNBC-1993, and97.6% respondents never heard about it. The result is too insignificant that it
cannot be cross-analyzed. We only cross with educational qualification andas shown in Figure-18, we found that only some of the graduates know
about it, but their idea is not specific. Therefore, people are not following
the guidance of BNBC in construction or re-construction of buildings. This

New Technologies for Urban Safety of Mega Cities in Asia

is one of the main causes of buildings constructed in an unregulated mannerwithout earthquake consideration. Then we checked the present status of
BNBC in construction practice.

Figure-17: Know BNBC 1993

Figure-18: Know BNBC per qualification

4. BNBC 1993 AND CONSTRUCTION PRACTICE
4.1 Implementation status of BNBC 1993:
We had taken photos of respondent’s houses. We analyze some ofthem to see the present status of implementation of BNBC. Photos shown in
Figure-7 are some of the houses that’s owner neither heard about the BNBC,
nor could check if the design and construction had followed the BNBC ornot. These houses did not follow the approved design too, for example,
photo#1, 2, and 3 shows ‘heavy overhangs’ or ‘short column’ approach,which was not in design. Photo#2 shows that this house has been occupied
before completion and without getting the ‘occupancy certificate’ from theconcerned authority. Photo#4 is the entrance of the house shown in Photo#5,
which also did not follow the proper design. Thus, as explained in section
3.4, most of the houses are constructed in Dhaka without following proper
design (32.6%). In an interview, Housing and Building Research Institute(HBRI) informed that house owners in Dhaka, while constructing newbuildings use two sets of design, one is approved design and another isworking design, which is not approved. In this practice, we found therelation with cost cut, as explained in section 3.4 that 24% people believethat if the house is destroyed in big earthquake, cost cut will be the maincause. In between comes the response of lack of information, which we
found 28.6% as the cause for destroyed house. Photo#6 is an old masonry
type building, which followed old typical construction practice.
1

Constructed after 1993

4

Constructed after 1993

Constructed after 1993

52

Constructed after 1993

Constructed after 1993

6

3

Constructed before 1993

Figure-19: Photos of some residential houses in Dhaka

People’s Seismic Risk Recognition in Dhaka and Bangladesh National Building Code (BNBC) 1993

October 2010, Kobe, Japan

According to this study, 67% buildings were constructed before
1993. But the BNBC said nothing about them. It is not well circulated with
common people’s knowledge, thus they cannot check or monitor whether it
is followed in construction or not. Based on this circumstance, common
people should know about the basic guidelines of BNBC, so that they can
implement or monitor the implementation of BNBC in construction andreconstruction practice. The BNBC 1993 came into effect with a gazettenotification of the Bangladesh Government on November 15, 2006. It has
been made mandatory to comply with in any building construction under the
Building Construction Act of 1952 to ensure accountability in the
management of overall building construction and safety of the buildings. As
per section 2.1 of Chapter 2 of Part 1 of the BNBC 1993, the government isunder obligation to establish a new or designate an existing agency
responsible for the enforcement of this code with a given area of jurisdiction.
However, the government is yet to set up any Code Enforcement Authority.
Thus, absence of regulatory authority to care for all safety aspects ofbuilding as per BNBC is a major concern (Shafi 2010).
4.2 Interview with experts on implementation of BNBC 1993:
We have conducted four interviews on this issue with (1) the ViceChancellor of BRAC University, (2) Director, Bangladesh Network Officefor Urban Safety (BNUS) of Department of Civil Engineering, Bangladesh
University of Engineering and Technology (BUET), (3) Director,
Development Control of Rajdhani Unnayan Kartipakkha (RAJUK) [Capital
Development Authority], and (4) Director, Housing and Building ResearchInstitute (HBRI). The outcome of the interviews are explained below.
4.2.1 Interview with the Vice-Chancellor, BRAC University:
In reply to a question why only 2.4% people know about the BNBC,he said that the BNBC is not for the common people. It is for the use of theprofessionals. It was not needed for gazette notification by the government.
The professionals should follow it while designing and constructing newbuildings, and RAJUK should monitor all the steps. But he was worried thatRAJUK is not doing this type of job as it does not have much capacity to doso. For the buildings constructed before 1993, he said that professional
followed other standard construction guidelines like American or British
construction code before the enforcement of BNBC in 1993.
4.2.2 Interview with the Director, BNUS:
In replying to the same question, the director said that common
people need not to know about the BNBC. It is very sophisticated andprepared only for the professional engineers, who will be responsible forbuilding designing and construction. He said HBRI could publish some easy
version message or poster from BNBC. So that common people canunderstand and monitor while professionals work on the construction. In
response to another question of why buildings do not legally follow BNBC

New Technologies for Urban Safety of Mega Cities in Asia

during construction, the director said that it is very tough to implement this.
RAJUK is responsible to implement the BNBC as a designated enforcing
agency. But it does not have enough manpower to do so. He suggested thatRAJUK should outsource this issue to outside developers initially forseveral years. By this time, RAJUK can develop its capacity. In replying toanother question of how to ensure the capacity of buildings that wereconstructed before 1993, he said that BNBC does not have such provision ofevaluating existing building’s capacity. But the BNBC is going to be revised
immediately. Direction for old and existing buildings and retrofitting
guidance will be there. He said that the advantage of including BNBC under
law is that it will ensure some punishment provision for those who violate
the implementation. But the great disadvantage is that there is no authority
to check this. He agreed with the question that local government should be
included in the process of implementation of the BNBC.
4.2.3 Interview with the Director, RAJUK:Director development control of RAJUK also thinks that common
people need not to know about the BNBC. The structural engineer should be
responsible for designing and implementation. He should issue a completion
certificate and based on that RAJUK will issue occupancy certificate. About
the building constructed before 1993, he said that RAJUK does not havemuch to do on that but some important social structure should be checked
and improved their capacity to use in disasters. He does not think that local
government can be involved in the implementation process of BNBC since
they do not have any power and technical capacity.
4.2.4 Interview with the Director, HBRI:
The director HBRI said that common people should know thegeneral idea of BNBC, but they need not to know more. It is for thetechnical person. People should know that they have to take a completion
certificate from the technical person after completion of the building
construction and an occupancy certificate from the concerned authority
before they occupy the building to live. He said that he is not sure about thedirection for the buildings that were constructed before 1993, but
professionals would follow other standard code in designing andconstructing buildings. He said that at present there is an evaluation
program going on in Dhaka to check the status of buildings that wereconstructed before 1993. After getting the result, the government can takeaction for retrofitting if needed. House owner may also do some retrofitting
which will be not much expensive. He said that BNBC should not be a partof law. It should be flexible for anytime revision. He also said that RAJUK
should employ Building Officials for inspection and local government
should be involved with the implementation process.
5. CONCLUSION
Dhaka is the fastest growing megacity in Asia with a high population
growth rate (3.34%) (Shah 2009). The city is characterized by poverty, risk

People’s Seismic Risk Recognition in Dhaka and Bangladesh National Building Code (BNBC) 1993

October 2010, Kobe, Japan

of natural hazards, shortage of housing, evacuation places and poor
infrastructures. Dhaka’s increasing population and expanding building
structure will be subject to high risk in large earthquake. The paper checkedinhabitant’s risk recognition and intention for safety measures through aquestionnaire survey. It described the following major results.
(1) Inhabitants anticipate earthquake as the most catastrophic
disaster for Dhaka, which may occur in 5-10 years time;(2) Building without proper design and engineering supervision willbe the main cause of destructed house in large earthquake;(3) BNBC 1993 is the guideline for earthquake resistant construction,
but it is not followed accordingly as mass people are not aware;(4) Inhabitants recognized risk and acceptable damage for theirbuildings. They showed their willingness to pay for safetymeasures of their buildings.
REFERENCES
Ansary, M.A., and Rashid, M.A., 2000. Generation of Liquefaction Map for
Dhaka, Bangladesh, paper presented at 8th ASCE Special Conference
on Probalistic Mechanics and Structural Reliability, University ofNotre Dame, Indiana, USA.
Ansary, M.A., 2004. Seismic loss estimation of Dhaka for an earthquake ofintensity VII. Oriental Geographer, Vol. 48, No. 1, January 2004
Al-Hussaini, T.M., 2003. Critical Elements for Earthquake Disaster in
Dhaka City, paper presented at USMCA 2003 Symposium on New
Technology for Urban Safety of Mega Cities in Asia, Tokyo, Japan.
Bilham, R., and England, P., 2001. Plateau 'pop-up' in the great 1897 Assamearthquake, Nature, 410, 806-809.
Hossain, Shahadat, 2008. Rapid Growth and Poverty in Dhaka City,
Bangladesh e-Journal of Sociology, v. 5, no. 1, Dhaka, Bangladesh.
Kamal, A.S.M. Maksud, and Midorikawa, Saburoh, 2004. GIS-based
geomorphological mapping using remote sensing data andsupplementary geoinformation: a case study of the Dhaka city area,
Bangladesh. International Journal of Applied Earth Observation andGeoinformation, v.6 (2004), p. 111-125.
Kato, Takaaki, Komiya, Mitstoyo, Kameno, Hiroaki, Sakei, Takuma, Murao,
Osamu, Ymazaki, Fumio, Kobiyama, Masayuki, 2002.
“Understanding the Local Characteristics of Earthquake Risk
Awareness of Residents in Sumida and Setagaya”, Proceedings of
the Japan Earthquake Engineering Symposium, Vol. 11, 2423-2428(in Japanese).
Shafi, Salma A, 2010. Implementation of National Building Code, paper
presented at Rights Workshop at National Press Club of Dhaka,Bangladesh.
Shah, Md. Faiz, and Murao, Osamu, 2009. A comparative study of urban
vulnerability between Dhaka and Tokyo, paper presented at USMCA
2009 Symposium on New Technology for Urban Safety of Mega
Cities in Asia, Incheon, Korea.

New Technologies for Urban Safety of Mega Cities in Asia

Application of Cluster Method on Integrated R
isk Analysis in a Building Fire

Yanyan CHU1, Xueming SHU1, Hong HUANG1, Dong LIANG2, Hui ZHANG1
1
Center for Public Safety Research, Department of Engineering Physics,
Tsinghua University, Beijing, China
chuyan@mail.tsinghua.edu.cn
2
The Key Laboratory of Guangdong Provincial Public Security Department on
Identification Technology of Fire Evidence,School of Engineering, Sun Yat-Sen
University, Guangzhou, China

ABSTRACTWith fire development and smoke propagation, occupant lives are threatened by
the dreadful environment, made up of high-temperature, smoke, carbon monoxide,
carbon dioxide, etc. It is crucial to analyze the fire condition and optimize theevacuation strategies to win the time for occupant evacuation. But the adverse
effect cannot be intuitionistic described by a mathematical model. So a multivariable statistics method is used to analysis the coupled effects of all the factors.
Using the two-step cluster analysis method, multi-factor injury risk can beevaluated considering adverse effect of high temperature, carbon monoxide andlack of oxygen. Fire simulation experiments have built a virtual fire information
platform to provide data for risk calculating and the multi-dimension data set canbe grouped automatically by calculating the similarity of space state and danger
state or safety state using the likelihood distance function. And a dynamical risk
map is generated to show the state of fire development and smoke propagation. l.
The model can get a dynamic integrated fire risk map, adverse factor range forevery risk level, etc. to support evacuation command and control.
Keywords: Two-step cluster; Building fire; Injury factors; Fire risk
1. INTRODUCTION
Decorated materials, furniture and office stationary in a modern building containsome kinds of chemical ingredients. In a fire, those elements can produce many
harmful substances such as high temperature smoke, carbon monoxide, carbon
dioxide, etc., which can affect the safety of the occupants. To make an effective
rescue plan, hazard level of every zone in a building should be analyzed
dynamically. Injury risk analysis in a fire space is a multi-factors problem. At
85℃, three degree burn injury can be formed in 10s (Cooper etc., 1985). Too highconcentration of carbon monoxide and carbon dioxide can harm the ability of
judgment and movement (Li Y Q, 2005). And impact on human of hightemperature, smoke, carbon monoxide, carbon dioxide, etc. can be coupled witheach other. The factors can reduce a person’s capability of judging, acting and0ctober 2010, Kobe, Japan

memory. Kataoka has explored the influence of high temperature of 40℃ on thechange of heart rate variability and blood pressure (2005); Yu Xuejun focused on
the thermoregulatory, cardiovascular, pulmonary, biochemical and molecularbiological responses of man to heat stress (2000). But there is no sufficient
medical data and the adverse effect cannot be intuitionistic described by amathematical model. To solve the problem, multi-statistics method may be useful
to fill up the deficiency and the integrated fire risk level can be got by thecomparison of similarity of space state and danger state or safety state. With thedevelopment of information and sensor technology, various sensors have been
installed in the building. It is possible to generate a risk map in a building fireutilizing sensor information. Such map will be important for occupant evacuation
and rescue planning.
In this paper, to demonstrate the function of algorithm, the fire risk algorithm has
been applied in a typical building. Instead of real sensor data, fire simulation is
performed to build an information platform to provide the necessary information
for risk calculating. An integrated risk map can be determined in a building fire
through information data classification by the likelihood distance measure. The
results can be useful to make evacuation and rescue decisions and make proper
emergency measures.
2 PROBLEM SETUP
An algorithm will be developed in the paper to discuss the fire risk map in a
typical building, shown as Figure 1. The office zone is usually divided into
several rooms by office divisions based on tenement requirements. Every officezone has at least an exit to the corridor. In the building, the office zone is about
900 m2. the height of building is 2.7 m. Smoke extraction vents lie in the ceilingshown as Figure 1. Locations of doors and walls are shown in Figure 1. The fire isassumed to occur in zone 25. Fire simulation will be used to generate a fire
scenario and sensors are assumed to locate in the office zones shown as Figure 1.

EXIT1

Figure 1: Fire simulation model
3 FIRE RISK EVALUATIONG ALGORITHM

New Technologies for Urban Safety of Mega Cities in Asia

With fire development and smoke propagation, various sensors, information
related to fatal factors, such as temperature, toxic material concentration, etc. canbe obtained and form an information network G ( E , A) , where the sensor location
is denoted by set E = {e1 , e2 , L , en } and the information type is represented by A .
If temperature, carbon monoxide and oxygen concentration are selected as
information characteristic values, the information type set will be described as
A = {T , CO, O2 }. Risk of each zone at every time can be analyzed using a two-stepcluster method.
3. 1 Fire risk analysis algorithm based on two-step cluster method
At present, most of fire risk analysis models focus on the impact of a single fatal
factor and cannot show the integrated impact of multiple factors. A multi-variable
statistics method is needed to realize analysis of multi-dimension data set. The
two-step cluster analysis method, a multivariable statistics method, can group themulti-dimension data set automatically by distance. Using the method, theintegrated fire risk map can be obtained based on sensor information which ismade by some fatal factors such as smoke temperature, oxygen concentration,
carbon monoxide concentration, etc. With this method, fire risk can be obtained to
optimize evacuation path.
(1) Construction of the cluster feature tree (CFT)During the course of constructing the cluster feature tree (CFT), first step is tosearch class centers. All the measured data is reviewed to ensure the class centerand a likelihood distance is used as similarity measure criterion. The measured
data can be classified by the similarity measure with nodes in CFT and become a
new node of the tree. Finally CFT tree can be constructed. The safe criterion
sample and dangerous criterion sample are selected as two class centers. And theclassification information includes three continuous variables. The likelihood
distance can be calculated by the logarithm likelihood function as follows:d (i, s ) = ξ i + ξ s + ξ (i ,s )

(1)

 p 1

q



 j =1 2

j =1

ξi = −ni  ∑ log(σˆ ij2 + σˆ 2j ) −∑ Eij 

(2)

mj

Eij = ∑ πˆ ijl log(πˆ ijl )

(3)

l =1

Where, σ ij2 variance of continuous variable wiakTj ； π ijl the probability of variable
having L value in zone k.
(2) Bayesian information criterion (BIC) classification
Second step is to group leaf node in CFT using bayesian information criterion(BIC). If BICk / BIC1 < 0.04 , K is the cluster result of every node. BICk can be got
as follows :Application of Cluster Method on Integrated Risk Analysis in a Building Fire0ctober 2010, Kobe, Japanklk = ∑ ξ v

(4)

v =1

BICk = −2lk + rk log n(5)Where, lk is the maximum value of likelihood function; rk is number of modelqparameter rk = k ×(2 p + ∑ n − 1) .
k =1

3.2 Zone risk calculating
Risk level of every sensor in the zone has been obtained by two-step cluster
analysis. And zone fire risk can be got by risk level probability calculation. Zone
fire risk can be calculated as follows:3

Risk ' = ∑ riski ×p (riski )

(6)

i =1

Where, Risk ' is zone fire risk； riski the risk level of some sensor in the zone；
p (riski ) is

theprobability

of

the

risk

level

riski inthezone ，p (riski ) = NUM (riski ) / n .

4 EXPERIMENT RESULTS AND DISCUSSION
The purpose of this paper is to generate the dynamical risk mapping during thefire if the information is available. It is noted that in reality, only part of
information can be obtained. Such study will provide the maximum possibility inoccupant safety using fire information from simulation results. High temperature,
carbon monoxide poisoning and lack of oxygen are selected as characteristics offire risk. Fire risk evaluation method is applied to the building as shown in Figure
1. The fire risk is set to be four levels, e.g., safe, low risk, moderate risk, and highrisk, indicated as levels 1~4. Information type will be set as {T, CO, O2}. Safe orhigh risk criterion is selected according to criteria such as NFPA101 and Japanesebuilding fire protection design, evacuation and refuge safety design method, etc.
Most dangerous criterion parameter value is set as (80, 150, 0.15). Normal indoor
state is selected as the safest criterion parameter value, which is (20, 0, 0.25).

4.1 Fire simulation results
FDS from NIST is selected for fire simulation. Fire source is assumed to be thepropane gas combustor and located at the right top of the floor. Fire source islocated in the floor and the area is about 4 m2. Fire location is shown in Fig. 1.
Office fire is developed under sprinklers and smoke extraction equipments action.
Meshes are divided using the non-uniform partitioning method. The total numberof mesh is 100×50×12. Simulation time is 1800 s. Fire heat release is assumed to
be developed according to t2, heat release can be obtained as follows:

New Technologies for Urban Safety of Mega Cities in Asia

Q = 0.0469 × t 2(7)

The maximum fire power is set to be 2MW and fire develops to the maximum fire
power at 180 s. Average temperatures, carbon monoxide concentrate and oxygen
concentrate distribution at 1.8m height in 500 s is shown as Figure 2.

(a)

T/(℃)

(b)

(c)

CO/(mg.m-3)

O2/(%)

Figure 2: (a) Temperature; (b) carbon monoxide concentration; (c) oxygen
concentration distribution at 1.8m height.

4.2 Multi-factors fire risk analysis
Using simulation results as sensor information, building risk can be analyzed
using the risk evaluation model. Factors importance was be ranked by significancetesting. The risk of each zone and fire risk map can be obtained.
(1) Ranking of variable importanceAn integrated risk map is generated based on evaluating the influence of hightemperature, too much carbon monoxide and lack of oxygen. Every factor has
different importance to risk analysis. By significance test, the importance of every
variable to high risk cluster can be sorted. Significance test is performed todetermine if an observed variable of statistics differs enough from the overall data
set. A p value is reported for the test of probability of a variable with thesignificance different in the overall data set. And a tolerant confidence level p
should be set for the test of probability of a variable's distribution within high riskcluster results versus the overall variables.
Figure 3 were plotted to show the importance rank of each variable. And atolerance confidence value is set as 95, shown as vertical lines in Figures 3. From
the figure, it is shown that weather the importance of the variables reaches the
specified confidence level. From the plot, it is shown that CO is obviously more
important at the early period of fire. With fire developed, temperature becomes
the key factor gradually. At 500s, significance of all the factors is beyond theconfidence level. Fire risk map should be developed based on all types of sensor
information.

Application of Cluster Method on Integrated Risk Analysis in a Building Fire0ctober 2010, Kobe, Japan

Figure 3: Ranking of importance at (a) 100s; (b) 200s; (c) 350s; (d) 500s
(2) Fire risk analysis by two step cluster
In case of a fire in zone 25(shown as the red zone in Figure 4(a)), smoke willpropagate along the ventilation network of building (shown as Figure 4), Based on
the virtual fire information platform by simulation results, integrated risk
assessment was applied to the building, shown as fig. 1. temperature, CO and O2
were selected as indexes and risk assessment results of room with fire, the roomand corridor neighbor fire room at 100 s～400 s are shown as Figure 4 (a).
At 100 s, fire is at the early stage of development. The change of temperature, CO
and O2 concentration of the room with fire and the corridor neighbor fire room are
greater than other rooms. So the adverse environment of the room with fire may
cause person causality. By calculated, risk level of the room with fire and thecorridor neighbor fire room are low risk and other rooms are safe because thehigh-temperature smoke has not be propagated to them. At 200s, temperature andtoxic content of room with fire are increased and oxygen content is decreased
rapidly with the development of fire. The probability of injury persons of hightemperature and other adversities of room with fire and the corridor neighbor fireroom is high relative to other rooms. By calculated, risk level of the room withfire is high risk and the corridor neighbor fire room is moderate risk and otherrooms are low risk. At 500s, with smoke propagation, the corridor neighbor fireroom is dangerous. The state of the corridor is similar to fire room than otherrooms. By calculated, risk level of the room with fire and the corridor neighborfire room are high risk and other rooms are moderate risk. An integrated fire risk

New Technologies for Urban Safety of Mega Cities in Asiamap at 100s, 200s, 350s, 500s by multi-factor analysis has been generated shownas Figure 5. From Figure 5, it is shown that the rooms of the building gradually
become dangerous with the smoke propagation from fire room to the corridor andthe other rooms with development of the fire.

（b）

EXIT
2
7
2

1
EX
IT2

19

20

18

21

17

3
16

4
15

14

22

5
13

12

23

24

11

6

8

10

9

25

(a)

Figure 4: Risk evaluation results of zones. (a) Smoke Propagation Network; (b)risk evaluation result of zones.

Figure 5: Fire risk map of building at 100s, 200 s, 350 s, 500s

5 CONCLUSION
Fire risk evaluation algorithm has been developed to generate fire risk map
utilizing sensor information. It can generate a fire risk map considering adverse
effect of high temperature, carbon monoxide and carbon dioxide, and realize thetransformation of real-time signal to visualization risk distribution. The fire risk
map is a comprehension result of multi-factors influence and conforms to thedevelopment of fire. It is the intuitionistic presentation of the impact on human by
fire. And the risk map is useful to grasp the development of fire. Factuality of themethod depends on the type and amount of the information. Information
requirements should be analyzed to get an optimum fire risk map.

ACKNOWLEDGEMENT
Application of Cluster Method on Integrated Risk Analysis in a Building Fire0ctober 2010, Kobe, Japan

This Research is supported by National Natural Science Foundation of China(Grant No. 70833003) and China Postdoctoral Science Foundation (Grant No.
20100470114).

REFERENCES
Purser D A. Toxicity assessment of combustion production. SFPE handbook offire protection engineering, National Fire Protection Association, Quincy,
Massachusetts, Third edition, 2002
Cooper L Y, Stroup D W. ASET-A computer program for calculation available
safety egress time. Fire Saf J 1985;9 (1) : 29–45
Li Y Q. Building Fire Performance-based Design. Beijing: Chemical Industry
Press, 2005
Kataoka Y, Yoshida F. The change of hemodynamics and heart rate variability on
bathing by the gap of water temperature. Biomed Pharmacother 2005; 59: s92—
s99
Yu Xuejun. Human Physiological reactions to Heat Stress in Space Flight.
XiAn：Fourth Military Medical University,2000
Zhang Guogao. Biology and Health in High Temperature. ShangHai: ShangHai,
Science Technology Pr, 1989
Liu Naian, Liu Qiong, Deng Zhihua, et al. Burn-out time data analysis on
interaction effects among multiple fires in fire arrays. P Combust Inst, 2007;
2:2589-2597
Chu Yanyan, Zhang Hui, Rui Yang, et al. Simulation Study on Building Fire
Smoke Control Strategy Based on Fire and Occupant Information. J Tsinghua
University 2010; 8:1-7
Chu G Q, Sun J H. Decision analysis on fire safety design based on evaluatingbuilding fire risk to life. Safety Sci 2008;46(7): 1125– 1136
CHU Yanyan, ZHANG Hui, et al. Development a mode to generate a risk map in
a building fire. Sci China Ser E-Tech Sci 2010; 2(53):1-9
Zhu Y C. Application of two step cluster model (in Chinese). Market Res
2005;1:40–42

New Technologies for Urban Safety of Mega Cities in Asia

Emerging web and geospatial technology
revolutionizes disaster responsewith public involvement
Akiyuki KAWASAKI1, and Kimiro MEGURO2
Project Assoc. Prof., ICUS, Institute of Industrial Science,
The University of Tokyo, Japanakiyuki@iis.u-tokyo.ac.jp
2
Professor, Director, ICUS, Institute of Industrial Science,
The University of Tokyo, Japan

1

ABSTRACTThis paper examined how disaster response and relief efforts changed in recent
years, driven by new web-based geospatial technologies. The purpose of thisarticle is to examine how disaster response and relief efforts have been changing
along with recent geospatial technological development, mainly from Haiti
earthquake response in 2010. This paper outlined how conventional disaster
responses used GIS, which were mainly provided by government agencies andnon-profit organizations; and how they have been transformed into a more
dynamic, transparent and decentralized process with broader participation. The
paper started with a brief overview of historical changes in the utilization of
geospatial technologies in major devastating disasters, including the Haiti
earthquake in 2010. We documented changes in available geospatial dataset types
and responders, examined new trends in data creation, management, sharing andvisualization; analyzed the impact of geospatial technology development on relief
efforts; discussed lessons learned from recent disaster responses; and shared ourthoughts for future improvement.
Keywords: web-mapping, public involvement, crowd-sourcing, disaster response,
Haiti earthquake

1. INTRODUCTION
Mortality and direct economic loss appear to be highly concentrated
geographically and associated with a very small number of disasters (ISDR, 2009).
Five of the ten disasters with the highest death tolls since 1975 have occurred injust the last five years1. Also, five of the ten disasters with the highest economic
loss have occurred in the last six years1. Management and use of maps andlocation information were critical for effective response activities in many ofthese disasters. The approach of disaster response and relief efforts has beenchanging with the current development of geospatial technologies such as
Geographic Information System (GIS), Remote Sensing, and Global Positioning
System (GPS).

October 2010, Kobe, Japan

In conventional geospatial response to disasters, mapping activities wereconducted mainly by professional geospatial groups from governmental agencies,
relief response organizations and GIS vendors in support of decision making on
the ground. Damage information was intensively collected and decision-support
maps were created, edited and printed at a centralized emergency operation centerin the damaged areas using desktop and workstation GIS systems, and information
was disseminated in top-down manner. However, in addition to conventional
centralized disaster response by professional groups, recent development of web
mapping technology has led to more dynamic, more transparent, and more
decentralized disaster response supports conducted with a wider range ofparticipation, including both formal and informal individuals and organizations
from both inside and outside the damaged area. This movement started to emerge
in the disaster response during the Chuetsu earthquake in 2004, and during
Hurricane Katrina in 2005 it was further developed with additional technologicaldevelopment and the changes in social awareness. Finally, its form was fully
revealed in the Haiti earthquake in January 2010.
The purpose of this paper is to outline how disaster response and relief efforts
have been changing along with recent web-based geospatial technologicaldevelopment, mainly from the Haiti earthquake response, and investigates which
factors of these technological developments affect disaster response support.
Although emerging interactive information technologies such as wiki, Twitter,and blogs are also playing important roles for recent disaster response and relief
efforts (Mills et al., 2009, Zook et al., 2010, Underwood, 2010), this paper focuseson outlining how web-based geospatial technological development has beenchanging approaches to disaster response and relief effort.
At the beginning, historical changes in the utilization of geospatial technologies inmajor devastating disasters are briefly reviewed until the Haiti earthquakes in2010. We examine the change in available dataset type and geospatial disaster
responders, then the impact of geospatial technological changes on disaster relief
effort are examined in order to investigate which factors of the technologicaldevelopments affect disaster response support. Finally, the paper discusses lessons
learned from recent responses and some thoughts for future development.
2. MAJOR CHANGES IN DISASTER RESPONSE
For the most part, it’s generally assumed that government or other relief entities
such as the United Nations are the primary actors in disaster response and relief,
with NGOs playing a secondary role. However, public interest and demand forgeospatial information in disaster response and relief has been rapidly increasing,and the opportunity for volunteers to assist in disaster response via mapping andspatial analysis has significantly grown along with geospatial technologicaldevelopment. This section describes how development of web-based geospatial
technologies has affected the awareness and involvement of a wide range ofdisaster response participants.

New Technologies for Urban Safety of Mega Cities in Asia

2.1 Availability of aerial and satellite imagery from the private sector
Regarding satellite and aerial remote sensing imagery, the tendency to provide
high-resolution (high-res) satellite imagery to the public for free has been
increasing, not only by space agencies and institutes in various countries, but also
by commercial companies (Table 1). Nowadays, observation frequency of sensors
and satellites is increasing year by year. Within five days of the earthquake in
Haiti, many high-res satellite images from more than 15 organizations in eight
countries were collected and made freely accessible at the websites of theInternational Charter, UN-SPIDER, etc. The list of remote sensing imagery used
for the Haiti earthquake is shown in Table 1. The quality and quantity of available
satellites and sensors have greatly increased since the time of the World Trade
Center attacks in 2001. In Haiti, more than half of the satellite data providers werecommercial companies from various countries such as DigitalGlobe and GeoEyefrom USA, RapidEye from Germany, and SpotImage from France. Some
organizations such as DigitalGlobe and NIED (National Research Institute for
Earth Science and Disaster Prevention) and JAXA (Japan Aerospace Exploration
Agency), distributed acquired imagery using their WMS (Web Map Service)server, which enabled users to easily obtain and use this geospatial datasets,
including the ability to deploy them in their own web mapping applications andmashups.
Table 1: Remote sensing imagery used during the Haiti earthquake in 2010
Data provider
NOAA (National Oceanic andAtmospheric Administration), USA
GeoEye, Inc., USA
DigitalGlobe, Inc., USA
EROS (Earth Resources Observation
Satellite) Corp., US and Israel
CNES (Centre National d’Etudes
Spatiales) and Spot Image, France
SpotImage

Satellite
Cessna Citiation
II (aircraft)

Prevention), and JAXA (Japan

1/13

IKONOS

1/17

Business type+

Commerc ial+

Commerc ial+

QuickBird

1/15
1/14

WorldView-2

1/15

EROS B

1/17

Commerc ial+

Spot 5

1/14

Non commercial

+

1/13

Commerc ial

Formosat-2

1/23 (Pan-sharpened)
ALOS

1/23 (PRISM)
1/13 (AVNIR-2)

Non commercial

1/16 (PALSAR)
1/15

Commerc ial

Radarsat-2

1/14

Commerc ial

China

HJ-1-A/B

1/14

RapidEye AG, Germany

RapidEye

1/13

Commerc ial

Infoterra GmbH, Germany

TerraSAR-X

1/14

Commerc ial

1/15

Non commercialand Associates Ltd., Canada

NASA, USA

Earth Observing
One (EO-1)

European Space Agency,

ERS-2

European Union

Envisat

KARI (Korea Aerospace ResearchInstitute, Republic of Korea

at OSMNon commercial

COSMO-SkyMed

MacDonald, Dettwiler

The useWorldView-1

Aerospace Exploration Agency),Japan
e-GEOS S.p.A., Italy

1/18

GeoEye-1

NIED (National Research Institute for
Earth Science and Disaster

First datesof acuirement

KOMPSAT-2

Non commercial
1/15

Non commercial

Emerging web and geospatial technology revolutionizes disaster responsewith public involvement+

October 2010, Kobe, Japan

Resolution of satellite images and aerial photographs has been improving andeven made it possible to identify damaged areas or blocked roads. After the
Kashimir earthquake, high-resolution images created controversy due to concernsthat national security could be compromised in the region where Pakistan andIndia have long fought (Butler, 2005a, Butler, 2005b) . However, the use of highres satellite imagery is absolutely imperative for response to devastating disasters.
Following the Haiti quake, many high-res satellite sensor images were madeavailable and used to create OpenStreetMap features. In this case, volunteers
viewed the imagery within the webmap mashups (such as the Haiti CrisisMap),then logged in with editing privileges to trace new features over the imagery or to
add textual annotations in the same mashup application (OpenStreetMap, 2010,
Zook et al., 2010).
2.2 Emergence of new geospatial responders
The largest change in awareness of geospatial response has been the increase inpeople willing to participate via the Internet (Zook et al., 2010, Laituri andKodrich, 2008, Underwood, 2010, Mills et al., 2009). This includes individuals
and organizations, professionals and amateurs, and people from both inside andoutside the damaged area. Traditionally, government agencies tend to depend on
their own internal information for the decision-making in response and relief
effort, but now the government is accepting external datasets created by nonauthorized people from outside the damaged area for decision-making.
OpenStreetMap data was broadly used by multiple agencies and NGOs on the
ground in Haiti; in fact, voluntarily-created geospatial information played acritical role in emergency response. This is especially true for volunteer labor.
Crowd-sourced mapping allows aid agencies to focus their limited resources onother needs that cannot be easily met via distributed volunteer workers (Zook etal., 2010). This has led to the development of a kind of divisional cooperation
between those inside and outside the damaged area, individuals and organizations,and experts and amateurs, and has changed the available dataset types andgeospatial responders as shown in Figure 1.
In many traditional disaster responses, prepared “GIS base maps” (mainly used
for daily work) such as buildings, land-use, critical infrastructure, andtransportation network were used as the core data source for emergency responseby overlaying these maps with the actual “damage information on the ground”
collected through patrols, calls from citizens, or “remote sensing imagery” taken
after the event, with professional geospatial response teams in charge of the entire
geospatial operation (Figure 1). The professional teams generally consist of a
“GIS specialist” for editing vector datasets and analyzing and producing maps forsupporting decision-making; a “remote sensing specialist” for georeferencing andprocessing satellite and aerial imagery; a “database specialist”; a “project
coordinator”; a “field data collector” who collects damage information andresponse progress on the ground using hand-set equipment with GPS; and a “webspecialist” for setting up a web mapping server and creating web applications.
They are primarily composed and managed by governmental agencies, relief
response organizations, GIS software venders, and organized volunteer groups

New Technologies for Urban Safety of Mega Cities in Asia

such as the above-mentioned GISMO in New York City, and mainly work at a
centralized emergency operation center on-the-ground.
Besides the traditional response participation by government agencies and relief
response organizations, the general public’s involvement in response activities via
the Internet has been growing drastically with the emergence of new technologies,
resulting in the emergence of a new style of disaster response – a networked
disaster response community – in addition to the traditional professional response
team as shown in the gray zone in Figure 1. These communities are comprised offormal and informal networks of people collecting, processing, and delivering
information where it is needed.
Plenty of actual damage information on the ground was disseminated by the ad
hoc citizen groups, local victims of the event and their families, and computerbased disaster response volunteers who collected and disseminated data in theform of text, blogs, video, pictures and maps (Laituri and Kodrich, 2008). “Field
data collectors” provided actual “damage information on the ground” throughtheir mobile phones using SMS (Short Message Services) or GPS cell phones withcameras. For example, the Ushahidi project disseminated victim’s reports as
mapped information about the suffering families, damaged housing and needs forfood sent via SMS from mobile phone. Such live information reportage included
items such as: children trapped in a collapsed school screaming for help; an 80year-old woman with a crushed leg who needed evacuation; the location of adrum of water-purifying solution (Smith, 2010). These real-time updates on where
help was most urgently needed or available -- originating as a wave of 20,000 text
messages and then mapped as 3,500 incidents -- helped to save lives and get
crucial aid to thousands of Haitians in the weeks after the quake (Smith, 2010,
Provencher, 2010).
Available dataset type

Geospatial disaster responder
GIS base maps
Transportation, land-use,building, infrastructure

Traditional
response
datasetRemote sensing imagery
Commercial
and non-commercial
Damage information on
the ground(Mobile, SMS, GPS)

Crowd-sourced
datasetPeer-production geospatial
data (OpenStreetMap)

Traditional
professional
responder(Government
al agency,
relieforganization,organized
volunteer)

Crowd-sourced responder(Individual
volunteers)- GIS specialist(Vector editing, map design)- Remote sensing specialist(Satellite imagery processing)- Database specialist- Project coordinator- Web specialist(Web mapping, mash-up)- Collaborative data generator(OpenStreetMap)- Field data collector(Mobile, SMS, Field
computing with GPS)

Public domain shared data
(GeoCommons)Figure 1: Change in available dataset type and geospatial disaster responders

Emerging web and geospatial technology revolutionizes disaster responsewith public involvement

October 2010, Kobe, JapanAs a “collaborative data generator”, OpenStreetMap has played an important rolein the response activities in Haiti. OpenStreetMap is a project to create free “peerproduction geospatial data” such as road and railway networks available for use
by anyone through the web. Thousands of volunteers from outside the country
joined the project to create and edit maps on a wiki-like environment. Within a
few days of the Haiti earthquake, OpenStreetMap community started to help the
response teams by tracing Yahoo imagery and other data sources and createdvarious datasets on the island such as roads, railway, waterways, place names fortowns, and buildings including damage assessment information. Extracts of thesefrequently updated datasets for Haiti are also downloadable in OpenStreetMap assource files, Garmin GMAPSUPP.IMG files, and ESRI shapefiles. The details of
this activity are described by Zook et al.(2010).
As a “public domain shared data” site, GeoCommons was used to promote
geospatial data sharing on the web. This allows us to upload, organize and share
geospatial data and to quickly find data with easy search tools. It also has
functions for visual analytics through maps which require no prior training orexperience using traditional mapping tools. At GeoCommons, new contents were
uploaded or downloaded in KML, CSC or shapefile formats. GeoCommons canbe a powerful platform for data management and sharing with visualization
functionality as well as analytic features because it has both raw data sharing
function for researchers and professionals, and provides visualization andanalytical tools for the general public. Crowd-sourcing is not limited to amateurs,
and the GeoCommons project illustrates how institutions can crowd-source theirinternal data to facilitate better data sharing and collaboration (Zook et al., 2010).
3. RELATIONSHIP BETWEEN WEB-BASED GEOSPATIALTECHNOLOGICAL DEVELOPMENT AND CHANGE IN DISASTERRESPONSE SUPPORT
It is said that “the year 2005 was a watershed for GIS on the Internet” (Butler,
2006), and there have been many major technological developments since then.
We believe this affected awareness over a wide range of participants indevastating disaster response in terms of available datasets and geospatial
responders. Through the response activities for the three recent devastating
disasters in Sichuan, Haiti and Chile, we found that current web-based geospatial
technology development has been changing the way disaster response and relief
efforts are conducted. The Haiti earthquake is the first disaster in which opensource, online platforms are being heavily utilized (Forrest, 2010, Zook et al.
2010). This section describes three incremental stages of web-based geospatial
technological development, namely “web mapping and geospatial data browsing,”“web-based data exchange and development,” and “mash-up live editing on theweb”. The timeline of this technological development and devastating disasterhistory and the total image of the impact of web-base geospatial technologicalchanges on disaster response effort, are shown in Figure 2.

New Technologies for Urban Safety of Mega Cities in Asia

Figure 2: An overview of recent devastating disasters and the impact of changes
in geospatial technology on disaster relief effort
4. LESSONS LEARNED AND SOME THOUGHTS FOR THE FUTURE
4.1 Power of crowd-sourcing
At the time of the Sichuan and Haiti earthquakes, organizations were responding
separately and coordination among interested parties had by no means beensolved. This led the Center for Geographic Analysis (CGA) to establish ageospatial portal, and through their experience CGA found that the sooner the
portal starts, the more likely connections to the wider community would occur.
The data had to be both portable for users to acquire and at the same time easy tobrowse online, and all of the content had to be freely available to everyone.
Historically, both data creation and mapping in support of disaster response
required professionals skillful in GIS who also had access to a broad set of datafor base mapping (Curtis et al., 2006, Radke et al., 2000, Zook et al., 2010).
However, advanced GIS skills are no longer required to meaningfully contributespatial data for disaster response. Oftentimes, GIS information that is needed for
immediate emergency response is inherently simple, requiring not complex
analytical procedures but rather reliable and adequate data (Laituri and Kodrich,2008). Geographic information need only be good enough to assist recovery
Emerging web and geospatial technology revolutionizes disaster responsewith public involvement

October 2010, Kobe, Japan

workers using the maps, meaning that crowd-sourced information is likely to bejust as helpful as that produced by more centralized means. Given the need indisaster response for reliable maps the model of peer-produced mapping provides
a number of new avenues for producing and accessing spatial data, besides the
traditional top-down GIS provision models (Zook et al., 2010).
Perhaps the greatest benefit to this form of distributed mapping is in the greater
quantity of geodata that can be produced and published in a shorter period of time,allowing scarce technical resources to be diverted elsewhere. This is oftentimes
faster than government agencies (Laituri and Kodrich, 2008). Crowd-sourcing isabout more than just volunteers and amateurs, however – it is about creating
fluidity in data sharing and collaboration by breaking down barriers to technology
and participation through the web, open standards, and simplified interfaces.
However, the rapid response and reliable data are only part of the picture ofcrowd-sourcing: we also need to consider how the crowd-sourced information was
actually processed and vetted, then fed into the live mash-ups. We have torecognize this basic part of the infrastructures to understand why the Ushahidi
team was so successful. Ushahidi set up a system of SMS and phone banks where
volunteers received information in real time, which other teams of volunteers
checked and evaluated as incoming streams of information, then approved items
that would appear instantly on their website (Smith, 2010, Provencher, 2010). The
data management process of a crowd-sourcing operation is the key element that
determines the success or failure of this new data creation endeavor.
4.2 Need for disaster response plans which utilize networked disaster
response community
Disaster communications used to be strictly top-down, hierarchical and linear,where public officials and experts were the ones who pushed the information out(Mills et al., 2009), but experience has shown that this approach to data sharing indisaster management is not entirely effective (Radke et al., 2000). Except for
special cases such as Haiti, where the central government collapsed, agovernmental agency or relief response organization should play a centralized rolefor coordinating general disaster response. Considering the scale and complexityof the problems presented by recent disasters it was evident that no stakeholder
alone could tackle them, exposing the need for greater collaboration (Pezzoli et al.,2007). Therefore, government and relief response organizations have tounderstand how to harvest energy from this new movement in the web-based
geospatial technological development and emergence of crowd-sourced
responders. Crowd-sourced disaster response demonstrated the power and speedwith which people could disseminate information (Laituri and Kodrich, 2008). It
is important to have an established plan that includes this crowd-sourced
movement in order to maximize the use of volunteers in the geospatial responseand direct resources from all over the world (Zook et al., 2010, Curtis et al., 2006).
In addition, collaboration and coordination between governmental agencies, relief
organizations, and commercial companies remain problematic due to conflicting
missions, data security issues, and inadequate funding of emergency response
technologies (National Research Council, 2007, Laituri and Kodrich, 2008).
New Technologies for Urban Safety of Mega Cities in Asia

Understanding the capabilities of the crowd-sourced disaster responders offers an
opportunity for integration of local perspectives and skills to augment agencies
stretched to capacity by a devastating disaster and inadequate funding (Laituri andKodrich, 2008).
At the same time, some effort needs to go into coordinating the crowd-sourced
data streams (which can be collected and processed anywhere) with disseminating
live information to the people on the ground (which can only be done on site andwhich usually has no power, no internet access, etc.). From an author’s
conversations with US Department of Health and Human Services staff and thefirst responder agencies, what was really missing was the ability to feed the
updated info about the situation on the ground directly into the hands of the onsite responders. For example, Ushahidi did a brilliant work of getting
OpenStreetMap coverage digitized for Port Au Prince and added tons of useful
fresh information about road blockages, food and water distribution points, etc.
However, those webmaps were not available to the responders on the ground.
What was missing was just a clearinghouse at ground zero, like a phone bank orjust a black board, where some kind of live updates could be kept track of,indicating which hospitals had open beds and what kind of surgeons orequipments on site. The responders just need to immediately get an injured person
to the facility that was closest and had staff and capability of treating the casualty.
There are discussions whether governmental agencies should lead this role for
information centralization or other entities in the distributed network should takethis role (Rajabifard, 2006). Governmental agencies tend to hesitate in sharing
data to external entities due to its organizational characteristics (Elwood, 2008,
Harvey and Tulloch, 2006, Tombs, 2005), but creating barriers for collaboratingwith crowd-sourcing responders should be avoided. Even though a government
agency needs to limit data sharing to some degree, they also have to maximize
their limited sources by integrating external resources. Data sharing has to always
remain highly available for the public.
4.3 Quick response vs. long-term strategy of geospatial database development
Zook (2010) suggested that detailed databases which used to take years to create
now had to be accomplished in a matter of days using collaborative user
environment such as OpenStreetMap. It is true that this kind of activities is usefulfor emergency response against disaster. At the same time, however, we wonder ifthese datasets can be utilized in long-term recovery planning and rebuild. Featuredatasets created through OpenStreetMap are in a simple GIS format; this is not awell-structured spatial data model with modeling and analytical capabilities suchas ESRI’s geodatabase data model. It is a good opportunity to creating geospatial
datasets after a devastating disaster, especially in developing countries. A newcomprehensive geospatial database could be useful not only in emergency
response but also in long-term national or regional planning, including addressing
other issues such as climate change adaptation and global warming mitigation.
The development of multifunctional databases allows a variety of applications
such as revenue collection, natural resource protection, land-use planning, andinfrastructure planning as well as disaster planning (Laituri and Kodrich, 2008,
Montoya, 2003). Long-term strategy for building and utilizing such
Emerging web and geospatial technology revolutionizes disaster responsewith public involvement

October 2010, Kobe, Japan

multifunctional geospatial database should be considered so that we do not waste
the effort to create a variety of datasets which was intensively devoted to disaster
response through humanitarian crowd-sourcing.
5. CONCLUSIONSThis paper examined how disaster response and relief efforts have been changing
along with recent geospatial technological development through Haiti earthquake
responses. This paper outlined how conventional GIS disaster responses bygovernmental agencies and relief response organizations and the means forgeospatial data sharing have been innovatively transformed into a more dynamic,
more transparent, and decentralized form with a wide range of participation.
Web mapping and geospatial data browsing with high-res satellite images andadvanced data exchange and web mapping technologies have combined
professional expertise and public involvement on a common geospatial platform.
In addition to the conventional governmental approach, open source and voluntary
activities are greatly expanding and developing. Coordination of interactive
collaboration for using such crowd-sources and conventional professional
response is essential for better response, but to achieve that an understanding of
the trend in technologies is essential.
Geospatial technology is still rapidly expanding and growing. Looking towards
the future, we hope to extend the overview of disaster events into topical sections
devoted to particular fields of research, such as public health, civil engineering,
economics, and more by tracking the lives of those displaced by the earthquake
and by observing remediation efforts. We hope this paper shows such aperspective on the future.
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New Technologies for Urban Safety of Mega Cities in Asia

Classification of Building Area
using Slanted Angle and Density Indices
Derived from Polarimetric SAR Data
Shogo IWASA 1 and Junichi SUSAKI 2
Master Student, Department of Urban and Environmental Engineering,
Graduate School of Engineering, Kyoto University, Japanmiwasan1023@yahoo.co.jp
2
Associate Professor, Graduate School of Global Environmental Studies andGraduate School of Engineering, Kyoto University, Japan
1

ABSTRACT
Urban extraction is one of the most expected applications using remote sensing,but the automatic extraction has been challenging. Especially in the field ofsynthetic aperture radar (SAR) applications, the complex scattering in the urban
area is sensitive to the building spatial arrangement, and it prevents from theextraction. Spaceborne polarimetric synthetic aperture radar (POLSAR), an
advanced approach to SAR, has been operated since ALOS/PALSAR was
launched in 2006. Several indicators derived from POLSAR data have beendeveloped to classify landcovers, and some of them have been utilized to extract
the geometric features of the target. So as a first step, we measured thebackscattering from the concrete blocks arranged in different slanted angles anddistances in an anechoic radio wave chamber. In this experiment, it was found theinterrelation between spatial arrangement and such polarimetric indices. As aresult, it is demonstrated that Polarization Orientation Angle (POA) is a good
detector for slanted angle of man-made structures, and of all the indicators,
entropy has the highest correlation with building density. Then, using satellite
polarimetric data, we discriminated urban areas according to the classifier using
POA and entropy. The comparison with aerial photo indicated that POA is aneffective indicator to extract the slanted buildings and that there are some areas
where entropy distinguishes the difference of building density.
Keywords: urban extraction, POLSAR, POA (Polarization Orientation Angle),
entropy

1. INTRODUCTION
From the viewpoint of city planning or disaster prevention, spatial arrangement
and structures of buildings in urban areas are important data. While accurate
measurement of such urban features using terrestrial sensors such as LiDAR(Light Detection and Ranging) is quite costly, the airborne or spaceborne sensors
are expected to measure the widespread data at a relatively low-cost. Especiallysynthetic aperture radar (SAR) is highly expected for immediate observation after
disasters and so on, for it is available even at night or in bad weather. However,accurate urban monitoring by SAR has been difficult so far, because the result is

October 2010, Kobe, Japan

seriously affected by relative slanted angle of measured buildings to observation
direction.
Polarimetric synthetic aperture radar (POLSAR), an advanced approach to SAR isreported to detect various information of land surface which cannot be acquiredby optical sensor. Several indicators derived from POLSAR data have beendeveloped, and some of them have been utilized to extract the geometric featuresof the target. One of such indicators is Polarization Orientation Angle (POA),
which is reported to estimate slanted angle of the target (Kimura et al., 2005). In
addition, the indicators related to the density of the target are also proposed.
Utilizing these indices in urban area, reliability of monitoring could be better.
Therefore, the objective of this research is to improve the accuracy of extractionof urban area from POLSAR data, and we aim at the method which is independentof slanted angle and can detect spatial arrangement (density, height) of thebuildings.

2. USED INDICESPOLSAR data has the complex scattering matrix given by
S

S hh

S hv

S vh

S vv

a c
c b

(1)

assuming that Shv and Svh are equivalent. The indices shown in this section are
derived from this scattering matrix. Further, some indices utilize the coherency
matrix represented by
a b

T11 T12 T13T2(a b)(a b)2

T21 T22 T23(a b)(a b)a b

T31 T32 T33

2c(a b)2c(a b)2(a b)c2(a b)c4c(2)

2

2.1 Polarization Orientation Angle (POA)
Polarization Orientation Angle
S( )

cos
sin

compensates scattering matrix as follows
sincos

a c cosc b sin

sin
cos

(3)

is determined so that the target would stand perpendicular to the orbit
4 Re( a b c )
1
tan 1
2
2
4
4c
a b

(4)
4

4

New Technologies for Urban Safety of Mega Cities in Asia

This is the same as the minimization of T33 element of coherency matrix, and
POA is equal to the phase term of circular polarization coefficient. POA isreported to estimate slanted angle of the target.
2.2 Entropy (Cloude and Pottier, 1997)
Coherency matrix can be diagonalized using unitary matrix U as follows

T

where

1,

2 and

T11 T12 T13

1

T21 T22 T23
T31 T32 T33

U 0
0

0

0

2

0 U

0

3

(5)

3 are the eigenvalue of the matrix T. Entropy H is given by3

H

Pi log3 Pi

(6)

i 1

where
i

Pi
1

2

(i 1,2,3)(7)

3

Entropy shows the randomness of scattering. Only surface scattering would occur
in H=0, while various scattering (e.g. surface scattering, volume scattering, double
bounce scattering) would randomly occur in H=1. Entropy is often used in land
cover classification.
2.3 Four-Component Decomposition (Yamaguchi et al., 2005)
Four-component decomposition has been developed from three-component
decomposition (Freeman and Durban, 1998). In this method, measured
polarimetric scattering wave is decomposed into scattering components based on
physical scattering process: surface scattering (Ps), volume scattering (Pv), double
bounce scattering (Pd), and helix scattering (Pc). Scattering matrix is decomposed
into the summation of the basic scattering matrices of the four components, andthen coefficients of the four matrices are calculated, which determines the powerof each component.
2.4 Target Decomposition Method (Dong et al., 1998)
Dong et al. proposed another decomposition model that is fit for urban structures.
The components derived after decomposition are double bounce scattering (DB),
odd bounce scattering (OB), bragg scattering (BS), and cross-polarized scattering(CS).

3. ANALYSIS OF X-BAND EXPERIMENTAL DATAClassification of Building Area using Slanted Angle and Density Indices Derived from
Polarimetric SAR Data

October 2010, Kobe, Japan

3.1 Experiment
On September 8 and 29, 2009, we carried out an experiment in the anechoic radio
wave chamber in Wave Engineering laboratory, Department of Information
Engineering, Faculty of Engineering, Niigata University. One of the purposes is to
examine whether POA is sensitive to slanted angle of man-made targets, the otheris to judge which index has the strong correlation with density of them. Used
radar system and object are explained below.
3.1.1 Radar System
The polarimetric measurement system which is capable of synthetic aperture
process was used. Figure 1 shows the radar and the zoom of its antennas. Each of
the four antennas corresponds to horizontal polarization transmit, horizontal
polarization receive, vertical polarization transmit, and vertical polarization
receive. The wave frequency is X-band (10 GHz), the antenna height is 180 cm,
and the incident angle is 45°.

10 10
10

d

Figure 1. (Left) Radar system for theexperiment. (Right) Zoom of its
antennas.

dφFigure 2. Schematic diagram of themeasured structure. d is the distance ofthe blocks (three distances), is theslanted angle of the blocks (sixangles).

3.1.2 Object to Measure
Nine concrete block cubes were arranged to measure and analyze thebackscattering. The cube has 10-cm length, and the arrangement of the blocks isdisplayed in Figure 2. As illustrated in the figure, blocks were placed on 3×3 grid.
The slanted angle of the structure was defined as 0° when the sides of the blocks
are perpendicular to the radar path. First, the structure was measured at 0°, then
the whole structure was rotated right-handedly in steps of 15°. Following the sameprocedure, the data at six slanted angles were measured. Moreover, at each slanted
angle, the structure was measured three times with the distance of blocks 10 cm,
15 cm, and 20 cm, i.e., the measurement was done eighteen times in total.
3.2 Results and Discussion
From the data acquired in the experiment, each index described in the previous
section was calculated.

New Technologies for Urban Safety of Mega Cities in Asia

The left graph of Figure 3 shows the relationship between POA and the slanted
angle of the blocks. It was found that POA and actual slanted angle have linear
relationship when slanted angle is set between 15° and 75°. Moreover, in theanalysis using four-component decomposition (Iwasa et al., 2009), it is provedthat Ps and Pd become greater if buildings are perpendicular to the radar path (theresult is shown in the right graph of Figure 3); thus slanted angle of the building
may be estimated using four-components together with POA.

0.25

6
4
2
0
-2
-4
-6

pow er ratio

P.O.Angle (°)

Next, Figure 4 demonstrates the relationship between entropy and the distance ofthe blocks. Entropy increases in all slanted angles when the distance changes from
10 cm to 15 cm, while it decreases in almost all the slanted angles when the
distance changes from 15 cm to 20 cm. Therefore, entropy and building density
may have nonlinear relationship. Furthermore, the relationship between fourcomponents and the distance of the blocks is shown in Figure 5. As seen in figures,no component has better correlation with the distance than entropy. Target
Decomposition Method was also investigated, and it was found that it did notshow good relationship with the distance of the blocks, either.

0

15

30

45

60

slanted angle (°)

75

Ps
Pv
Pd
Pc

0.2
0.15
0.1
0.05
0
0

15 30 45 60
slanted angle(°)

75

Figure 3. (Left) Relationship between POA and the slanted angle of the blocks.
(Right) Relationship between four-components and the slanted angle of the blocks.
Power ratio in the vertical axis means the ratio to the total power acquired in themeasurement of a conductor sphere. In this case, the distance of the blocks is 20
cm. The result was very similar when the distance is 10 cm or 15 cm.

Classification of Building Area using Slanted Angle and Density Indices Derived from
Polarimetric SAR Data

October 2010, Kobe, Japan

0.86

entropy

0.85

0°
15°
30°
45°
60°
75°

0.84
0.83
0.82
0.81
0.8
10

15
distance(cm)20

70

Pv contribution( ％ )Ps contribution( ％ )Figure 4. Relationship between entropy and the distance of the blocks.

60
50
40
30
20
15
distance(cm)

75
65
55
45
35
25
10

15
distance(cm)

20
15
10
5
0

20
Pc contribution( ％ )Pd contribution( ％ )

10

25

20

10

15
distance(cm)

20

10

15
distance(cm)

20

5
4
3
2
1
0

Figure 5. Relationship between four-components and the distance of the blocks.
(Upper left) surface scattering. (Upper right) volume scattering. (Lower left)
double bounce scattering. (Lower right) helix scattering

4. APPLICATION TO L-BAND POLSAR FOR BUILDING
CLASSIFICATIONIn the experiment described in the previous section, two indices turned out to beavailable for the estimation of urban structural quantities; POA is for slanted angle,
and entropy is for density. In this section, to discriminate urban areas extracted
New Technologies for Urban Safety of Mega Cities in Asia

from ALOS (Advanced Land Observing Satellite) / PALSAR (Phased Array typeL-band Synthetic Aperture Radar) polarimetric images, a decision-tree classifier is
proposed, which utilized the two indices. In addition to ALOS/PALSAR data,
ALOS/ AVNIR-2 (Advanced Visible and Near Infrared Radiometer type 2), oneof the optical sensors, is utilized to divide urban area and non-urban area.
4.1 Data
The 1.1 level PALSAR data provided by JAXA was analyzed. Level 1.1 is therange- and azimuth-compressed complex data (single look complex: SLC). It
contains latitude-longitude information in a slanted-range coordinate. Phase andamplitude of the scattered wave can be calculated from the image.
ALOS/AVNIR-2 data, which is used together with ALOS/PALSAR, is composedof 4 bands belonging to visible or near infrared bandwidth.
4.2 Classification Algorithm
Figure 6 shows the classification algorithm using POA and entropy. Each step of
the classification is explained below.
4.2.1 Urban Area Extraction from Optical Data
Using optical data, it is relatively easy to divide urban area and non-urban area. In
this step, all pixels are classified with Maximum Likelihood Method into five or
six landcovers; “urban”, “farmland”, “forest”, “water”, etc. Then the classes
except for “urban” are merged, and removed as non-urban area.
4.2.2 Non-Building Area Removal using Total Power
Compared with building area, non-building (flat) area generally has lower Total
Power (TP), the summation of the elements of scattering matrix. Therefore, pixels
which have lower TP value than certain threshold are extracted as non-building.
4.2.3 Perpendicular Building Extraction using Four-Component
In the previous research (Iwasa et al., 2009), it is ensured that the buildings
perpendicular to the radar path are detectable using four-component
decomposition. Based on this, pixels which have higher Ps and Pd value thancertain thresholds are extracted as perpendicular building.
4.2.4 Segmentation using POA
Remaining pixels, which are regarded as slanted buildings, are divided using
value into several categories. Before the segmentation, value is averaged with
7×7 filtering window. The segmentation is done so that each category
approximately contains the same number of pixels.
4.2.5 Segmentation using Entropy
All building categories (including perpendicular buildings extracted at 4.2.3) are
divided using value into several clusters. Before the segmentation, H value isaveraged with 7×7 filtering window. The segmentation is done so that each cluster
approximately contains the same number of pixels. After the segmentation,
isolated pixels, whose all adjacent pixels are in other clusters, are reclassified.
Classification of Building Area using Slanted Angle and Density Indices Derived from
Polarimetric SAR Data

October 2010, Kobe, Japan

all pixels
Maximum Likelihood
Method
4.2.1

water, forest,
farmland etc…

urban
yes

opticalTP < TP0
POLSARnononbuilding(flat area)building

4.2.2

yes

Ps > Ps0,
Pd > Pd0

4.2.3

noNon-perpendicularbuilding

4.2.4
θ1<θ<θ2

θ2<θ<θ3･･･

perpendicularbuildingθn<θ<θn+1

4.2.5
H1 < H < H2
building 1-1

･･･

･ ･

･･･

Hk < H < Hk+1

building 1-k

･ ･ ･

･ ･ ･

･･･

building (n+1)-1

･･･

･ ･

building (n+1)-kFigure 6. Building classification algorithm.
4.3 Results and Discussion
In the algorithm above, the number of the categories generated using POA is set
to 5, and the number of the clusters generated using entropy is set to 10.
First, the data of coastal region in Urayasu city, Japan, is analyzed (Region 1).
PALSAR and AVNIR-2 data was observed on July 17, 2006 and August 4, 2006,
respectively. In Figure 7, classification result is compared with aerial photographof the same region. In image (B), buildings are extracted from aerial photographand colored according to their slanted angle. From the classification result (C), it
can be seen that the center and right part of the image are classified into blue area,
while the left part is into light blue area. Similarly, aerial photograph shows thatthese two parts have different trend in slanted angle of buildings.
Second, the data of plain region around Kyoto city, Japan, is analyzed (Region 2).
PALSAR and AVNIR-2 data was obtained on June 2, 2007 and May 15, 2008,
respectively. Figure 8 exhibits classification result and aerial photograph of thesame region. From the classification result (C), it can be seen that the right side of
the image is classified into purple, perpendicular area, while the left side is mainly
into blue area. Correspondingly, it is found from aerial photograph that thisdivision roughly follows the distribution of the actual slanted angle of thebuildings. Consequently, segmentation of buildings according to their slanted
angle can be clearly done using POA and four-component decomposition.
New Technologies for Urban Safety of Mega Cities in Asia

Moreover, the lower left part of image (C) is classified into high entropy area.
Considering that relatively small buildings are densely distributed in the same partof aerial photograph, entropy seems to be working well to detect the change ofspatial distribution in this region.

(A)

(B)

(C)

0

0.5

1.0
(km)

POA

N
high

entropy
low
high

low
perpendicular

Figure 7. Classification result in Region 1 (A) Aerial photograph from Google
Earth. (B) Extracted buildings from photograph (A). (C) Classification result
using the proposed decision-tree classifier. POA value corresponds to the rainbow
color, and tone of each color differs according to entropy value.

(A)

(B)

(C)

0

0.1

0.2
(km)

POA

N

high

entropy
low
high

low
perpendicular

Figure 8. Classification result in Region 2. (A) Aerial photograph from Google
Earth. (B) Extracted buildings from photograph (A). (C) Classification result
using the proposed decision-tree classifier. POA value corresponds to the rainbow
color, and tone of each color differs according to entropy value.
5. CONCLUSIONSIn this research, we examined the effectiveness of polarimetric indices as urban
structural detectors through the analysis of laboratory experiment data, and we
also applied some of the indices to ALOS/PALSAR data according to thedecision-tree classifier based on the experimental results.
Classification of Building Area using Slanted Angle and Density Indices Derived from
Polarimetric SAR Data

October 2010, Kobe, JapanThe experimental results demonstrated that POA has linear relationship withbuilding slanted angle. Also, it confirmed that entropy has the highest correlation
with building density.
Through the analysis of satellite images, POA proved to classify buildings which
are not perpendicular to the radar path according to their slanted angle. In addition,
we found that there are some areas where entropy distinguishes the difference ofbuilding density. Considering these results, the algorithm using polarimetricindices applied in this research seems effective for the classification of urban area.
Furthermore, in the beginning of the proposed algorithm, optical data is also used
to separate urban area from natural areas. As less affected by factors of
topography and terrestrial objects, classification results become more robust.
One of the future works is further improvement of classifier for POLSAR
processing. In our analysis, the classifier may cause classification results to beunstable, especially when homogeneous areas with similar slanted angle of thebuildings are relatively small. In addition, it is difficult to remove all the flat area
using single threshold only. Therefore, refinement in both pre-classification andpost-classification is needed. Besides, this kind of approach is expected to be
applied immediately after disaster, e.g., detection of the area damaged byearthquake or tsunami. Thus, a case study in actually devastated area is desirable.

REFERENCES
Cloude, S. R., and Pottier, E., 1997. An entropy based classification scheme forland applications of polarimetric SAR, IEEE Transactions on Geoscience andRemote Sensing, 35, 68–78.
Dong, Y., Forser, B. C., and Ticehurst, C., 1998. A new decomposition of radar
polarization signatures, IEEE Transactions on Geoscience and Remote Sensing,36(3), 933-939.
Freeman, A., and Durden, S. L., 1998. A three-component scattering model forpolarimetric SAR data, IEEE Transactions on Geoscience and Remote Sensing,36(3), 963-973.
Iwasa, S., Susaki, J., and Tamura, M., 2009. Development of urban model using
polarimetric synthetic aperture radar, JSPRS Annual Conference, 15-18, In
Japanese.
Kimura, H., Papathanassiou, K.P., and Hajnsek, I., 2005. Polarization orientation
effects in urban areas on SAR data, Proceedings of the 2005 International
Geoscience and Remote Sensing, 4863-4867.
Uchida, N., Uchiyama, K., Yamaguchi, Y., and Yamada, H., 2009. A study on
detection of urban area using Polarization Orientation Angle, IEICE Technical
Report, 109(181), SANE2009-59, 37-42, In Japanese.
Yamaguchi, Y., Moriyama, T., Ishido, M., and Yamada, H., 2005. Fourcomponent scattering model for polarimetric SAR image decomposition, IEEE
Transactions on Geoscience and Remote Sensing, 43(8), 1699-1706.
Yamaguchi, Y., 2007. Radar Polarimetry from Basics to Applications, IEICE,
101-151.

New Technologies for Urban Safety of Mega Cities in Asia

Comparative Study of Satellite Remote
Sensing Systems for Earthquake Disaster
Mitigation
1

Hiroyuki KOMA1and Haruo SAWADA2
Graduate Student, School of Eng., The University of Tokyo, Japankkoma@iis.u-tokyo.ac.jp
2
Professor, Director, ICUS, IIS, The University of Tokyo, Japan

ABSTRACT
A lot of earthquakes occur all over the world everyday and big earthquakes werereported in last few years, ex. in Sichuan (China), Java (Indonesia), Port-auPrince (Haiti), and Concepcion (Chile). These earthquakes severely damaged
infrastructures and human beings. Quick and appropriate information is required
for mitigating the damages and recovering from the devastated condition.
Therefore, the International Charter has been established to provide a unified
system of space data acquisition and delivery to those affected by natural disaster.
Each member agency has committed resources to support the provision of theCharter and thus is helping to mitigate the effects of disasters on human life andproperty. The damaged countries can freely use its satellite data but theirappropriateness is not clear. This study made up a decision rule to select theappropriate data from the Disaster Charter according to the characteristics ofspatial and time resolution as well as spectral characteristic. We took into
account the observation cycle time, the geometrical parameters of observation
data and land cover types of damaged area.
Keywords: Satellite remote sensing, earthquake, Disaster Charter

1. INTRODUCTION
The use of remote sensing technology had been widespread for monitoring theearth. One of the reasons for that is satellite’s performance became better thanpast. The new satellites have high resolution and/or high performance sensor, forexample IKONOS which is used from September in 1999, has resolution of 1.0m
and QuickBird which is used from October 2001, has that of 0.61m. These areNASA’s Earth Observe (EO) Satellite. As for Japanese EO Satellite, ALOS’s
PRISM which is used from September 2005 has that of 2.5m. Thanks to thatcapacity to provide a lot of information about earth’s global coverage and thespecific area, using satellite data enabled us to monitor pre- and post- disaster’sdamage caused by disaster. And about the mitigation of the disaster, using satellite
data is valid because a lot of (more than 3000) Earth Observe (EO) Satellites areavailable. Though one satellite’s cycle time is very long, for example ALOS’s
cycle is 46days, it enabled us to monitor the earth in short cycle time by utilizing a
lot of EO satellites which is total numbers of EO Satellites. But in fact, utilizing
more than all 3000 satellite data is not realistic. Therefore utilizing each country’s

0ctober 2010, Kobe, Japan

main satellite imageries is valid and enough for example IKONOS, QuickBird,
ALOS, SPOT.
Monitoring the disaster needs to select and use satellite data. Each Satellite data
has strength and limitation as high resolution imageries don’t have wide
observation width. That is because the satellite which has wide observation width
is in high altitude; therefore that satellite has low resolution compared with that in
low altitude. Satellite’s resolution and observation width have trade-off
relationship. Because natural disasters occur suddenly and cause unpredictabledamage, it is necessary for us to use each satellite so that the merit of which istaken. It is necessary to decide which Satellite data we should use as the situation
demands. Though satellite imagery for disaster management is widely used by thecountry where Space Agency exist and good-neighbor country with that country,
the opportunity to use Satellite to the countries which don’t have satellite
restricted to the small part of the world. Then International Disaster Charter
system was initiated by ESA and CNES to unify the world’s satellite trade system.
This system established effective mechanism in the way that joining members
trade not raw data but analyzed information and with no funds being exchanged
among them. International Disaster Charter is the only system to unify satellite
systems of all over the world although there are some systems to unify the specificarea like Sentinel Asia and Disaster Monitoring Constellation.
Picking up International Disaster Charter system helps us to understand current
reality about Disaster Management by using satellite data in the world. This paper
focuses on the current reality and what has been achieved thorough IDC activity.
In this study, analyzing the earthquake is the main theme because about 20% of
the total number of earthquake occurred in Japan and mitigating the earthquake issignificant problem in Japan. Therefore analyzing the earthquake disaster is very
useful to mitigate disaster damage in Japan and eventually in Asia in the future.
2. International Disaster Charter (IDC)
2.1 About the International Disaster Charter (IDC)
ESA (European Space Agency, Europe) and CNES (Centre National d’Etudes
Spatiales, French) set up and initiated the International Disaster Charter (IDC)
following the Third United Nations Conference on the Exploration and Peaceful
Use of Outer Space (UNISPACEⅢ)in 1999. In the UNISPACEⅢ,using spacescience and technology for solving common problems of regional or global
significance was discussed with searching international coordination and using
space technology of remote sensing in developing countries. IDC was establishedto pursue such objective along mitigating natural or man-made disasters. The ESA
and CNES initiated the International Charter "Space and Major Disasters", with
the Canadian Space Agency (CSA) signing the Charter on 20 October 2000. Now
IDC induct 9 Space Agencies –ESA and CSA from 2000, NOAA (National
Oceanographic and Atmospheric Administration, USA)/USGS (United States
Geological Survey, USA), ISRO (Indian Space Research Organization, India)
became the member of IDC in 2001, CONAE (Comission Nacional de
Actividades Espaciales, Argentina) in 2003, BNSC (British National Space Centre,UK) and JAXA (Japan Aerospace Exploration Agency, Japan) in 2005 and CNSA
New Technologies for Urban Safety of Mega Cities in Asia

(China National Space Administration, China) in 2007. IDC aims at providing aunified system of space data acquisition and delivery to those affected by natural
or man-made disasters through Authorized Users. Each member agency has
committed resources to support the provisions of the Charter and thus is helping
to mitigate the effects of disasters on human life and property. The unique point of
the charter is to provide satellite image and analyzed data free of charge toaffected areas or countries, once the charter activation was set in motion. It is very
helpful especially to developing countries which don’t have satellite because theycannot afford to buy the satellite imageries and cannot understand what thesatellite imagery and data means watching about satellite imagery. Each Space
Agency member makes a contribution to open to the public and analyze the eachsatellite data. All charge of each Charter activity cost the Space Agency whichorganizes the Charter Project Manager which observes, obtains and analyzes thesatellite data. For these reasons, the afflicted countries or area can obtain thesatellite image and data free of charge.
2.2 Mechanism to activate the Charter
If heavy disaster occurs, the officers in the afflicted area first make contact withassigned AU (Authorized User). AU are civil protection, rescue, defense andsecurity bodies of the country to which the participating Agencies belong. AU arerecognized to be the Charter associated Bodies. Then main unit of the Charter
office receive notification from AU and assign a Project Manager (PM). Heremain body of the Charter includes ODO (On-Duty Operator) and ECO(Emergency on Call Officer). ODO Receives calls requesting space data
imageries and information, Obtains and confirms with the AU when theinformation required. ECO processes the information which is received from
ODO, identifies the timeliest and appropriate satellite resource, prepares a draft
plan and gets the Space Agency user's approval. In the Charter, Project Manager
takes all responsibilities for obtaining satellite images, analyzing the satellite data
and distributing to End User.
In this Charter Operational Loop, afflicted Nations need contact with not directly
the Space Agency but by way of a lot of mediations. This is because considering
about developing countries which cannot analyze, understand and recognize theimage data. Then Charter set up the mechanism which the main body decides
which satellite data is suited for and distributes the analyzed data.

Comparative Study of Satellite Remote Sensing Systems for Earthquake Disaster Mitigation

0ctober 2010, Kobe, Japan

Figure1: Charter Operational Loop
3. About the Charter Activation
Although IDC accomplished good results in disaster management by using
satellite, simultaneously there are some shortcomings. In this section, here aresome shortcomings which need to be discussed.
3.1 Insufficient information
There are a lot of problems about insufficient problem. In the case of Earthquake
and landslide in Costa Rica on 8th of January 2009, there are 8 satellite images ofafflicted area. But all are described no information of Lat-Lon data anddiminishing scale. This disaster occurred especially in mountains and it caused
landslides. Many rural towns had been under serious landslide threat. Electricalinfrastructure and roads were also seriously damaged. Especially for landslidedisaster or disaster which occurred in mountains, Lat-Lon data and diminishingscale needs to attach because almost all the people go there to rescue anddetermine the extent of the damage where they hardly know and cannot
understand what the image means.
3.2 No activation image
Simultaneously there are the problems about no activation occurred in charter
activation. Although once charter was activated, no one answered and no satellite
image was delivered. In case of earthquake disaster, 10 of 36 disasters correspondto this problem. All these 10 activations were activated in developing countries.
For developing countries which don’t have satellite, there is no other way to getsatellite data without IDC’s approach. Because developing countries need to be

New Technologies for Urban Safety of Mega Cities in Asia

delivered satellite images and data and this is an objective of IDC, this problem
must be discussed.
3.3 Response Time
According to the IDC’s 2008 Annual Report, Response Time of the Charter
activation is very close to 2 days in average. This time is faster than past days:
that in 2003 is 2.5days according to 2003 Annual Report. But this is not sufficientbecause faster response time is required in disaster area. According to theinformation of Government of Japan, getting imageries 8times in one day isenough to monitor the earth using satellite in disaster management. And there islittle information in afflicted area. Because ground is heavily damaged little
information is delivered by way of ground. Only way to obtain information isusing remote sensing technique. For these reasons satellite data by using remotesensing technique is so valid.
The problem of the late delivery is also necessary to be discussed. In case of
Earthquake of Turkey occurred on 1st of May 2003, date of Activation is 8th of
May and data delivered time of data is 8th of May or later than 8th due to no ftp
transfer’s problem. The problem is no ftp access in remote areas interferes in datadelivery. Like this instance, some nations or areas don’t have well operating
infrastructure. For disaster management, the internet is the fastest and valid way.
But developing countries may not possess enough infrastructures to meet theirdemands. For these reasons, considering developing countries, building
infrastructure may be crucial for disaster management.
3.4 Coverage of the IDC
In disaster management, there is 4 stages in disaster management; preparedness,
mitigation, response and recovery. IDC is intended for only mitigation, response
and recovery then preparedness is not intended for. So for example in case of
volcano eruption, IDC does not intend for it though volcano eruptions need tomonitor before eruption occurred. It is necessary to broaden the IDC activation’s
coverage. As the comprehensive disaster management, it is necessary to cover all
stages, pre- and post- disaster so that IDC will become more useful framework.
4. Conclusion and Discussion
IDC is the only worldwide international association for disasters using remotesensing technique. In their works, IDC met objectives and achieved theaccomplishments below as the international association.
•
IDC makes mechanism to exchange each state’s satellite images andanalyzed data and is helpful for developing countries because they don’t
have satellite data, data analyzing skill and engineering.
•
IDC made mechanism all free of charge although satellite image andsatellite data is commonly charge for obtaining and analyzing.
•
Although each association made a role of satellite monitoring
unsynchronized before IDC set up, IDC unified each Disaster
Management Constellation and each Space Agency.

Comparative Study of Satellite Remote Sensing Systems for Earthquake Disaster Mitigation

0ctober 2010, Kobe, Japan

Although IDC made great accomplishment, simultaneously IDC needs to be
discussed to become better association.
•
There is no rule about satellite data’s information and politics whichshould be delivered. Then satellite information is unsynchronized by eachSpace Agency.
• Although a lot of association and Space Agency belong to IDC, there is norule on satellite data’s information and politics. So it spreads
responsibility so widely that each association’s accountability is blurred.
• Afflicted areas or nations cannot access the satellite data and obtain theexact kind of data when they want to get it.
5. Future Works
Interviews to the officers associated with IDC are necessary to make it clearer
IDC’s current condition. Interviewing to them is taken into consideration in near
future.

Table 1: Earth Observation Satellite Chart

REFERENCES

New Technologies for Urban Safety of Mega Cities in Asia

J.-L.Bessis, J.Bequignon, A.Mahmood, 2003, The International Charter ‘Spaceand Major Disasters’ initiative, Acta Astronautica 54, 183-190
J.-L.Bessis, Use of the International Charter Space and Major Disasters for
Damage Assessment,
J.-L.Bessis, J.Bequignon, A.Mahmood, 2004, Three Typical Examples ofActivation of the International Charter ‘Space and Major Disasters’ Advancesin Space Research, 33, 244-248
International Disaster Charter, Executive Secretariat annual reports, No.1-No.8
International Charter ‘Space and Major Disasters’ Website:www.disasterscharter.org
Application of Satellite SAR Based Damage Detection Technique to the 2004
Niigata-ken Chuuetsu Earthquake and Its Upgrade, Japan Architecture
Structure Association, 1-8
Data Book on Asia Natural Disasters in the 20th Century;
www.adrc.asia/hilights/Newsno007.pdf
RESTEC Website; http://www.restec.or.jp/databook/index.html
USGS website; http://earthquake.usgs.gov/earthquakes/world/historical.php/
Ministry of Education, Culture, Sports, Science, and Technology, JAPANWebsite (all sentences are in Japanese);
http://www.mext.go.jp/b_menu/shingi/chosa/kaihatu/004/toushin/06103014/00
1.htm

Comparative Study of Satellite Remote Sensing Systems for Earthquake Disaster Mitigation

Automatic co-registration of SAR images andclose-range photographs using SIFT
Kamolratn CHUREESAMPANT1, Yuki OHTA2, Junichi SUSAKI3
1
Ph.D Student, Graduate School of Engineering,
Kyoto University, Japan
kamolratn.c@ft5.ecs.kyoto-u.ac.jp
2
Master Student, Graduate School of Engineering,
Kyoto University, Japan
3
Associate Professor, Graduate School of Global Environmental Studies andGraduate School of Engineering, Kyoto University, Japan
ABSTRACTThis paper presents methodology for automatic co-registration of multi images
with different coordinates. Two types of images are focused on, namely
spaceborne fully polarimetric synthetic aperture radar (SAR) images and closerange photographs. Scale-invariant feature transform (SIFT) is applied to extract
points observed in a pair of images. The points are regarded as ground control
points (GCPs) for satellite images, and passpoints for photogrammetry. Hereafter,
the points are referred as “common points”. In the process of matching
candidates of common points in each image, the nearest neighbor rule is used for
initial matching. The two-way matching method is proposed to eliminate false
matches. The proposed algorithm also removes matching points with large root
mean squared error (RMSE) and refines the expected location of points through afirst-degree polynomial wrapping method. In addition, information entropy andspatial dispersion quality constraints are used to quantify the spatial distributionof common points for robustness of matching. In terms of the fully polarimetric
SAR registration, it was found that the location and combination of GCPs weredifferent for each type of polarization data (HH, HV, VH or VV). Therefore, we
propose co-registration using total power (TP) images, rather than eachpolarization image, to minimize the total registration error of all the polarization
data. The proposed method is applied to imaging of four areas in Japan, namely,
Chiba, Shinjuku, Kyoto and Sapporo. As a result, it was demonstrated that inalmost all cases, the TP combination generated the least total RMSE of theautomatic co-registration. On the other hand, it was examined to automaticallyestimate the orientation of dozens of close-range photographs using SIFT. The
results demonstrated that the more pairs of photographs are processed, the higher
accuracy of result is obtained. Therefore, we propose an acceptable approach tothe automatic orientation for close-range photogrammetry.
Keywords: automatic co-registration, ground control points (GCPs), passpoints,
polarimetric synthetic aperture radar (SAR), close-range photographs, scale
invariant feature transform (SIFT)

0ctober 2010, Kobe, Japan

1. INTRODUCTION
Co-registration of multi-temporal images is a crucial preprocessing step in several
applications. Particularly in remote sensing system, an automatic co-registration
methodology for SAR images should be capable of promptly generating aninterferogram from interferometric SAR (InSAR) data when a natural disasteroccurs. In term of photogrammetry, the extraction of passpoints from stereo-pairof photographs is essential to build the three-dimensional (3D) models. The
complete procedure for image co-registration consists of four stages: feature
extraction, feature matching, mapping function estimation and imagetransformation (Cheng et al., 2008). Image co-registration can be performed
manually or automatically. In manual registration, the common points of theimage pair are collected by visual interpretation. Even though this approach iswell established, the procedure can lead to inaccurate results, and can be slow to
execute, especially if a large number of images need to be registered. In addition,common points should be well distributed across the entire image so that theregistration accuracy is stable. Therefore, the development of a method forautomatic image co-registration is strongly needed to produce reliable andaccurate results. In addition, the use of polarization data makes geometricalcorrection difficult because the same GCPs are not necessarily derived fromdifferent polarization images. Therefore, a superior image matching algorithm thatcan be applied to polarimetric SAR should be developed for adapting to a broad
variety of geometric transformations and to provide robustness against noise.
Recently, scale-invariant feature transform (SIFT), proposed by Lowe (Lowe,2004), has been widely used for automatic detection of feature points on images.
SIFT is an approach to detecting and extracting local feature descriptors that arereasonably invariant with changes in illumination, image noise, rotation andscaling, as well as with small changes in viewpoint. SIFT detects keypoints by
calculating the convolution of the image with Gaussian filters at different scales,
and the generation of difference-of-Gaussian (DoG) images from the difference ofadjacent blurred images. Local maxima and minima of the DoG images aredetected from keypoints across different scales. After the keypoint’s orientation is
obtained, a keypoint descriptor is computed as a set of orientation histograms on
the neighboring pixels. When SIFT eigenvectors of two images are generated, theEuclidean distance of eigenvectors of keypoints is used to measure the similarityof keypoints in two images. Then, the two keypoints that are nearest to each otherin Euclidean distance are selected as a pair of matching points (Liu et al., 2008).
In this paper, a robust methodology to achieve automatic common points
extraction by using SIFT algorithm is proposed. The proposed method does not
require any user intervention and allows for a flexible number of common points
based on information entropy and spatial dispersion quality constraints because
sufficient and well-distributed common points are required for suitable coregistration precision. In Section 2, the proposed method for automatic coregistration of multitemporal fully polarimetric SAR images is presented. Section
3 describes the automatic extraction of passpoints on stereo-pairs of photographs.
The paper is concluded in Section 4.

New Technologies for Urban Safety of Mega Cities in Asia

2. AUTOMATIC CO-REGISTRATION OF MULTI TEMPORAL FULLYPOLARIMETRIC SAR IMAGES
The proposed method for co-registration of multi-temporal and polarimetric SAR
images is classified into two parts. The first is an automatic GCP extraction
procedure, as shown in figure 1. The second is an automatic procedure for
optimizing co-registration, as shown in figure 2.
START
Base Image
HHb

HVb

VHb

Wrap Image
HHw

VVb

HVw

VHw

VVw

Total Power Production

Total Power Production

TPb

TPw

Keypoints Extration

Keypoints Extration

START
TPgcp
(HHgcp, HVgcp, VHgcp, VVgcp)
Transformation Function Computation

Two-way Keypoint Matching

TPfn(HHfn, HVfn, VHfn, VVfn)

Searching for Identical Keypoints
Minimizing RMSE by Using Polynomial Wrapping Method

Co-registration

Information Entropy & Spatial Dispersion Quality Constraints

Total RMSE Calculation

Robust and Accurate GCPs

END

END

Figure 1: Automatic GCP extraction procedure

Figure 2: Automatic optimal
co-registration procedure

2.1 Automatic GCP extraction procedure
The proposed method starts with the base (HH b , HV b , VH b and VV b ) and wrap
(HH w , HV w , VH w and VV w ) of polarimetric SAR images. In the following, eachstep of the method is delineated. The total power (TP) received by the fourchannels of a polarimetric radar system can be calculated as the sum of thesquares of the magnitude of all polarization data:
TP = HH mag

2+ HVmag2+ VH mag2

2+ VVmag .

(1)

2.1.1 Keypoint extraction with SIFT algorithm and filter strategies
The candidate keypoints are extracted with Lowe’s SIFT algorithm. An extremely
large number of candidate keypoints are extracted, which may contain many false
matches. Therefore, the filter strategies namely, two-way keypoint matching,searching for identical keypoints and minimizing RMSE are used to exclude thefalse matches while preserving the correct ones. The matches are identified byfinding the two nearest neighbors of each keypoint from the base image among
those in the wrap image, and only accepting a match if the Euclidian distance tothe closest neighbor is less than a threshold. By matching each keypoint from thebase image to those in the wrap image and vice versa, the identical keypoints are
identified by using two matching results which are obtained through the two-way

Automatic co-registration of SAR images and close-range photographs using SIFT

0ctober 2010, Kobe, Japan

matching method. To ensure that no false matches remain, the RMSE minimizing
method is used by removing GCPs with the large errors and by refining thepositions of the pixels. The first-degree polynomial wrapping method is applied
by provides interpolation calculations using the following equations:
X i' = a1 + a2 xi + a3 yi + a4 xi y i , Yi ' = a5 + a6 xi + a7 yi + a8 xi yi(2)where x i and y i are the input source coordinates, X i ’ and Y i ’ are the retransformed
coordinates, and a 1 to a 8 are polynomial coefficients.
2.1.2 Information entropy and spatial dispersion quality constraints
To quantify the spatial distribution of GCPs, the information entropy of local
regions and the spatial dispersion quality are used and can be derived as255

H i = −∑ Pj log 2 Pj ,

(3)

j =0

where H i is the entropy of local regions, j is the grayscale intensity value (0-255)
and P j is the probability of j within the region of interest. The index Disp isdefined as
n
n
n

 n
2
2
 ∑ wi xi ∑ wi y i ( xi − x wmc ) + ∑ ( y i − y wmc )∑ . (4)i =1, ( x wmc , y wmc ) =  i =1n, i =1nDisp = i =1


n
wi 
 ∑ wi∑i =1
 i =1
Here, x i and y i are the coordinates of the point of interest, w i is the weight of point
i, and n is the number of points.
The Disp value expresses the quality of spatial dispersion: smaller and larger Disp
values indicate worse and better spatial distribution, respectively. The maximum
Disp is selected in order to define the number of GCPs for a co-registered image.
2.2 Automatic procedure for optimizing co-registration
In the proposed method, TP images are assumed to be used, and the function TP fn
is estimated by using GCPs, thus giving TP gcp . For reference and comparison, thetransformation functions of the original four polarization data (i.e., HH fn , HV fn ,VH fn and VV fn ) are calculated using each GCP (i.e., HH gcp , HV gcp , VH gcp andVV gcp ). The first-degree polynomial method is adopted as the transformation
function. The total RMSE is computed by applying the transformation functions
obtained from dispersed GCPs of the HH, HV, VH, VV or TP combination to all
four polarization data combinations (referred to as RMSE total1 ), and by applying
the transformation functions to all four polarization data and TP combinations,that is, five combinations in total (referred to as RMSE total2 ). In fact, RMSE total1 is
an indicator for the validation of the co-registration and RMSE total2 is a reference.
The minimum total RMSE is used to examine the optimal transformation functionthat can be applied to any polarization data. The appropriate resampling algorithm(cubic convolution) is selected to meet the requirements of the application andregister the images.
New Technologies for Urban Safety of Mega Cities in Asia

2.3 Experiment and discussion
Table 1: Properties of multi-temporal and fully polarimetric SAR images
Properties
Area
Type

Kyoto
Base

SAR images (ALOS-PALSAR, Level 1.1, CEOS format and HEOC)
Chiba
Shinjuku, Tokyo
Sapporo, Hokkaido
Wrap
Base
Wrap
Base
Wrap
Base
Wrap

Acquired Date(yyyy/mm/dd)

2007/04/17

2009/04/22

2006/08/15

2007/04/02

2006/08/19

2006/10/04

2007/05/25

2008/11/27

Scene Center
Latitude/Longitude
Size(Sample x Line)
Orbit ofObservation
Off-Nadir Angle

35.298/ 135.669

35.295/ 135.660

35.787/ 140.368

35.778/ 140.380

35.839/ 139.697

35.831/ 139.685

43.246/ 141.389

43.240/ 141.360

Topography

1,248 x 18,432

1,280 x 18,432

1,088 x 18,432

1,088 x 18,432

Ascending

Ascending

Descending

Ascending

21.5
Mountain areas; andObama bay and Wakasa
bay

21.5
Agricultural areas, someurban areas and Narita
International Airport

23.1

23.1
Urban areas, mountainareas and the JapaneseSea

Flat areas, commercial
and residential areas

BW

WB

Dispersion

Identical

Revision

Refinement

Dispersion
Quality

RMSE

Minimizing
RMSE

Polarization
HH
HV
VH
VV
TP
HH
HV
VH
VV
TP
HH
HV
VH
VV
TP
HH
HV
VH
VV
TP

Number of GCPs
Two-wayMatching

Identical

SapporoShinjuku

Chiba

Kyoto

Areas

Images

360
791
769
293
213
121
404
413
106
590
557
616
524
697
406
349
459
449
235
831

358
801
764
304
217
117
416
435
117
613
555
599
506
719
307
356
449
446
220
838

289
645
614
235
181
86
310
320
75
470
437
475
387
553
311
275
352
339
179
675

79
156
154
57
77
21
63
68
25
164
118
99
79
148
119
52
80
58
36
221

21
35
154
23
31
21
49
31
20
74
21
27
45
125
34
34
35
55
30
30

8.164
8.363
7.549
8.904
5.623
11.515
11.44912.089
9.560
5.723
6.676
8.614
8.167
6.337
4.611
9.902
8.684
8.795
8.197
5.992

1.017
0.980
1.063
0.968
1.012
0.931
0.877
1.086
1.058
0.980
1.108
1.090
1.097
1.087
1.031
0.948
1.103
0.998
0.921
1.066

0.054
0.032
0.011
0.114
0.079
0.022
0.035
0.035
0.006
0.031
0.030
0.013
0.010
0.014
0.016
0.098
0.031
0.026
0.166
0.058

0.019
0.030
0.011
0.004
0.040
0.022
0.018
0.018
0.014
0.030
0.006
0.020
0.013
0.016
0.026
0.053
0.013
0.061
0.088
0.018

Maximum
Dispersion Value(×103)
ComputationTime(second)

Table 2: GCP extraction results for multi-temporal and polarimetric SAR images

4.74
4.18
4.38
4.53
3.67
3.69
5.50
5.64
5.11
4.78
5.06
6.52
5.50
4.70
4.18
2.99
4.52
4.33
2.48
4.56

82
130
128
63
66
57
70
71
52
88
83
90
82
95
65
89
78
80
65
145

Table 2 shows the number of GCPs and the RMSE in each consequent step of the
proposed method. The RMSE in each consequent step was reduced continuously
in all cases of the polarimetric SAR images including the TP images. The results
after applying the two-way matching indicate that this filter strategy is rapid andeffective for removing false matches. The RMSE minimization was considered inorder to remove the large error of GCPs (i.e., revision) and implement repositioning of GCPs (i.e., refinement) of wrap images. Consequently, the numbers

Automatic co-registration of SAR images and close-range photographs using SIFT

0ctober 2010, Kobe, Japanof GCPs were decreased and the results are extremely accurate in terms of RMSE.
In addition, the entropy information and spatial distribution quality constraints
were utilized in order to quantify the spatial distribution of GCPs and to selectrobust GCPs. In a few cases, we found that RMSE slightly increased because
points with very low RMSE were eliminated. However, because the effect of thisphenomenon is small, the methodology is effective for selecting GCPs. Moreover,the computation time of the processes is short. Figure 3 and 4 show GCPs wereobtained after refinement and spatial dispersion quality steps, respectively.

(HH base ) (HH wrap ) (HV base ) (HV wrap ) (VH base ) (VH wrap ) (VV base ) (VV wrap ) (TP base ) (TP wrap )Figure 3: GCP extraction results for Kyoto area for base and wrap of HH, HV, VH, VV
and TP with 1,248 × 18,432 pixel original images. GCPs are shown as red marks. The
numbers of GCPs after minimizing RMSE are 79, 156, 154, 57 and 77, respectively(HH base ) (HH wrap ) (HV base ) (HV wrap ) (VH base ) (VH wrap ) (VV base ) (VV wrap ) (TP base ) (TP wrap )Figure 4: GCP extraction results for Kyoto area for base and wrap HH, HV, VH, VV andTP with 1,248 × 18,432 pixel original images. The numbers of GCPs remaining after
applying the information entropy and spatial dispersion quality constraints are 21, 35, 154,
23 and 31 with the least RMSE (less than 0.04), respectively
New Technologies for Urban Safety of Mega Cities in Asia

Tables 3 to 6 show that in almost all cases, the TP combination generated the least
total RMSE, although in Table 6 the total RMSEs (RMSE total1 ) of the VH
combination is slightly lower than the TP combination. This can be negligible,
namely 0.01 differences in RMSEs. Let us consider the meaning of the proposed
method. Equation (1) indicates that TP is the sum of each polarization power.
Thus, TP images can be considered to express a combination of the characteristicsof the four polarization images. It reasonably follows that the GCPs obtained fromTP images reflect all four polarizations. Therefore, the proposed method issuitable for automatic co-registration of multi-temporal and polarimetric SAR
images. Finally, in the experiment of the four areas include different types of
topography. When we take a close look at the obtained results, no clear trend isfound in the co-registration results. Therefore, the proposed method can function
independently of land cover type.
Table 3: Total RMSE of the automatic
co-registration for Kyoto in Japan

GCPs
POL
HH
HV
VH
VV
TP
RMSE total1
RMSE total2

#
21
35
154
23
31
233
264

Transformation Function of
Kyoto
HH
HV
VH
VV
TP
0.02 2.17 2.27 2.30 1.96
2.10 0.03 1.71 1.49 1.72
2.19 1.73 0.01 1.47 0.56
1.80 1.45 1.19 0.00 0.51
1.54 1.53 1.38 0.41 0.04
2.04 1.62 1.02 1.50 1.01
1.98 1.61 1.07 1.41 0.95

Table 4: Total RMSE of the automatic
co-registration for Chiba in Japan

GCPs
POL
HH
HV
VH
VV
TP
RMSE total1
RMSE total2

#
21
49
31
20
74
121
195

Transformation Function of
Chiba
HH
HV
VH
VV
TP
0.02 2.03 2.48 2.89 1.92
1.66 0.02 0.91 1.88 0.69
1.12 1.09 0.02 1.44 0.90
2.99 1.99 1.61 0.01 1.90
1.76 0.78 0.89 1.74 0.03
1.71 1.29 1.35 1.85 1.28
1.73 1.13 1.20 1.81 1.01

Table 5: Total RMSE of the automatic
co-registration for Shinjuku, Tokyo

GCPs
POL
HH
HV
VH
VV
TP
RMSE total1
RMSE total2

#
21
27
45
125
34
218
252

Transformation Function of
Shinjuku
HH
HV
VH
VV
TP
0.01 0.76 0.91 1.14 0.25
0.82 0.02 1.37 1.09 0.64
1.04 1.54 0.01 1.54 1.10
1.29 0.74 1.47 0.02 0.10
0.24 0.79 1.16 1.05 0.03
1.12 0.93 1.25 0.88 0.56
1.05 0.91 1.24 0.90 0.52

Table 6: Total RMSE of the automatic
co-registration for Sapporo, Hokkaido

GCPs
POL
HH
HV
VH
VV
TP
RMSE total1
RMSE total2

#
34
35
55
30
30
154
184

Transformation Function of
Sapporo
HH
HV
VH
VV
TP
0.05 1.16 1.21 1.96 0.77
1.72 0.01 0.52 2.94 0.56
1.21 0.58 0.06 2.96 0.60
1.86 1.49 1.41 0.09 1.55
1.62 0.56 0.77 4.48 0.02
1.37 0.92 0.88 2.44 0.89
1.41 0.87 0.86 2.87 0.82

3. AUTOMATIC EXTRACTION OF PASSPOINTS ON STEREO-PAIRSOF PHOTOGRAPHS
When 3D building models are generated through photogrammetry, extraction of
passpoints from stereo-pair of photographs is a key issue. In usual, it is timeconsuming and an efficient method is desirable. In the present research, SIFT
algorithm was examined for the efficient extraction of passpoints.

Automatic co-registration of SAR images and close-range photographs using SIFT

0ctober 2010, Kobe, Japan

3.1 Applying SIFT algorithm to extraction of passpoints
In the preliminary examination, 25 stereo-pairs of photographs taken in the Old
Quarter, Hanoi were used. As a result, it was found that many false passpoints
were extracted. This may be caused by a large difference in shift and rotation
between two viewing points shown in figure 5. In other cases, this sunlight
condition difference may lower the accuracy of passpoint extraction. Therefore,
photographs for stereo-pair were carefully reselected in terms of the viewing
geometry and illumination.

(a)

(b)

Figure 5: The example of the stereo-pairs that have many false extractions ofpasspoints. (a) The view points are different largely. (b) The date and time thatthe photographs was taken is different.
3.2 Removing the false extractions by using perspective projection equation
The extracted passpoints may include false one. Therefore, perspective projection
equation is used in order to remove the false extractions. Perspective projection isrepresented by Equation (5). a i , b i and c i denote coefficients. First a i , b i and c i are
estimated from the photographic coordinates of the extracted passpoints on thestereo-pair by using the least squares method. Next, each passpoints' RMSE
defined by equation (6) is calculated from a i , b i and c i . Finally, the passpoints
whose RMSEs are bigger than a certain threshold are removed.
x' =a x + b2 y + c 2
a1 x + b1 y + c1
, y' = 2a0 x + b0 y + c0
a0 x + b0 y + c02

a x + b1 y + c1   ' a 2 x + b2 y + c 2  +y −

RMSE =  x ' − 1
a 0 x + b0 y + c0 
a 0 x + b0 y + c0  


(5)
2

(6)

New Technologies for Urban Safety of Mega Cities in Asia

3.3 Result of simultaneous relative orientation for many successive stereopairs
Simultaneous relative orientation for reselected 40 stereo pairs is computed fromthe photographic coordinates of the refined passpoints by photogrammetry
software (Image Master, Topcon). As a result, it was found that the simultaneous
relative orientations of only successive 13 stereo-pairs were calculated
successfully. The rest of stereo-pairs included some sets of two successive stereopairs whose passpoints didn't include tiepoint. Passpoint that is common to
adjacent stereo-pairs is called a tie point as shown in figure 6. There must be
tiepoint on each set of two successive stereo-pairs in order to determine therelative orientations of all stereo-pairs simultaneously. In the present research,some tiepoints were removed excessively in the refinery process.
Stereo-pair1
photo1

Stereo-pair2
photo2

photo3： Passpoints on stereo-pair1： Passpoints on stereo-pair2: Tiepoints

Figure 6: Tiepoint

The result of simultaneous relative orientation for 13 stereo-pairs is shown on
Table 7. Residual y-parallax and residual error in each passpoint positions areoften used as the indexes to represent the accuracy of relative orientation. In the
result shown on Table 7, almost all of the values are less than one pixel, and theaccuracy of simultaneous relative orientation is acceptable. In addition, the moreaccurate result was achieved after selecting manually three passpoints on image
30 and image 31 whose residual errors were large, removing them, and computing
simultaneous relative orientation again.
Table 7: Result of simultaneous relative orientation

Image
No.
27-28
28-29
29-30
30-31
31-32
32-33
33-34
34-35

Before manual refinement
After manual refinement
Residual error in
Residual error in
Residual
Residual
each passpoint
each passpoint
y-parallax (pixel)
y-parallax (pixel)
positions (pixel)
positions (pixel)
0.09
0.36
0.09
0.36
0.65
0.52
0.65
0.52
0.92
2.17
0.92
0.60
6.42
2.17
1.04
0.60
0.33
1.95
0.33
0.47
0.19
0.45
0.19
0.37
0.73
0.40
0.73
0.37
0.39
0.33
0.39
0.28

Automatic co-registration of SAR images and close-range photographs using SIFT

0ctober 2010, Kobe, Japan

Image
No.
35-36
36-37
37-38
38-39
39-40

Before manual refinement
After manual refinement
Residual error in
Residual error in
Residual
Residual
each passpoint
each passpoint
y-parallax (pixel)
y-parallax (pixel)
positions (pixel)
positions (pixel)
0.10
0.27
0.10
0.20
0.19
0.28
0.19
0.21
0.56
0.32
0.56
0.27
0.21
0.32
0.21
0.27
0.26
0.23
0.26
0.13

4. CONCLUSION
To increase the robustness and accuracy in automatic co-registration of multi
images with different coordinates, the proposed method has been introduced asfollows. The keypoints were extracted based on SIFT algorithm. Two-way
keypoint matching was proposed to reduce the number of unstablecorrespondence keypoints. The first-degree polynomial wrapping method predicts
coordinates of the GCPs candidates, and the candidates with large error are
removed. In term of close-range photographs, the perspective projection equation
was used to eliminate the false extracted passpoints. By using the information
entropy and spatial dispersion quality constraints, only common points with highquality spatial dispersion distribution are selected. The SAR image matchingproduced the high rate of correct matches and the relative orientations of stereopairs were computed with higher accuracy. In automatic co-registration, thetransformation function of the TP combination generated the least total RMSE,
and is reasonable to apply to dispersed GCPs extracted from the other fourpolarization data. The proposed method can be successfully applied to automatic
co-registration for full scene multi-temporal and polarimetric SAR images. In
addition, the acceptable approach can be implemented to the automatic orientation
for close-range photogrammetry.
REFERENCES
Cheng, L., Gong, J., Yang, X., Fan, C., and Han, P., 2008. Robust affine invariant
feature extraction for image matching. IEEE Geoscience and Remote Sensing
Letters, 5 (2), 246-250.
Liu, J., and Yu, X., 2008. Research on SAR image matching technology based on
SIFT. Proc. of 21st International Archives of Photogrammetry, Remote Sensing
and Spatial Information Sciences, 37 (part B1), 403-408.
Liu, L., Wang, Yu., and Wang, Yi., 2008. SIFT Based Automatic Tie-Point
Extraction for Multi-temporal SAR Images. International Workshop on Education
Technology and Training & 2008 International Workshop on Geoscience andRemote Sensing, 1, 499-503.
Lowe, D. G., 2004. Distinctive image features from scale-invariant keypoints.
International Journal of Computer Vision, 60 (2), 91-110.

New Technologies for Urban Safety of Mega Cities in Asia

Wessel, B., Huber, M., and Roth, A., 2007. Registration of near real-time SAR
images by image-to-image matching. Proc. of Photogrammetric Image Analysis,
179-184.

Automatic co-registration of SAR images and close-range photographs using SIFT

Automatic three-dimensional modeling ofbuildings in dense urban areasusing airborne LiDAR
Junichi Susaki1 and Atsushi Kora2
1
Associate Professor, Graduate School of Global Environmental Studies andGraduate School of Engineering, Kyoto University, Japanjunichi.susaki@at2.ecs.kyoto-u.ac.jp
2
Obayashi Corporation
ABSTRACT
These years in Japan, the demand for three-dimensional (3D) urban model is
growing in various applications, such as preparedness to fire spread caused byearthquakes. Airborne LiDAR (Light Detection and Ranging) has been reported
to be potential to effectively generate 3D urban model because it measures point
clouds containing 3D coordinate which may be easily processed into the 3Dmodel. For this purpose, the technique to classify the point clouds into each houseunit is required, but it is found that existing algorithms cannot function effectively
especially in the districts where Japanese traditional houses exist because they
have almost same height of slant roofs, which are difficult to distinguish fromeach other. In the present research, an algorithm was developed to automaticallygenerate 3D models using airborne LiDAR, focusing on the accurate extraction of
the norms of roof planes and the estimation of roof combination. This algorithm
requires tuning of several critical thresholds, i.e. horizontal and vertical distances
between houses, and the maximum error to the estimated roof plane. While thesystem still needs to improve the optimization of such thresholds, it generates 3Dmodels of the Japanese traditional houses more accurately than the existingalgorithms.
Keywords: airborne LiDAR, building model, dense urban area, algorithm

1. INTRODUCTION
Urban building models are expected in various fields and laser scanner is capableof providing three-dimensional (3D) data necessary for the modeling. As the dataacquired using laser scanner are point clouds, modeling is required to classify
point clouds into a certain categories. Biosca and Lerma (2008) proposed an
unsupervised robust clustering approach based on fuzzy methods for thesegmentation of huge volume of terrestrial laser scanning data.
Airborne laser scanner is capable of estimating the building height and simple
building models can be produced using airborne LiDAR (Light Detection andRanging). Existing researches focused on modeling of buildings fusing airborne
laser scanner and other sources, e.g. satellite imagery (Sohn and Dowman, 2007),
aerial imagery (Huber et al., 2003) and terrestrial LiDAR (Haala et al., 2007)

October 2010, Kobe, Japan(Caceres et al., 2007). While terrestrial LiDAR provides detailed data of sidesurfaces of buildings, airborne LiDAR has potential to meet the demand to
generate building models in a wide area.
However, in the dense urban areas in Japan, modeling of buildings using airborne
LiDAR data is challenging. In dense urban areas where gable-roof houses andhip-roof houses are popular, some of houses with the same height of gable roofs
are located very closely to each other, and it is quite difficult to identify theboundaries of the houses from ALS.
Therefore, in the present paper, the authors report an algorithm to generate threedimensional building models in dense urban areas using airborne LiDAR.
2. STUDY AREA
Kyoto is famous as the old Japanese capital city, and it still has plenty of
traditional houses and landscape. The area in Higashiyama-ku, Kyoto wasselected as study area. The area is famous for traditional temples and shrines, and
it is a hilly area. Figure 1 shows Ninen-zaka near Kiyomizu-temple. Threedimensional building models in this area are desired for the planning of thepreservation of old temples against fire caused by earthquake. The details on theused airborne LiDAR are shown in Table 1.

Figure 1: Ninen-zaka, Higashiyama-ku, Kyoto
Table 1: Details on airborne LiDAR
Measurement dateDensity
Altitude
Horizontal accuracy
Vertical accuracy

June 2002 to February 2003
Approximately 1 point / m2
900 to 1,000m
±50cm
±15cm

New Technologies for Urban Safety of Mega Cities in Asia

3. ALGORITHM OF 3D BUILDING MODELING IN DENSE URBAN
AREA
Following is a procedure of the algorithm of 3D building modeling in dense urban
area using airborne LiDAR data.
(1) Estimating digital terrain model (DTM) and filtering to separate point clouds
on roof from the other point clouds, such as the point clouds on road, river,(2) Classification of the roof point clouds into individual roof, and estimation ofroof type,(3) Delineation of roof boundary, and(4) Estimation of height to DTM and generation of 3D building model.
4. FILTERING OF POINT CLOUDS TO DISCRIMINATE ROOF DATA
Airborne LiDAR measures the reflectance from the surface of the objects on thesurface, i.e. building, tree or road. Three-dimensional modeling of buildings fromairborne LiDAR requires preprocessing to separate point clouds on roof from theother point clouds. In essence, points with local minimum height are extracted,
and then DTM is estimated using the points. However, our preliminary
examination confirmed that the traditional algorithm cannot estimate DTM when
the area is hilly like the study area in the present research or the area has a riverwhich runs lower than roads. The present paper reports an algorithm to extract
points which should be on DTM by examining the connectivity to local minimum
height points. Hereafter, the procedure is described.
(1) Search the points around the point with local minimum height and select the
points which meet vertical and horizontal difference between the local
minimum height points. There points are regarded as “candidate of points on
DTM”. This is shown in Figure 2.
(2) Using candidate points within a certain range, estimate a plane using leastsquare method (LSM)(3) Among non-candidate points, select the points which meet following
conditions:(i) The horizontal distance from the point to the candidate point is within athreshold, and(ii) The distance from the point to the estimated plane is within a threshold.
(4) The point selected in (3) is newly regarded as a candidate point on DTM and isused for another searching in (2).
(5) Repeat (2) to (4) and finish when no DTM candidate point is available.
(6) Generate DTM through interpolation using DTM candidate points.
(7) Extract point clouds on roof when the distance from the point to DTM is larger
than a threshold.
The extracted DTM is shown in Figure 3. If DTM is accurately estimated, thedifference between DTM and DSM of the data near the roads should be quite
small. This difference can be a good indicator for the DTM validation. Therefore,
as for the data with less than 50 cm difference between DTM and DSM, theAutomatic three-dimensional modeling of buildings in dense urban areas using airborne
LiDAR

October 2010, Kobe, Japandifference was examined. As a result, the data with less than 50 cm difference
between DTM and DSM were 3,583 points among 20,118 points, and the mean ofthe difference was -0.006 m. The negative figure indicates the DTM was lower
than the DSM. In addition, 2,792 points, approximately 78 % of 3,583 points were
within ± 10 cm difference range. These results indicate that the proposed
algorithm can accurately estimate DTM.

Airborne LiDAR data
Points with local minimum height
Candidates of points on DTM

Figure 2: Searching points around points with local minimum height

Height (m)Figure 3: Extracted roof point clouds. (Left) area for the extraction is expressedwith a box. (Right) blue points denote ground points, green points denote roof
points and red mesh denotes the estimated DTM. Viewing direction is expressedin the left figure.

New Technologies for Urban Safety of Mega Cities in Asia

5. CLASSIFICATION OF ROOF DATA
Traditional Japanese houses, such as gable-roof houses or hip-roof houses shownin Figure 4, are arranged so that roof ridges are parallel or orthogonal in Figure 5.
Proposed algorithm utilizes this feature. First, planes are estimated using several
points. Next, histogram of azimuth angle of the plane norm is generated, and thepeak of the histogram is determined. This peak indicates main direction of roof
ridges. Then, after the main direction is determined, the azimuth angle space inFigure 6 is divided into four zones. Finally, according to the azimuth angle ofeach plane norm, roof points are classified into subgroups. The classification
result in Figure 7 indicates that while the discrimination of roofs in both sides of
the ridge was successful, roofs of several houses on the same side are still
unclassified.
To solve this problem, distance to the planes estimated from points is used as aclassifier. The result of this classification is shown in Figure 8. As a result, points
were classified into several groups which are consisted of one or two roofs. Fivehouses can be found in Figure 8. Left two houses have a quite small difference inroof height, approximately less than half a meter. Similarly, right two houses havea similar difference. Therefore, the points of those houses still remained
unclassified at this stage.
Here, feature of points around ridges is focused on. Assuming gable-roof houses,
roofs on both sides of the ridge are symmetric to the ridge in most of the gableroof houses. Thus, the plane norm obtained from points can be a key to matchinga pair of roofs of a house. This feature can be applied to discriminate other types
of houses. The results of the implementation are shown in Figure 9. For example,
Gable-roof

Hip-roof

FrequencyθFigure 4: Traditional Japanese houses

Azimuth angle
Zone 4

(4)
(1)

(5)
(2)

Zone 3
Zone 1(3)

Figure 5: Spatial arrangement oftraditional Japanese housesθMaindirection

Zone 2

Figure 6: Determination of main
direction

Automatic three-dimensional modeling of buildings in dense urban areas using airborne
LiDAR

October 2010, Kobe, Japan

middle pair of roof was successfully extracted, but relationship of 1 roof to 2 roofs
can be found. In this research, if such 1 to 2 matching relationship is found, twopairs are generated by dividing into or merging subgroups. Figure 10 exhibits theconcept of this pair generation. The results of the pair generation are shown in
Figure 11. It demonstrates that points were successfully classified into each roof
and each house.

Figure 7: Classification using
main direction

Figure 8: Classification of points into
roofs

Figure 9: Classification of points
considering the symmetry to the roof ridge

New Technologies for Urban Safety of Mega Cities in Asia

paird is more thanthreshold

pair

d

pair
d is less thanthresholdpair

d is more thanthresholdpair

Each roof has different colorpairdd is less thanthresholdpair

Figure 10: Generation of roof pair

Each building has different color
Figure 11: Matching roofs bygenerating roof pairs

6. DELINEATION OF ROOF BOUNDARY AND GENERATION OFWIREFRAME MODEL
Until the processing above, points are classified into each building. Modelingrequires the boundary of the buildings. It is assumed that most of buildings in thedense urban areas in Japan have rectangular boundaries or boundaries consisted ofa few rectangles when the buildings are projected to the ground. The sides of therectangle are estimated so that they
are parallel or orthogonal. In
addition, the norms of a pair ofgable or hip roofs are modified sothat they are symmetric to the ridge.
As shown in Figure 12, threedimensional wireframe models
with different types of roofs are
Hip roof
Gable roof
generated by referring the height toDTM. Finally, 3D wireframe
models were produced using the
proposed algorithm. The models
from the nadir view are shown in
Figure 13.
One-side ridgeroof

Flat roof

Figure 12: Wireframe models of different
types of roofs
Automatic three-dimensional modeling of buildings in dense urban areas using airborne
LiDAR

October 2010, Kobe, Japan

Approx.
100m

Approx. 65m

Figure 13: Three-dimensional wireframe model. (Upper left) area
photograph. (Upper right) extracted models with filtering result. Red point
denotes roof, green point road and blue frame building boundary. (Bottom)
extracted models where blue flame denotes gable-roof house, purple hiproof, green one-side-ridge-roof, and red flat-roof.

New Technologies for Urban Safety of Mega Cities in Asia

7. DISCUSSIONS
Figure 13 demonstrate that relatively large houses are successfully extracted andmodeled, but that it failed to model some of small roofs, accordingly small houses.
This was partly due to the low airborne LiDAR density. When less number of
LiDAR data was available on a roof, i.e. a few points, identification of a roof
plane was difficult and the points on a roof plane were misclassified into different
roof planes. To avoid this misclassification, adjustment of threshold, e.g.
thresholds for horizontal and vertical distances, is one of the effective
countermeasures. However, the threshold optimal for the small house extraction
is not always optimal for the large house extraction. This tuning of the threshold isa difficult issue and one of the approaches is to tune it in accordance with theaverage size of houses. This will be one of the future tasks.
In addition to the number of extracted buildings, size of the extracted buildings is
discussed here. When the estimated size is smaller than the actual size, it isbecause the LiDAR data were not enough to identify the actual boundary. Whenthe horizontal or vertical distance between points is larger than designatedthresholds, the points are classified into separate groups. Therefore, whenmodeling in the dense urban area using the proposed methodology, more densityof airborne LiDAR than the used data will be preferable, e.g. 1.5 points / m2.
Contrary, there were some houses whose estimated sizes were larger than theactual sizes. In such cases, it was confirmed that roof heights of houses were
almost same, and classification of points into individual roofs was not successful.
This problem shares the cause with another problem, overlapping of extracted
roofs. When the classification is not successful and roof shape is assumed asrectangle, overlapped oversize roof will be extracted. To avoid this failure, it
should be checked whether extracted roofs are not overlapped to each other. If it
is overlapped, the roof’s shape should be modified. In this regard, thismodification will be valid for simple rectangular roofs. When it comes to houses
with non-rectangular boundary, it may be difficult to automatically model them inthe dense urban areas.
Finally, discrimination of trees should be referred. At the stage of filtering todiscriminate roof points in the proposed algorithm, the threshold of height for theroof points from DTM was set as 3.0 m. As a result, points reflected from tall tree
were also included in the roof points, and building models were produced wheretall trees exist. To exclude this failure, a technique to use standard deviation ofheight per unit area can be useful to separate roof points from tree points. This
separation will be examined near future.
8. CONCLUSIONSIn this paper, an algorithm was reported to automatically generate threedimensional building models in dense urban areas using airborne LiDAR. The
algorithm starts with filtering to separate point clouds on roof. Next, roof point
clouds are classified into individual roofs, and roof type is estimated. To classify
Automatic three-dimensional modeling of buildings in dense urban areas using airborne
LiDAR

October 2010, Kobe, Japan

roof point clouds into individual roofs, arrangement of traditional Japanese houses
and norm of roof planes are utilized. Further classification requires examining
roof plane arrangement on both sides of roof ridge. After roof boundary isdelineated, finally, height to DTM is estimated and 3D building model isgenerated. The proposed filtering functioned quite effectively even in the dense
urban and hilly areas. In addition, generated 3D wireframe models were
acceptable in terms of the number and size of extracted buildings. However, there
still remain a few future tasks such as roof overlapping and invalid modelingcaused by misclassification of points from tall trees. In addition, the developed
algorithm requires tuning of several critical thresholds, i.e. horizontal and verticaldistances between houses, and the maximum error to the estimated roof plane.
While the algorithm still needs to improve the optimization of such thresholds, it
generates 3D models of the Japanese traditional houses more accurately than theexisting algorithms. In future, these tasks will be solved through further analysis.
REFERENCES
Biosca, J.M., and Lerma, J.L., 2008. Unsupervised robust planar segmentation ofterrestrial laser scanner point clouds based on fuzzy clustering methods. ISPRS
Journal of Photogrammetry and Remote Sensin, 63, 84-98.
Caceres, J.J., and Slatton, K.C., 2007. Improved classification of building
infrastructure from airborne Lidar data using spin images and fusion with groundbased Lidar. Proceedings of 2007 Urban Remote Sensing Joint Event.
Haala, N., Becker, S., and Kada, M., 2007. Cell decomposition for building model
generation at different scales. Proceedings of 2007 Urban Remote Sensing Joint
Event.
Huber, M., Schickler, W., Hinz, S., and Baumgartner, A., 2003. Fusion of LIDAR
data and aerial imagery for automatic reconstruction of building surfaces.
Proceedings of 2nd GRSS/ISPRS Joint Workshop on “Data Fusion and Remote
Sensing over Urban Areas”, pp. 82-86.
Sohn, G., and Dowman, I., 2007. Data fusion of high-resolution satellite imagery
and LiDAR data for automatic building extraction. ISPRS Journal of
Photogrammetry and Remote Sensing, 62, 43-63.

New Technologies for Urban Safety of Mega Cities in Asia

Trend of International Charter
for Environmental Disasters
Haruo SAWADA
Professor, ICUS, IIS, The University of Tokyo, Japan
sawada@iis.u-tokyo.ac.jp
ABSTRACTThe International Charter has been established for providing a system of spacedata acquisition and delivery to those affected by natural or man-made disasters.
Each member agency is requested to commit resources to support the Charter andthus is helping to mitigate the impacts of disasters on human life and property. In
2010, nineteen organizations are involved in this activity. The Charter deals withcyclone, earthquakes, fire, floods, oil spills, volcanoes and other disasters. The
charter activation started in 2000 and the number of activated charter isincreasing. We analyzed the trend of disaster charters for environmental issues
which might be strongly correlated with global environment changes. Strong
cyclone, severe forest fire, and heavy flooding were the main environmental
disasters in this Charter. Different remote sensing characteristics as well as
preprocessing system influenced their applicability for disaster mitigation
Keywords: remote sensing, disaster charter

1. INTRODUCTION
Many disaster management policies and programs have been developed andimplemented in the last decade in many countries, both in developing anddeveloped countries. Efforts of such disaster management programs are very
important, especially in spatial analysis involving modeling, visualization,satellite data, socio-economic data, and field data.
Satellite remote sensing data provide historical databases and their products now
have a history of over three decades in terms of land cover datasets and recent
products have significant high resolutions, both temporally and spatially.
Data and information derived from earth observation satellite have been used for awide range of application in disaster management. Image-based damage mapping
is constrained by the spatial resolution of the available data and the average sizeof the destroyed objects. Suitable sensors are also constrained by their actual
availability, a function of positioning and pointing capabilities of the system.
GIS systems have been used for combining remote sensing data with otherrelevant data for risk analysis and assessment. Using these capabilities of GIS andvisualization analysis, risk assessment maps are produced. This serves as warning
information which is useful for mitigating disasters.

October 2010, Kobe, Japan

There are number of space-based information which is available to the disastermanagement community. International initiative such as GEOSS, IGOS-P and
Sentinel Asia are helping the space community take on stronger role in solving the
problems on the earth, including disasters.
This report aims to review these international activities using space-based
information for disaster mitigation, especially focussing on the International
Charter.
2. INTERNATIONAL ACTIVITIES
2.1 IGOS-P
The IGOS-P (the Integrated Global Observing Strategy Partnership) is aninternational partnership established in June 1998, which brings together anumber of international organizations concerned with the observation of global
environmental issues, from a research pint of view as well as from an operational
one. For instance, the IGOS GeoHazards Theme was established as the initiativeof three IGOS members, UNESCO, CEOS (Committee on Earth Observation
Satellite) and ICS (International Council for Science).
2.2 UNISPACE III
UNISPACE III with the theme ‘Space benefits for humanity in the twenty-first
century’ was held in Vienna in 1999. The Vienna Declaration on Space andHuman Development was adopted as the output of the conference, in which 33
specific actions were recommended that should be carried out to enable spacetechnologies to contribute to the global challenges of the new millennium.
One of the recommendations was the need ‘to implement an integrated, global
system, especially through international cooperation, to manage natural disastermitigation, relief and prevention efforts, especially of an international nature,through Earth observation, communications and other space-based services,making maximum use of existing capabilities and filling gaps in worldwide
satellite coverage’. The recognition of this need has led to a number ofinternational initiatives that have been contributing to help developing countries
access and use space-based information for disaster management (Stevens, 2008).
2.3 INTERNATIONAL CHARTER
The International Charter ‘Space and Major Disasters’ is an example of an
initiative specific to disasters, which aims to achieve the Coordinated Use ofSpace Facilities in the Event of Natural or Technological Disasters (Disaster
Charter).
At the UNISPACE III, a proposal to create a charter that would provide a unified
system of space data acquisition and delivery to those affected by natural or manmade disasters through Authorized Users was discussed. ESA (European Space
New Technologies for Urban Safety of Mega Cities in Asia

Agency) and CNES (Centre National d’Etudes Spatiales) signed the Charter inJune 2000. The Canadian Space Agency followed them and there are nineteen
members in 2010. Each member agency has committed resources to support theCharter activities and thus is helping to mitigate the impacts of disasters on humanlife and property.
2.4 UN-SPIDER
The ad-hoc expert groups developed a number of important space-related
initiatives that could support different phases of disaster management, such as
GEOSS (Global Earth Observation System of Systems), the International Charter‘Space and Major Disasters’, IGOS-P, GMES (the Global Monitoring ofEnvironment and Security) and the Sentinel Asia.
The United Nations General Assembly agreed to establish UN-SPIDER (Spacebased Information for Disaster Management and Energy Response) in 2006 toprovide universal access to all types of space-based information and services fordisaster management. Their objectives are to be a gateway to space information
for supporting disaster management, to be a hub to connect the disastermanagement and space groups, and to be a facilitator of capacity building. The
UN-SPIDER works closely with end-users, particularly in developing countries,
through a network of regional support offices.
2.5 HYOGO FRAMEWORKThe importance of space technology to support disaster preparedness was also
recognized at the World Conference on Disaster Reduction, held in Kobe, inJanuary 2005. Representatives from 168 countries recognized the contribution of
space technology to disaster reduction and emphasized the need to incorporate
with space-based services to support risk reduction.
A list of commitments is set out as the document, the ‘Hyogo Framework of
Action 2005-2015: Building the Resilience of Nations and Communities toDisasters’. The document was adopted by the General Assembly in 2005 (United
Nations, 2005). The Hyogo Framework recognizes the need to ‘promote theapplication of in situ and space-based earth observations, space technologies,
remote sensing, GIS, hazard modeling and prediction, weather and climate
modeling and forecasting, communication tools and studies of the costs andbenefits of risk assessment and early warning’.
2.6 GEOSSThe Global Earth Observation System of Systems (GEOSS) integrates Earthobservations with other information to help planners reduce vulnerability,
strengthen preparedness and early-warning measures and, after disaster events,
rebuild housing and infrastructure with low future risks.
GEOSS is also working to reduce risk over the long term by providing a better
understanding of the relationship between natural disasters and climate change.

Trend of International Charter for Environmental DisasterOctober 2010, Kobe, JapanBy making it possible to integrate different types of disaster-related data andinformation from diverse sources, GEOSS aims to strengthen analysis anddecision making for disaster response and risk reduction.
GEOSS coordinates many complex and interrelated issues simultaneously. Thisapproach avoids unnecessary duplication, encourages synergies among systems
and ensures economic, societal and environmental benefits.
2.7 SENTINEL ASIA
Sentinel Asia is a voluntary basis initiative led by the APRSAF (Asia-PacificRegional Space Agency Forum) to support disaster management activity in the
Asia-Pacific region by applying the Web-GIS technology and space based
technology, such as earth observation satellites data.
JAXA (Japan Aerospace Exploration Agency) makes strong commitment to thisactivity together with many international organizations. The participating
institutions from within the region are able to access ALOS data to support
monitoring wildfire and flood. The project also provides capacity building.
3. CONDITIONS OF INTERNATIONAL CHARTER
By the end of August 2010, the Charter had been activated 266 times in response
to cyclones, earthquakes, forest and bush fires, floods, oil spills, volcanoes andothers. The Charter has successfully demonstrated the importance and the benefitof producing timely satellite-based information to support emergency response.
3.1 Satellite Data
More than 100 products were developed and delivered last one and a half years
and about a half of them were images related to flooding caused by heavy rains
and cyclones (Fig. 1).
Landsat has a history of more than 30 years and has been used as a main satellite
data for various fields. Main satellite data used for the Disaster Charter were
MERIS, ASAR, Landsat, Aster, PALSAR, RADARSAT, AVNIR, SPOT,
Formosat, TerraSAR, QuickBird, GeoEye and others, in order of spatial resolutionof sensors. Most of the data have higher ground resolution than Landsat (Figure 1).
The spatial resolution, for example, of QuickBird and GeoEyes are about 60 cm
and 40 cm, respectively.
Although previous conditions of the disaster affected area are important fordamage assessment, these new sensors have short history of their data storage.
Other disadvantages of high spatial resolution satellite are their long revisit timeand small spatial coverage area. Therefore it is sometimes necessary to introduce
Landsat and other lower resolution satellite data for disaster assessment coupledwith recent high resolution data in spatially and radiometrically (Fig. 2). The
composition techniques of various types of satellite sensors are indispensable.
New Technologies for Urban Safety of Mega Cities in Asia

Figure 1. Number of satellite data used for the products of
the Disaster Charter in 2009 and 2010

Figure 2. Number of satellite data (before and after the events)
used for the products of the Disaster Charter in 2009 and 2010
3.2 Available data
The average days of satellite data observed after disaster events in 2009 and 2010
(until Aug.) were 4.0 days. Fig 3 shows that most of the data were observed
within a few days after disaster events occurred.

Figure 3. Number of satellite data used for the Products(x: date of satellite data observed after disaster events)
3.3 Processing days
The average days used for creating Products after satellite observation was 4.1
days and more than a half of the processing was done within 3 days. Some new
Products could be found even 20 days after. Most of these data were delivered forrehabilitation purposes with very high spatial resolutions.

Trend of International Charter for Environmental DisasterOctober 2010, Kobe, Japan

Figure 4. Number of products of the Charter(x: days after satellite data were collected)
4. DISCUSSIONS
Recent products have significant high resolutions, both temporally and spatially.
Landsat and other medium resolution satellite, however, still have important roles
related to their large area coverage and historical databases.
Current distribution of map products is almost entirely internet-based, whichallows rapid circulation.
Although there have been worldwide contribution of remote sensing experts todisaster mitigation, there is no single global coordination mechanism toimplement an integrated disaster monitoring system. At least a gateway to connect
disaster datasets must be implemented in some international organization for nonexpert users.
The International Charter provides on demand access to space-based informationfor emergency response. But there is still the need to help the end user transform
such information into usable products and introduce these products into theiractivities. The Charter was activated and damage maps were produced, but
knowledge from the field is seldom incorporated in the process. User workshop orconference must be required for making the international activities more useful incollaborations among users and data distributors.
REFERENCES
Disaster Charter, http://www.disasterscharter.org/home
Sentinel Asia, http://dmss.tksc.jaxa.jp/sentinel2/topControl.action
Stevens, D., 2008. Increasing the Use of Geospatial Technologies for Emergency
Response and Disaster Rehabilitation in Developing Countries, Nayak S. and S.
Zlatanova (editors), Remote Sensing and GIS Technologies for Monitoring andPrediction of Disasters, Springer, 57-71.
United Nations, 2005, Report of the World Conference in Disaster Reduction, 42p., http://www.unisdr.org/eng/hfa/docs/Final-report-conference.pdf

New Technologies for Urban Safety of Mega Cities in Asia

Risk management of cultural heritage
in Kyoto
Kenzo TOKI
Professor and Director, Research Center for Disaster Mitigationof Urban Cultural Heritage, Ritsumeikan University, Japan
toki-t@fc.ritsumei.ac.jp

ABSTRACTThe field of cultural property protection is wide and varied, with the problem ofnatural disaster alone having been overlooked. This lack of attention isparticularly prevalent in measures for seismic hazard. Experts in the field of
cultural property preservation recognize that cultural property fire-prevention
measures thus far, having focused on accidental fires and arson within the
precincts of shrines and temples, have been ineffective in preventing fires fromspreading to historical buildings during simultaneous outbreaks of fire in
surrounding areas where are of concern during an earthquake. In the Great
Hanshin-Awaji Earthquake of 1995 Kyoto was shaken by seismic intensity 5 , butdamage was relatively slight. In some instances, such as famous temples with highprestige at Ninnaji and Daigoji temples, the firefighting equipments were
disrupted, precluding efforts to extinguish the flames. Kyoto is located some 50 or
60 km away from Kobe. Since the densely populated Kyoto basin of today iscovered with flammable materials, if multiple fires were to break out there
simultaneously, as in the Kobe event, many National Treasures would definitely
be lost. The importance of cultural heritage disaster mitigation is recognized in2003 by the national government and a National Committee was organized.
The report of the committee discusses the importance of protecting both cultural
assets and local regions, collaboration between local citizens, custodians ofcultural assets, and government, and the types of measures required in the future.
Complying with the Kyoto city’s request, the national government approved
funding for the first phase of the project in its budget request for fiscal 2006. Thisis the first national project for protecting cultural assets against natural disaster.
The focus of the project is two 1,500-ton underground water storage tanks near
Kiyomizu temple and San’nei-zaka area. Equipped with a pressurized water
sprinkler system and other fire control facilities, not only will it be used to fightfires during big earthquakes, but as an easy-to-operate fire hydrants for otherfires as well.
Keywords: cultural heritage, post-earthquake fire

1. A FORGOTTEN POINT OF VIEW
The Cultural Assets Preservation Act was established in 1950, one year after the
Kondo Mural Painting at Horyuji Temple was destroyed by fire. Since then,0ctober 2010, Kobe, Japan

thanks to continuous effort by the central and local government and the cultural
heritage community, Japan has achieved significant and brilliant results in cultural
heritage preservation. These wide-ranging results include the prevention andmitigation of age-induced changes to cultural heritage, the excavation andexamination of buried cultural assets, and protecting cultural heritage from fire.
This is not to say, however, that there has been enough done in preparing fornatural disaster. Many treasures have been lost due to natural disasters — forexample the damage of the stage on the sea at Itsukushima Shinto Shrine during
Typhoon No. 18 in September 2004, and the damage to the five-story pagoda at
Murouji Temple from a fallen tree in September 1998.
The field of cultural property protection is wide and varied, with the problem ofnatural disaster alone having been overlooked. This lack of attention isparticularly prevalent in measures for seismic hazard, as recognized by leading
cultural properties protection expert Kakichi Suzuki, former director of the Nara
National Research Institute for Cultural Properties (Fig. 1). Tamae Ohnishi, thenmanager of the Traditional Culture Division in the Agency for Cultural Affairs,
who was in charge of protecting the government’s cultural properties,
acknowledges that cultural property fire-prevention measures thus far, having
focused on accidental fires and arson within the precincts of shrines and temples,
have been ineffective in preventing fires from spreading to historical buildings
during simultaneous outbreaks of fire in surrounding areas which are of concern
during an earthquake. In other words, experts in the field of cultural property
preservation recognize the need to focus on this problem in the future. Meanwhile,
there are nearly two thousand researchers nationwide involved in preventing andmitigating natural disaster. But such researchers and technicians have not worked
organizationally to tackle the problems inherent protecting cultural properties
from disaster. While individual research, encouraged by an interest in scholarship,
has been conducted on a small scale for historical buildings and other cultural
assets, it has not been organized. That is to say, since cultural properties andassets are irreplaceable, they should be viewed from a different perspective thanother assets of society. However, research in the area of natural disaster thus far
has not been conducted from such an all-encompassing perspective.
Kakichi Suzuki, former director of the Nara National
Research Institute for Cultural Properties: “Measuresfor coping with big fires caused by earthquakes havebeen completely lacking in policy for cultural assets
preservation.”
Tamae Ohnishi, then-manager of the Traditional
Culture Division in the Agency for Cultural Affairs:“Protecting cultural properties from fires caused byearthquakes differs from the cultural property
preservation policy that the national government has
pursued thus far.”Figure 1 Problems in cultural heritage preservation

New Technologies for Urban Safety of Mega Cities in Asia

As shown in Figure 2, safeguarding against natural disaster has been neglectedamong cultural property preservationists. Similarly, people involved in natural
disaster prevention or mitigation have neglected to treat cultural properties assomething special. The problems involved in protecting cultural properties fromdisaster, then, have been overlooked in both cases. However, the way ofrethinking of the problems of cultural heritage disaster prevention following theGreat Hanshin-Awaji Earthquake (commonly referred to as the Kobe Earthquake)of 1995 has gradually been assimilated over a wide spectrum. This is because thisformerly neglected issue has come to the attention of many people, including
those of the cultural assets community, those involved in natural disasterprevention and mitigation, and people who are not directly involved in either ofthese areas. But now this new way of thinking is gradually coming to the fore.

Figure 2 Protection of cultural heritage from natural disaster2. SO, WHAT’S THE PROBLEM?
In the Great Hanshin-Awaji Earthquake of 1995 Kyoto was shaken by seismic
intensity 5 , but damage was relatively slight. Thirty people were injured, andmore than 1,000 homes were damaged, including those that received only slightdamage. Also more than eighty shrines and temples were damaged, including
cases of partial damage to earthen walls and other structures. All of that damage
was slight. In some instances, such as at Ninnaji and Daigoji temples, thefirefighting equipments were disrupted, precluding efforts to extinguish the flames.
The resulting damage was as indicated in Figure 3.
Firefighting equipment from the mountainsidetank damaged by fire
Firefighting equipment damaged by a strong
earthquake
What would happen if a big earthquake hit
Kyoto?

Figure 3 Damage to temples in Kyoto during the 1995 Kobe earthquake

Risk management of cultural heritage in Kyoto

0ctober 2010, Kobe, Japan

Kyoto is located some 50 or 60 km away from Kobe. If an earthquake were to
strike closer to Kyoto, it is not hard to imagine that many more temples andshrines would be damaged. Though firefighting and fire-prevention equipment,
including underground and mountain-based water tanks and fire cannons, areconnected by underground pipes, most of those pipes are of low quake-resistance.
While historic and important temples and shrines have been equipped with such
facilities for many years, until the 1980s seismic effects on underground pipe lines
had not been considered in seismic resistand design. As a result, historic temples
and shrines have little protection from earthquakes. In addition to this lack ofequipment and facilities to combat earthquake-induced fires, there is one more
important inadequacy that must be pointed out.
So what is lacking in the existing facilities? As indicated in Figure 4, there is a
shortage of reserve water. Since most firefighting facilities at temples and shrines
are used to extinguish flames from accidental fires and arson within temple andshrine precincts, they only have enough water to fight the flames for the shortperiod until the fire engines arrive or during the early stages of the fire. However,since multi-cites fires can be anticipated after strong earthquakes in big cities,
chances are very slight that enough fire engines could be sent to a specific temple
or shrine. Even if they were, they would probably not be able to get through,because the narrow streets would probably be blocked by fallen buildings andflames. Therefore, it must be assumed that fire engines would not come during
and after an earthquake. This means, of course, that there are not enough water
reserves, since they are set aside under the assumption that fire trucks will indeed
show up. Without enough water reserves, fires in surrounding areas will not be
prevented from spreading to the precincts of temples and shrines. (Fig. 5)•Action taken by temple authorities tocombat accidental fires and arson within
precincts

spread of fire from outside the precinctof temple during an earthquake•Shortage of reserve water

self-efforts to extinguish the flames
until fire engines arrive•Existing facilities and equipment areuseless against earthquake-induced fires.

Figure 4 Problems with existing fire-prevention andfire fighting facilities and equipment
This inadequacy in facilities to combat fires must not be overlooked. Exacerbatingsuch inadequacies is the problem of a lack of quake-resistance of water cannon
pumps and power-generating equipment at temples and shrines. If any of thesepieces of equipment are disrupted, even partially, they lose their overall capacity
to combat fires. Nevertheless, thus far the quake-resistance of firefighting and

New Technologies for Urban Safety of Mega Cities in Asia

fire-prevention facilities has rarely come under scrutiny. So while facilities andequipment used to protect cultural assets must be urgently inspected for quakeresistance and seismically strengthened, the biggest problem is that measures forcontaining the spread of fire are not even a topic of consideration.

Figure 5 Wooden residential buildings situated closely together
in an area containing cultural assets

3. DANGER OF FIRE UP FIVE-FOLD
SINCE THE TURN OF THE 20TH CENTURY
Kyoto has one of the lowest rates of fire outbreak among large cities in Japan.
This is probably due to a visceral sense of potential danger among the citizenry of
Kyoto, which contains many old wooden buildings — which, along with the city
itself, were spared from the destruction of World War II. However, a low rate offire outbreak and high resistance to fire are two different things. Since there are somany old buildings, if a fire were to break out, it would probably be very difficult
to extinguish.
The areas of dense population in Kyoto of about 120 years ago (in 1887) (Figure6)was about the same as they were at the time of the great fire of the Tenmei era(1788), during which 80% of the city was burned out(Fig. 7). According to an
Ordnance Survey map, just one hundred years ago Kyoto’s population lived
between Higashiyama-dori and Senbon-dori streets, and Kitaohji-dori and Kyoto
Station — while the rest of the city was farmland. Today the Kyoto basin iscovered with residential buildings from every corner to corner, with the populatedarea expanding about fivefold in just a century.
Today there is not even one wooden building which is a National Treasure (Nijo
Castle) in the area that burned during the Tenmei Great Fire. National Treasuresin the areas which were not burned only survived because of the sparse scatteringof houses in and around those areas. Since the densely populated Kyoto basin of
today is covered with flammable materials, if multiple fires were to break out
there simultaneously, as in the Great Hanshin-Awaji Earthquake of 1995, many
National Treasures would definitely be lost.

Risk management of cultural heritage in Kyoto

0ctober 2010, Kobe, Japan

Figure 6 Areas of densely populated area in the middle of Meiji era
and location of National Treasure buildings
Daisen-in
Kamigamo jinja
Kousan-ji
Kinkaku-ji

Daitoku-ji

Ryuko-inShimogamo jinja

Ryo’an-ji
仁和寺金堂
Nin’na-ji
Kitano tenmangu

京都の国宝建造物

Senbon shakado
Kouryu-ji
Tenryu-ji

Ginkaku-ji
Nannzenn-ji
Kiyomizu-dera
Houkoku-jinja

Nijo-joMyouho-in
Sanju sannden-dou

Nishi hongan-ji
西本願寺飛雲閣ほか

Touhuku-ji
Tou-ji

Ryogin-an
Houkoku-jinja

Wooden Buildings of
National Treasures in Kyoto

Daigo-ji

Myoki-an
Ujigami-jinja
7

Byodou-in

Figure 7 Existing cultural assets and area burned out by the Ten’mei Great Fire
Some people assume that if something burns down, it can be rebuilt. But suchreconstruction entails extreme difficulty. The reason is that while many historicaland cultural properties were privately owned by political leaders or the nobility,
many of those that had been destroyed by fire were rebuilt or restored throughNew Technologies for Urban Safety of Mega Cities in Asia

donations by political and religious leaders. The reason that so many of Kyoto’s
rebuilt or restored historical buildings date back to around the turn of the 17th
century is because that was a time when the leaders of the government held firm
political power.
But such a degree of political power no longer exists in Japanat present tme. Nor
are private individuals apt to donate funds to restore and rebuild historicalbuildings. What’s more, the national government is not allowed to provide
support to specific religious institutions. If many cultural properties were lost tofire, they would not be rebuilt as they were in the past. That this was a problem
even in the modern age is clear from the fact that there are not many buildings
currently designated or likely to be designated as National Treasures in the area
destroyed by the Tenmei Great Fire.

4. KINKI REGION IN AN ACTIVE SEISMIC PERIOD
During the sixty years since WWII, Japan has caught up with and even surpassed
Western societies in its drive for economic advancement, and since the Fukui
Earthquake in 1948 and the Typhoon Isewan (Vera) in 1959, the country has notbeen hit by a natural disaster that would kill thousands of people. There were only
two earthquakes of magnitude 6 or greater in the Kinki Region during the forty
years between the Fukui and Great Hanshin-Awaji earthquakes. However, during
the fifty years between 1900 and the Nankai Earthquake of 1949, there were morethan thirteen earthquakes of a magnitude of 6 or greater in the Kinki Region alone(Fig. 8), with all of them coming during the short eighteen-year period between
1925 and 1943.

1649～1718

1719～1788(69years)(69years)

1789～1858

1859～1890(69years)（31years)

Active Period

Non‐active
Period1891～1961

1962～1994(70years)

1995～(10years)（32years）

To occur within next
30‐40 years

Figure 8 Many earthquakes occurred inland in the Kinki Region
before the Tohnankai and Nankai earthquakes

Risk management of cultural heritage in Kyoto

0ctober 2010, Kobe, Japan

In light of these facts, it would be a misunderstanding to think that there are notmany earthquakes in the Kansai Region, as concluded during the fifty years since
the end of the war. The entire seismic environment from the Kansai Region to theTokai Region is a product of the Tokai, Tohnankai, and Nankai Earthquakes along
the Nankai Trough. History clearly shows that these earthquakes recur over cyclesof 100 to 120 years. (Fig. 9) Therefore, the earthquakes of these regions must be
looked at not in terms of fifty years, but in terms of a hundred years.

（
１９９５年）

阪神・
淡路大震災

（
１９９４年）

猪名川群発地震

京都大地震（
Ｍ７級）

年地震（
Ｍ７級）

2

（
１８３０年）（
１８１９年）

2

文政

年地震（
Ｍ７級）

（
１６６２年）（
１５９６年）

慶長大地震（Ｍ７級）

寛文

Intra-plate earthquakes
南海地震の約60年前から約10年前までが､内陸の活断層地震が起こりやすい
活動期

Active period（
２０４０年ごろ）

2000

次の南海地震（
Ｍ８級 ）

南海地震（
Ｍ８級）

（
１９４６年）

1900（
１８５４年）

宝永地震（
Ｍ８級）

1800
安政南海地震（
Ｍ８級）

慶長地震（
Ｍ８級）

（
１７０７年）

1700（
１６０５年）

1600

2050

Inter-plate earthquakes
京都市防災協会（財）「大地震が京都を」平成(10)Figure 9 Earthquakes causing damage in Kyoto
From this point of view, it can be said that we are in an active period like the onethat began in 1925, starting with the 1995 South Hyogo Prefecture (Kobe)
Earthquake. It would seem that the Western Tottori Earthquake in 2000 and theGeiyo Earthquake in 2001 are part of a series of inland quakes. Though none of us
hope for disaster, the fact is that an inland quake in the Kansai will definitely
occur in the not-to-distant future. But since we do not know when it will be, we do
not have a sense of imminent danger — and our desire for an earthquake not to
occur somehow transforms into the notion that there will never be a quake in anarea where we live. “I never thought an earthquake would strike where I live,”
said a victim of the Mid Niigata Prefecture Earthquake in October 2004 in a
televised interview. Most people would probably feel the same way. In the Great
Hanshin-Awaji Earthquake more than six thousand people died. However, it isdoubtful that anyone thought, “Tomorrow morning I might die in an earthquake.”
But unlike then, currently the experts tell us that the Kansai is in an active seismic
period. We must not look upon this problem unscientifically, based on wishful
thinking.

New Technologies for Urban Safety of Mega Cities in Asia

5. EARTHQUAKE MEASURES ARE A KIND
OF “LIFE INSURANCE” FOR KYOTO
Some 47 million tourists flock to Kyoto each year. Since they come to see thehistoric buildings and cultural properties at the temples and shrines (Fig. 10), theloss of these cultural assets would hurt Kyoto terribly, and the number of people
who visit the city would drop drastically. One might say, then, that culturalproperties and historical heritage are a kind of lifeline of Kyoto.

80% of Wooden structure of National
Treasure is concentrated in Kinki district！

Figure 10 Concentration of wooden structure National Treasures in Kinki district
If cultural assets determine the fate of Kyoto, shouldn’t it have an insurance
policy to protect itself? Such insurance is to be found in disaster prevention
measures. At the present time, however, Kyoto’s cultural assets do not seem to be
sufficiently insured. The reason we say this is because since firefighting
equipments and facilities at temples and shrines are not sufficiently earthquakeresistant, in case of an earthquake those facilities would loose firefighting
functions. The previously mentioned two famous temples in Kyoto were unable tofight fires after the quake in Kobe some 50 or 60 km away. If an earthquake wereto strike Kyoto, then, most of its historical buildings would be devastated.
Also, as things currently stand, there is not enough reserve water to protect thesebuildings until fire trucks arrive. But in a big quake there would probably be
multiple fires breaking out simultaneously, and fire trucks would be unable to getto the scene through the narrow and burning streets. What’s more, Kyoto has
more than twice as many pre-WWII wooden buildings than does Kobe. In light ofthese facts, it is not hard to imagine that if a big earthquake were to hit Kyoto or
its vicinity, many cultural assets would be burned out by fire.
Considering the degree of potential danger, certainly everyone would agree thatmeasures against disaster, particularly earthquake-induced fire, must be urgently
implemented as a form of insurance. We wonder, then, why such measures havenot been put in place. Most adults have life insurance. However, the reason people
Risk management of cultural heritage in Kyoto

0ctober 2010, Kobe, Japando not become seriously involved in countermeasures against disaster — i.e., life
insurance policies for the cities and towns in which they live — must be because
they are concerned about the non-collectable nature of such insurance. But
certainly nobody wants to collect on life insurance. Even if disaster measures are
put in place as insurance, it doesn’t mean that there will necessarily be a big
earthquake in Kyoto that will destroy many of its cultural assets. If people do notworry about the fact that they can never collect on their life insurance policies,
there should be no problem if all types of insurance were made to be noncollectable.
Cultural properties contain the cultural remnants of the mentality of people of pastages. Through cultural properties we can learn about that mentality. Since culture
itself is and invisible, without cultural properties it would be impossible to get a
glimpse of the hearts and minds of people of ages past. Thanks to the wealth of
information from past ages contained in cultural properties, these objects help us
learn about our history, particularly mental activities. It is for this very reason thatwe, who are alive today, must make every effort to preserve cultural heritages for
future generations.
But one wonders if we truly make the same effort to hand down cultural assets tofuture generations as we do in the pursuit of the everyday comforts of modern
civilization. During the sixty years since the end of WWII we have pursued
economic prosperity and material comfort. Now that we have achieved a
relatively high degree of comfort, isn’t it time that we start thinking about future
generations?

6. WHAT MUST BE DONE NOW
The importance of cultural heritage disaster mitigation is recognized by thenational government and some local governments. As indicated in Figure 11, forexample, in June 2003, the Cabinet Office established an Inspection Committee to
Protect Cultural Assets and Local Regions from Natural Disaster, and in July
2004 it issued a report on “Measures Needed to Protect Cultural Assets and Local
Regions from Seismic Hazard.” (Fig. 12) This committee is made up of academic
experts, with relevant government agencies acting as offices of the committee.
The report discusses the importance of protecting both cultural assets and local
regions, collaboration between local citizens, custodians of cultural assets, andgovernment, and the types of measures required in the future.
It also presents the case studies on the areas around Kiyomizu Temple andSan’nei-zaka in Kyoto, and on the Shibamata Taishakuten area in Tokyo. There isa separate page appended to the end of the report, which begins with the words“Relevant government agencies.” This could be interpreted as demonstrating akind of national will to prevent cultural assets from disaster. This page also saysthat relevant government agencies will collaborate to raise the level of importanceplaced on cultural assets in efforts to prevent disaster in local areas, helping to
implement those projects in the near future.

New Technologies for Urban Safety of Mega Cities in Asia

Central Disaster Prevention Council(Cabinet Office, organized in June 27, 2003)◇Academic experts on the committee
15 experts and Chairperson◇Committee members representing the government and public sectors
Disaster-prevention specialist from the Cabinet OfficeFire and Disaster Management Agency
Agency for Cultural Affairs, Ministry of Education, Culture, Sports,
Science and Technology
Ministry of Land, Infrastructure, Transport and Tourism
Local public agencies (Tokyo Metropolitan Government, Kyoto City)

Figure 11 Committee organization
Measures Needed to Protect Cultural Heritage andLocal Regions from Seismic Hazard
Chapter 1: Background of Plan
Chapter 2: Basic Views in Protecting Cultural Heritage and Local
Regions from Seismic Hazard
Chapter 3: Basic Views in Protecting Cultural Heritage and Local
Regions from Seismic Hazard
Chapter 4: Specific Measures
Chapter 5: Tasks in Realizing These Measures
Relevant government agencies will pursue the following toward
protecting cultural heritage and local regions from seismic hazard:
1.Raise the level of importance placed on cultural heritage disastermitigation measures, as part of a disaster-mitigation project
2. Support local regions in realizing these objectives.

Figure 12 Contents of reportThus, relevant government agencies at least recognize the importance of cultural
heritage disaster prevention measures. The city of Kyoto, with its wealth ofcultural properties, has for the past several years expressed concern over theseissues. Determined to maintain its historical ambience, the city has set up acommittee to find a way to create a water supply system for use in disasterprevention efforts. Meanwhile, The Society for Protecting Cultural Assets from
Disaster, an NPO, has been active for thirteen or fourteen years, though formerly
as a different organization. The society has conducted case studies for the abovementioned committee. In addition, at the request of the national government, thesociety, Kiyomizu Temple and local citizens have collaborated to formulate
specific disaster prevention measures for Kiyomizu Temple, Sanneizaka, and thesurrounding area. As the local government, Kyoto City is also involved. After theplan was completed in March 2005, it was established as an official plan of Kyoto
City and submitted to the national government. Thus, the implementation of
Risk management of cultural heritage in Kyoto

0ctober 2010, Kobe, Japan

cultural heritage disaster mitigation measures requires not only the cooperation ofcustodians of cultural properties, but also a specific plan that is acceptable to local
citizens.
The current activities in the vicinity of Kiyomizu Temple consist of a pilot project,
and the similar methods and procedures will most likely be required to realize
disaster mitigation measures in a specific area focusing on cultural assets. Since
formulating such a plan requires specialized knowledge, including technicalexpertise, it is no small task for this NPO, which consists of volunteers andexperts from various fields. At any rate, since it is important to form a rational andeffective plan which will be acceptable to the temples and shrines housing thecultural assets, as well as to the local citizens, efforts have been urgently initiatedto find the optimum means for realizing such a plan. However, there is not awhole lot of time left before the next earthquake will strike. (Fig. 13)

Figure 13 Cycle of collaboration

7. THE WORK HAS BEGUN
While paying due attention to historical ambience, the Society for Protecting
Cultural Assets from Disaster has also explored the particulars of a water supply
system for use in disaster mitigation efforts. In order to arrive at a viable system
and implement it, the society has been talking with Kiyomizu Temple and local
citizens, realizing the necessity of not only knowing the geographical features of
the area but also forming a relationship with the temple and the local citizenry.
That is to say, the NPO has formed a Study Group for Maintaining a Disaster
Mitigation Water Supply System, and crafted a plan thereof, with the cooperationof Kiyomizu Temple, Kodaiji Temple, representatives from local governments,
and the Kyoto City Fire Department. It also held a workshop in supplying waterfor environmental disaster mitigation, involving people from the city governmentand others. After more detailed study, it was decided that further technicalinvestigation was required. The NPO, then, obtained small amount of financial
assistance from the national government in its collaborative efforts, playing acertain role in administrative actions.

New Technologies for Urban Safety of Mega Cities in Asia

The resulting proposal was to dig a tunnel (to avoid blemishing the landscape)through the mountains of Higashiyama for storing water (Fig. 14); and to installfire hydrants and a water sprinkler system in the area bounded on the east andwest by Higashioji Road and Higashiyama, and on the north and south by
Maruyama Park and Otani Honbyo (Otani Mausoleum). One of the proposedwater sprinkler systems is equipped with “mist defense” (Fig. 15) that envelops
endangered buildings and facilities with a protective mist.
Well
Sedimentation pool
Water Tunnel

Pipe

Figure 14 Water storage tunnel in Higashiyama

Figure 15 Mist defense system in action
After the concrete proposal was presented to Kyoto City, it was slightly revised,
and in June 2005, the mayor asked the national government to prepare a budget
for the project. Complying with the city’s request, the national government, inturn, approved funding for the first phase of the project in its budget request for
fiscal 2006. This is the first national project for protecting cultural assets tankagainst natural disaster. The focus of the project is a 1,500-ton underground water
storage tank beneath the “disaster-prevention park” adjacent to the parking lot at
Kodaiji Temple. Equipped with a pressurized water sprinkler system and otherfire control facilities, not only will it be used to fight fires during big earthquakes,
but as an easy-to-operate fire hydrants for other fires as well.
The construction work of underground water tank was completed in January 2007.
(Fig. 16) Still in its initial phase, the project seems very promising as it moves
forward, and must be further developed to include not only Kiyomizu Temple but
areas containing historical assets nationwide. The current project for protection ofcultural heritages from earthquake fire (Fig.17) will be completed in March 2011.

Risk management of cultural heritage in Kyoto

0ctober 2010, Kobe, JapanAt the present time (2010), two tanks colored in light blue have been constructed
and underground trunk pipe line by polyethylene pipe was buid up. Water in thissystem are used for ordinary fire in the vicinity of the area through hydrant by fireengines and also inhabitants of the area can use water for daily purpose to sprinkle
on nearby streets by making use of ordinary hand pump. Namely, this system isdesigned as a multipurpose usage, not only for fire after earthquake.

Pump

Pipe

Water storage tank

Figure 16 Water storage tank in the “disaster-prevention park” at
Kodaiji Temple (completed in January, 2007)

Yasaka Shrine

Water tank
Water pump
Water distribution pipe
(polyethylene pipe)
Water hydrant
Devices to protect
cultural heritages

Kiyomizu temple

Figure 17 Project for protection of cultural heritage from post-earthquake fire

REFERENCE
Kenzo TOKI: Cultural Heritage and Seismic Countermeasures, “Introductory
Volume” to Cultural Heritage Disaster Mitigation Studies, Ritsumeikan
University, 2010.

New Technologies for Urban Safety of Mega Cities in Asia

Risk management of cultural heritage in Kyoto

How long can we use concrete structures?
Taketo UOMOTO
Chief Executive, Public Works Research Institute, Japan

ABSTRACT
To maintain the human society, the civil structures are one of the most importantand fundamental structures for the people to live in safety and in comfortablemanner. Although a large number of civil structures are built elsewhere
throughout the country, it is expected to use these structures for more than 100
years. Deterioration of these structures become obvious may be after 10 to 20
years after the construction. Deterioration is an inevitable phenomenon evenwhen the structures are carefully made and used. This paper describes how thedeterioration affects the safety of these structures, especially concrete structures,and explains how we should treat the structures to prevent further deterioration
although their lives.
Keywords: civil infrastructure, deterioration, maintenance

1. INTRODUCTION
Japan experienced a rapid economic growth in the period of 1960 to 1980. Morethan 100 million cubic meters of concrete were used to construct the structures
such as buildings, bridges, tunnels, dams, etc. to support the activities of Japanesepeople. As a result, large stock of these infrastructures is reaching 50 years ofservice, and due to deterioration of the structures, maintenance of these structures
has become a major interest among the owners and the civil engineers.
On the other hand, population of Japan will reduce from now on because of fewer
babies in a family (approximately 1.2 children per family) than needed to sustain
the present population. Although high technologies have been developed inrecent years, it is sure that fewer engineers will have to take care of this hugeamount of structures from now on, which has never experienced in the past. Dueto reduction in the economical growth, the budget for both construction andmaintenance will be reduced in the future.
The maintenance of existing structures must be done with the following
conditions: 1) rapidly increasing amount of existing structures reaching the age of
50 years, 2) less amount of engineers to maintain the structures, 3) less amount ofbudget to maintain the structures. Although there are many hazards in eachcountry, concrete structures are expected to be safe for long period of time. If thestructure is deteriorated before the hazards, the structure may easily collapse and it
would be difficult to maintain the safety of the people.

October 2010, Kobe, Japan

In order to keep the safety of urban area, it is important to study and investigate
not only on hazards but also on durability aspects of existing structures. Even asmall amount of concrete spalling may cause large scale traffic accidents as we
experienced in Sanyo-Shinkansen in 1999.
Considering these situations now, this paper explains what is happening now inJapan and how we are dealing with the problems through research andengineering.

2. GENERAL MAINTENANCE METHODS USED UNTIL NOW
The maintenance of concrete structures has been done mostly by the owners of thestructures. In case of public structures, the ministries, etc. maintain the structure
after the structures are completed. For the time being, the methods for the
maintenance differ according to the owners of the structures. Although there aresome differences, the main concept of the maintenance can be summarized asfollows (Uomoto and Misra, 2001):
1. Periodic inspection and evaluation of deterioration degree
2. Detailed inspection and decision making
3. Repairing and strengthening of deteriorated structures
For periodic inspections, the inspectors inspect the structures visually, sometimes
with the help of binoculars and hammers, once a year or once in several years
according to the importance and time after the structure is completed. The
inspectors are mostly trained engineers with experiences. The detailed inspection
is done when the estimated degree of deterioration exceeds certain limit, or whensome new phenomenon is found during the periodic inspection. The detailed
inspection is done by visual inspections with the aid of non-destructive tests or
taking core samples out from the inspected structure. The purpose of theinspection is to decide the cause of the deterioration and also to evaluate whether
repair and/or strengthening is needed or not.
To repair or strengthen the existing structures, it is important to design and selectsufficient methods and materials. The most popular repair method for corrosionof steel bars due to carbonation is to eliminate the carbonated concrete and replace
it by new concrete and apply coatings with and without FRP sheets. But in case ofsteel corrosion due to chlorides from the surrounding environment, the highchloride concentration portions of concrete are taken out, anti-corrosive treatment
is applied to the surface of the bar, and polymer cement mortar is generally used
to repair the concrete before coating the concrete surface.

3. MAINTENANCE METHODS BY JSCE
The methods used in the new Standard Specification of JSCE are basically thesame as the conventional method. The differences are that the new method

New Technologies for Urban Safety of Mega Cities in Asiarequires maintaining the structure within their required performances throughout
their service life.
Firstly, the listed below issues have to be clearly specified.
1) To maintain a structure, performances required for the structure must be clearly
defined.
2) The performances required for general structures are “safety”, “serviceability”,“hazards to the public”, “aesthetics and landscape” and “durability”.
And the basic principles of maintenance works are as follows:
1) Structures must be maintained according to a designated maintenance category
by formulating a maintenance program to retain the performance within thespecified tolerances throughout their service life. And maintenance system
includes adequate “initial inspection”, “deterioration prediction”, “inspection”,“assessment/judgment”, “remedial action”, and “record”.
2) To maintain a structure, in addition to the assessment and evaluation at the timeof inspection, assessment and evaluation must be made throughout the service lifeof the structure based on prediction of deterioration.
3) To predict the deterioration, required performances of the structure must be
clearly defined, and also the design service life must be made clear.
4) The records on design, construction, initial inspection, deterioration prediction,
periodical inspection, assessment and/or evaluation, and remedial actions must be
kept throughout the service life.
Standards for maintenance of concrete structure deteriorated by different
mechanisms are also discussed. The lists below are the standard maintenancemethod published in this standard:
1.
2.
3.
4.
5.
6.

Carbonation induced deterioration
Chloride induced deterioration
Frost attack
Chemical attack
Alkali aggregate reaction
Fatigue of RC slabs and beams

In detail, for an example, the standard method for chloride induced deterioration
recommends the model to predict chloride ion diffusion, progress of steel
corrosion, and correction of the prediction. Also the methods of initial inspection,
routine inspection, periodic inspection, and detailed inspection as well evaluationand judgment method are also discussed. Finally, for recommendation remedial
measures, information on measurements of both repair and strengthening also
have to be recorded.

How long can we use concrete structures?

October 2010, Kobe, Japan

電流量
Ik (mA/cm)
Current
Amperage(mA/cm)One of the difficulties is how to predict the degree of deterioration at the end of
their service life. There are several researches being done to predict thedeterioration in numerical manner. In the published Standard, several numericalprediction methods are introduced as references for structures suffering cyclic
fatigue loads, carbonation induced corrosion and chloride induced corrosion. In
case of cyclic fatigue, S-N curves are used to predict the service life. In case ofcarbonation induced and chloride induced corrosion of steel bars, diffusion
equations for carbon dioxide and chloride are used to predict the degree ofcorrosion. Using these prediction methods, deterioration degree can be estimatedto certain degree. (See Figure 1) But for other deterioration problems, which has
not been studied numerically, a quantitative model has not been proposed yet. To
deal with the problem, a qualitative method, namely “Grading method”, isintroduced in the Standard.
（Temperature:20℃、Crack depth: 7cm）

0.1

Cathode

0.05

Crack

0
-0.05

days
28日
days
91日
days
180日

Anode

-0.1
-0.15

year
1年
years
2年

-0.2
-0.25
0

2

4
6
8
10
モデル端部からの距離(cm)
Distance (cm)12

14

Figure 1: Quantitative prediction of corrosion in marine environment with cracks(Tsukahara et al., 2000)

4. PROBLEMS IN ACTUAL EXISTING STRUCTURES
When a civil engineer is asked by the owner to check the safety of an old existing
structure, one of the largest problems is that there are neither drawings nor
construction records of the structure available. No problem may occur in case ofimportant facilities, which is maintained with great care. But in case of normal
structures, the owners do not know the importance of these documents.
To deal with the problem, NDI is not enough. Fortunately, our structures are not
too old, and they are mostly designed and constructed by the method specified by
JSCE, AIJ or other associations. Considering these, the only way is to re-design
the structure again using the methodologies used at the time of construction.
Figure 2 shows an example of re-designed bridge pier constructed about 35 years
ago. From the figure, it is much easier for a civil engineer to check the safety ofthe structure under several hazards. It will become more important for the owners
and engineers to keep these documents throughout the service life of a structure.

New Technologies for Urban Safety of Mega Cities in Asia

D131201907,300

85 0 65 0
D16

4,500

65 0
4,500

250
D25

1,000 30 0

12 023 0

21@300１

1,300

280 8@200

210

50 280 9@200

18,390CL

9,390
280 16@200280

120@125
15,620120

Figure 2: Re-designed reinforced concrete pier of a bridge (Okazaki, 2005)
If the re-designed structure is correct, we can easily estimate the service life of thestructure using deterioration model considering the present deterioration degree ofthe structure. As mentioned in the JSCE Standard Specification, we can check
whether the deterioration of the present structure is within estimated range or not.
By modifying the estimation model, we can estimate the life of the structure moreaccurately.

5. NON-DESTRUCTIVE INSPECTIONSNew NDI Technologies are developed by many researchers and engineers.
Although it is believed that NDT is the most powerful technology to check thesafety of a structure, it is not so easy to utilize them. Some says if we monitor the
structure by NDI, 1) we can easily get accurate information of the structure easily,2) we can easily estimate when the structure may collapse by NDI, etc. To obtain
useful results, we must know how we can get the important information. I would
like to introduce some examples related to NDI.
5.1 Tunnel Lining Inspection
An example of the inspected result of a concrete tunnel lining is shown in Figure
3. As shown in the figure the cracks are observed elsewhere and the cracks areconcentrated especially from S10 to S11. Most of these cracks are vertical to thetunnel axis, indicating that the cracks may be made by force rather thandeterioration such as corrosion or alkali aggregate reaction.
After the construction, the tunnel has been used for 30years and quite a large
amount of settlement was observed. Every year, the height of the tunnel ismeasured. Figure 4 shows the height and settlement of the tunnel just after theconstruction and after 30 years. As shown in the figure, the largest settlement wasobserved in the span No. S 13, and another portion was in the span No. 69. On
the contrary, a large rise was observed in the span No. 43. These figure showsthat the tunnel has moved downwards in some places, but also some portion
moved upwards after the construction.

How long can we use concrete structures?

October 2010, Kobe, Japan

CenterSide (left)

Top

Side (right)
Span No.

S-2

S-6

補強区間

S-10

100

-8

Elevation from sea level (m)

-9
50
-10
-11
0
-12
-50

-13
-14

-100
-15
-16
-150
-17
-18

-200
0

20

40

60

80

100

Total amount of Settlement (mm)Figure 3: Crack distribution of a concrete tunnel from Span S2 to S14(Takeuchi and Suzuki, 2007)

Original
Measured
Elevation
Settlement

120

Number of Span

Figure 4: Level of the tunnel and amount of settlement measured after 30 years(Takeuchi and Suzuki, 2007)

New Technologies for Urban Safety of Mega Cities in Asia

Height of the ground (m)

700

35

Dike

30

600
500

25

400

20

300

Height of surface (m)15Amount of
Settlement (mm)Tunnel

10

200
100
0

5

Ａ

0
0

250

-100

Reinforced
500

Amount of Settlement (mm)

800

40

-200
750

1000

1250

1500

Length of the tunnel(m)Figure 5: Comparison of the tunnel and the structures on the ground surface(Takeuchi and Suzuki, 2007)
These results indicate that the tunnel was affected by the structures constructedabove the tunnel. When dikes are newly constructed, the tunnel sunk down withthe movement of the ground and when the load above the tunnel reduces, thetunnel rise upward as in the case of the pond excavated after.
Comparing the measured height with the structures above, we can easily find thatthe tunnel just underneath the dikes has large amount of settlement and the tunnel
below the pond has the rise as mentioned in the Figure 5.
5.2 Continuous Monitoring of a Structure
In case of an important structure, continuous monitoring may be needed to keep
the structure safe. One of the problems is that it is difficult to monitor all themembers of a structure continuously, considering the expense. How should weselect the member to inspect is a big problem. The following example shows ananswer to select the member in case of a truss bridge.

Figure 6: Estimation of the movement of a steel truss bridge when a member isdeteriorated (Yazuawa, 2007)
The figure 6 shows how the steel bridge behaves if a member of the steel truss
bridge is deteriorated. The calculation is done by 3 dimensional analysis,
How long can we use concrete structures?

October 2010, Kobe, Japan

checking all the members what may happen if the member is deteriorated and can
not support the load. As can be seen from the figure, the vertical member at the
point of support is very important to maintain the bridge safe enough for thepeople to go across.
Knowing the evidence, we can monitor the bridge at this point. May be strain
measurement is enough to check the safety of this bridge. Further, if we wish tomonitor the structure as a whole, several points may be enough for the monitoring.
We can reduce the cost to maintain and monitor the structure not to cause
catastrophic failure.

6. CONCLUDING REMARKS
Engineering is not always complete, and further research works are needed. To
sustain existing structures, durability of the structure is important. One good
method is to construct durable structures, but for the existing structures,
maintenance is the only way to deal with the problem. Although concretecommittee of JSCE has set up a good system for maintenance of existing concrete
structures, there are still many things to be done: not only researches but also
education to the students and engineers about durability and maintenance. I hope
this paper may become a help to the concrete engineers of the world who aretrying to design, construct and maintain concrete structures.
REFERENCES
Concrete Committee of JSCE, Standard Specifications for Concrete Structures2007 “Design”. JSCE, Tokyo.
Concrete Committee of JSCE, Standard Specifications for Concrete Structures2007 “Materials and Construction”. JSCE, Tokyo.
Concrete Committee of JSCE, Standard Specifications for Concrete Structures2007 “Maintenance”. JSCE, Tokyo.
Tsukahara, E., Koyama, R., Hoshino, T., and Uomoto T., 2000. Estimation
Method of Corroded Portion of Reinforcing Steel Bar by Natural Potential
Measurement. Non-destructive Testing in Civil Engineering 2000, Elsevier.
Okazaki, S., 2005. Development of monitoring system for RC bridge based on
restoration design method. Thesis submitted to the University of Tokyo for
Master of Engineering degree.
S. Suzuki, K. Kinoshita and T. Uomoto: Fundamental study on crack distribution
and settlement of Shield Tunnel Lining, JSCE General Meeting of Kantoshibu, 2008
M. Takeuchi, Y.S hirane and T. Uomoto: Fundamental study on relation between
crack and surface load on Tunnel Lining, JSCE General Meeting of Kantoshibu, 2008
S. Yasuzawa and T. Uomoto: Estimation of dangerous points of an existing steel
truss bridge, JSCE General Meeting of Kanto-shibu, 2008

New Technologies for Urban Safety of Mega Cities in Asia

Application of Cement Stabilization Methods
to Earthquake Disaster Mitigation
Masaki KITAZUMEDistinguished Researcher, Port and Airport Research Institute, Japankitazume@pari,go.jp
ABSTRACTIn Japan, soft alluvial clay ground has frequently encountered in on land andmarine constructions. The ground is so soft and compressible that large
settlement and failure can take place. Sandy soil has relatively better properties
for compressibility, but liquefaction might happen during earthquake in a case ofloose and saturated condition. In fact, port and harbor facilities at Kobe Port
were heavily damaged in the Hyogoken-Nambu earthquake in 1995, where
gravity type of sea revetments displaced a couple of meters toward sea together
with large ground settlement at backfill yard. There are many kinds of soil
stabilization techniques developed and available in Japan for countermeasure ofstability, ground deformation and liquefaction. Among these techniques, cement
stabilization techniques have been also frequently applied to improvement ofclayey and sandy soils. In this paper, some applications of three cement
stabilization techniques to earthquake disaster mitigation are briefly introduced.
Keywords: cement stabilization technique, liquefaction, disaster mitigation

1. INTRODUCTION
In Japan, soft alluvial clay ground has frequently encountered in on land andmarine constructions. The ground is so soft and compressible that large settlement
and failure can take place. Sandy soil has relatively better properties forcompressibility, but liquefaction might happen during earthquake in a case ofloose and saturated condition. In fact, port and harbor facilities at Kobe Port wereheavily damaged in the Hyogoken-Nambu earthquake in 1995, where gravity typeof sea revetments displaced a couple of meters toward sea together with large
ground settlement at backfill yard. Table 1 shows the amount of damage to port
facilities caused by strong earthquake (Noda, 1991), and demonstrates quite large
difference between with and without liquefaction. According to the table, theamount of damage when liquefaction takes place is about 20 to 50 times greaterthan that without liquefaction. This highlights the importance of liquefaction
mitigation to minimize earthquake disasters.
There are many kinds of soil stabilization techniques developed and available inJapan for countermeasure of stability, ground deformation and liquefaction.
Among these techniques, cement stabilization techniques have been alsofrequently applied to improvement of clayey and sandy soils. In this paper, some
applications of stabilization techniques, Deep Mixing Method, Premixing Method

0ctober 2010, Kobe, Japanand Lightweight Treated Soil Method, to earthquake disaster mitigation arebriefly introduced.
Table 1 Comparison of amount of damage
Earthquake
Niigata,
1964
Tokachi Oki,
1968
Miyagiken
Oki, 1978
Urakawa
Oki, 1982
Nihonkai
Chubu, 1983

MagnitudePort

Soil typeMax.
accel. (gal)Liquefaction

Damage(millionyen)

7.9

Hachiohe

Sand

233

No

1,980*

7.5

Niigata

Sand

159

yes

49,700*

7.4

Shiogama

Clay

273

No

160*

7.4

IshinomakiSand195-210Yes

3,008*

7.3

Muroran

Sand

164

No

120

7.7

Akita

Sand

205

Yes

6,400

* converted into 1978 prices.
2. DEEP MIXING METHOD
2.1 Outline of the method
Deep Mixing Method (DMM), an in-situ admixture stabilization technique using
cement and/or lime as a binder, has been applied in many construction projects forvarious improvement purposes (CDIT, 2002). DMM was put into practice inJapan in the middle of 1970s to improve soft marine deposits, then spread into
China, South East Asia, and recently to the other part of the world. Two decades

New Technologies for Urban Safety of Mega Cities in Asia

(a) for on land construction(a) for marine construction
Figure 1: DM machineof practice have made equipment improved, binders changed, and applications
diversified. Lime is replaced with cement in Japan. Figure 1(a) and 1(b) show a
DM machine for on land and marine constructions. The special machines used tostabilize soft soil are basically composed of several mixing shafts and blades, anda binder-supplying system. In one operation, a column of treated soil isconstructed in a ground. Through a series of construction steps, any arbitrary
shape of improved mass (such as block, wall and grid types) can be formed in the
ground. For liquefaction mitigation, the block and grid types of DMM have been
applied.
2.2 Applications to earthquake disaster mitigation
Figure 2 shows an application at Kushiro port for liquefaction mitigation of
backfill, where sandy ground was stabilized by a block type improvement with
100% improvement area ratio, the ratio of the improved soil area to the whole sitearea. The design field strength, q u , was 100 kPa, which was considerably low
level compared with that for clay soil improvement. The revetment was subjectedto the Toho-Oki earthquake in 1994, which caused huge damages withliquefaction and cracks at unimproved area. However, due to the ground
improvement, negligible damage took place at the revetment, which has
confirmed the high applicability of DMM for earthquake disaster mitigation.

Your paper title

0ctober 2010, Kobe, Japan

Figure 2: Application of DMM at Kushiro port
DMM was applied to foundation of a building at Kobe port, where sandy ground
was improved by a grid type improvement to prevent excess pore water pressure
generation during earthquake. A 14-story building located on Meriken Wharf inKobe was experienced the Hyogoken-Nambu earthquake in 1995. The soil profileat the site consisted of 10 - 12 m of soft reclaimed sand and gravel layers over theseabed. The seabed soil consisted of alternating layers of clay, sand and gravel.
The building was supported by cast-in-place reinforced concrete piles with adiameter of 2.5 m extending to dense diluvial sand and gravel at a depth of 33 m.
Its section and plan diagrams are shown in Fig. 3. A grid type improvement wasapplied to prevent liquefaction in the upper loose fill. The improvement area ratio
was approximately 20 %. The unconfined compressive strength of the improved
soil after about six weeks curing was 4 - 6 MPa (Suzuki et al., 1996; Namikawa etal., 2007).

Figure 3: Application of DMM at Kobe port
Figure 4(a) shows the damage of quay wall near the building after the earthquake.
The concrete caisson type quay walls on the west, south and east displaced
horizontally by 1 m, 2 m, and 0.6 m respectively and settled by 0.5 m, 0.6 m and
0.3 m. Sand boils and ground fissures were observed at the ground surface. In thebuilding, however, there was no crack at the surface of the improved ground as
shown in Fig. 4(b). The head of the cast-in-place piles supporting the building was
found to be intact. Moreover, negligible differential settlement was observed on
the first floor of the building. These have indicated that the cement stabilization
improvement could mitigate the damage to pile foundation and superstructure.

New Technologies for Urban Safety of Mega Cities in Asia

(a) sea revetment near the building(b) parking area in the building
Figure 4: Damage due to the earthquake
3. PREMIXING METHOD
3.1 Outline of the method
Premixing Method has been developed for liquefaction mitigation where a small
amount of binder and a chemical additive are mixed with sandy materials (CDIT,
2003). Recently, it has been also frequently applied for reducing the earth pressure
acting on the revetment, backfilling behind sheet walls and concrete caisson, andland reclamation material. After mixing these materials in a mixing plant at field,
the stabilized soil is transported and placed at a designated area to construct astabilized reclaimed ground (Zen et al., 1990). Conventional liquefaction
remediation techniques have been generally applied to existing sandy ground.
This method, however, has been applied to fill material which is anticipated toliquefy. The basic principle of the method is that the shear strength of stabilized
soil does not decrease to zero and liquefaction does not take place even if the porewater pressure is generated up to the overburden pressure at site.

Your paper title

0ctober 2010, Kobe, Japan

In the execution, sandy soil is mixed with binder and separation inhibitor and thenplaced at site, where belt conveyor mixing with dumper chutes and mechanicalmixing by screw type mixer are available. In placement of stabilized soil,
spreading, chute and direct placement methods are available.

Figure 5: Premixing Method
3.2 Application to earthquake disaster mitigation
Figures 6(a) and 6(b) show an application at Kobe port where a concrete type
quay wall was damaged in the Hyogoken-Nambu earthquake, in which theconcrete caisson displaced horizontally and titled. As the amount of displacements
were within the allowable values, the caisson was used without re-positioning but
the backfill was excavated and replaced by the stabilized soil in order to reduce
the static and dynamic earth pressures acting on the caisson. The design strengthof the stabilized soil was 100 kPa and blast furnace cement type B of 7.5 % instabilized ratio was mixed with the soil as well as separation inhibitor agent of 75
mg per unite dry weight of sand to achieve the design strength.

(a) section view

New Technologies for Urban Safety of Mega Cities in Asia

(b) execution of improvement at site
Figure 6: Application of Premixing Method at Kobe port
4. LIGHTWEIGHT TREATED SOIL METHOD
4.1 Outline of the method
Lightweight Treated Soil Method was developed to reduce residual and unevensettlement, decrease earth pressure, prevent lateral displacement and improve
earthquake resistance of port and airport facilities in which dredged slurry is
mixed with stabilizing agent and either air foam or expanded polystirol (EPS)
beads of 1 to 3 mm in diameter (Tsuchida, 1995; CDIT, 2004). Density of thestabilized soil can be obtained from 0.6 and 1.5 g/cm3 by controlling amount of air
foam or polystirol beads, and water content of soil. As clayey soil to be mixed hasa relatively high water content, the treated soil has high liquidity at mixing stage
and then looses liquidity quickly. Execution procedure of the method is very
similar to Premixing Method, which includes dredging, transporting, mixing,
placing and curing steps.
The earth pressure of the stabilized soil is very small by the effect of its relatively
large strength as well as light-weight, which can downsize superstructure such as
caisson and sheet wall. The method has been applied to landfill or backfill behinda newly constructed quay wall, reinforcement of existing structure, embanking ofadjacent work, and submerged backfill and embanking on soft ground.
4.2 Application to earthquake disaster mitigation
Figure 7 shows an application of the method at Kobe port where a concrete type
quay wall was damaged by the Hyogoken-Nambu earthquake (Wako et al., 1998).
The concrete caisson displaced horizontally and titled in the earthquake. As theamount of displacements were within the allowable values, the caisson was usedwithout re-positioning but the backfill was partially excavated and replaced bystabilized soil in order to reduce the static and dynamic earth pressures acting onYour paper title

0ctober 2010, Kobe, Japanthe caisson. The design unit weight and strength of the stabilized soil were 1.4
tf/m3 and 100 kPa respectively.

(a) section view(b) execution of improvement at site
Figure 7: Application of Lightweight Treated Soil Method at Kobe port
CONLUDING REMARKSIn this paper, the applications of three soil admixture stabilization techniques,
Deep Mixing Method, Premixing Method and Lightweight Treated Soil Method,to earthquake disaster mitigation are briefly introduced. The improvement typeand mechanism of the technique are different each other. However, theapplications introduced in the manuscript clearly reveals that all the methods havethe high applicability to earthquake disaster mitigation. These stabilization
techniques have been applied successfully to various site and improvement
purposes in the past and expected to develop further for more various sites andimprovement purposes in the future.
New Technologies for Urban Safety of Mega Cities in Asia

REFERENCES
Coastal Development Institute of Technology., 2002. The Deep Mixing Method principle, design and construction-, Balkema publishers, 123.
Coastal Development Institute of Technology., 2003. The Premixing Method principle, design and construction-, Balkema publishers, 140.
Coastal Development Institute of Technology., 2004. The Lightweight Treated
Soil Method -new geomaterials for soft ground engineering in coastal areas-,
Balkema publishers, 120.
Namikawa, T., Koseki, J. and Suzuki, Y., 2007. Finite element analysis of latticeshaped ground improvement by cement-mixing for liquefaction mitigation, Soils
and Foundations, Vol.47, No.3, 559-576.
Noda, S. 1991. Waterfront development and liquefaction, Journal of the JapaneseSociety of Soil Mechanics and Foundation Engineering, 'Tsuchi-to-Kiso',Japanese Geotechnical Society, Vol.39, No.2, 1-4 (in Japanese).
Suzuki, Y., Saitoh, S., Onimaru, S., Kimura, G., Uchida, A. and Okumura, R.,
1996. Grid-shaped stabilized ground improved by deep cement mixing method
against liquefaction for a building foundation, Journal of the Japanese Society of
Soil Mechanics and Foundation Engineering, 'Tsuchi-to-Kiso', Japanese
Geotechnical Society, Vol.44, No.3, 46-48 (in Japanese).
Tsuchida, T., 1995 Super geo-material project in coastal zone -development ofhigh quality geo-material by recycling bulky urban wastes-, Proc. of theInternational Symposium on Coastal Ocean Space Utilization, 391-401.
Wako, T., Tsuchida, T., Matsunaga, Y., Hamamoto, K., Kishida, T. and Fukasawa,
T. Use of artificial light weight materials (Treated soil with air form) for port
facilities, Journal of the Japan Society of Civil Engineers, No.602/6-40, 35-52 (inJapanese).
Zen, K., Yamazaki, H., and Sato, Y. 1990. Strength and deformation
characteristics of cement treated sands used for premixing method, Report of thePort and Harbour Research Institute, Vol.29, No.2, 85-118 (in Japanese).

Your paper title

Analysis of traffic flow
at bottleneck intersections in Dhaka andproposal of traffic control improvement plan
Shinji TANAKA1, Keshuang TANG2 and Sungjoon HONG3
1
Assistant Professor, ICUS, IIS, The University of Tokyo, Japan
stanaka@iis.u-tokyo.ac.jp
2
Postdoctoral Fellow, IIS, The University of Tokyo, Japan
3
Research Associate, IIS, The University of Tokyo, Japan

ABSTRACT
There are various kinds of vehicles used in road traffic in developing countries. In
such a condition of mixed traffic, it is not easy to estimate SFR (Saturation Flow
Rate), which is an important factor in the signal control design. As a result, traffic
signals are controlled inappropriately, which sometimes produces serious
congestion at the intersection. Moreover, driving manners are not so good and it
makes the situation more complicated.
This study aims to analyze traffic flow at intersections in order to identify thecause of traffic congestion under mixed traffic situation. Video observation was
conducted at a bottleneck intersection in Dhaka City, Bangladesh, and the traffic
flow was analyzed to estimate the SFR and the capacity of the intersection. Basedon the result, some improvement plans were proposed and discussed to increase
the capacity of the intersection.
According to the result, improvement plans of signal phasing redesign and roadgeometric design modification had significant effects on the capacity improvement.
And also, assuming disciplined behaviors of drivers, such as following lane
marking and no stopping inside intersection etc, the situation became improved alot. Therefore, it was implied that appropriate traffic control strategies andpeople's disciplined behaviors are both important to improve the situation of
mixed traffic.
Keywords: mixed traffic, signal control

1. INTRODUCTION
1.1 Background
Traffic congestion is one of the most common and serious problems among Asianmega cities. It generates a lot of economical and social loss, and sometimes raises
risks of traffic accident, which causes another loss. Therefore, it is very importantto alleviate traffic congestion in order to realize a reliable and sustainable urban

October 2010, Kobe, Japanenvironment. For this purpose, traffic phenomena in the actual field should beappropriately understood first.
In the developing countries, road is used not only by normal passenger cars,
trucks and motorbikes but also by various kinds of vehicles such as jeepneys, tuktuks, (auto-)rickshaws, tricycles, handcarts and so on. Traffic flow in such mixed
traffic conditions is quite different from the ones in developed countries, so weneed to know the characteristics of the mixed traffic flow to make appropriate
countermeasures to alleviate traffic congestion.
Dhaka has a very large and dense population which is growing rapidly. However,there are no mass transit systems like subway or suburban railway which areessential transportation modes in large cities. As a result, a lot of traffic
congestion happens (Figure 1) and it leads to serious environmental problems
such as air pollution and traffic noise etc. Its traffic is characterized by mixed flowof traffic modes, especially auto-rickshaws and (manpowered) rickshaws asshown in Figure 2. It is very urgent issue to alleviate the congestion to support its
urban activities.

Figure 1: Traffic congestion in Dhaka

Figure 2: Auto-rickshaws and (manpowered) rickshaws

1.2 Purpose

New Technologies for Urban Safety of Mega Cities in Asia

The purpose of this study is to clarify the characteristics of the mixed traffic flow,
especially saturation flow rate (SFR) which is an important factor to deal withtraffic at an intersection. A field survey at bottleneck intersections in Dhaka is
conducted to obtain necessary data for this purpose. And based on the results, acouple of possible strategies to alleviate the traffic congestion are proposed.

2. STUDY SITES
Figure 3 shows a map of Dhaka. The old town and the city center are located in
the southern part of the city and new residential areas which hold relatively richpeople and their private vehicles are developed in the north. Therefore, the major
direction of traffic is from the north to the south in the morning peak hours.
Airport Avenue and Kazi Nazrul Islam Avenue are major streets to connect theseareas and suffer from serious traffic congestion during the daytime. We selected
two intersections along these streets according to the opinion from transportation
experts in Dhaka, that is, Sonargaon intersection and Shahbag intersection.
Morning peak

Morning peak

Morning peak

Airport Ave.
Sonargaon
Kazi Nazrul Islam Ave.
Shahbag

CBD

Old Dhaka
2 km©2010 Google

Figure 3: Location of the study sites

2.1 Sonargaon intersection
Sonargaon is one of the busiest intersections in Dhaka located at the entering
point to the city center from the north. It has 5 approaches and a big circularisland in the center. The right-turn traffic is circulated around this circle like one
at a roundabout. Because of this complex structure, different movements of traffic
merge and diverge, which causes serious traffic congestion.
2.2 Shahbag intersection
Shahbag is an intersection located at the north end of the old town. It has 4
approaches and all left-turn traffic is separated by the dedicated channels. A lot ofbuses run and stop around this intersection to let passengers get on and off.
Rickshaws are allowed to run only in the southern area form this intersection.

Analysis of traffic flow at bottleneck intersections in Dhaka and proposal of traffic control improvement plan

October 2010, Kobe, Japan

Figure 4: Video images at Sonargaon (left) and Shahbag (right) intersection

3. DATA COLLECTION
A field survey was conducted to collect necessary traffic data for the traffic flow
analysis as follows.
3.1 Video observation
The two intersections were observed using video cameras. Video shooting points
were set to cover all approaches of the intersections from the buildings around theintersections as shown in Figure 4. Video images were recorded from 7:30 am to
9:00 am to observe the morning peak hours.
3.2 Probe vehicle survey
Probe survey was conducted in conjunction with the video observation. 6 vehicles
carrying handy GPS logger were prepared as probes. Figure 5 shows the driving
routes of these probe vehicles. They were set to traverse the target intersections togather information of the approaching roads.

2

4

1

6

3

Sonargaon
5
Shahbag

3

4

1

2
6

GPS logger
2 km©2010 Google

Figure 5: Routes of probe vehicle survey
New Technologies for Urban Safety of Mega Cities in Asia

4. TRAFFIC FLOW ANALYSIS
4.1 Traffic volume and signal settings
Traffic volume and vehicle types were counted for all approaches from theobserved video images. Signal control settings such as the total cycle time and thegreen time of each phase were also measured. The results are shown in Figure 4
and 5.
The major traffic flow enters Sonargaon intersection from approach I and III, that
is, Kazi Nazrul Islam Avenue. Approx. 60% of the vehicles are cars and trucks,
and there are relatively many auto-rickshaws, too. The cycle time of Sonargaon
intersection is extremely long (413 sec). It often generates a long waiting queue ofthe right-turn vehicles which blocks the through traffic then traffic officers
sometimes interrupt the traffic flow to let the waiting right-turn vehicles pass,which may give a further delay.
I

Ⅰ: 4306
5.64%

686

840

V
Ⅴ: 876

II

0

2781

365

1003

95

471

Ⅱ: 1129342

24.96%

0 316

9.69%

0 415

59.70%

887

0851(Unit: veh/h or ped/h)

IV

III Cnes/Spot Image, GeoEye©2010 Google, Digital Globe,

7

2878
758

708

0

Ⅳ: 1745

Ⅲ: 4344

Φ1:295s

Type 1

Type 2Type 3

Type 4

Φ2:64s

(Ⅰ )

(Ⅴ )

(Ⅰ )

(Ⅱ )

(Ⅳ )

(Ⅲ )

(Ⅲ )

Cycle length=413s; Total lost time=54s;

Figure 6: Traffic demand and signal settings at Sonargaon intersection

At the Shahbag intersection, the major direction of traffic is east-west. The ratioof cars and trucks is almost same as Sonargaon, but the ratio of buses are higher
than that of auto-rickshaws in Shahbag. The cycle length (194 sec) is shorter thanthat of Sonargaon but it is still long compared with ones in developed countries.

Analysis of traffic flow at bottleneck intersections in Dhaka and proposal of traffic control improvement plan

October 2010, Kobe, Japan

Ⅰ: 1093
7.72%

I
325

367

402

404

IV

610
545

Ⅳ: 1251
237

567
280

56.05%

250

505

II

18.41%

Ⅱ: 1362
17.82%

153(Unit: veh/h or ped/h)

III Globe, Cnes/Spot Image, GeoEye©2010 Google, Digital

Ⅲ: 938

Φ1: 64s

Φ2: 56s

(Ⅰ )

(Ⅰ )

(Ⅳ )

Type 1

Type 3

Type 4

Φ3: 54s
(Ⅰ )
(Ⅳ )

(Ⅳ )
(Ⅱ )

(Ⅱ )

(Ⅲ )

Type 2

(Ⅲ )

(Ⅱ )
(Ⅲ )

Cycle length=194s;Total lost time=20s

Figure 7: Traffic demand and signal settings at Shahbag intersection

4.2 Saturation flow rate (SFR)
Saturation flow rate (SFR) is a value of traffic flow per unit time which passes thestop line when there is enough traffic demand approaching from the upstream.
Usually SFR is obtained as lane-based value, but the traffic in Dhaka rarely
follows the lane discipline, therefore this study calculated SFR as approach-basedvalue. Furthermore, a lot of drivers behave in undisciplined manner in Dhaka, forexample, not following designated directional lanes, stopping inside theintersection, ignoring traffic signals etc. These behaviors of course deteriorate theefficiency of the intersection, which means, a significant drop of SFR.

Saturation Flow Rate (pcu/h)

Figure 8 shows the SFR value of each approach. Left bar of the graph is thecurrent SFR value obtained from the video observation, and right one is theestimated value assuming disciplined driving behaviors by all drivers around theintersection. From this result, SFR could be increased by 10 – 20 % if the driving
manner of the road users is improved.
7000
6000
5000
4000
3000
2000
1000
0
App. 1 App. 2 App. 3 App. 4 App. 5 App. 1 App. 2 App. 3 App. 4
Sonargaon
Current

Shahbag

Under disciplined behavior condition

Figure 8: Saturation flow rate of each approach

New Technologies for Urban Safety of Mega Cities in Asia

4.3 Travel time
Travel time and travel speed was obtained from the location data recorded by GPS
logger on the probe vehicles. Table 1 shows the results in each route in the time
period of 7 am and 8 am. The value of average speed dropped from 7 am to 8 am,
which means the congestion became worse as time proceeded. Figure 9 shows the
trajectory of the probe vehicle running on the route 1 in a time-space diagram.
Gentle or flat parts of the slope mean that the speed of the vehicle was slow. We
can understand it took more travel time in the period of 8 am and there were acouple of long waiting periods in front of major intersections.
Table 1: Travel time and speed of probe vehicles (from suburbs to center)
7 am
8 am
travel distance travel time average speed travel distance travel time average speed
route
(km)
(s)
(km/h)(km)(s)(km/h)
1
6.575
887
26.7
6.900
2043
12.2
2
9.490
1694
20.2
5.500
2868
6.9
3
9.123
1169
28.1
8.617
1358
22.8
4
9.874
1631
21.8
9.901
2624
13.6
5
11.3561312
31.2
11.221
3672
11.0
6
6.300
849
26.7
5.503
1700
11.7
average:25.2
average:
12.0
12Location (km)10

Travel 26.7 16.4
Speed(km/h)

8

12.2

Return11.9

7.5

Return6

Shahbag

4

Sonargaon

2
0
6:30

Farmgate
7:00

7:30

8:00

8:30

9:00

9:30
.

Time

Figure 9: Time-space diagram of probe vehicle in route 1

5. PROPOSAL OF IMPROVEMENT STRATEGIES
Through the field observation and analysis mentioned above, the causes of traffic
congestion in Dhaka can be explained as follows.
Firstly, undisciplined behaving manners of many drivers are pointed out. It makes
the situation very complex and amplifies the congestion. It also generates safety
risk, which may leads to traffic accidents. Secondly, the signal control scheme is
not appropriate. The cycle time is too long (especially at Sonargaon), which

Analysis of traffic flow at bottleneck intersections in Dhaka and proposal of traffic control improvement plan

October 2010, Kobe, Japancauses gradual drop of SFR and leads to inefficient use of green time. Besides,
manual control by traffic officers based on their experience and feeling sometimes
makes the situation worse. And thirdly, geometric design of the intersection is not
appropriate. For example, the size of Sonargaon intersection is very large, which
requires long clearance time and makes big loss. On the contrary, Shahbag
intersection has relatively narrow upstream approaches even though the width at
the stop line is wide, then it cannot utilize the full capacity of the intersection.
Based on this consideration, strategies to improve the current traffic congestion
are proposed as follows.
5.1 Dissemination of disciplined driving behavior
As undisciplined behaviors cause not only traffic congestion but also traffic
accidents, it is important to disseminate disciplined driving manners among
drivers. This improvement makes benefit not only at the target intersections but
also in other area of the city. Some kinds of educational program should beoffered to have people comply the traffic rules.
5.2 Redesign of signal phasing
The signal phasing plan can be modified in order to increase the capacity of theintersections. Based on the traffic demand and SFR obtained from the fieldobservation, the optimum cycle time and split (ratio of green time) are calculated
as shown in Figure 10. Here, the cycle time is shortened significantly and thephasing pattern is changed to reduce the drop of SFR and the loss time.
(a) Sonargaon
Φ1:108s

Φ3:21sΦ2:27s
(Ⅰ )

(Ⅰ )

(Ⅴ )

(Ⅰ )

(Ⅱ )

(Ⅳ )

(Ⅲ )

(Ⅳ ) (Ⅲ )(Ⅲ )Cycle length=180s; Y=3s, AR=5s; Total lost time= 24s(b) Shahbag
Φ1:31sΦ2:34s

(Ⅰ )

(Ⅰ )
(Ⅳ )

(Ⅳ )

(Ⅱ )

(Ⅱ )
(Ⅲ )

(Ⅲ )

Φ3:14sΦ4:21s

(Ⅰ )

(Ⅰ )
(Ⅱ )

(Ⅳ )

(Ⅱ )

(Ⅳ )

(Ⅲ )

(Ⅲ )

Cycle length=120s; Y=3s,AR=2s; Total lost time=20s

Figure 10: Proposed signal phasing plan

5.3 Modification of geometric design
Figure 11 shows the modification plan of the geometric design as well as the
updated signal phasing plan of the target intersections. At Sonargaon intersection,
the central island is downsized so that the right-turn vehicles can move near side
each other, which can reduce the conflicts and the through traffic blockage. The
New Technologies for Urban Safety of Mega Cities in Asia

stop line is also shifted forward so as to reduce the clearance loss time. Signal
control parameters like cycle time and split are recalculated due to these changes,
too.
At Shahbag intersection, the width of the approach II and IV (East-West) is
widened for a certain length. It allows more traffic to enter the intersection
simultaneously and keeps the SFR high during the green time. As a result, thegreen time for this direction can be saved and this can be converted to the green
for the other movements.
(a) Sonargaon

Φ1:112sΦ3:22sΦ2:28s

(Ⅰ )

(Ⅰ )
(Ⅴ )

(Ⅰ )

(Ⅱ )

(Ⅳ )

(Ⅲ )

(Ⅳ ) (Ⅲ )(Ⅲ )Cycle length=180s; Y=3s, AR=3s; Total lost time=18s(b) Shahbag

Φ1:25sΦ2:26s

(Ⅰ )

(Ⅰ )
(Ⅳ )

(Ⅳ )

(Ⅱ )

(Ⅱ )
(Ⅲ )

(Ⅲ )

Φ3:16sΦ4:33s

(Ⅰ )

(Ⅰ )
(Ⅱ )

(Ⅳ )
(Ⅲ )

(Ⅱ )

(Ⅳ )
(Ⅲ )

Cycle length=120s; Y=3s, AR=2s; Total lost time=20s

Figure 11: Proposed modification of geometric design

Finally, the amount of the capacity improvement by these proposed strategies areshown in Figure 12. Case 1 to 3 corresponds to the strategies described in Section
5.1 to 5.3. The intersection capacity increases significantly, by approx. 50% at
Sonargaon and approx. 100% at Shahbag. These values are large enough toalleviate traffic congestion generally, so we believe that an appropriate
infrastructure design, traffic control and education have a large potential to
improve the traffic condition in Dhaka drastically.

Analysis of traffic flow at bottleneck intersections in Dhaka and proposal of traffic control improvement planTotal Traffic Capacity (pcu/h)

October 2010, Kobe, Japan

14000
12000
10000
8000
6000
4000
2000
0
Current Case 1

Case 2

Sonargaon

Case 3 Current Case 1

Case 2

Case 3

Shahbag

Figure 12: Improvement of the intersection capacity

6. CONCLUSIONSThis study focused on the analysis of the traffic flow in Dhaka, which holds avariety of vehicle types on the road. The characteristics of the mixed traffic were
understood and the causes of the traffic congestion were identified through thefield survey and the analysis. Then a couple of improvement strategies which
cover infrastructure design, traffic control and human behavior were proposed,
and they were evaluated to have a good potential to improve the traffic condition.
This study revealed only a few aspects of the traffic situation in a developing
country, which is sometimes quite different from the one in developed countries,
so we cannot apply conventional theories as it is. Further studies are needed toclarify the characteristics in such societies and to explore the possibility to apply
our experience.

New Technologies for Urban Safety of Mega Cities in Asia

Turkish experience on river floodrisk management** The research study, this paper is based on, was conducted for the PhD Thesis in City andRegional Planning Department which was submitted to the Middle East Technical University in
Ankara, TURKEY (2009).

Meltem SENOL BALABANPhD Candidate, Urban Safety and Information Systems Lab., Urban Engineering,
The University of Tokyo, Japanmeltem@city.t.u-tokyo.ac.jp

ABSTRACT
Turkey’s current flood protection structure seems to be based on the surveys andassessments of a central authority and on its limited powers of intervention. The
local municipal administrations are under different interests and pressures fordevelopment and land-use. It seems essential to integrate flood risk mitigation
efforts with the local planning system and to involve municipalities in theirestimations of risks and its declaration on official duty, as contemporaryinternational approaches indicate. This conviction is based on a sample survey offour cases of riverine cities; namely Bartin, Batman, Aydin, Hatay in Turkey, andon a review of current approaches in a sample of international cases.
Findings on case cities indicate that river floods turn into destructive disasters
mainly due to tolerant land-use decisions. Inaccurate and discrete
implementations and developments in and through the river basins are secondsource of flood losses. Currently, neither urban development plans nor available
flood plans are equipped with necessary measures to mitigate risks.
Findings also indicate that current vulnerabilities are greater in value thaninvestments made to curb flood risks. Independent and discrete efforts ofmitigation seem to generate illusory feelings of safety, which aggravates
vulnerabilities.

Keywords: flood risk management, urban planning in Turkish riverine cities

1. INTRODUCTION
This paper mainly considers flood disasters which have been continually effective
and which will most likely increase in intensity and frequency in urban areas ofTurkey due to global warming and climate change. The research, the paper isbased on, is conducted on four riverine cities; namely Bartin, Batman, Aydin,
Hatay, each of which has different climatic and geomorphologic conditions. Since
the main purpose of the research is to reveal the causes of continual losses otherthan hydro-meteorological factors, urban development processes are mostly
investigated in a historical perspective for each case. Instead of basically focusing
on case-specific planning decisions and development processes, the common
approaches of central and local governments towards flood events are identified

October 2010, Kobe, Japanand conceptualized to describe the relation between flood protection, so-called‘management’ strategy and the urban planning processes in Turkey. In this respect,moreover, current international agenda, related literature and implementation
strategies of various countries about flood ‘risk management’ issue are crucial tobe mentioned. For this reason, the main aspects of flood risk management and its
prevailing strategies that are shared by most of the other flood prone countries are
examined in order to make a comparison with Turkey case.
The main claim of this paper, as a result, current urban planning system that hasformed Turkish cities of today has not conformed to ‘flood risk management’approach. In other words, the cities that have been developed by such prevailingplanning system and control mechanisms are prone to high flood risks due toineffective planning tools and settings that could not comprehend the innermechanisms of ‘risk concept’. The final interpretations on the research results andcontributory interventions for the improvement of current planning system aremostly based on a kind of quantitative research on recent vulnerability states ofcase areas according to available hazard maps.

2. CONTEMPORARY APPROACHES ON FLOOD RISK MANAGEMENT
Through centuries the most common way of dealing with flood disasters has beenprotective walls, levees, dunes whose heights were defined depending on thehighest water level observed in previous event. However, each following event
has proven that only depending on such structural works have not been sufficientenough; contrarily they have caused even more devastative losses. In addition,
behind the levees ‘so-called absolute safe areas’ have attracted investments
together with dense populations. For instance; 1993 Mississippi flood disaster due
to the failure of protective levees was the milestone for flood risk management in
U.S. (Cigler, 1996). Similar to that in the Netherlands due to 1993 and 1995
disastrous floods it was admitted that a reform was required which can be done byintegrating risk management strategies into flood issues (Jorissen, 1998). Hence,
today’s prevailing approach shared by many countries claims ‘living with floods’
opposed to the conventional one that tries keeping floods away from the humanlife.
Last two decades on the international arena the great impacts of many great
disasters have pointed out that today’s communities, regions and nations can nolonger afford simply respond to and recover from natural disasters. Hydrometeorological disasters including floods have taken larger amount among theother disaster types (EM-DAT, 2005). It is also evident that the number of flood
disasters, from 20 to 160 events per year has increased since 1975 (Pilon, 2003).
The adverse effects of global warming as well as the increase in populations
settled on vulnerable areas are considered as principle reasons. It is also claimed
that the magnitude and frequency of flood events tend to be aggravated in the near
future due to global warming and climate change according to some scenarios andprojections (Lehner et al., 2006).
Hence, above mentioned first hand experiences of many countries and common
concerns on the international arena like United Nations (Albrito, 2008) have
Turkish Experience on River Flood Risk Management

admitted the main idea which requires not only ‘disaster response’ but also
‘disaster risk reduction and mitigation’ while dealing with natural disaster risks.
2.1 Flood risk management: definition and main aspects
Risk concept, originally designed in the area of modern business administration,
contributes to the management of flood disasters like any other natural disasters. It
is simply defined as a probability that a hazard will turn into a disaster. As afunction of hazard and vulnerability it can be managed by a sequence of actions;such as identifying possible damages, estimating how much risk concentrated inwhich places and taking measures to reduce risks before the real event occurs(ISDR terminology; Kaplan and Garrick, 1981; Mileti, 1999; Balamir, 2001). In
order to achieve risk mitigation in an effective and economic way the priorities
should be defined in three sub-areas; namely risk avoidance, reduction andsharing (Balamir, 2000).
According to the results of descriptive research on flood risk management
literature common approach, which is still developing and becomes wide-spreadin many countries is to integrate structural (engineering) and non-structural
measures (urban policy and planning) into whole watershed area. It is admitted
that this approach requires first of all dynamic and holistic modeling, detailed
recording, and regular monitoring for identifying and assessment of the risks.
Secondly, it requires mitigation planning that defines basically spatial planning
integrated with flood risk management. Reclamation of river beds, constructing
levees, flood walls, dams are several structural measures that keep the flood
waters away from the settlements, counted as risk reduction strategies. Based on
the spatial information about flood hazards and up-to-date flood risk maps nonstructural strategies such as land-use decisions and settlement lay-out planningcan be used as the avoidance of risks by which settlements can be kept away fromdisaster prone areas. However, there are always residual risks that cannot be
absolutely eliminated but instead can be reduced to a great extent. By the help ofeffective funding system including aids, donation and taxation strategies, as wellas well-established insurance system together with reliable early warning systemsuch residual risks can be reduced as much as possible. In short, flood risk
management can be conceptualized as the process of sequential actions shown infigure 1.

Turkish Experience on River Flood Risk Management

October 2010, Kobe, Japan

Figure 1: Conceptualization of flood risk management process (Senol Balaban,
2009)
2.2. Implementation strategies: research on country-specific examples
As explained above, flood risk management explores new methods to live withfloods with reduced risks. Deep surveys on countries; namely Netherlands, Franceand Germany give us several examples about such methods and implementation
strategies. For instance, in the Netherlands case water elements that may cause
flooding sometimes can be used as complementary, multifunctional area in order
to be considered as strategic instrument rather than just being a regulatory task
(Woltjer and Al, 2007). In German case, limiting urban development and reducing
damage potential are main policies while restraining flooding decentralized inorder to give ‘more room for rivers’ (Friesecke, 2004; Wilke, 2004). A committeeof stakeholders at ‘river basin district level’ can also work actively for concerted
and coordinated action using several compulsory restrictions based on flood risk
levels in France river basins (MEDD, 2006).
As a result, common key points that are observed in these countries can besummarized as follows. Administrative bodies from central to local levels are
responsible for managing basin-wide risk maps, mitigation plan alternatives, landuse zoning and urban design solutions basically to raise retaining capacity andease drainage. A certain risk level can be reduced at the source of a hazard, suchas increasing the water retention capacity of the catchments, frequently inundated
flood-plains as urban parks, nature areas or ecological reserves, while prohibiting
the locating of investments and assets in these flood plains. On the other hand,less frequent and low risk areas can be used for residential purposes, however theyought to be constructed and located above the pre-determined flood level. In orderto implement such policies certain planning tools are used and followed by wellestablished control mechanisms (Senol Balaban, 2010).

Turkish Experience on River Flood Risk Management

3. TURKEY’S FLOOD PROFILE AND RESEARCH RESULTS
Floods which are the most wide-spread hydro-meteorological hazards in Turkey
turn into disasters in two-ways. Rivers can overflow from their inadequate beds
when heavy rainfall occurs. Secondly, after sudden rainfall inner city inundations
as flash floods can be observed due to inadequate drainage and infrastructure aswell as closed river channels in urban areas. Since almost all provinces have been
affected from flood event, it can be said that most of the riverine cities are prone
to chronic flood disasters and have frequently lost lives and properties. For
instance, last 60 years 1232 casualties and 23 million hectares of flooded land in1930 separate events was observed according to official records of State
Hydraulic Works (SHW, 2009). Annual economic loss is estimated approximately
100 million US dollars as declared by General Directorate of Disaster Affairs(GDDA) (Taymaz, 2008).

Figure 2: Spatial distribution of flood events and flooded areas (SHW, 1998;
Gokce and others, 2008)
According to climate scenarios of the region Turkey belongs to, nationwide mean
temperature is expected to increase 2-3 C° while total annual precipitation is
expected to decrease in next 70 years (Demir and others, 2008). On the other hand,
it is also expected to observe increase in regional and local extremes inprecipitation. In fact, until 2009 actual weather statistics indicates that normal
then warmer temperatures as a continuous anomaly have been observed since
1993 (Turkish State Meteorological Service-TSMS, 2010).
3.1 Purpose and scope of the study
Contrary to the recent improvements in flood risk management approach in theinternational agenda Turkey has still depended on conventional protection
methods mainly. Despite such methods, however, it is observed that damages onlife and property still continue particularly in urban areas. For example, recently

Turkish Experience on River Flood Risk Management

October 2010, Kobe, Japan(September 2009) in Istanbul and Marmara region, 32 people were killed and
6766 housing units, 903 working places were damaged or collapsed due to flash
floods. Economic losses from floods every year are also increasing because thedense urban areas, metropolitan centers that are located on highly valuable land
are prone to flood hazards like the example above. Therefore, it is necessary tofind out the main causes that have resulted in continual damages on life andproperty. For this reason this study aims to analyze not only the flood events
chronology of selected urban areas but also city development history together
with (un)planned decisions which affect the scale of the next flood disaster. For
this purpose, it is crucial to select case areas that have continual flood history withvery few similarities in geomorphologic and climatic settings in order to focus oncommon causes that are independent from physical settings (figure 3).

Figure 3: Selection criteria and selected 4 river basins and riverine cities (Gokce
and others, 2008; Taymaz, 2008; SHW 1998 and 2009)
3.2 Research Methodology and Results
First of all, empirical research was carried out for each selected case areas shownin figure 3 under following topics:- Physical settings of major river basin located- Previous flood events, reports and recommendations- Plan preparations and major decisions- Impacts of settlement’s growth regarding floods- Existing territorial (regional) plan decisions- Persisting vulnerabilities and values in cities
Although such topics providing city flood profile is extremely necessary for
implementing flood management strategies, it is hardly possible to get all related
records from one institution. Another difficulty is that there is also nostandardization for the data recording and sharing. Therefore, one or another topic
cannot be obtained in some cases. For example, flood vulnerability analysis weredone for only two of them, ‘Bartin’ and ‘Batman’, since the other two have noavailable flood hazard map to be referred. Individual case study results will besummarized in the section 3.2.1.

Turkish Experience on River Flood Risk ManagementAs mentioned several times from the beginning, it is essential to find out maincauses behind the continual flood losses in urban areas some of which are selected
as case areas. It is also necessary to understand inconsistencies between urban
planning and flood protection works. For this reason second part of researchrequires more deep analysis on existing institutional structure to conceptualize
what could be done to improve the system. Results of such research can be foundin the section 3.2.2.
3.2.1 Results of research on individual cases
Findings of the case-study research lead us to classify these causes in two broad
categories, observed at basin level and at urban level. There is a lack ofmonitoring, control and coordination at the basin level. Local ad-hoc
interventions may temporarily solve the flood problem at a specific location.
However, this leads to the transfer of flood problem to another location. Anychange in land-use or in the course of river generally has basin-wide impacts
depending on the hydrological cycle.
At the urban level, many examples of implementations and developments thathave caused greater losses of river floods and inundations are observed in allcases. Tolerant land-use decisions and loose development controls have createdsubstantial vulnerabilities in urban areas. These interventions are listed as follows:- Capacities of infrastructure systems in urban areas are decreased, andbecome inefficient due to the decisions of density rise in built-up areas,- Permeable surfaces (forests, parks, green areas, valleys, recreation areas)
are engulfed by expanding hard surfaces (concrete spaces, pavements,
buildings),- Riverbeds, flood-prone lands and valley bottoms are not only occupied byunauthorized developments but also by some public facilities and services likestreets, public buildings closing river tops. Also flow discharges of rivers are
decreased by a number of inaccurate interventions (discharging direct
sewage/rainwater system, damping solid-wastes and debris, and insufficientcleaning and maintenance services),- Infrastructural deficiencies caused by inaccurate and discrete engineeringinterventions such as inaccurate design of transport bridges and concrete
channel construction are also observed in most of the cases.
Due to the availability of official flood hazard maps the vulnerability analysis for
2 cases was conducted in order to determine, and to assess the probable volumesof losses together with their values within the flood-prone areas (figure 4).
Besides, the likely losses are compared with the costs of measures applied to curb
flood risks. In ‘Bartin’, it’s calculated that current (2009) vulnerabilities in value
terms are 5 times larger than the structural investments made to mitigate flood
risks. Value of current vulnerabilities in ‘Batman’ appears to be 3 times more thanthe value of previous structural investments.

Turkish Experience on River Flood Risk Management

October 2010, Kobe, Japan

Figure 4: Inventory of Vulnerabilities of one of the case areas (Senol Balaban,
2009)
3.2.2 Results of research on institutional structure
Findings on institutional system and planning legislation indicate that Turkey’s
current flood protection structure seems to be based on the surveys andassessments of a sole central authority, State Hydraulic Works, and on its limited
powers of intervention. Since there is no administrative power and mechanism tomonitor and control major river basins, both development decisions and partial
flood protection measures in any part of basin may also cause flood losses in otherparts. The local municipal administrations, on the other hand, are under different
interests and pressures for development and land-use. Besides neither urban
development plans nor available flood hazard maps are equipped with necessary
measures to mitigate risks.

4. CONCLUSION
Recent disastrous events have shown that flood disasters are going to be more
frequent and widely destructive on our cities due to the adverse impacts of global
warming. The size of the consequences of such impacts could be beyond thesocial and financial capacities of many countries. Therefore, it is necessary to beprepared for the worse case scenarios and the most probable situations beforehand.
Such approach seems to be provided by the concept of risk and risk management
system whose wider scope includes all risks to be clearly identified, classified,assessed, analyzed and effectively mitigated. Hence, in the case of Turkey there isan urgent need for preparation and active use of flood hazard, vulnerability andrisk mapping. Such maps should be provided for main river basins across thecountry. Then each local authority should take into consideration before the urban
development planning and implementation processes. Such maps are powerfultools for directing mitigation policies either at regional or local level both in new
developing and already developed areas. However, policy implications indeveloped areas could be the challenging process which requires further research
and analysis.

Turkish Experience on River Flood Risk Management

Moreover, from the wider perspective it is quite necessary to restructure thecurrent administrative and legal framework in order to establish an integrated
flood risk management system for Turkey. To establish for each major river basin‘The Commission of Integrated River Basin Management’ which may be based on
the Law of Local Government Union can be one alternative structure. This
commission will be responsible for preparation of ‘Flood Mitigation Plan’ that isbased on flood hazard and risk maps supported by the consent of related
institutions. It is also necessary to include public people, NGO’s and Professionals
during such decision-making process. Such kind of planning scale corresponds tocurrently used Territorial Plan scale that takes into account basin-wide
establishments, settlements, strategic spots and decisions. Development plans foreach settlement in a basin be prepared in accordance with Territorial Plan
Decisions. Such kind of administrative systems is described in figure 5.

Figure 5: Proposal on river basin flood management and spatial planning (Senol
Balaban, 2009)
On the other hand, it is also crucial to provide more effective mitigation control at
local level. Therefore, the compulsory declaration of flood vulnerabilities bymunicipalities themselves in their entitlement for special subsidies could raise thegeneral level of awareness, could curb further vulnerabilities, and contribute to thearticulation of planning methods. Besides, such vulnerability analysis isappropriate for the rational decision-making and strategy development avoiding
urban developments on flood-prone areas because once development is notcontrolled or permitted on such areas the volume of potential losses goes beyond
the structural investments, which only bring some partial and temporary solutions
rather than effective mitigation. As a result, it appears essential to integrate floodrisk mitigation efforts with the local planning system and to involve
municipalities in their estimations of risks and its declaration on official duty, as
contemporary international approaches indicate.

Turkish Experience on River Flood Risk Management

October 2010, Kobe, Japan

REFERENCES
Albrito, P., 2008. “Building a Local Governmental Alliance for Disaster Risk Reduction”,
in the International Workshop, For a New Governance of Natural Risks, in 27-28 October
2008, Istanbul.
Balamir, M., 2000a. “Is a New Earthquake Strategy Developing in Turkey? Law andInstitutional Changes and Recent Priorities after 17 August 1999”, in Journal ofArchitecture, (295) (In Turkish) .
Balamir, M., 2000b. “Reproducing the Fatalistic Society: An Evaluation of the Disasters
and Development Laws and Regulations in Turkey, in Urban Settlements and Natural
Disasters, edited by Emine Komut, UIA-Chambers of Architects Publication.
Cigler, B. A., 1996. Coping with Floods: Lessons from the 1990s, in Disaster
Management in the U.S. and Canada, pp. 191-213, Richard T. Sylves and W. L. Waugh,
Jr. eds, Charles C. Thomas Publisher LTD, U.S.
Demir İ., Kılıç G. and Coşkun M., 2008. ‘Climatic Projections for Turkey by PRECIS
Regional Climate Model: HaDAMP3 SRES A2 Scnario, IV. Atmospheric Sciences
Symposium, 25-28 March 2008, Proceedings, s. 365-373, ITU, Istanbul (In Turkish)
EM-DAT, 2005. http://www.unisdr.org/disaster-statistics/occurrence-trends-century.htm.
Friesecke, F., 2004. “Precautionary and Sustainable Flood Protection in Germany –Strategies and Instruments of Spatial Planning”, pp. 1-17, in 3rd FIG Regional
Conference, 3-7th October 2004, Jakarta, Indonesia.
Gokce O. and others, 2008. Disasters Inventory: Spatial and Statistical Distribution ofDisasters, General Directorate of Disaster Affairs, Ankara (In Turkish).
Jorissen, R. E., 1998. Safety, Risk and Flood Protection Policy, in RIBAMOD, pp. 57- 72,
edited by R. Casale.
Lehner B., Döll P., Alcamo J., Henrichs T., Kaspar F., 2006. ‘Estimating The Impact ofGlobal Change on Flood and Drought Risks in Europe: A Continental, Integrated
Analysis’, Climate Change, Vol 75, p 273-299, Springer.
MEDD, 2006. Presentation of Water Department of Ministry of Ecology and Sustainable
Development.
Pilon, P. J. ed., 2003. “Guidelines for Reducing Flood Losses”, United Nations.
Senol Balaban, M., 2009. Risk Society and Planning: The Case of Flood Disaster
Management in Turkish Cities Unpublished PhD Thesis, Middle East Technical
University (METU), Ankara.
Senol Balaban, M., 2010. ‘Reducing flood vulnerabilities in urban areas of Turkey bymeans of integrated basin management’ in the Proceedings of 15th Inter-University
Seminar on Asian Mega-Cities’ in the International Symposium on City andWaterfront, 11-13th March 2010, The University of Tokyo, Tokyo
SHW, 1998. Flood Annuals, Volumes 5, 6, 8, Ankara (In Turkish)
SHW, 2009. Statistics based on Annual Flood Records done by Investigation and
Planning Division of General Directorate of State Hydraulic Works.
Taymaz, M., 2008. Power-point Presentation in 10th Roundtable Meeting (11 January2008) held by Middle East Technical University - Disaster Management and ResearchCenter, Ankara (In Turkish).
TSMS (Turkish State Meteorological Service) Official Web-site, 2010. Evaluation
Report of Climate Data of the year 2009, Ankara (In Turkish).
Wilke, K., 2004. WMO/GWP “Integrated Flood Management Case Study – Germany:
Flood Management in the Rhine and Elbe River Basins” in Associated Programme on
Flood Management, Technical Support Unit eds.
Woltjer, J. and Al, N., 2007. “Integrating Water Management and Spatial Planning:
Strategies Based on the Dutch Experience”, pp. 211-221, in Journal of the American
Planning Association, Vol. 73, No.2.

Turkish Experience on River Flood Risk Management

Disaster Risk Reduction of Highly Vulnerable
Urban Areas through Urban Re-Development
Case Study of Barangay Rizal, Makati,
Philippines
Fouad BENDIMERAD
Chairman of the Board, EMI, Quezon City, Philippines
fouadb@emi-megacities.org.
Violeta SEVA
General Secretary, EMI, Quezon City, Philippines
Nathanial von EINSIEDEL
CEO, Consultants for Comprehensive Environmental Planning (CONCEP),
Makati City, Philippines

ABSTRACTThe United Nations General Secretary Global Assessment Report on Disaster
Risk Reduction (GAR/DRR) (UNISDR 2009) lists urban risk as one of the key
threat to the safety of humanity. It particularly emphasizes the challenge ofreducing the impact of disasters on the poor. Yet, the vulnerability of the urban
poor is escalating due to pressure from urbanization, the competition for scarce
resources, and weaknesses in governance structures. In most cases, vulnerability
reduction action resolves to displacing communities from high risk areas.
However, these approaches are not always viable.
What then are the solutions for reducing the vulnerability of highly-vulnerable
poor communities short of the undesirable option of displacing its populationelsewhere? This project attempts to find an approach through Risk-Sensitive
Urban Redevelopment. This approach combines in a single solution the reductionof risk and the improvements of emergency management capacity, with the
improvement of the socio-economic and the living conditions of the residents.
Risk-sensitive urban redevelopment requires a different planning approach that islittle known and largely untested elsewhere by planners. The Risk Sensitive Urban
Redevelopment Plan of Barangay Rizal demonstrates how a long-term plan canbe developed to guide future development within the ultimate goal of reducing
exposure to hazards. The plan was developed using a participatory approach by
an integrated team consisting of technical experts, barangay leaders,
representatives of the community, and Makati city officials.
Keywords: disaster risk reduction, risk sensitive urban redevelopment planning,
mainstreaming, participatory process, urban poverty reduction

October 2010, Kobe, Japan

1. THE CASE OF THE POOR AND HIGHLY VULNERABLE URBAN
AREAS
The vulnerability of the poor and less privileged is indicated as a significant
challenge to improving socio-economic equity and reducing human and economic
losses from disasters. Disasters add to poverty by further depriving the poor andaffecting those who are at the margin of poverty. Relieving the vulnerability of
the urban poor has been faces formidable challenges, including lack of public andprivate investment, unclear land and property ownership, profiting from theinformal housing market, and political influence. In some cases, government has
resorted to relocation to deal with areas of informal settlers that are highly
vulnerable (e.g., unstable hills, water ways, etc.). However, in many cases
relocation is not a viable and in-situ re-development solution must be found.
2. RISK SENSITIVE URBAN REDEVELOPMENT
For highly urban settings, redevelopment is often the preferred
methods for development since mostof the land is already developed.
Urban
re-development
isofparticular interest to disaster risk
reduction since it represents anopportunity for reducing risk to older
structures and facilities, which areoften associated with the highest
physicalandsocio-economic Fig. 1 Process for Risk Sensitive Urban
Redevelopment
vulnerabilities.
The
redevelopment processes are typically driven by economic objectives and are mostof the time rely on private investments. In exceptional cases (e.g., slum
rehabilitation programs), re-development is used as a means to reduce informal
housing. Just like in the case of land use planning, urban redevelopment projects
most often are not risk sensitive, thus missing one of the very few opportunities toreduce urban risk. Traditional planning methodologies need to be reviewed andre-formulated to be risk sensitive.
3. GENERAL DESCRIPTION OF THE PLANNING AREA
The Barangay1 Rizal Risk-Sensitive Urban Redevelopment Planning Project wasundertaken by the Earthquakes and Megacities Initiative (EMI) in partnershipwith the Makati City Government, the community representatives of Barangay
Rizal, and the Philippines Institute of Volcanology and Seismology (PHIVOLCS).
It involves the urban redevelopment planning of selected zones in the Barangay tomodify and lessen the physical, social, and economic vulnerability of the1

Barangay is the smallest geo-political unit in the Philippines.

New Technologies for Urban Safety of Mega Cities in Asia

community to earthquake-related hazards,
while at the same time improving the
livelihood and living conditions of theresidents.
Barangay Rizal (Figure 2) is one of the 33
barangays of Makati City. The barangay waschosen as pilot area for the project becauseof the negative combination of its
susceptibility to earthquake hazards and its
socio-economic conditions. Makati is one of
the 17 cities and municipalities thatcomprise Metro Manila (See insert of Figure3). It is considered as the country’s financial Fig. 2: Bird’s-eye view ofand business center, being home to the Barangay Rizal
headquarters of 40 percent of the top 1,000
multinational and local corporations. It has a total resident population of 510,383(2007 Census) but this balloons to almost 3.7 million during weekdays because ofpeople who come here to work, do business, or shop.
4. HAZARDS, VUNERABILITIES AND RISKS
Barangay Rizal in Makati City
Philippines sits on an active fault,
which makes it highly vulnerable toearthquake hazards such as surface
rupture,groundshaking,
land
subsidence, liquefaction and fire
following earthquake. The West Valley
Fault runs along the northwestern
portion of the barangay (see Figure 3).
According to the Metro Manila
Earthquake Impact Reduction Study(MMEIRS 2004), rupture of the fault
can cause a magnitude 7.2 earthquake,
which has the potential to cause severe Fig. 3 Map of the Planning Area
damage to approximately 40% of the showing the trace of the West Valley
total number of residential buildings Fault
within Metro Manila, with an estimated
34,000 deaths and 114,000 injuries. Certain portions of the barangay are expected
to suffer serious damage due to ground rupture. A rapid visual screening ofbuildings for seismic vulnerability revealed that at least 1 out of every 3 of theinspected structures may not withstand a seismic event of magnitude 7.2 orYour paper title

October 2010, Kobe, Japanhigher. 2 Buildings along the fault trace are particularly vulnerable. Factors that
contribute to vulnerability of structures include old age, weak structural systems,
irregularities in building form, and poor construction with substandard materials.
Its physical make-up of congested streets and lack of open spaces makeemergency access and evacuation very difficult. The presence of unsafe buildings
and structures and narrow and obstructed roads are the main contributors to thephysical risk of the area. There are very few open spaces which can serve as spacefor evacuation, temporary shelter, and storage for debris in case of an earthquakeor other disaster. Debris could block the roadways, fire could spread, and there
could be thousands of people displaced from their homes for months. Barangay
Rizal is also subject to frequent flooding and other hazards such as fires.
The physical risk of the area is exacerbated by the area’s socio-economic
vulnerability. The population is generally low-income with a high level of
unemployed. Results of socio-economic surveys conducted in the area reveal that
16 percent of households have a combined monthly income that falls below thepoverty line. More than half (54 percent) of the community’s productive
population are unemployed. About 45 percent are employed, but only 28 percent
have permanent employment, while the rest either have contractual work or are
self employed. 3 The inadequate economic capacity and the presence of highly
vulnerable households contribute to the socio-economic vulnerability of the area.
Moreover, there is inadequate capacity in terms of emergency preparedness andresponse.
5. RISK SENSITIVE URBAN REDEVELOPMENT FRAMEWORK(RSURF)The risk-sensitive urban redevelopment framework (RSURF) in Figure 4 showssustainability, livability and disaster risk/ vulnerability (planning parameters) as
the core considerations for the redevelopment planning of the pilot site. Further,
the community and stakeholders’ participation and political support which wasapplied cross-sectorally to identify and validate site development planningconsiderations; to assess and validate disaster risk and vulnerability; to identify
issues/problems, goals, objectives; to develop and identify strategies and2

Fernando Germar, Tabassam Raza, and Fouad Bendimerad, “Report on Rapid Visual Screeningof Buildings for Seismic Vulnerability,” Working Paper, Makati Risk-Sensitive Redevelopment
Planning Project, Earthquakes and Megacities Initiative, Philippines, June 3, 2009.
3 Marino Deocariza, Marqueza Reyes, Nadia Pulmano, “Vulnerability And Capacity Analysis(VCA): An Assessment of the Social and Economic Vulnerabilities in the Redevelopment
Planning Site,” Working Paper, Makati Risk-Sensitive Redevelopment Planning Project,
Earthquakes and Megacities Initiative, Philippines, December 10, 2009.

New Technologies for Urban Safety of Mega Cities in Asia

programs, projects and activities (PPAs); todevelop, validate and advocate alternative
scenarios/RSURP; and to refine and selectthe most appropriate RSUPR and Ordinancecontaining institutional framework.
This is the first project of its kind in thePhilippines to address the redevelopment ofa built-up urban area, keeping in mind the
reduction of risk. Thus there are no local
precedents which can serve as guide. In
addition to the physical risks, theredevelopment plan took into account the

Urban
Sustainability

Urban Livability

Disaster Resiliency
and Risk Reduction

following considerations related to Fig. 4 Risk-Sensitive Urban
implementation: 1) the stakeholders andRedevelopment Framework
their interests; 2) the nature of property(Source EMI, 2010)
ownership; 3) finance; and 4) politicalcommitment. The stakeholders may not have the same intensity of interest, but
their support and cooperation are essential to achieving success.
6. PARTICIPATORY APPROACH
The planning process used a highly participatory approach. A single integrated
Project Implementation Team was put together that included technical specialists
and officials from Barangay Rizal, Makati City and PHIVOLCS. Stakeholders
were involved in all stages of the planning process.
A series of planning workshops was undertaken to engage the representatives of
the community in the redevelopment process. First, they were oriented on thehazards and their vulnerabilities. Then they were asked to formulate their vision
for the community, identify the major problems, and suggest solutions. Then, they
participated in the identification of programs, projects and activities, and thevalidation and acceptance of findings and proposed redevelopment plan. This
helped ensure that the plan reflected all stakeholders’ interests, needs andaspirations. All findings and outputs from the projects were shared and validatedwith the community representatives. To create ownership in the redevelopment
plan, the need for a continuous information and education campaign wasemphasized. To further develop trust, members of the community were engaged
in the data collection process. Training for disaster preparedness and skills
training for livelihood improvement were also undertaken. The participatory
planning process goes hand-in-hand with the planning process as indicated in
Figure 5.

Your paper title

October 2010, Kobe, Japan

Social Investigation

SocialPreparation

Social
AcceptanceFig. 5 Process for Participatory Risk-Sensitive Urban
Redevelopment Planning (Source EMI, 2010)

7. RISK-SENSITIVE REDEVELOPMENT CONSTRAINTS
The project involved the preparation of a plan with the goal of transforming thehigh risk community into a safer, disaster-resilient neighborhood while
simultaneously enhancing its urban fabric, economic vibrancy, social cohesion,
public safety, and environmental quality. The challenge is to work with thestakeholders to develop options to reduce these risks and to have these options
understood and accepted by the community.
The redevelopment plan for the site needs to consider how to reduce risk for thesethree major aspects: physical vulnerability, social and economic vulnerability; atthe same time, it needs to improve the emergency management potential. For
physical vulnerability, the main concern pertains to the structures built on top of
the fault zone and the other highly vulnerable structures scattered throughout thearea. For social and economic vulnerability, the high density and increasing
population is a concern, as well as vulnerable households who may not have theeconomic capacity to cope when disaster strikes, and those with vulnerable
members, such as those with disabilities, chronic sickness, female heads, andchildren and the elderly. Related to emergency management is how to improve themobility in the site, given the narrow and often blocked roads. The need forevacuation areas and temporary shelter is a concern given that twenty percent(20%) of the structures in the area have more than 10 people living inside.
8. FORMULATING THE RISK REDUCTION OBJECTIVES
The planning process needs to consider explicit objectives for both reduction ofdisaster risk and improvement of emergency management capabilities. The
objectives constitute the main drivers behind the re-development solution. For
this purpose the following risk reduction objectives were formulated:

New Technologies for Urban Safety of Mega Cities in Asia

1. There should be no permanent human settlement in structures with a“Very High 4” Vulnerability rating. All structures located on or within 15
meters from the fault are considered to have very high vulnerability.
2. Structures with “High Vulnerability” rating should be further studied toascertain their vulnerability level.
3. There should be a voluntary seismic retrofitting program for structures
rated as “High Vulnerability”, supported by an incentive package andawareness program.
4. The acquisition of structures/lots for open space should be clusteredaround structures with Very High and High Vulnerability to minimize thenumber of displaced households.
5. Critical facilities such as schools and health facilities as well as structures
which can be used for post-emergency centers should be identified andseismically retrofitted or replaced depending on a benefit/cost analysis.
6. Infrastructure and critical lifelines (e.g., water, sanitation, power,
communication, etc.) should be upgraded for seismic performance as anintegral part of the redevelopment plan.
7. No intervention is planned for structures with vulnerability of Moderate to
Low. However, households of these structures will be encouraged toparticipate in the voluntary seismic retrofit program.
9. VULNERABILITY AND RISK ASSESSMENT STUDIESThe evaluation of physical, social and economic vulnerability to the households ofBarangay Rizal is core to the redevelopment project. How each of the residents is
affected by these criteria is determined from the physical risk survey. The socioeconomic surveys provide crucial information to devise the compensation schemethat will need to be put in place for the re-development plan.
The physical vulnerability of individual structures was done through a “Rapid
Visual Screening for Seismic Vulnerability of Buildings.” This was carried out
by means of a “sidewalk survey”. Trained engineers from Makati City filled up adata collection form for each structure based on visual observation supplemented
by data obtained from the City’s engineering office. Special attention was also
paid to evaluate liquefaction potential. 5 A total of 1,150 structures covering 44
blocks in Zones 7, 8, 9, and 10 were surveyed. This constitutes around 94 percentof the total number of structures (1,229) in the planning area. A special algorithm
was designed to classify the structures into four risk levels: Very High, High,
Moderate and Low (see footnote 5).
Vulnerability and Capacity Analysis (VCA) was undertaken to determine theexisting conditions that predispose the community to potential socio-economic
losses and damages in the event of a disaster. The VCA assessment specificallyseeks to identify individuals and households who will be adversely affected by a

4 Structures with a very high likelihood of collapse or extreme damage to earthquakes.
5

Liquefaction Susceptibility Report Brgy. Rizal, Makati City, Bijan Khazai, 2009Your paper title

October 2010, Kobe, Japandisaster event, and also identify and assess the capacity of households and thecommunity to respond and recover from a disaster event.
The results of the surveys were shared with the community to raise awarenessand for educating the community in risk-sensitive re-development. The results areshown in Figure 6.

Fig. 6 Results from the Physical, Economic and Social Vulnerability Assessments (Source EMI,2010)

10. THE PROPOSED RISK-SENSITIVE REDEVELOPMENT PLAN
The redevelopment plan is designed for a 10-year timeframe with short term,
medium term and long term actions. The priorities in the action planning were
driven by the input from the stakeholders and were driven mainly by ensuringcommunity acceptance and developing community trust and support. The
redevelopment plan proposes the following interventions:
Fault zone park. An easement zone along the fault needs to be established withaccess roads on both sides (see Figure 7). The access roads will provide theopportunity to redesign new utilities and fire protection systems that considers
appropriate earthquake motion. Drainage systems will be incorporated to reduce
the risk of flooding. Further, the easement can be used as a park, open market,
recreational area, playground, parking space and a community garden. Residents
within the fault zone will need to be relocated.
Housing program and pocket open space. New medium density social housing
will be provided for the households that will be affected by the redevelopment.
The re-housing program should be based on the premise that all relocation will be
on-site, i.e., within the Barangay itself.
Retrofit program for high risk structures. A voluntary retrofit program issuggested for structures classified as “High Risk.” However, prior to retrofit,
more competent structural analysis needs to be undertaken on these structures toascertain their level of risk considering their construction characteristics andlocation.
Aside from the abovementioned interventions which directly address physical risk,
the following measures are proposed:
New Technologies for Urban Safety of Mega Cities in Asia

Compensation scheme. For those who will be displaced because their existingdwellings are considered to be at very high risk, a compensation scheme that isbased on pertinent legal provisions and regulations should be developed.
Incentive program. The voluntary seismic retrofit program needs to be supported
by an incentive scheme to favor the engagement of private owners to participate.
The incentive scheme can be in various forms such as undertaking all the studies
free of charge, providing soft low interest loans, allowing variations in zoning formixed uses, and others.
Raising Income Level and Improving Economic Conditions. Measures to raise
the income and uplift the economic conditions of to reduce the social andeconomic vulnerabilities include (i) development of neighbourhood commercial
centers; (ii) development of educational facilities; (iii) formulation of strategic
livelihoods and skills enhancement program and (iv) preparation of business andentrepreneurship support program which includes improving people’s access toaffordable financing and market linkaging.
Other proposed interventions include: the establishment of development controls
and density controls, development of an information education communication(IEC) campaign to improve social acceptability of the project, improvement ofcirculation network and emergency access, traffic management, open spacedevelopment, disaster preparedness and emergency management and upgrading of
critical infrastructure.

Figure 7. Proposed fault zone park for Barangay Rizal (Source: EMI 2010)

11. CONCLUSION
The project confronted the core issues of mainstreaming DRR in land use
planning and urban (re)-development. It doing so, it has to tackle a relatively new
area of practice. The project has generated valuable knowledge in terms of boththe substantive content and redevelopment planning process for addressing theearthquake risks of a high-risk community. The fact that the project site isvirtually all built-up, with small lots and narrow streets, and occupied by
predominantly low-income households place extreme limitations on the range ofredevelopment options. It was shown that formulating an acceptableredevelopment plan is possible if the planning process is systematic, transparent,Your paper title

October 2010, Kobe, Japan

participatory and consensus-based. The systematic approach in data gathering,
analysis, and presentation at the stakeholder workshops helped significantly indeveloping a deeper appreciation of the risks that the community faces. A strong
multi-disciplinary technical team is needed to collect the detailed data andintegrate the many parameters driving the redevelopment while at the same time
pursuing the participatory approach. The sensitivity of the City Government
representatives and technical experts to the particular culture, socioeconomic circumstances, and constraints on the part of the affectedhouseholds was especially helpful in maintaining a spirit of collaboration andcooperation throughout the planning process. The project demonstrates that land
use and redevelopment planning can be powerful tools to lessen the physical,
social, and economic vulnerability of high-risk communities.

REFERENCES
Bendimerad, F., Buika, J., Fernandez, J. Mattingly, S., Reyes, M. and Van
Boskirk, E., 2007. Urban and Megacities Disaster Risk Reduction: Manual ofSound Practices, Earthquakes and Megacities Initiative Publication. Web
reference at: http://www.emi-megacities.org/?page=resources.
Earthquakes and Megacities Initiative, 2008. Mainstreaming Disaster Risk
Reduction in Megacities: A Pilot Application in Metro Manila and Kathmandu,
Quezon City, Philippines.
Japan International Cooperation Agency, Metro Manila Development Authority,
and Philippine Institute of of Volcanology and Seismology, 2004. Metro Manila
Earthquake Impact Reduction Study.
German Federal Foreign Affairs Office and EMI, 2010. Risk-Sensitive Urban
Redevelopment Plan of Barangay Rizal, Makati City, Philippines, Reports 1 to 5.
Earthquakes and Megacities Initiative, 2007. Evaluation of the 3cd Program
Preparatory Phase (2005-2006) Implementation in Metro Manila, 16 Feb. 2007.
Webreference:
http://www.emimegacities.org/upload/3cd_2007_02_MMEvalWS_PR0701.pdf.
Earthquakes and Megacities Initiative, 2008. Mainstreaming Disaster Risk
Reduction in Megacities: A Pilot Application in Metro Manila and Kathmandu.
Quezon City, Philippines.
Earthquakes and Megacities Initiative, 2010. Risk Sensitive Urban
Redevelopment of Barangay Rizal, Makati City, Philippines, in Mainstreaming
Disaster Risk Reduction in Megacities: A Pilot Application in Metro Manila andKathmandu. Vols. 1 and 2. Quezon City, Philippines.
ACKNOWLEDGMENTS
The financial support of the German Federal Foreign Affairs Office is greatly
appreciated. This project would not have been possible without the collaborative
spirit and engagement of officials, staff and community representative of Makati
City and Barangay Rizal, and the technical support and valuable input fromPHIVOLCS.

New Technologies for Urban Safety of Mega Cities in Asia

Your paper title

Comparison of Urban Recovery Planningand Designing for Tsunami Hazard between
Sanriku Coastal Areas, Japan,and Hilo, Hawaii

1Osamu MURAO1 and Walter C. DUDLEY2
Associate Professor, Graduate School of Systems and Information Engineering
University of Tsukuba, Japanmurao@risk.tsukuba.ac.jp
2
Professor, The University of Hawaii at Hilo, USA

ABSTRACTSanriku Coastal Areas, in the northern part of the main land of Japan, survived
the catastrophic tsunamis in 1896, 1933, and 1960. The city of Hilo in Hawaii
Island also experienced the destructive tsunamis in 1946 and 1960. Having somesimilarities as tsunami-prone areas, both the areas incurred enormous damage
and recovered in their history. However, the post-tsunami urban recovery
planning and the future strategy for tsunami management demonstrate differences
in both areas. It is important for tsunami disaster management for urban safety torecognize these similarities and differences presented in both areas, and sharing
information will be helpful for the future urban planning in the world as well as inboth the countries. This paper demonstrates the similarities and differences asfollows: (1) outlining both areas’ characteristics and those historical tsunami
disasters, (2) explaining recovery process after the tsunamis, (3) demonstratingtimeline of the tsunami-related events including the aftermaths and the publishedplanning and policies for tsunami disaster management, (4) comparing thecontents for urban safety management in recent governments’ guidelines andthose historical transition in the United States and Japan.

Keywords: the 1896 Sanriku Tsunami, the 1933 Sanriku Tsunami, the 1946
Aleutian Tsunami, the 1960 Chilean Tsunami, post-tsunami urban recovery
planning, urban safety planning for tsunami

1. INTRODUCTION
Sanriku Coastal Areas, in the northern part of the mainland of Japan, and Hilo, thesecond biggest city in Hawaii State in the United States, are both tsunami prone
areas. Sanriku Coastal Areas survived the catastrophic tsunamis in 1896, 1933,
and 1960, and the city of Hilo experienced the destructive tsunamis in 1946 and1960. Having some similarities as tsunami-prone areas, exemplified by the factthat both the areas were damaged by the 1960 tsunamis from Chile, both areas

0ctober 2010, Kobe, Japan

incurred enormous damage and recovered in their history. However, the posttsunami urban recovery planning and the future strategy for tsunami management
present differences in both areas.
Generally, a natural disaster damaged area devises an urban recovery plan toreduce future damage based on the learning from the experience, but its contents
and recovery process show diversity according to regional, historical, economical,
social, or geographical background.
In May 2010, Sanriku and Hilocommemorated the fiftieth anniversary of the 1960 Chilean Tsunami. For thehalf-century, both areas had been involved in post-tsunami recovery processrespectively, and at the same time tsunami-related research had been improved in
the United States and Japan. As a result, each country has own idea of the urban
safety management for tsunami disaster reduction.
Murao (2010) reported the post-tsunami recovery process in Hilo. Including thecontents of the previous report, this paper examines the similarities anddifferences of urban recovery planning and designing for tsunami hazard
presented in both countries because it is important and helpful for the future urban
planning to recognize them and to share the information not only for these twocountries but also for other needful countries in the world.

2. USED MATERIALS AND METHODS
Although the comparative study has rarely been conducted in a much volume,
there are many reports and books covering the tsunamis occurred in Sanriku
Coastal Areas and Hilo, so those existing materials are used for the comparative
study. In order to arrange the information of Sanriku Tsunamis, the authors refers
the books comprehensively written by Yamashita (1982, 1984, 1985, and 1995)
and Yoshimura (2004), and the government reports on the 1986 Meiji Sanriku
Tsunami (Central Disaster Management Council, 2005) and the 1960 Chilean
Tsunami (Central Disaster Management Council, 2010). For the tsunamis in Hilo,the information is obtained from the books written by Dudley and Lee (1988),
Dudley and Stone (2000), DOI and USGS (1999), and González and Kamphaus(2000).
The comparative research in this paper is carried out as follows: (1) outlining bothareas’ characteristics and those historical tsunami disasters, (2) explaining
recovery process after the tsunamis, (3) demonstrating timeline of the tsunamirelated events including the aftermaths and the published planning and policies fortsunami disaster management, and (4) comparing the contents for urban safety
management in recent governments’ guidelines and those historical transition in
the United States and Japan.

3. OUTLINE OF SANRIKU COASTAL AREAS AND HILOThis section outlines Sanriku Coastal Areas and Hilo as tsunami-prone areas that
represent Japan and the United States. Fig. 1 illustrates the locations of cities inboth areas, and Table 1 shows deadly tsunamis since the nineteenth century with
the number of casualties and maximum tsunami height. Hilo and the cities inSanriku Coastal Areas are located in the east coast in Hawaii Island and the

New Technologies for Urban Safety of Mega Cities in Asiamainland of Japan facing the Pacific Ocean respectively. Geographically bothareas have been influenced by volcanic activities and seismicity that sometimes
cause tsunamis. Also these locations are prone to receive tsunamis coming from
North and South America, or around the Pacific basin including nearby waters.

Figure 1: Locations of cities in Sanriku Coastal Areas and Hilo on a same scale
Table 1: Deadly tsunamis and the number of casualties in both areas
Sanriku Coastal Areas

Hilo(Yamashita, 1982)(DBEDT, 2008)

Date

Location of
SourceNumber of
Casualties

1837.11.7
1877.5.10
1896.6.15
1923.2.3
1933.3.3
1946.4.1
1960.5.23

Chile
Chile
Sanriku Area
Kamchatka
Sanriku Area
Aleutians
Chileapp. 22,000
3,064
182

Maximum
TsunamiHeight
38.2m
28.7m
6m

Number of
Casualties
14
5
1
96
61

Maximum
TsunamiHeight
6.0m
4.8m
6.1m
16.4m
10.5m

Hilo is the county seat of Hawaii County and the second-largest city in the Stateof Hawaii with a population of 40,759 according to 2000 Census of the US. The
number of deaths resulting from tsunamis since 1837 in Hilo is 177, and it
comprises over sixty percent of those in all of the state. Geographically Hilofaces on the crescent shaped Hilo Bay and spreads on an open plain with gentle
slope. The downtown and other residential districts such as Shinmachi andYashijima had been thrivingly developed in front of the ocean since latenineteenth century until the 1940s, but the tsunamis in 1946 and in 1960
devastated the most of them. The urban recovery process replaced the crowded
residential districts into beautiful green belt after 1960.
Comparison of urban recovery planning and designing for tsunami hazard between
Sanriku Coastal Areas, Japan, and Hilo, Hawaii

0ctober 2010, Kobe, JapanOn the other hand, Sanriku Coastal Areas are known as tsunami hazardous placein Japan, as Koshimura (2005) mentioned: “Judging by the existing materials, it
seems that they had tsunamis averagely once per fourty-six years in the history.”
The most of the town and village communities along the coast of 300km long,from Onagawa in Miyagi Prefecture to Taneichi in Iwate (Figure 1), experienced
several catastrophic tsunamis. The number of damaged towns and villages in
Miyagi and Iwate by the 1896 Tsunami was approximately fifty-four, and thedeath-toll ranged from 111 for to 6,986. The number of “shuraku” communities,
the minimum jurisdiction unit with a population of hundreds in the region, wasapproximately 250. Today, there are seventeen municipalities in the coastal areas
resulting from municipal mergers after the World War II. Geographically,
Sanriku is rias coast, so most of the districts have steep slopes or cliffs behind.
However, spatial characteristics of districts show diversity: some are surroundedby mountains in all directions except ocean; others are open to nearby villages.
These geographic characteristics directly influenced regional development
through post-tsunami recovery process in the areas.

4. TSUNAMI DAMAGE AND URBAN RECOVERY IN THE AREAS
4.1 Making of Timeline
This section gives chronological accounts of tsunami-related events in both areasusing the timeline shown as Table 2. It marks tsunamis, recovery activities,
aftermaths, tsunami management, and issue of planning and policies for tsunami
disaster management in both countries.
In general, a catastrophic urban disaster influences its post-disaster recovery andrelated disaster management in the next generation. Therefore, the authorsclassify the time of about 150 years in Table 2 into five periods divided bysignificant events respectively: (J1) before the 1896 Meiji Sanriku Tsunami, (J2)
after the 1896 Meiji Sanriku Tsunami, (J3) after the 1933 Showa Sanriku Tsunami,(J4) after the 1960 Chilean Tsunami, and (J5) after the publication of Guideline toStrengthen Tsunami Disaster Management in Local Plan for Disaster Prevention(NLA et al., 1997) until today for Sanriku Coastal Area in Japan; (H1) downtown
development era before 1941, (H2) after making of Master Plan of the City ofHilo, (H3) after the 1946 Aleutian Tsunami, (H4) after the 1960 Chilean Tsunami,and (H5) after the publication of Designing for Tsunamis (NOAA et al., 2001).
Table 1: Timeline table of tsunamis and urban recovery in Sanriku Coastal Areas(Japan) and Hilo (the US)
Year

Events in Sanriku Coastal Areas (Japan)

1854

The Ansei Toukai/Nankai Earthquake and Tsunami[J1](320+713)
Embankment and planting in Hiro, Wakayama, to reducetsunami damage

1858
1868
1877
1888
1896

Events in Hilo (the United States)[H1]

The 1868 Great Earthquake and Tsunami in Hawaii (47)
The 1960 Chilean Tsunami (5)Tokyo City and Ward Transformation Act 1888
The 1896 Meiji Sanriku Tsunami (app. 22,000)[J2]
Sanriku Coast Railway Project (not realized)
43 communities (7 as organized groups) relocated to higher
land, but most of them returned

New Technologies for Urban Safety of Mega Cities in Asia

1899
1908
1919
1920
1923
1925
1929
1933

1934

1936
1941
1944
1946

The Hilo Railway (Hawaii Consolidated Railway) opening
Breakwater for Hilo Bay commenced
The City Planning Act/Law 1919
The 1923 Great Kanto earthquake (109)
The first public radio broadcast delivered
The 1933 Showa Sanriku Tsunami (3,064)[J3]
Guideline to Prepare for Tsunami Disaster
The 10th Anniversary of the Great Kanto Earthquake: The
Memorial Project
Building Regulation by Miyagi Pref.
Call for slogan on the monuments for the future
Recovery Plan by Ministry of Home Affairs
Planting of tsunami control forest
Tsunami observation tower constructed in Kamaishi
Tsunami warning organization established for Sanriku Coast
The 1944 Tounankai Earthquake and Tsunami (1,223)
The 1946 Nankai Earthquake (app. 1,400):
The embankment in Hiro worked well

1948
1949

1951
1952

Disaster Rescue Team Regulation in Kochi Pref.
Systematic Tsunami Forecast and Information Transmission
Plan approved, and exercised
The 1st tsunami warning given
The Tokachioki Earthquake and Tsunami:
The Tsunami Warning System worked

1957
1958
1960

1961

1968

1969
1972
1974
1975
1977
1979
1983

1984
1985
1991
1993
1994
1997

Breakwater for Hilo Bay completed
Tsunami warning given after the earthquake in Sanriku,
Japan, but not satisfied

Master Plan of the City of Hilo

[H2]

The 1946 Aleutian Tsunami (96 +63)

[H3]

Pacific Tsunami Warning Center created following the 1946
TsunamiOfficial tsunami warning capability in the U.S. start at
Honolulu Geomagnetic Observatory

The 1952 Kamchatka Earthquake and Tsunami (0)The 1957 Aleutian Tsunami (0):Buildings damaged, but no death toll because PTWS worked

Coastal Conservation Facility Construction Guideline
establishedThe 1960 Chilean Tsunami (182)[J4]
Disaster dangerous area and building regulation designated in
Hamanaka Town in Hokkaido

The 1960 Chilean Tsunami (61) :[H4]The system of warning sirens changed, People confused
Hawai'i Redevelopment Agency established
Coastal development with expansion of buffer zone andlandfill considered

The Chilean Earthquake and Tsunami Disaster
Countermeasure Project (Policy, Contents, Tsunami
breakwater plan…)
The 1st tsunami breakwater in the world constructed in
OfunatoHazardous district designated in Nagoya City by Waterfront
Disaster Hazardous District and Building Act

1964
1965
1966
1967

The first radio news program broadcasted
The 1923 Kamchatka Earthquake and Tsunami (1)The 1964 Alaska Earthquake and Tsunami (0):Partially inundated
Kaiko'o Project
Emergency Taskforce for the Chilean Tsunami dissolved

The 1968 Tokachioki Earthquake and Tsunami (53):
No mentionable damage in Sanriku Coastal Area because of
the constructed breakwaters
The City Planning Act/Law 1969

West Coast & Alaska Tsunami Warning Center (WC/ATWC)
established
The Intergovernmental Coordination Group for the PacificTsunami Warning System (ICG/PTWS) established
The National Flood Insurance Program (NFIP)
The 1972 Coastal Zone Management Act (CZMA)
Hilo Downtown Development Plan approval
The 1975 Hawaiian Tsunami (2)Estimated Tsunami Inundation Map released in Sizuoka Pref.
Submarine Earthquake Observation System Start (JMA)
Proposition of Guideline for Systematic Tsunami Disaster
Management for Tsunami Hazardous Areas (MC and JFA)
The 1983 Nihonkai-Chubu Earthquake and Tsunami (104)
Karakuwa Tsunami Museum open
Downtown Hilo Redevelopment Plan approval (Chapter
27:Flood Control of the Hawaii County Code)The 1st Evacuation maps for Hawaii publishedThe 1993 Hokkaido Nanseioki Earthquake and Tsunami (200)
Network of Earthquake Observation System for Urgent
Disaster Warning of Earthquake and Tsunami (JMA)
Tsunami Disaster Estimation Manual[J5]
Guideline to Strengthen Tsunami Disaster Management in
Local Plan for Disaster Prevention (NLA et al.)The Pacific Tsunami Museum establishedState Emergency Alert System (EAS) startComparison of urban recovery planning and designing for tsunami hazard between
Sanriku Coastal Areas, Japan, and Hilo, Hawaii

0ctober 2010, Kobe, Japan

1998
1999
2001
2003
2004

2005

2006

2008

The Pacific Tsunami Museum open
Tsunami forecasted area expanded and estimation accuracy
improved (JMA)
Designing for Tsunamis
The 2003 Tokachioki Earthquake and Tsunami (2)Tsuami and Tidal Wave Hazard Map Making Manual (MLIT)
Local Governments’ tsunami hazard map release ratio on theInternet: 9.6%
Guideline for Management of Tsunami Evacuation Buildings(CAO)
Systematic Emergency Drill for Wide Area Tsunami
exercised (MLIT)
Improvement of tsunami warning system using the
Earthquake Early Warning System (JMA)
Local Governments’ tsunami hazard map release ratio on theInternet: 34.9%[H5]

EnVision Downtown Hilo 2025 start

Guidelines for Design of Structures for Vertical Evacuationfrom Tsunamis
Tsunamis that damaged to Sanriku Coastal Areas and Hilo are expressed in bold type, and death tall is shown in parentheses.

4.2 Tsunamis and urban recovery in Sanriku Coastal Areas
The time before the 1896 Sanriku Tsunami [J1] was a conventional age in whichtsunami phenomena had not been scientifically explained. After the 1854 Ansei
Earthquake and Tsunami, an embankment was built and pine trees were forested
in Hiro, Wakayama, in order to reduce future tsunami damage, yet theeffectiveness had not been judged until the 1946 Nankai Earthquake.
After the 1896 Sanriku Tsunami [J2], consideration was given to relocation tohigher land in many damaged villages, but most of it was lead by influences in thecommunities or was conducted individually. As a result, 43 communities moved
to higher places, but most of the residents returned to the previous land because of
conveniences for fishery. Besides high land relocation, evacuation route andtsunami control forest were proposed, but they were not realized in the period. In
1925, the first public radio broadcast was delivered, and it became a leadingmeans for tsunami warning in the twentieth century.
In the period of [J3] after the 1933 Showa Sanriku Tsunami, national and local
governments’ support system basis established even though it was not enough.
Scientific basic strategy for post-tsunami recovery was proposed in Guideline to
Prepare for Tsunami Disaster. Consequently tsunami control forest was planted
and reinforced piers were constructed. After World War II, tsunami mitigation
facilities such as seawalls were constructed in some places, and tsunami-warning
system started in the 1950s.
In the period of Japanese rapid economic growth after the 1960 Chilean Tsunami[J4], urban physical environment for tsunami mitigation such as seawalls andbreakwaters were constructed, and related land use regulations were carried out inmany places in Japan. In the 1970s, several software for tsunami disastermanagement, for example tsunami inundation maps, tsunami information systems,
and educational activities, was developed in addition to physical environmental
countermeasures. As a result of the thirty-year tsunami experience after the
Chilean Tsunami, Tsunami Disaster Estimation Manual and Guideline toStrengthen Tsunami Disaster Management in Local Plan for Disaster Prevention(NLA et al., 1997) were published to show comprehensive tsunami management.
It was a new gate into contemporary era [J5], in which hazard maps and tsunami
evacuation buildings have been planned and realized in many coastal areas inJapan.

New Technologies for Urban Safety of Mega Cities in Asia

4.3 Tsunamis and urban recovery in Hilo
Urban fabric of Downtown Hilo formed in the early twentieth century [H1] after
Kingdom of Hawaii was overthrown in 1893. In this thriving period, the Hawaii
Consolidated Railway was opened, and construction of the breakwater for
maritime safety commenced.
In the early 1940s, Master Plan of the City of Hilo (Territorial Planning Board,1941) was published. Herein, tsunami related matter was not contained, but urban
effectiveness of replacement of waterfront residential districts by a green belt waspointed out. This suggestion probably may affected the urban development after
the two great tsunamis in Hilo (Murao, 2010).
The 1946 Aleutian Tsunami damaged to many buildings along the coast. In therecovery period [H3], the government banned building construction along thewaterfront to prevent future damage and to create urban green belt. However,some houses were rebuilt in the district to be destroyed by the 1960 Chilean
Tsunami again. As well as Japan, some tsunami mechanism were scientificallyelucidated in the period, and it triggered tsunami warning system operation.
After the 1960 Chilean Tsunami [H4], which devastated waterfront districts again,
beautiful waterfront green belt was realized by Kaiko’o Project. Also, the factthat pacific coast areas were influenced by the tsunami caused the establishmentof the Intergovernmental Coordination Group for the Pacific Tsunami Warning
System. In the 1990s, State Emergency Alert System started, and Tsunami
Museum opened as a tsunami education center.
Recently [H5], systematic idea of tsunami disaster management such as Designing
for Tsunamis (NOAA et al., 2001) has been proposed and been realized in coastal
areas in the US.

5. COMPARISON OF URBAN RECOVERYDESIGNING FOR TSUNAMI HAZARD

PLANNING

AND

5.1 Scheme of urban Recovery planning and designing for tsunami
This section demonstrates differences of basic tsunami management concept andhistory between the US and Japan based on materials published by bothgovernments. In order to think up a scheme, Guideline to Strengthen Tsunami
Disaster Management in Local Plan for Disaster Prevention (National Land
Agency et al., 1997) for Japan and Designing for Tsunamis (NOAA et al., 2001)
for the US are used. The scheme is chronologically classified into four basicstages in the disaster life cycle, (1) mitigation, (2) preparedness, (3) emergency
response, and (4) recovery and reconstruction, with a sub stage (5) early warning.
Table 2 shows comparison of history of urban recovery planning and designing
for tsunami hazard in both countries based on the concept. The vertical axis
demonstrates related items chosen by the two guidelines in the five stages, and thehorizontal axis arranges critical materials published by governments or important
events.
Table 2: Comparison of history of urban recovery planning and designing fortsunami hazard in Sanriku Coastal Areas (Japan) and Hilo (the US)
Comparison of urban recovery planning and designing for tsunami hazard between
Sanriku Coastal Areas, Japan, and Hilo, Hawaii

0ctober 2010, Kobe, Japan

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Slowing

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Tsunami Control Forest

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Breakwater
SeawallCompacted
Terraces and Berms

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Tsunami Resistant Buildings

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Parking Structures
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Building Design Guideline interms of functions○○

Existing Building
Reinforcement○

Reinforcement Piers
Earthquake Reinforcement
Tsunami Reinforcement
Industrial Facilities

X

Preparedness Damage
Estimation
Disseminate
Risk
Informationof#

Evacuation Map
&

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Damage Estimation

Hazard Map
Education
Edification○

Ditches

Paved Surfaces
Blocking

Designing for Tsunamis○>

Kaiko'o Project

>

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2001

#

>

Pacific Tsunami Warning Center created

>

1965

>

Recovery after the 1946 Aleutian Tsunami

>

1948

Tsunami warning given, but not satisfied○

Master Plan of the City of Hilo

Breakwater for Hilo Bay completed

1933

○

1946

Guideline for Tsunami Evacuation Buildings

1926

Tsuami and Tidal Wave Hazard Map Making Manual

Guideline to Strengthen Tsunami Disaster Management

>

H4 H5

1940

Avoiding

Guideline for Systematic Tsunami Disaster Management>

Recovery after the 1960 Chilean Tsunami>

Planning in Inundation Area
Construction
Forestation

Estimated Tsunami Inundation Map in Sizuoka

Tsunami warning organization for Sanriku Coast

2005

#

2004

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1997

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1983

>

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H2 H3

1977

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1961

Relocation to Higher Land

Recovery after the 1933 Showa Sanriku Tsunami

The Memorial Project of the 1923 Kanto Earthquake

Building Regulation

Guideline to Prepare for Tsunami Disaster

Recovery after the 1895 Meiji Sanriku Tsunami

1933

Buffer Zone

J5

1941

LanduseRegulation

1934

LanduseItem

Embankment and planting in Hiro, Wakayama

Subtopic

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1933

Mitigation

Topic

1896

Phase

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1858

J1 J2

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Organization for
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New Technologies for Urban Safety of Mega Cities in Asia

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Early Warning Observation
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Emergency Task Force
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Sign

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Care for thedisabilities

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Recovery and Systematic
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Commemoration
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#: realized, ○: planned or proposed, ●: realized but not satisfied, X: planned but not realized, >continued

5.2 Comparison of urban recovery planning and designing for tsunami
hazard in the US and Japan
Although we can discuss several topics based on the Table2, the two references,which are used for the scheme, are compared here. Both materials containhardware and software for tsunami management, but those descriptions forstructural aspect of buildings are different. The followings are three examples.
Firstly, unlike Guideline to Strengthen Tsunami Disaster Management in Local
Plan for Disaster Prevention, in Designing for Tsunamis, “there are four basic
site planning techniques that can be applied to projects to reduce tsunami risk: 1)
avoid inundation areas, 2) slow water currents, 3) steer water forces, [and] 4)
block water forces,” and it systematically and concretely explains how physicalenvironment should be prepared to mitigate tsunami damage.
As for evacuation, Designing for Tsunamis divides it into two types, vertical andhorizontal. Probably, it was so natural for people in Sanriku Areas to evacuate
toward high land through steep hills because their living place was located alongrias coast that they were not conscious whether it was vertical or horizontal. On
the other hand, the evacuation in Hilo meant horizontal because of its flat
geography.
Third example is the meaning of monument. Construction of memorial after adisastrous event is common as well as wars, but it is to the memory of it in the US
as exemplified by Laupahoehoe monument; it is to enlighten or to educate people
to mitigate future disaster with aphorisms like “escape after shaking” in Japan.

6. CONCLUSION
This paper demonstrates the similarities and the differences of post-tsunami urban
recovery and tsunami management between Sanriku Coastal Areas and Hilo using
timeline. The timeline is classified into five chronological phases separated by
critical tsunamis or important events for urban safety planning respectively: the1896 Sanriku Tsunami, the 1933 Sanriku Tsunami, the 1960 Chilean Tsunami,
and the year of the Guideline to Strengthen Tsunami Disaster Management in
Local Plan for Disaster Prevention published by Japanese Government in 1997 forSanriku Coastal Areas; the year of 1940 Master Plan of the City of Hilo, the 1946
Comparison of urban recovery planning and designing for tsunami hazard between
Sanriku Coastal Areas, Japan, and Hilo, Hawaii

0ctober 2010, Kobe, Japan

Aleutian Tsunami, the 1960 Chilean Tsunami, and the year of Designing for
Tsunamis published by FEMA et al. in 2001 for Hilo. The timeline and thecomparative study of the contents for urban safety management clearly illustrate
how both the countries had struggled and evolved the urban strategies fortsunamis since 1894.

ACKNOWLEDGEMENTS
The research was supported by Fulbright Scholar Program 2009-2010 for“Comparative Study of the Policy and Urban Planning for Disaster Management
in USA and Japan.” I would like to give special thanks to the staff of PacificTsunami Museum who gave useful information and pleasant working
environment, Ms. Donna Saiki, Ms. Colleen DeSa, Ms. Crystal Ogata, Ms. Kini
Gonzalez, Mr. Roy Daimaru, and especially Ms. Barbara Muffler. I also thankMs. Mary Louise Haraguchi at Mookini Library in the University of Hawaii at
Hilo for the information of the history of Hilo and Waiakea Town. I am
enormously grateful to Council for International Exchange of Scholars and theJapan-United States Education Commission.

REFERENCES
Central Disaster Management Council, 2005. Report on the 1986 Meiji Sanriku
Earthquake and Tsunami, Cabinet Office, Government of Japan,
http://www.bousai.go.jp/jishin/chubou/kyoukun/rep/1896-meijisanrikuJISHINTSUNAMI/index.html (in Japanese).
Central Disaster Management Council, 2010. Report on the 1960 Chilean
Earthquake and Tsunami, Cabinet Office, Government of Japan,
http://www.bousai.go.jp/jishin/chubou/kyoukun/rep/1960chile%20JISHINTSUNAMI/ (in Japanese).
The Department of Business, Economic Development & Tourism, State of Hawaii,
2008. 2008 State of Hawaii Data Book Individual Tables ，http://hawaii.gov/dbedt/info/economic/databook/2008-individual/.
Dudley, W. C., and Lee, M., 1998. Tsunami ! (2nd ed.). Honolulu: University of
Hawai’i Press.
Dudley, W. C., and Stone, S. C. S., 2000. The Tsunami of 1946 and 1960 and theDevastation of Hilo Town, Virginia Beach: Donning.
González, F., and Kamphaus, R., 2000. May 2000 Tsunami Inundation Mapping
Progress Report, http://nthmp-history.pmel.noaa.gov/may00.pdf.
Koshimura, S., 2005. Chapter 1: Outline of Tsunami Disaster in Sanriku Region,
Report on the 1986 Meiji Sanriku Earthquake and Tsunami, Central Disaster
Management
Council,CabinetOffice,GovernmentofJapan,
http://www.bousai.go.jp/jishin/chubou/kyoukun/rep/1896-meijisanrikuJISHINTSUNAMI/index.html, 3 (in Japanese).
Murao, O., 2010. Post-Tsunami Urban Recovery Plan and Recent Situation in
Hilo, Hawaii: On-site Report on the 50th Anniversary of the 1960 Chilean
Tsunami, Reports of the City Planning Institute of Japan, No.9-1 (CD-ROM), 1217 (in Japanese).

New Technologies for Urban Safety of Mega Cities in Asia

National Land Agency et al., 1997. Guideline to Strengthen Tsunami Disaster
Management in Local Plan for Disaster Prevention.
NOAA et al., 2001. Designing for Tsunamis Seven Principles for Planning and
Designingfor
TsunamiHazard,http://nthmphistory.pmel.noaa.gov/Designing_for_Tsunamis.pdf.
Territorial Planning Board, Territory of Hawaii in collaboration with County
Board of Supervisors County of Hawaii, 1941. Publication No.9 December 1940
Master Plan of the City of Hilo, County of Hawaii, Hawaii. Honolulu: Advertiser.
U.S. Department of the Interior and U.S. Geological Survey, Compiled by
Atwater, B. F., Cisternas V., M., Duldley, W. C., Hendley, J. W. II, and Stauffer,
P. H., 1999. Surviving a Tsunami–Lessons from Chile, Hawaii, and Japan, U.S.
Geological Survey Circular 1187. United States Government Printing Office.
Yamashita, F., 1982. Sorrowful History of Sanriku Great Tsunamis (Aishi Sanriku
O-Tsunami), Seijisha (in Japanese).
Yamashita, F., 1984. Record of Photograph of Modern Tsunami History in Japan(Shashin Kiroku -Kindai Nihon Tsunami-shi), Seijisha (in Japanese).
Yamashita, F., 1985. Disaster Management Lecture -Knowledge of Tsunami(Bousai Kouza -Tsunami no Kokoroe-), Seijisha (in Japanese).
Yamashita, F., 1995. The 100th Anniversary of the Meiji Sanriku Tsunami -The
Great Meiji Sanriku Tsunami with Pictures- (Meiji Sanriku Hyaku shunen Kinen Shasin to E de Miru Meiji Sanriku O-Tsunami-) (in Japanese).
Yoshimura, A., 2004. The Great Tsunamis in Sanriku Coastal Areas (Sanriku
Kaigan O-Tsunami), Bungei Shunju (in Japanese).

Comparison of urban recovery planning and designing for tsunami hazard between
Sanriku Coastal Areas, Japan, and Hilo, Hawaii

0ctober 2010, Kobe, Japan

APPENDIX

Tsunami Inundation Limits in Hilo (Dudley and Lee, 1998) and Population
Distribution as of December 1940 (Board of Supervisors County of Hawaii, 1941)©2010Google

Present Situation in Hilo

New Technologies for Urban Safety of Mega Cities in Asia

A Study on Flood Disaster Mitigation by
Local Government Regulation
and Guidance in Japan
1

Yuto SHIOZAKI1, Takaaki KATO2 and Hitoshi NAKAMURA2
Department of Urban Engineering, The University of Tokyo, Japanyuto@city.t.u-tokyo.ac.jp
2
International Center for Urban Safety Engineering,
Institute of Industrial Science, The University of Tokyo, Japan

ABSTRACTIn Japan, in preparation for large-scale flood, municipalities are legallyobligated to make and publish “Flood Hazard Map” for evacuation from flood. In
the short term, the improvement of evacuation is important. At the same time, it isneeded to reduce the vulnerability of city to flood from a long-term perspective
because it is estimated that climate change will increase the occurrence frequencyof flood in the future. Though flood risk control should be considered in theprocess of urban planning, the concept of flood control has been lacked inJapanese urban planning system. However, some municipalities implement urban
planning regulation and guidance for flood disaster mitigation.
Through the Internet and literature search, ten cases were picked up. The
authors had interviews to the administrative officers of ten cases and qualitatively
evaluated the effect and problem of each case. In this study, it is found thatmunicipalities are negative to introduce regulation for flood disaster mitigation
because they hesitate to impose a burden to citizens, and it is difficult to establish
the standard for regulation. The effect of guidance and subsidy is limited to thepart of citizens. The role-sharing among river administrators, municipalities andcitizens is needed to improve flood risk management in urban planning.
Keywords: flood disaster mitigation, urban planning, flood hazard map,climate change adaption measures

1. INTRODUCTION
In Japan, flood countermeasures have been mainly held by building water
works like dams and levees to completely prevent floods since the River Law wasestablished in 1896. However, recent some floods in urban area like the Fukuoka
Flood Disaster in 1999, Tokai Flood Disaster in 2000 were wake-up call to remindthat the countermeasures were needed in preparation for flood disaster. The Flood
Prevention Law revised in 2003 and 2005 obligates municipalities to make andpublish flood hazard map on rivers which would damage the municipality in case0ctober 2010, Kobe, Japanof flood. Flood hazard map shows the estimated flooded area, the estimated flood
depth and the location of refuges in case of a specific large-scale flood.
In the short term, it is important to improve evacuation planning by flood
hazard map. At the same time, it is also needed to reduce the vulnerability of city
to flood from a long term perspective because climate change will increase theoccurrence frequency of large-scale flood in the future. Though flood risk control
is should be considered in urban planning process, the concept of flood risk
control has been lacked in Japanese urban planning system. However, somemunicipalities implement urban planning regulation and guidance for flood
disaster mitigation.
The purposes of this study are as follows: 1) to investigate the actual
situations of municipal regulation and guidance for flood disaster mitigation, 2) toqualitatively evaluate the effect and problem of each case and 3) to discuss thecondition for developing flood risk control in urban planning.
2. CASE STUDY
Through the Internet and literature review, the ten cases of municipal
urban planning regulation and guidance for flood disaster mitigation weresearched. Interviews were conducted on the municipal officers in charge of ten
cases. The cases are classified into four types depending on implementation
systems (Table 1).
Table 1: Investigated cases in this study
Implementation type
Regulation
Guidance
Regulation and guidanceSubsidy

Municipal regulation and guidance
Nagoya City Building Ordinance
Setagaya City Building Guideline
Suginami City Building Guideline
Shinjuku City Building Guideline
Kusatsu City Building OrdinanceNakano City Subsidy to High-floored Building
Suginami City Subsidy to High-floored Building
Shinagawa City Subsidy to Flood Protection Shield
Suginami City Subsidy to Flood Protection Shield
Komaki City Subsidy to Flood Protection Wall

2.1. The case of flood disaster mitigation by municipal regulation
2.1.1. The outline of the building ordinance in Nagoya CityIn 1959, the storm surge of Isewan typhoon broke down coast and riverlevees causing ruinous damages to Nagoya city. The dead and disappeared were
1,851, the afflicted people were 530,000, and the damaged houses were 118,000
in the city. Learning from the Isewan typhoon disaster, Nagoya City established abuilding ordinance in 1961 to introduce flood disaster mitigation in preparation
for the case that coast and river levees were breached by storm surge or river

New Technologies for Urban Safety of Mega Cities in Asia

flood. This building ordinance is based on a provision of Building Code,“designation of disaster risk zones”, which legally enables a municipality todesignate disaster-prone areas as disaster risk zones and to establish building
restrictions on the area. Nagoya City Building Ordinance is the only case in Japanthat flood disaster mitigation is implemented in a vast urban area by thedesignation of disaster risk zones.
Table 2: The restrictions of Nagoya City Building OrdinanceDistrict
1st
2nd- Harbor area
- Outside of tidal
barrier- Urbanized area
- In danger ofdeep flooding

3rd- Urbanized area

4th

- Urbanizationrestricted area

Ground floor
HeightStructure

N.P. +4.0m

Wooden construction isbanned.

N.P. +1.0m

A room must be
established on second
floor and above.

N.P. +1.0m
N.P. +1.0m

A room must be
established on second
floor and above.
(Source: Nagoya City)

Figure 1: Four districts of Nagaya City Building Ordinance (Source: Nagoya City)

A Study on Flood Disaster Mitigation by Local Government Regulation and Guidance inJapan0ctober 2010, Kobe, JapanThe area in application of Nagoya City Building Ordinance extends
6,000ha. The area is classified into four districts depending on the estimated flood
damage and the land use situation. The regulations on ground-floor level andbuilding structure are established on each district (Table 2, Figure 1). The aim of
this regulation is to secure safety refuges for saving human lives in case of largescale flood including storm surge.
The 1st district is in danger of being swept away by storm surge because
this district is located outside tidal barriers. Hence, in the 1st district, the groundfloor level of building must be higher than N.P.1 +4m, and wooden structure isbasically banned to build.
In the 2nd, 3rd and 4th districts which are located inside tidal barriers, theground-level of building must be higher than N.P. +1m. The 2nd district isestimated to be deeply flooded by storm surge. In the 4th district, since it isurbanization-restricted area, buildings are so scattered and safety refuges are few.
Hence, safety evacuation spaces are needed to be secured in individual buildings.
For these reasons, making a room on second-flood and above is obligated in the
2nd and 4th district. In the 3rd district, restriction on building structure is not
imposed because this district is located inland, and it is estimated to be not deeply
flooded comparing with other districts.
Additionally, in the 2nd, 3rd and 4th district, the building ordinance puts
further restrictions on public buildings like schools, hospitals, community centersand government offices which are refuges in case of flood disaster. The
restrictions are as follows: 1) the ground-floor level must be higher than N.P. +2m,2) one or more rooms must be established higher than N.P. +3.5m and 3) wooden
structure is banned to build.
The observance of restrictions is verified in the process of building
certification base on Building Act. Correction order is given to the building when
the restrictions are violated. The punishment based on Building Act is applied incase that the correction order is also neglected.
2.1.2. Effect and problem
The effects of Nagoya city building ordinance are as follows: 1) the safetylevel in the area has been improved up to now in preparation for the breach offlood barriers and dikes by storm surge, and 2) the building ordinance leads to theenlightenment for promoting further flood disaster mitigation than the restrictions.
On the other hand, it can be said that the ordinance has already fulfilled aroll appropriate to the needs of the times after Isewan typhoon. The ground floor
height of building is settled in the ordinance, but it is not strict comparing withground level. Additionally, the most of recent buildings are higher than two-story.
Another ordinance appropriate to current situation is needed for developing
further flood disaster mitigation.
Another problem of the building ordinance is that some flood disastermitigation measures are not suitable for barrier-free building. For example, raisingground-floor makes the length of wheelchair ramps longer.

New Technologies for Urban Safety of Mega Cities in Asia

2.2. The cases of flood disaster mitigation by municipal guidance
2.2.1. The outline of municipal guidance cases
The number of flood damage to basement room by local heavy rain has
increased for these years. For this reason, Setagaya, Suginami and Shinjuku Cityin Tokyo established each building guideline for flood damage mitigation. These
guidelines aim to inform building owners on flood risk and flood damage
mitigation measures.
These cities employ the notification procedure as the following. In theprocess of building certification, the owner who will construct a building shownin table 2 is supposed to turn in a document for showing the type and the extent of
measure which is employed for flood damage mitigation. In Suginami City andShinjuku City, the notification procedure is applied to the area which would be
flooded according to the flood hazard map of each city.
Table 2: The target of notification procedure

Setagaya Building
Guideline(2005~)

Suginami Building
Guideline(2005~)

Shinjuku Building
Guideline(2009~)The target of notification procedure
New-built or rebuilt building- which has a floor under the surrounding ground or road,- or in which discharge water might flow back because of
the surroundings
New-built or rebuilt building- which is located in the flood-hazard area shown on theflood hazard map,
- and which has possibilities of flood due to locating
lower than the surrounding ground or road
(Source: Setagaya, Suginami and Shinjuku City)

These cities advise the owners to mound up the entrance to basement, put
in a mobile flood protection shield or a drainage pump and so on. However, theextent of flood mitigation measure is left to the owner’s choice in all of theseguidelines.
The owners are not legally obligated to employ a flood mitigation measure
because these guidelines are not based on any law. These cities are making efforts
so that flood mitigation measures are devised on the target buildings throughguidance.
2.2.2. Effect and problem
The targets of the building guidelines are limited to the part of buildings,
but they have functions to inform flood risk and promote flood mitigation
measures in the process of urban planning. If an owner does not employ theappropriate flood mitigation measure following the guideline, it is important that

A Study on Flood Disaster Mitigation by Local Government Regulation and Guidance inJapan0ctober 2010, Kobe, Japan

this system gives the owner the information on flood risk and an opportunity tomake a decision whether the owner employs flood mitigation measure.
2.3 The case of the combination of regulation and guidance
2.3.1. The case of building ordinance in Kusatsu City
Kusatsu City is located in Shiga Prefecture, and facing Biwa Lake whichis the largest lake in Japan. Some ceiling rivers are running through the city. Thiscity had suffered from floods of Biwa Lake and ceiling rivers. After river
improvement work was recently completed, large-scale flood has never occurredin Kusatsu City. However, in 2006, Kusatsu City established a building ordinancefor promoting flood disaster mitigation in reaction to the publication of the flood
danger area maps of Biwa Lake and some rivers in 2002 or later. This ordinancedoesn’t have legal obligation because it is not based on any law.
In this building ordinance, the estimated flooded area and the estimatedflood depth are shown on one map which is made by overlapping the flood danger
area maps of Biwa Lake and some rivers. The depth in the map is the deepest
water level in the flood danger area maps (Figure 2).

Figure 2: The areas in danger of being flooded (Source: Kusatsu City)
Disaster-prevention facilities and refuges are designated “specificbuilding” in the building ordinance. When a specific building is built, it isobligated to employ flood mitigation measure considering the estimated flood
depth shown on the map. The specific buildings are mainly public buildings like

New Technologies for Urban Safety of Mega Cities in Asia

government office, school and hospital. Hence, the regulation on specificbuildings is implemented as self-imposed regulation of public sector.
Notification procedure is employed in regard with ordinary buildings.
The owner who will build a building with a basement or an emergency elevator is
supposed to turn in a document for showing a flood mitigation measure employedin the process of building certification. However, the owner is not obligated to
employ flood mitigation measure in the same way as Setagaya, Suginami andShinjuku City.
2.3.2. Effect and problem
Kusatsu City is preparing for large-scale flood by introducing flood
mitigation measure into disaster-prevention facilities and refuges considering theflood depth shown on the flood danger maps. It leads to securing the function ofdisaster-prevention facilities and refuges in case of flood. In regards to ordinary
buildings, though the target is limited, it is important that the guidance based on
the ordinance gives the owner the information on flood risk and an opportunity tomake a decision whether the owner employs flood mitigation measure in the same
way as Setagaya, Suginami and Shinjuku City.
2.4. The cases of flood disaster mitigation by municipal subsidy
2.4.1 The cases of subsidy to high-floored building
In 1970’s, floods of rivers running through urban area occurred frequently
in the west part of Tokyo because river improvement work did not catch up withthe speed of urbanization. For this reason, Nakano and Suginami City started thesubsidy device to build a house which of the ground-floor is elevated above
ground level. Afterward, the subsidy device was abolished once because thenumber of subsidies decreased. However, in September 2005, heavy rain caused
flood damage to both of the cities. Nakano and Suginami City restarted thesubsidy each in 2005 and 2008.
Nakano City gives the subsidy to the owner who will construct orreconstruct a building in the areas which have flooded since 1981 and which isstill danger of being flooded because of the delay of river improvement work.
Additionally, Nakano City eased the height regulation of building on the subsidy
object area. Nakano City will downscale the subsidy object area following the
progress of the river improvement work.
Table 3: The standard price of subsidy to high-floored building
Construction method, structure type
Standard price (yen/m2)
Elevation of existing building
78,000Wooden construction
55,000New construction Steel construction
42,000Reinforced concrete structure
29,000(Source: Nakano and Suginami City)
A Study on Flood Disaster Mitigation by Local Government Regulation and Guidance inJapan0ctober 2010, Kobe, Japan

Suginami City gives the subsidy to the areas which would be flooded
higher than 0.5m in Suginami City Hazard Map in addition to the areas whichhave flooded so far. Suginami City will continue the subsidy regardless of the
progress of the river improvement work.
In both of Nakano and Suginami City, the given subsidy is half the amount
multiplying the high-floored space (m2) by the standard price (yen/m2) shown intable 3. However, the limit is 2,000,000 yen in both of them.
Nakano City had given 101 cases by May 2009, but Suginami City had
never given subsidy at the time of December 2009. Comparing the number ofsubsidy with the occurrences of flood damage in Nakano City, it is found that the
number of subsidy increases soon after flood damage, but afterward gradually
decreases.
2.4.2. The cases of subsidy to flood protection shield
Shinagawa City, in Tokyo, started the subsidy to mobile flood protection
shields in 1989 because floods of rivers running through the city frequently
caused damages in 1980’s. Shinagawa City gives the subsidy to the building
owner and user who will establish the shields on house, store and office. Thissubsidy aims to cover the delay of the flood control measures in the city.
According to the officer of Shinagawa City, it will be abolished at the time whenflood control measures are improved and flood damages are solved.
Suginami City started the subsidy to mobile flood protection shields in2008 in addition to the subsidy to high-floored houses. Suginami City gives thesubsidy to the building owner and user who will establish the shields. Suginami
City will also continue the subsidy regardless of the river improvement work.
Table 4: The subsidy to flood protection shield

Shinagawa City
Suginami City

Subsidy content
To person: 3/4 of the expense for flood protection shield
To company: 1/2 of the expense for flood protection shield
However, the limit is 1,000,000 yen.
1/2 of the expense for flood protection shield
However, the limit is 500,000 yen per one building.
(Source: Shinagawa and Suginami City)

By May 2009, Shinagawa City had given 119 cases, and Suginami City
had given 3 cases. Comparing the number of subsidy with the occurrences offlood damage in Shinagawa City, it is found that the number of subsidy increases
soon after flood damage, but afterward gradually decreases in the same way of thesubsidy to high-floored houses in Nakano City.
2.4.3. The case of subsidy to flood protection wall
Komaki City, in Aichi Prefecture, have offered subsidy to flood protection
wall since 2006. It is impossible to completely prevent flood damage by river or

New Technologies for Urban Safety of Mega Cities in Asia

sewage improvement in regard with the buildings which are located lower than
the surrounding roads or water channels. The subsidy aims to mitigate flood
damage on those buildings.
2.4.4. Effect and problem
The effects of subsidies for flood disaster mitigation are as follows: 1)
citizen’s self-motivated flood damage mitigations are promoted, and 2) the flood
damages on small spots which are lower than the surrounding roads or water
channels can be individually managed.
Generally, the number of subsidy gets increased soon after flood damages,
but the flood damage mitigation by subsidy is not developed after a certain periodof time. It is pointed out that the people who employ flood mitigation measure
getting subsidy are almost those who got damaged by flood.
Additionally, the flood damage mitigation by subsidy is apt to be
conducted as municipal measure which covers the delay of river improvement
work. For developing flood mitigation measures from long-term viewpoint,municipalities have to reconsider the role of the subsidy for flood damage
mitigation and put forward flood risk information with the subsidy.
3. DISCUSSION
From the results of case studies, the condition for developing flood risk
control in urban planning will be discussed below.
Flood disaster mitigation employing the designation of disaster risk zones
like Nagoya City Building Ordinance raises a safety level of whole the designatedarea because the targets of regulation include all buildings. Additionally, it iseffective from a viewpoint of implementation because the ordinance is based on
Building Code. However, except Nagoya City, no municipality introduces thedesignate of disaster risk zones into vast urban area. As a result of interviews to
the municipal officers, the municipalities are negative to introduce the regulation
flood disaster mitigation because of the following reasons: 1) they hesitate toimpose a burden to citizens, and 2) it is difficult to establish the standard forregulation.
The reason why Nagoya City could introduce the designation of disasterrisk zones is considered that Isewan typhoon convinced both the government andthe citizens the necessity of flood disaster mitigation. At the same time, it is foundthat the standard of flood disaster mitigation was determined from the result of
Isewan typhoon disaster.
Currently, flood hazard map is published, but citizens are not familiar withthe maps because flood risk itself is not enough shared in society. In this current
situation, like Kusatsu, Setagaya, Suginami and Shinjuku City, informing floodrisk in the urban planning process is effective. In those cities, however, the target
is limited to the part of buildings. Flood risk information should be informed tomore persons concerned like building owners, users, constructors and designers.
For example, the system that the flood risk and mitigation measure on building
must be informed to customer is conceivable. Like Kusatsu City, flood mitigation

A Study on Flood Disaster Mitigation by Local Government Regulation and Guidance inJapan0ctober 2010, Kobe, Japanmeasures on disaster-prevention facilities and refuges should be also implemented
by regulation.
Up to now, in Japan, the responsibility for countermeasure to large-scale
flood beyond flood control facility has never been discussed. For developing floodrisk management in urban planning, flood risk should be shared in society, and therole-sharing among river administrators, municipalities and citizens needs to be
discussed and clarified.
NOTES
1. N.P. ±0m is the water level of Nagoya Port at the time of low tide.
REFERENCES
Katada, T., Kimura, S., and Kodama, M., 2007. Desirable utilization of flood
hazard maps for risk communication. Doboku Gakkai Ronbunshu D, Vol.63, No.4,
p.p.498-589 (Japanese)
Panel on Infrastructure Development, 2008. Climate change adaptation strategies
to cope with water-related disasters due to global warming, Ministry of Land,
Infrastructure, Transport and Tourism
Building Research Institute, Ministry of Construction, 1960. The investigation ofurban area and building damage in Nagaya City by Isewan Typhoon and thedisaster prevention plan, Nagoya City (Japanese)

New Technologies for Urban Safety of Mega Cities in Asia

Study on Town Development Rules
Considering Disaster Reduction and
Neighborhood Characteristics in DenselyBuilt Areas, Process of Town Planning in
Shonai Area, Toyonaka City
Akihiko HOKUGO1, Keisuke HIMOTO2, Tamiyo KONDO3, Takeyoshi TANAKA4
and Yasuo AKIMOTO5
1
Professor, Research Center for Urban Safety & Security, Kobe University, Japan
hokugo@kobe-u.ac.jp
2
Research associate, Pioneering Research Unit, Kyoto University, Japan
3
Associate professor, Graduate school of Engineering, Kobe University, Japan
4
Professor, Disaster Prevention Research Institute, Kyoto University, Japan5
Mitsubishi UFJ REsearch and Consulting Co.,Ltd., Japan

ABSTRACTIn the Hanshin Awaji Great Earthquake on 17 January 1995, fires which brokeout in and around Nagata and Hyogo wards caused severe damage. In Japan,
there still are many densely-built residential areas and the fire disaster prevention
ability in such areas should be improved as soon as possible. In this study,
therefore, a model of town development rules is examined from the perspectives ofboth "disaster reduction" and "neighborhood characteristics" through a casestudy in Shonai area, Toyonaka, Osaka prefecture. In examining disaster
reduction, authors named one of the methods to reduce disaster damage in thearea using fire blocking belts as "Roadside Method" and the other to increase thedisaster prevention performance of each building as "Individual Method", thencompared the disaster prevention performance of the current town and two virtual
towns, each using one of the two methods, by fire-spreading risk assessment. The
results indicated that structural reform can be quicker and more realistic thanwidening roads in the enhancement of the disaster reduction performance in adensely-built area. The neighborhood characteristics of a "normal densely-built
residential area" were grasped by survey on the views and wishes of the residents.
The results suggested that a townscape created by either "Roadside Method" or"Individual Method" should be accepted unless the buildings are rebuilt into ones
which are too high relative to road width. Regarding the space in front ofbuildings, many people found bicycle parking undesirable while planting wasconsidered most "desirable". When combined with planting, however, bicycle
parking became more acceptable. Following the above mentioned factors, amodel of town development rules considering disaster reduction andneighborhood characteristics is proposed.
Keywords: densely-built residential area, town planning, fire spreading risk,
disaster prevention performance, neighborhood characteristic

0ctober 2010, Kobe, Japan

1. INTRODUCTION
1. 1 Background and Purpose of the StudyIn the Hanshin Awaji Great Earthquake on 17 January 1995, fires which broke out
in and around Nagata and Hyogo wards caused severe damage. In Japan, there
still are many densely-built residential areas and the fire disaster reduction ability
in such areas should be improved as soon as possible.
After the Great Earthquake, therefore, improvement projects have been promoted
in urban areas where wooden houses are densely built. Apart from some special
areas such as preservation districts for groups of traditional buildings, such
improvement projects in "ordinary densely-built residential areas" often
exclusively focus on "disaster reduction performance" neglecting "neighborhood
characteristics".
It is important in these areas, however, to preserve"neighborhood characteristics" . The "disaster reduction performance" also,
however, cannot be understated.
In this study, therefore, the purpose is to propose a set of model town
development rules considering both disaster reduction and neighborhood
characteristics in a "ordinary densely-built residential areas".
1.2 Study Method
Through a case study in Shonai area, Toyonaka, from the perspectives of both"disaster reduction" and "neighborhood characteristics", a set of model town
development rules in a densely-built residential area was examined in order tofind a way for it to include both goals.
Possible methods of securing disaster reduction in a densely-built residential area
were examined and applied to virtual towns, then fire spreading risk was assessedby the physical fire spreading predicting model for urban fires, developed by
Himoto(2007) and Akimoto(2008).
The elements of the neighborhood characteristics in a densely-built residential
area were examined. The method of securing disaster reduction were taken inconsideration, to determine "Shonai-like, favorable elements from a survey onwhat the residents think and wish.

2. FIRE SPREADING RISK ASSESSMENT
2.1 Outline of the Subject Area
In Shonai area in Toyonaka, Osaka, the case study area of this research, there still
remain constructions unsafe in a disaster as a result of rapid urbanization with theurban infrastructure such as roads and parks left inadequate in the period of rapid

New Technologies for Urban Safety of Mega Cities in Asiaeconomic growth in the 1960s. There are also many small lots of about 50m2,
which makes it difficult for the houses to be rebuilt.
On the other hand, it is an area where town development has been proceeded sincethe 1970s with the participation of residents. Three residential environmental
improvement projects have been implemented and currently the resident-led town
development is in progress in S area with the Town Development Committee as
the center, utilizing the Project for Actors for Plan Making in Town Development
promoted by the Ministry of Land, Infrastructure, Transport and Tourism.
2.2 Methods to Secure Disaster Reduction in Densely-Built Areas
In the current regional plan in the S area in Shonai, Toyonaka city, the case study
area, the enhancement of the disaster reduction ability of a zone along the
highways and main community roads with fire blocking belts is considered toenhance the disaster reduction ability in the entire area.

Figure 1: Regional plan in Shonai area, Toyonaka city (draft)
However, whilst fire blocking belts enhance the disaster reduction ability in thearea as a whole, the risk of fire spreading in high-risk densely-built residential
areas may not decrease sufficiently.
In this study, therefore, authors named the method to reduce disaster damage in
the area using fire blocking belts as "Roadside Method" and another method toincrease the disaster prevention performance of each building as "Individual
Method", then compared the disaster prevention performances of virtual towns,
each using one of the two methods, by fire-spreading risk assessment.
2.3 Town Conditions
Eight virtual towns of Shonai area, the subject of the case study, were createdbased on above-mentioned "Roadside Method" and "Individual Method" as well
as over time. Along with the condition of the actual town, fire-spreading risk isassessed for a total of nine town conditions.
Study on Town Development Rules Considering Disaster Reduction and Neighborho
od Characteristics in Densely-Built Areas.

0ctober 2010, Kobe, Japan

Table 1: Conditions for Fire-Spreading Risk Assessment
CategoryA

Details
Current Town

B1
B2
B3
B4
C1
C2
C3
C4

Roadside method (with 40% of buildings in the area improved)
Roadside method (with 60% of buildings in the area improved)
Roadside method (with 80% of buildings in the area improved)
Roadside method (with 100% of buildings in the area improved)
Individual method (with 40% of buildings in the area improved)
Individual method (with 60% of buildings in the area improved)
Individual method (with 80% of buildings in the area improved)
Individual method (with 100% of buildings in the area improved)

Conditions
Current
condition
VirtualVirtualVirtualVirtualVirtualVirtualVirtualVirtualFirst of all the risk was assessed for A, with the current conditions. Then for B, ina virtual town where the Roadside Method, which has now been planned in
Shonai, the risk was assessed. Lastly the virtual cases where the Individual
Method is applied were examined, then the effectiveness of the Roadside Method
and the Individual Method were studied by comparison with the current
conditions.
Regarding B and C, the effectiveness of each one were compared by assessing thecases from B1 to B4 and from C1 to C4 with the improvement of 40%, 60%, 80%
or 100% respectively according to the rules, taking the time passage into theconsideration.
2.4 Definition of Fire-Spreading Risk
In this study, the concept of fire risk has been introduced and essential fire safety
capacity existing in an urban area was assessed as a fire-spreading risk in the firespreading simulation. In general, fire risk R is defined as a product of loss
possibility P and loss L, or the expected loss, as below.
NR   Pi Li 

(1)

i 1

In this study, in order to assess the fire-spreading risk by individual buildings, theloss possibility P is defined as the possibility that an individual building would be
involved in a spreading fire, and loss L as whether or not each building is
destroyed in each run. Also, taking the scale of an urban fire into consideration,
the number of buildings destroyed in the 12-hour period after the outbreak of thefire is counted. The simulation was run 500 times.
2.5 Conditions for Calculation
The area of the S area, the subject in this case study, is approximately 8.7 ha.
Uncertain factors for risk assessment are the conditions of fire breakout andweather. The conditions at the time of the start of the fire, such as the locationand time of the fire breakout, were randomly chosen. For the weather conditions,the outside temperature and wind direction and speed were considered. Expanded
New Technologies for Urban Safety of Mega Cities in Asia

AMeDAS Weather Data was used for creating the input conditions whichmatched the randomly chosen time of a fire breakout.
2.6 Building Conditions
n the fire spreading simulation in this study, four categories were set for thebuilding structures, namely wooden structure, fire-proof wooden structure, semifire-proof structure and fire-proof structure. The fire spreading characteristics foreach structure are shown below.
Table 2: Fire Spreading Characteristics by Structure
UnitTime to burn throughmin( openings)
Time to burn throughmin( walls)

WoodenFire-proof
woodenSemi-fireproof

Fire-proof

10

10

20

20

20

30

45

No burning
through

2.7 Calculations, Result and Analysis
2.7.1 Comparison between A and B4
The comparison between A, the area of the current situation and B4, the virtual
town with the Roadside Method with 100% of buildings improved is shown in
Figure 2. The widening of main community roads and the area alongside theroads as a fire blocking belt are apparently effective. The northeast bloc, inparticular, benefits from the fire blocking belt.

(A) Current situation(B4) Roadside method, 100%

Figure 2: Comparison between A and B4

2.7.2 Comparison between A and C4
The comparison between A, the area of the current situation and C4, the virtual
town with the Individual Method with 100% of buildings improved is shown in
Figure 3. The fire spreading risk greatly decreased from the current situation, but
Study on Town Development Rules Considering Disaster Reduction and Neighborho
od Characteristics in Densely-Built Areas.

0ctober 2010, Kobe, Japan

there are some differences according the blocks. This is probably because someplaces have more factors to stop fires such as open spaces than other blocks.

(A) Current situation(C4) Individual Method, 100%

Figure 3: Comparison between A and C4

2.7.3 Comparison between B4 and C4
The comparison between B4, the virtual town with the Roadside Method with
100% of buildings improved, and C4, the virtual town with the Individual Methodwith 100% of buildings improved is shown in Figure 4. Fire spreading risk ishigher with Roadside Method as a whole, which is thought to be because theinfluence of fire spreading within the residential area is bigger than the effect of
stopping fires within a block by the fire blocking belt.

(B4) Roadside Method, 100%

(C4) Individual Method, 100%

Figure 4: Comparison between B4 and C4

2.7.4 Comparison between B and C over TimeComparison between B, virtual towns with Roadside Method and C, virtual townwith Individual Method is shown in Figure 5.

New Technologies for Urban Safety of Mega Cities in Asia

(B1)Roadside method, 40%(C1)Individual Method, 40%(B2) Roadside Method, 60%(C2)Individual Method, 60%(B3) Roadside Method, 80%(C3) Individual Method, 80%(B4) Roadside method, 100%

(C4) Individual Method, 100%

Figure 5: Comparison between B and C over Time

Study on Town Development Rules Considering Disaster Reduction and Neighborho
od Characteristics in Densely-Built Areas.

0ctober 2010, Kobe, Japan

In either case of Roadside Method or Individual Method, when 100%
improvement takes place, certain effects can be seen though different in features.
It is, however, many decades away that all the buildings will actually be improved
and, from a practical point of view, more immediate measures are required. The
comparisons over time indicate that Individual Method starts working at an earlier
stage, whilst Roadside Method makes a difference only when the fire blocking
belt is completed to a certain level.
These results suggest that structural reform can be quicker and more realistic thanwidening roads in the enhancement of disaster reduction performance in adensely-built area.

3. SURVEY ON THE VIEWS AND WISHES OF THE RESIDENTS
3.1 Purpose of the Survey
As mentioned in 1.1, it is important to consider both disaster reduction andneighborhood characteristics in an "ordinary densely-built residential area" in theprocess of town development.
So, a hypothesis was formulated about the components of the neighborhood
characteristics, based on which a questionnaire was made to survey the views andwishes of the residents. This was done in order to find out what elements theresidents in Shonai area find as "Shonai-like" and "favorable", then to formulate"Shonai-like, favorable elements".
3.2 Survey Method
The survey was conducted in S area, Shonai, Toyonaka-city, the subject area of
this case study, on the local residents who participated in "Our Town's Rules
Workshop" , by asking them to respond to a 30-item questionnaire during theworkshop.
Dates: 1 November (10 am and 1 pm), 3 November: total of three times
Subjects: 38 residents who participated in "Our Town's Rules Workshop"(including members of the Town Development Committee)
3.3 Contents of Survey
As the elements of the neighborhood characteristics in a densely-built residential
areas, a hypothesis was formulated with two categories of "townscape" and "spacein front of building" as follows.
A. Townscapes

New Technologies for Urban Safety of Mega Cities in Asia

In order to grasp the characteristics of the neighborhood with the two methods ofRoadside Method and Individual Method applied, the elements for "townscape"such as " building height (number of stories)" and "road width" were set as below.
A1: Two-story, frontal road with 4m width (+0.5m setback)A2: Three-story, frontal road with 4m width (+0.5m setback)
A3: Four-story, frontal road with 10m width (+0.5m setback)
A1

A2

A3

Figure 6: Items of Townscape
B. Frontal Space
For the space in front of a building, items were set as below regarding "walls""planting" and "bicycle parking", to understand how residents feel and what
influences these have on the townscape.
B1: Walls
B2: Planting
B3: Bicycle parking
B4: Planting and bicycle parking
Neighborhood characteristics is represented by a model of combinations of A andB above. One of A or B is fixed to facilitate comparison between combinations
such as those between A1B1 and A1B2 or A1B1 and A1B3, etc. Respondents
answered 30 questions regarding "Shonai like" and "favorable".
Thequestionnaire is laid out as Figure 7.

Figure 7: Questionnaire on Neighborhood Characteristics

Study on Town Development Rules Considering Disaster Reduction and Neighborho
od Characteristics in Densely-Built Areas.

0ctober 2010, Kobe, Japan

3.4 Result of Survey
The results of the questionnaire are shown in Table 3 and 4.
Table 3. Result of A, townscape

A1: Two-story, frontal road with 4m width
A2: Three-story, frontal road with 4m width
A3: Four-story, frontal road with 10m width

Shonailikeness
239
130
44

Favorability
128
81
185

The results indicated that A1 with two-story buildings and the 4m wide frontal
roads is most Shonai-like, while A3 with four-story buildings and 10m wide
frontal roads is most attractive.
Table 4: Results of B, frontal space

B1: Walls
B2: Planting
B3: Bicycle parking
B4: Planting and bicycle parking

Shonai Likeliness
78
130
172
164

Favorability
97
212
103
137

The results suggested that B3, bicycle parking, is the most Shonai-like, while B2,planting, is the most attractive.
3.5 Analysis
The questionnaire results show that people find low-rise buildings more Shonailike from the townscape viewpoint, and where the roads are of the same width, thelow-rise townscape is preferred. On the other hand, if the roads are sufficiently
widened, high-rise buildings are more likely to be accepted. There remain somedoubt, however, whether it is equally acceptable to replace buildings with highrises in the zones along the north-south road with a width of 10m and along theeast-west road with a width of 6.7m, since people did not highly regard high-risetownscape with narrow roads in A2.
Regarding the space in front of buildings, people found bicycle parking Shonailike, but not desirable. The most desirable factor is planting. Combined withplanting, however, bicycle parking became more acceptable.

4. CONCLUSION
In this study, a set of model town development rules is examined from theperspectives of both "disaster reduction" and "neighborhood characteristics". The
New Technologies for Urban Safety of Mega Cities in Asia

results obtained through the case study indicated what the rules should be liketaking disaster reduction and neighborhood characteristics into consideration.
The result of the fire-spreading assessments suggested Individual Method can bebetter than Roadside Method from the disaster reduction point of view because
Individual Method worked at an earlier stage. With the following two factors
based on the examination of the neighborhood characteristics, however, it cannot
be definitely said that one is better than the other.
1) Roadside Method to widen the main community roads can be appropriate
because wider roads are required.
2) Individual Method can be appropriate because people find low-rise townscape
Shonai-like and this method does not change the townscape much from thecurrent situation.
Therefore, it is probably desirable for the town development rules to consist ofRoadside Method and Individual Method. In other words, while widening themain community roads is one of the goals, basically disaster reduction
performance should be secured by reforming all the buildings into semi-fireproof
or fireproof structures. Also verticalization is acceptable along a road with asufficient width, but allowing high-rises to be built along a narrow road byrelaxation of district regulations is not desirable.
There is another point that when roads widened and buildings verticalized along
the roads the townscape may lose all the Shonai-like features. In order to avoid
that as much as possible and to create a "Shonai-like, favorable town", it can beeffective to include the usage of the frontal spaces in the town development rules
to be proceeded with planting.
REFERENCESHIMOTO K., TANAKA T., 2007. Development of a Physics-based Urban Fire
Spread Model, Journal of Environmental Engineering, No.607 (2007), pp.15-22
AKIMOTO Y. 2008. Study on Fire Safety of Densely-built residential areas
Based on Fire Risk Assessment, Master Thesis, Kobe University.

Study on Town Development Rules Considering Disaster Reduction and Neighborho
od Characteristics in Densely-Built Areas.

Understanding Chromium (VI) Transport
Through Concrete
1

Neha CHITNIS1, Purnendu BOSE2, Sudhir MISRA3
Former Graduate Student, Department of Civil Engineering
Indian Institute of Technology Kanpur
2
Professor
Department of Civil Engineering
Indian Institute of Technology Kanpur
3
Professor
Department of Civil Engineering
Indian Institute of Technology Kanpur
sud@iitk.ac.in

ABSTRACT
Hexavalent chromium [Cr(VI)], a highly toxic carcinogen, rarely occurs
naturally but is released as part of waste from chromate ore processing facilities
and some other chemical industries. Given its properties, concrete is an excellent
candidate for barricading and storing wastes containing hexavalent chromium.
However for effective long term performance of such barriers, it should be bornein mind that concrete is a porous material and allows ingress and migration ofwater and various dissolved ions. It is understood that the rate and extent of suchingress and migration depends on the nature of the pore structure of the concrete
matrix, i.e., size, distribution, interconnectivity, shape, and tortuosity of the pores.
Previous research has indicated that (i) concrete can sequester Cr(VI) ions, whichthen become a part of the matrix and this hexavalent chromium does not leacheasily, (ii) incorporation of hexavalent chromium in concrete does not adversely
affect it’s strength and durability.
This study was carried out to contribute to a rational design for concrete barriers
for hexavalent chromium. Concretes having a water-cement ratio between 0.4 and0.7 were used to study Cr(VI) migration including advective transport throughmicro-cracks, concentration-gradient driven diffusive transport, and uptake andsequestration.
It was found that though concrete with a low w/c and higher cement content
showed an ability to sequester more Cr(VI), the actual uptake of hexavalentchromium, was found to depend on both – the intrinsic sequestration capacity andthe ease of ingress of ions. Easy ingress of Cr(VI) into concrete with a high watercement ratio, resulted in an enhanced initial Cr(VI) uptake. However, due to thelimited intrinsic ability of this type of concrete to sequester Cr(VI), the uptake rate
slowed over time, and eventually, some Cr(VI) breakthrough was also observed.
Keywords: Hexavalent chromium, concrete, permeability, sequestering, porosity,
cementOctober 2010, Kobe, Japan

1. INTRODUCTION
Though hexavalent chromium [Cr(VI)] rarely occurs naturally, it is released aspart of waste from chromate ore processing facilities and certain chemicalindustries. It is important that efforts are made to ensure that this highly toxic
carcinogen [Syracuse Research Corporation, 1993] does not pollute theenvironment, especially the ground water. Given its properties, concrete is an
excellent candidate for barricading and storing wastes containing hexavalentchromium. However for effective long term performance of such barriers, it
should be borne in mind that concrete is a porous material and allows ingress andmigration of water and various dissolved ions. It is understood that the rate andextent of such ingress and migration depends on the nature of the pore structure of
the concrete matrix, i.e., size, distribution, interconnectivity, shape, and tortuosityof the pores, which in turn depend on the properties and proportioning of
constituent materials. Though previous research has indicated that (i) concrete cansequester Cr(VI) ions, which then become a part of the matrix and this hexavalentchromium does not leach easily, (ii) incorporation of hexavalent chromium inconcrete does not adversely affect its strength and durability. This study was
undertaken to contribute to a rational design for concrete barriers for hexavalentchromium by studying properties such as uptake of hexavalent chromium and its
diffusion through concrete.
2. EXPERIMENTAL DETAILS
2.1 Overall plan
The overall experimental programme is summarized in Table 1.
Table 1 Overall experimental programme

SeriesObjectiveA
Study uptakeof hexavalentchromium by
concretepowderB
Study uptakeof hexavalentchromium by
concrete discs
C
Study diffusionof hexavalentchromiumthroughconcrete discs

MethodDetermining the (a) (increase in)chromium content in concrete
powder, and, (b) recording
reduction in chromium levels inthe solution.
Using (b) outlined for Series A,
and estimating the uptake ofchromium by the concrete disc.
Setting up diffusion cells using
concrete discs exposed to solution
on one side and pure water on theother – allowing diffusion under aconcentration gradient. Changes in
the chromium concentration in thesolution on both sides of theconcrete disc was monitored.

Remarks
Samples (powder
or discs) wereobtainedfromcylinders having a
w/c ratio between
0.4 and 0.7, after
the concrete had
been cured for atleast 5 weeks tominimize effects
ofcontinued
hydration.
Samples were thenbrought in contact
withsolutionscontaining Cr(VI)

New Technologies for Urban Safety of Mega Cities in Asia

2.2 Materials usedRiver sand was used as fine aggregate along with 12.5 mm coarse aggregate andOPC [43 grade as per IS 8112, 1989]. Laboratory tap water was used for mixing
and curing. Table 2 gives details of the proportions of constituents used for thedifferent concretes.
Table 2

Mix

w/c

C40
C50
C60
C70

40
50
60
70

Mix proportions for different concretes (kg/m3)

Water

Cement

190

475
380
317
271

Aggregates
Fine
Coarse
486
1249
549
1281
606
1287
659
1279

2.3 Experimental procedure
Preparation of discs and powder: Hardened concrete was removed from moulds
after 24 hours and stored under water for 5 weeks, and then 20 mm thick discs
were cut using a diamond cutter, discarding the top and bottom 50 mm of thecylinder. These discs were stored under water for until use in experiments. In
Series A, the disks were crushed using a pulverizer. Powders were sieved and thefraction passing through 600 μm and retained in 300 μm sieves was stored
separately in plastic containers at room temperature until use in further
experiments. In Series B, before immersion in solutions of hexavalent chromium,concrete disks were dried at 50°C for several days to completely remove the freewater. In the case of Series C, water saturated discs were used without drying.
Preparation of chromium calibration curve: Solutions containing various predetermined amounts of chromium were prepared. The corresponding absorbancevalues were determined at 540 nm after addition of 1, 5 di-phenyl di-carbazide
using a spectrophotometer. Calibration curves were prepared for two ranges ofchromium mass – 1 to 5 μg and 5 to 20 μg, using cuvettes of 4 cm and 1cm path
length, respectively, for the two ranges.
Uptake by concrete powder: 2g of powder was accurately weighed and placed in
40ml glass vials and 25 mL aliquots of 5 mg/L Cr(VI) solution was added to eachvial, which was sealed and placed on the orbital shaker for mixing. Vials were
removed sequentially from the shaker after 2, 4, 6, 8, 10, 15, 20 and 25 hours ofcontact times with the chromium solution. The samples were then filtered and theresidue (concrete powder) with adsorbed Cr(VI) was dried in an oven for 24 hours
at 50oC, and preserved for further analysis. The filtrate was also analyzed forresidual Cr(VI).
Uptake by concrete disks: The disks were dried and placed in plastic containers
containing 800 mL of 5 mg/L Cr(VI) solution, taking care that there is noevaporation. The concentration of Cr(VI) in the solution was monitored with timeto estimate the uptake by the concrete disks.
Diffusion cell: A specially designed cell as shown in Figure 1 consisting of two
compartments – one containing 20 mg/L Cr(VI) solution and the other containing
pure water, separated by a concrete disk, was used for the purpose. The discs used
Using concrete for chromium barriersOctober 2010, Kobe, Japanin this series were initially saturated
with water to ensure that only ionic
diffusion occurred and any effect ofwater movement per se was minimized.
Holes in both compartments served as
sample ports. Every 15 days, a sample
of 2 ml was drawn from compartment
A and 2 ml of pure water containing
no Cr(VI) added before resealing thesampling port. This ensured that the
Figure 1 Diffusion cell usedvolume of liquid in the compartment
remained the same throughout the experiment. Similarly, 50 ml samples weredrawn from compartment B at regular intervals and an equal volume of pure water
added as replacement.
3. RESULTS AND DISCUSSION
3.1 Hexavalent chromium uptake in powdered concrete
Results for the uptake of hexavalent chromium as a function of the contact time(varied between 2 and 25 hours) as described above are shown in Figure 2. It isapparent that in all cases the uptake increases with the contact time and decreases
with the increase in the w/c ratio of the concrete. The uptake is essentiallycomplete after 10 and 25 hours for concretes C70 and C60, respectively, while in
the other two cases, the uptake continues to increase even after 25 hours of contact.
3.2 Hexavalent chromium uptake in concrete discs
The results on the basis of uptake by dry concrete disks immersed in Cr(VI)solutions estimated from the reduction in the chromium concentration in thesolution, are plotted in Figure 3. Comparison of chromium uptakes by powder andthe disc suggests (i) rate of Cr(VI) uptake by concrete disks was much slower thanthat by concrete powder, (ii) Cr(VI) uptake by C70 and C60 concrete over 30 days,
was found to be about 5 to 7 g Cr(VI) adsorbed per gram concrete, compared toa lower value of about 1 to 2 g in the case of concretes C50 and C40.
3.3 Hexavalent chromium migration in diffusion cell
In all cases, a drop from the initial Cr(VI) concentration in compartment A(initially 20 mg/L) was observed, though the extent and rate of this drop was
found to be related to the w/c of the concrete of disc. The actual uptake by thediscs of concrete C40, C50 and C70, as estimated by mass balance of chromium
within the system, is shown in Figure 4. It can be seen that though the initial
uptake of C70 is higher, the final uptake of C40 and C50 is much higher.
Converting this total uptake to a rate of uptake, it was also found that the flux of
Cr(VI) into concrete was 1.24 g/cm2/d for the disks of concrete C70, and, 1.92
and 2.05 g/cm2/d, respectively, in disks of concretes C50 and C40. Howeverthough flux was lower for 0.7 w/c ratio disks, it was found that Cr(VI) found its
way to compartment B (breakthrough) in only about 90 days [Chitnis, 2009].
New Technologies for Urban Safety of Mega Cities in Asia

40

10
Cr (VI) Uptake, g/g Concrete

Cr(VI) Adsorbed g/g Concrete

w/c Ratio
0.40
0.50
30
0.60
0.70
20

10

0

0

5

10

15

20

25

Time, hours
FigureCr(VI) Uptake, g/g Concrete30

2Uptake of chromium by
concrete powder (Series A)

20
15
10
5
0

0

20

40

60

80

100 120 140 160

Time, days

Figure 4

4
2
0

0

5

10

15

20

25

30

Time, days
Figure 3 Uptake of chromium by
concrete disks (Series B)

3.4 Discussion of results

w/c Ratio
0.40
0.50
0.70

25

30

w/c Ratio
0.40
8
0.50
0.60
0.70
6

Uptake of chromium by
disks in diffusion cells

As far as the uptake of chromium by
the concrete powder is concerned, it
can be summarized that since thespecific surface areas of the concrete
powders used were nearly the same(all powders having been drawn frombetween 300μm and 600μm, andhaving a specific surface area in the
narrow range of 2.28 to 3.03 m2/g),
the difference in uptake can be
attributed to only the difference in the
cement contents of the different
concretes, which in this case isdirectly related to the water-cement
ratio (the water content being
constant in all mixes) [Palmer, 2000].

In Series B it may be noted that the discs immersed in the chromium solution were
initially dry and thus, some initial uptake would be through the water movement
into dry concrete and also concentration driven diffusion into the pore solution of
concrete at later stages. Further, continued sequestration and adsorption into theUsing concrete for chromium barriers

35

October 2010, Kobe, Japanhydration products of concrete (similar to uptake in the powder) will also
contribute to generating the difference in concentration gradient. Thus the results
obtained are the overall result of the two processes. Now, whereas a lower watercement ratio reduces the porosity of the matrix and uptake due to the former
process, it tends to increase the uptake on account of the latter (because of thehigher cement content).
In the case of experiments using the diffusion cells in Series C, the uptake process
is similar to that in Series B, except that (a) concrete is saturated to begin with andtherefore it may be assumed that the uptake through direct movement of water isminimal, and, (b) the uptake takes place only from one face of the disc. Now, thelower final flux in case of disks of concrete C70 may be explained considering thelower intrinsic Cr(VI) adsorption capacity of this type of concrete due to its lower
cement content. The breakthrough in this concrete (C70) and also for C60 [Chintis,
2009] can be attributed to the higher porosity of this concrete. Results for discs
with other w/c also show that uptake is more for concrete powders with lower w/c
ratios (higher cement contents) [Chitnis, 2009].
4. CONCLUDING REMARKS
From the experiments carried out using concrete powders and dry and wet
concrete discs made from of different water-cements, it was found that concretes
with a higher w/c ratio, due to their higher porosity, allow faster diffusion of
Cr(VI) into concrete mass, which facilitates higher Cr(VI) uptake. However, these
concretes with limited cement contents have only a limited capacity to sequester
any chromium ions that penetrate into the concrete. Thus, these ions continue tomove through the pore structure and could breakthrough the concrete thickness.
However in the case of concretes with a lower w/c, the porosity being lower, theinitial uptake is low, and with the higher sequestration capacity because of ahigher cement content, the possibility of breakthrough is also reduced. In otherwords, in the case of low w/c ratio concrete, which has the intrinsic ability tosequester more Cr(VI), the net uptake of Cr(VI) by such a concrete mass is often
limited by low rate of Cr(VI) diffusion into the concrete mass.
REFERENCES
Chintis, NS, 2009, Understanding Cr(VI) transport through concrete, M. Tech
Thesis submitted to Indian Institute of Technology Kanpur
Palmer, CD, 2000, Precipitates in a Cr(VI) contaminated concrete, Environmental
Science and Technology, 34, 4185-4192
Syracuse Research Corporation, 1993, Toxicological profile for chromium, Reportfor the US Department of Health and Human Services, Public Health Service,
Agency for toxic substances and disease registry, Contract no 20588-0608

New Technologies for Urban Safety of Mega Cities in Asia

Trapdoor tests for the evaluation ofearth pressure acting on a buried structure
in an embankment
Reiko KUWANO1 and Hiroaki EBIZUKA2
1
Associate Prof., ICUS, Institute of Industrial Science,
The University of Tokyo, Japankuwano@iis.u-tokyo.ac.jp
2
Obayashi Corporation,
Former graduate student of the University of Tokyo, Japan
ABSTRACT
Earth pressures acting on underground structures are highly dependent on theinteraction between ground and structure. Increase in the vertical earth pressures
acting on a buried structure in high embankment should be, therefore, considered,depending on the size and depth of structure and type of foundation, sincedifferential settlements are often expected in such conditions. However, inpractice, the increment of vertical earth pressures on underground structures is
estimated in the empirical manner, mainly based on the information of past earthpressure measurements in the limited number of sites. In such estimation, thedegree of settlement and/or mechanical properties of backfill materials are notalways taken into account. A trap door test apparatus is newly developed in thisresearch, in order to evaluate distribution of earth pressures acting on a buried
structure. Detailed measurements were conducted and earth pressure change wasestimated by relatively simple calculation.
Keywords: buried structure, earth pressure, trapdoor test

1. INTRODUCTION
Vertical earth pressures on a buried structure in an embankment is likely to be
increased if the surrounding backfill soil settles, due to the downward shear forces
acting on a soil block above the buried structure, as schematically shown in Figure
1. In practice, the increment of vertical earth pressure is estimated, following“General guidelines for road earthworks (1999)”, in which the coefficient α, theratio of initial and increased earth pressure, are proposed as shown in Table 1. The
values of α had been determined in the empirical manner, mainly based on theearth pressure measurement records obtained from construction sites in 1980s.
They seem to be reasonable estimation, since no serious problem has beenrecognised so far on the buried structures within standard type embankment
construction. However, the detailed mechanism of earth pressure change is notwell understood and it may be an obstacle for the rational and economical designof buried structure.

0ctober 2010, Kobe, Japan

Ebizuka and Kuwano (2009) developed a trapdoor apparatus in order to evaluate
the effects of differential settlements on earth pressure distribution on a buried
structure. Base of a soil chamber consists of five separated parts, any combinationof those can move downward, in order to simulate the uneven settlement. In thispaper, overall results of the trapdoor tests are described.

hH0B0settlement
shear
forcesFigure 1: Earth pressure increment due to differential settlement of embankment
Table 1: Guideline of earth pressure incrementh/B 0
Coefficient of earth pressure increment, αh/B 0 <11.0
1≤h/B 0 <2
1.2
2≤h/B 0 <3
1.35
3≤h/B 0 <4
1.5
4≤h/B 01.6
h: depth of soil cover, B 0 : width of a culvert
2. APPARATUS AND TEST PROCEDURE
2.1 Trapdoor apparatus
Overall structure of the trapdoor apparatus is shown in Figure 2. It consists of asoil chamber, movable base blocks, sensors and a supporting frame.
A soil chamber can accommodate model ground of 700mm wide, 294mm longand 555mm high. The base of the chamber consists of five separated movable
blocks whose size is 99.8mm wide, 293.6mm long and 105mm high, and fixedparts in both sides, in order to create uneven settlement in the model ground, as

New Technologies for Urban Safety of Mega Cities in Asia

schematically shown in Figure 3. Descent or ascent of the lower shaft controlled
by a motor is transmitted to the upper shaft only when the upper clamp istightened, so that any combination of base blocks can be chosen to move or stay.
Each base block is equipped with five two-way load cells to measure the load
distribution on the base. A load cell is attached with a plate of 19.8×199.6mm. Its
loading capacity is 0.3kN for both normal and shear forces.

Upper shaft

Lower shaft

Figure 2: structure of the trapdoor apparatus

1 2 3 4 55 movable parts

Figure 3: Reproducing an uneven settlement in the model ground
2.2 Model ground and test procedure
A model ground was prepared by the multiple sieving method, using dry Toyoura
sand, uniform clean sand. The depth of soil cover, h, was varied to be 1B (B:width of a trapdoor), 2B, 3B, 4B and 4.5B. The relative density of the ground was
95% (ρ d =1.58g/cm3) and 40% (ρ d =1.44g/cm3). Therefore, 10 cases of model
ground were tested in total. In all cases, four trapdoors in both sides (base block 1,

Trapdoor test for the evaluation of earth pressure acting on a buried structure in an
embankment

0ctober 2010, Kobe, Japan

2, 4 and 5 in Figure 3) were descended at a rate of 0.012mm/min up to
displacement δ=10mm, while the central trapdoor (base block 3) was unmoved.
3. REDISTRIBUTION OF STRESS IN THE GROUND
The earth pressure distribution on the base in test case H= 4B, Dr= 95% ispresented in Figure 4. At the initial state (δ=0mm), normal as well as shear stress
distribution was almost uniform within 1 to 5 trapdoors, although there seem to be
scatter to some extent. The average of measured normal stresses was equivalent to
the overburden pressure calculated from the depth of soil cover. Redistribution ofstresses occurred as soon as descent of trapdoor started. Normal stress acting on
central base block (3) significantly increased while normal stress on descendingbase blocks (1, 2, 4, 5) decreased. At δ=1.5mm, the average normal stress of baseblock (3) became maximum and it was stabilized at around δ= 8mm. The
distribution of normal stresses on the base 3 was concave shape. The stress at thesides was higher than that at the center, but the difference became smaller at thelarger displacement. Shear stress distribution indicated that the there was somelateral symmetric displacement of the soil in the ground.

δ=1.5 (peak)

15

Center (3) average

10

Normal stress (kPa)

20

5Moving base (1,2,4,5) average
2

4

6

8

Displacement,δ (mm）10

δ=1.5 (peak)h : 400mm
Dr : 95%

δ=10
10

δ=0
5

4

0
0

15

0
-350

Initial state

Shear stress (kPa)

Normal stress (kPa)

20

3
2

-250

-150

-50

50

h : 400mm
Dr : 95%

150

250

350

250

350

δ=10
δ=1.5 (peak)

1
0

δ=0

-1
-2
-3
-4
-350

-250

-150

-50

50

150

Distance from center (mm)Figure 4: change of stresses on the base (h=4B, Dr=95%)
Deformation of the ground at δ=10mm is shown in Figure 5. Coloured sand wasplaced at the interval of 50mm to assist the observation of the ground deformation.
Shear planes developed from the edges between unmoved and moving baseblocks at an angle of 19˚ at early stage of test. In later stage, other shear planedeveloped at around 10˚. Those shear planes further developed until they formed
arching above the moving base blocks.

New Technologies for Urban Safety of Mega Cities in Asia

In Figure 6, normal stress distributions for test cases of various h, ranging from
100 mm to 450 mm, are presented. It is clearly shown that the normal stress on thecentral base block was larger at larger h for both at peak and δ=10mm.

ψ＝19°

ψ＝10°

Figure 5: Deformation of mode ground (h=4B, Dr=95%)

Normal stress (kPa)20h=400mm（δ=1.5mm）

Peak state

15h=300mm（δ=0.9mm）

105Initial state（δ=0mm）h=200mm（δ=1.4mm）

h=450mm
h=400mmh=300mmh=200mmh=100mm

0-350
20Normal stress (kPa)h=450mm（δ=0.7mm）

Dr : 95%

-250

-150

h=100mm（δ=0.7mm）

-50

50

250

350

250

350

土槽中央からの距離 (mm)Dr : 95%
δ＝10mm15150

h=450mm
h=400mm105h=300mm

Initial state（δ=0mm）h=200mmh=450mm
h=400mmh=300mmh=200mmh=100mm

0
-350

-250

-150

h=100mm

-50

50

150

Distance from center (mm)Figure 5: Relationship between h and normal stresses (h=4B, Dr=95%)
Earth pressure distribution for the cases of loose model ground (Dr= 40%) ispresented in Figures 6 and 7. Overall trend is similar to the case of dense ground,

Trapdoor test for the evaluation of earth pressure acting on a buried structure in an
embankment

0ctober 2010, Kobe, Japan

except that the stress redistribution developed gradually and there was no distinct
peak state.

Normal stress (kPa)20
15

δ=6.4 (peak)

10

Center (3) average
Initial state

5
0

2

4

6

8

Shear stress (kPa)δ=6.4 (peak)
δ=10

10

δ=0
5

4

10

Displacement,δ (mm）

3
2

-250

-150

-50

50

150

250

350

250

350

δ=10
δ=6.4 (peak)h : 400mm
Dr : 40%

1
0

δ=0

-1
-2
-3
-4
-350

-250

-150

-50

50

150

Distance from center (mm)Figure 6: Change of stresses on the base (h=4B, Dr=40%)
20

Normal stress (kPa)0ｈ : 400mm
Dr : 40%

15

0
-350

Moving base (1,2,4,5) average

Dr : 40%
Peak state

15h=450mm（δ=2.5mm）
h=400mm（δ=6.4mm）

105Initial state（δ=0mm）h=300mm（δ=2.7mm）

h=450mmh=200mm（δ=5.8mm）

h=300mmh=200mmh=100mm

0-350
20Normal stress (kPa)

Normal stress (kPa)20h=400mm

-250

-150

h=100mm（δ=0.9mm）

-50

50

150

250

350

土槽中央からの距離 (mm)Dr : 40%
δ＝10mm15h=450mm
h=400mm

10

Initial state（δ=0mm）h=450mm5h=300mmh=200mmh=100mm

0-350

h=400mmh=300mmh=200mmh=100mm-250 -150
-50
50
150
250
350
from
center(mm)
New DistanceTechnologies
for Urban
Safetyof Mega Cities in Asia

Figure 7: Relationship between h and normal stresses (h=4B, Dr=40%)
4. ESTIMATION OF EARTH PRESSURE INCREMENT
Earth pressure increment due to differential settlement can be estimated, assumingthat the soil above the buried structure was pulled down by shear forces acting on
the lateral surface of the soil block as shown in Figure 8a, applying Terzaghi’stheory. In that calculation, it is not easy to appropriately determine the earthpressure coefficient, K (Kikumoto et al. 2005, Kuwano et al. 2007).
On the other hand, in this study, based on the pattern of ground deformation
observed in trapdoor tests, overburden soil area for central and moving baseblocks was assumed as shown in Figure 8b. It was found that when arching area
was developed after the formation of shear plane, stress redistribution seemed to
be stabilized. Stone & Muir Wood (1992) reported that the angle of shear planedeveloped in trapdoor tests agreed to the dilatacy angle of the soil. Therefore, it
was considered that the moving base blocks carried only the soil within the
ground arching. It was formed by shear planes initiated from both edges ofmoving base blocks. Physical and mechanical parameters used for the calculation
is presented in Table 2.

Friction between
土塊境界部に作用すsoil blocks
る摩擦力（摩擦角φ）
Friction angle: φB0a) following Terzaghi’s theoryb) based on the observation of grounddeformation in trapdoor tests
Figure 8: Assumption of overburden soil area

Table 2: Physical and mechanical parameters for the model ground
Loose state
Dense state

Dry density, ρ d1.44 g/cm3
1.58 g/cm3

Relative density, Dr
40 %
95 %

Dilatancy angle, ψ
10˚
19˚

Values of earth pressure increment coefficient, α, were calculated by thesimplified manner described above and compared with the measured values in
trapdoor tests in Figure 9. The proposed simple calculation can give reasonableestimation of α for both loose and dense model ground. The difference of α at
Trapdoor test for the evaluation of earth pressure acting on a buried structure in an
embankment

0ctober 2010, Kobe, Japan

Coefficient of earth pressure increment, αpeak and residual state for dense ground can be explained when the angle of shear
planes for each state is taken into account. It is implied that if the displacement
reaches much larger and the dilatancy angle of soil becomes zero, it may approachto the assumption of Terzaghi’s theory.

3

Experiment
Dｒ=95%、peak

2.5

Dｒ=95%、δ=10mm

Calculation ：ψ=19°

Dｒ=40%、peak
Dｒ=40%、δ=10mm2

Calculation ：ψ=10°

1.5

Gideline for road earthworks

1
0

1

2

3

4

5

6

h/B0

Figure 9: Comparison of coefficient α
5. CONCLUSIONSIn order to evaluate the increase in vertical earth pressures acting on a buried
structure due to the differential settlements, a series of trap door tests was
conducted. The following conclusions have been obtained;• An increase in vertical earth pressures on a structure is affected by a depth of aburied structure, mechanical and physical properties of soil.
• Increments of vertical pressures obtained in series of experiment can beroughly simulated by the simple calculation, where the area of soil archingdeveloped above the descending base blocks is taken into account.
REFERENCES
General guidelines for road earthworks - culvert work -, 1999. Japan road association,
ISBN 978-4889504101, Maruzen Print Co. Ltd. (in Japanese).
Ebizuka,H. and Kuwano,R., 2009, Trap Door Tests for Evaluation of Stress Distribution
around a Buried Structure, Proc. 8th International symposium on new technologies forurban safety of mega cities in Asia, USMCA, Inchon, October 2009, 245-250.
Kikumoto, M., Kishida, K., Kimura, M. and Tamura, T., 2005. Formula for calculating
the distributions of vertical earth pressures around a tunnel, the 40th domestic conferenceof geotechnical engineering, Proceedings of the 40th annual conference, Japanese
Geotechnical Society, Hakodate, July 2005, Paper No. 918. (in Japanese).

New Technologies for Urban Safety of Mega Cities in Asia

Kuwano, R., Horii, T. and Kohashi, H., 2007, Increment of Earth Pressure Acting on a
Buried Box Structure due to Differential Settlements, New Frontiers in Chinese andJapanese Geotechniques, Proceedings of the Third Sino-Japan Geotechnical Symposium,
2007, 309-314.
Stone, K.J.L. & Muir Wood, D.,1992, Effects of Dilatancy and Particle Size Observed inModel Test on Sand, Soils and Foundations, Vol.32, No.4, 43-57.

Trapdoor test for the evaluation of earth pressure acting on a buried structure in an
embankment

Evaluation method of cover concrete
air permeability considering water content
Shota MIZUKAMI1, Kenji HAYAKAWA2,
Yoshitaka KATO3, Futoshi KATSUKI4
1
Graduate School of Engineering, Shibaura Institute of Technology, Japan
m509091@sic.shibaura-it.ac.jp
2
Engineering Researcher, Tokyu Construction Company Ltd., Japan
3
Assoc. professor, ICUS, Institute of Industrial Science,
The University of Tokyo, Japan
4
Professor, Shibaura Institute of Technology, Japan
ABSTRACT
Current verification of structural concrete quality is checked by printed records,
compressive strength test at acceptance inspection, and so forth. However, in real
structures quality of cover concrete should also consider durability. Consequently,
a non-destructive inspection method such as on-site air permeability test
(TORRENT) has been suggested as a durability evaluation method in recent years,
but there is a possibility that this method cannot consider the influence of watercontent. This research aims to propose a quality control method that can evaluate
the cover concrete quality of real structures. Specimens simulating structuralmembers were cast and experimental results were compared to study the influenceof different aspects such as dimensions and curing conditions on the nondestructive test results and, from this analysis, a method considering the influenceof water content on quality evaluation was proposed. Future research isnecessary to obtain more data for durability evaluation and to improvement theevaluation method.
Keywords: water content, air permeability, non-destructive testing, durability,
cover concrete

1. INTRODUCTION
1.1 Background and Aims
Durability of structural concrete is highly influenced by the thickness and qualityof cover concrete which protects steel bars from corrosion factors such as water,O 2 , CO 2 , chloride ion, and so on. However, although compressive strength testwith test pieces cured in water is used as the acceptance inspection and Schmidt
hammer is used as inspection for estimation strength of actual construction, theseare just used as substitute indices to evaluate durability. This means that it isnecessary to establish a complete inspection method which can evaluate thedurability of cover concrete directly.

October 2010, Kobe, Japan

In recent years, inspection utilizing air permeability test (Torrent method) has
been performed but it was found that water content has an influence on air
permeability. Therefore, it is necessary to consider water content in this method,
so this research aims to propose a complete inspection method using test pieces
and examines this method experimentally.
1.2 Conceptual method
To develop this method considering water content it is necessary to understand theinfluence of water content on quality of concrete cover by using non-destructive
inspection. A conceptual diagram of the inspection method suggested in this study
is shown in Figure 1. First, the coefficient of air permeability of standard cured
test pieces (KT-D) is measured at time of mix design. KT-D is compared with test
pieces gathered from the actual ready mix concrete which met acceptanceinspection and were cured in standard water conditions (KT-R1) in order toconfirm the quality of the ready mixed concrete. At the same time, test pieces are
cured and exposed in the same conditions as the actual structure (KT-R2). KT-R2
is compared with the coefficient of air permeability of actual structure (KT-S) to
confirm the difference between test pieces and actual structure considering theinfluence of the water content. Therefore, the influence of measuring point andconstruction (“α”) and the effect of dimensions on drying speed (“β”) were
examined experimentally.
Measuring
Test number

Flow of Inspection
DesignEvaluation

KT – D : Checked durability

Receiving Inspection

KT – R1 : Water cured
KT – R2 : Actual cured

Completion Inspection

KT – S

Determination

Difference between designed value
OK or NOT
and ready mixed concrete
Difference between test pieces
and actual structure

OK or NOT

Problem point

Ready mixed concrete

Construction

In - Service
Evaluation formula : KT - R2 > α * β * KT - S=

Coefficient
α : Construction changing (measuring point and construction)
β : The difference of dimensions between test pieces and structure

These item was examined in this study experimentally

Figure 1: Conceptual diagram
2. EXPERIMENTAL OUTLINE
2.1 Sample specifications
Specimens for simulating structural members (column and wall) and test pieces
for comparative examination were cast with concrete mix proportions given in
Table 1 and dimensional data and method of casting shown in Figure 2. The
surface of structural member specimens were sealed without using aluminum tape

New Technologies for Urban Safety of Mega Cities in Asia

to stop movement of water except through two faces. This was done to simulate
the sections of larger members. Test pieces for understanding the influence ofthickness and the number of drying faces were also sealed with aluminum tape.
The length of one side of the test pieces was set to double the actual length ”L”.
Table 1: Concrete mix proportions
W/C
(%)
52.7

s/a
(%)
45.8

W
175

Amount of unit (kg/m3)
C
S
G
333
806
974

AE
2.97

Slump
(cm)
13.5

Air
(%)
6.0

ex) The size of the general railroad viaduct

900

Aluminum tape

900

350
400

Water loss

600

450

450mm

150mm

ColumnWall
Two side opening
L
Assumed thickness of member
= “L”

150

One side opening
L

Test piece

150mm

2L
= “2L”

Aluminum tapeFigure 2: Dimensional data
Experimental factors are shown in Table 2. Assumed thickness of members wereprepared for standards from 100 mm to 900 mm by changing length and thenumber of open faces. The period of sealed curing was 5 days. After sealed curing,
specimens were cured under constant temperature and humidity (20℃, R.H.60%).

Evaluation method of cover concrete air permeability considering water content

October 2010, Kobe, Japan

Table 2: Sample conditions
Sampletype

Thickness(mm)

Numberof open faced

Assumedthicknessof member

C (Column)

450

1

900

W (Wall)

150

2

150

P-100

50

1

100

P-150

150

1

300

P-300

150

2

150

P-530

530

2

530

P-900

450

1

900

2.2 Measurement method
The main measurement item is air permeability and water content. The Torrent
method is a means for measuring air permeability which can be used in the field(Torrent, 1992). This method uses a two chamber cell, with an inner and outerchamber, based on the guard-ring principle (Figure 3). The coefficient of air
permeability by Torrent method (KT) is computed by following the numericalformula given in Equation 1. As a result of the investigations undertaken with thisdevice, a classification of the quality of the “covercrete” can be given as presented
in Figure 4, based on the values of KT measured on relatively young concretes,
which are relatively dry. For example, Grade A corresponds to well-cured andcompacted high strength concrete; at the other extreme, Grade E corresponds to
low strength concrete which is not subjected to any moist curing. In this research,
air permeability was transformed using base-10 logarithm (Log (KT)).
𝑉𝑐 2

𝜇𝑙𝑛(𝑃𝑎+∆𝑃𝜏⁄𝑃𝑎−∆𝑃𝜏)

𝐾𝑇 = � ��𝐴2∈𝑃𝑎√𝑡−�𝑡0

KT : Coefficient of air permeability (m2)
Vc : Volume of inner cell system (mm3)A : Cross sectional area of inner cell (mm2)µ : Viscosity of air (Ns/m2) (2.0*10-5)∈ : Estimated porosity of the cover concrete (m3/m3)
Pa : Atomospheric pressure (N/m2)
ΔP : Times (s) at the end of the test (N/m-2)
T : Times (s) at the end of the test
T0 : Times (s) at the beginning of the test (=60s)

2

�

(1)

New Technologies for Urban Safety of Mega Cities in Asia

Figure 3: Schematic of Torrent

Figure 4: Evaluation chart

Water content was measured using an electrical resistance concrete/mortar
moisture tester HI-800 (Figure 5). Compared to other methods for measuring
water content used in Japan, this method is simple and measurement of the watercontent in the depth direction is possible.

30mm

OperatingportionDrilling hole

ElectrodeFigure 5: Schematic of HI-800
3. RESULTS AND DISCUSSION
3.1 Air permeability test
The results of test pieces by assumed thickness are shown in Figure 6. The
standard deviation is also shown for the results of P-100 and P-900. The airpermeability of P-900 was lower and P-100 slightly higher compared to the otherconditions. However, the influence of thickness on air permeability in thisexperiment was small because the range of the standard variations was bigger thanthe difference of the assumed thickness. Regardless of conditions, air permeability
increased with increase of material age. It was very likely that the cause isinfluence of drying, but air permeability is affected by both water content anddevelopment of pore structure, so both factors need to be considered.

Evaluation method of cover concrete air permeability considering water content

October 2010, Kobe, Japan-15.6

Log (KT)

-15.8
-16

P-100

-16.2

P-150

-16.4

P-300

-16.6

P-530

-16.8

P-900

-17
7

28

59

Material age (day)Figure 6: Relationship between air permeability and material age
To understand the influence of height on air permeability, the relationshipbetween height of simulated structural members and Log (KT) is shown in Figure
7. The results showed that air permeability increased with increase in height. In
the upper part, air permeability increases greatly with the progress of the materials
age, but in the lower part there was little change due to age. This may mean thatdifference in quality influences drying speed. The result of the wall is constantregardless of height, which confirmed that quality was about the same.

Height (mm)

400
350

28

300

59

250
200
150
100
50
0
-17 -16.5 -16 -15.5 -15-17 -16.5 -16 -15.5 -15

Log (KT)

Figure 7: Relationship between height and air permeability
for column (left) and wall (right)
From the relationship between Log(KT) and material age some approximation
curves were calculated, where the slope of the curves was defined as the increase
speed of air permeability. These results are shown in Figure 8. The increase speedof the test piece is slightly smaller in comparison with both structural members.
This means that the quality of P-300 was better than both members because thetest piece is not influenced by construction. In addition, the influence of height issmaller for the wall than for the column. The wall has a smaller cross section thanthe column, so the influence of material segregation may have been small.

New Technologies for Urban Safety of Mega Cities in Asia

Log(KT) / day

0.025
0.02
0.015
0.01
0.005
0

Figure 8: Rate of increase of air permeability (all material age)
Next, the rates of change of air permeability over two time periods, 7 to 28 daysand 28 to 56 days, are shown in Figure 9. After 28 days, the rate of change
decreased and the difference in speed by thickness also decreased. As for thisreason, drying speed was different by quality of early age concrete. But, theinfluence of quality on drying speed was decreased with material age increased
after the 28th day, and it may become constant regardless of quality in future.
Therefore, when the drying speed of test pieces and members are same, it isnecessary to be examined whether air permeability evaluates quality expressing
true pore structure.

Log(KT) / day

0.025
0.02
0.015

7-28day

0.01

28-56day

0.005
0
P-300

C-centerW-centerFigure 9: Air permeability rate of change over time
3.2 Water content measurement results
Water content results as measured from the surface of test pieces are shown in
Figure 10. P-100 was small relative to the other test pieces, but the other test
pieces were generally similar regardless of thickness, with roughly a 3%
difference in water content ratio between the surface and at a 70 mm depth. 56
days results were roughly 1% to 2% less than 28 day results, regardless of depth
and specimen thickness.

Evaluation method of cover concrete air permeability considering water content

October 2010, Kobe, Japan

Next, the water content measurement results for test pieces and members areshown in Figure 11. The test piece results are slightly lower but at roughly thesame level as the member results, which are similar for both walls and columns.
Similar to the test piece results shown above from 28 to 56 days the water content
ratio decreased about 1% to 2% regardless of depth from surface. Therefore, it
might be said that drying influenced the increase in air permeability. However, theelectrical resistance may decrease with changing pore structure, which isdependent on the progress of the hydration reaction, so it is also necessary to
examine the influence of pore structure on water content ratio.

Water content latio (%)

8
7

P-100

6

P-150

5

P-300

4

P-530
P-900

3
2
10 20 30 40 50 60 70

10

20

30

40

50

60

70

Depth from surface (mm)Figure 10: Water content results in test pieces by thickness(left: 28 days, right: 56 days)

Water content latio (%)

8
7

P-300

6

C

5
4

W

3
2
10 20 30 40 50 60 70

10

20

30

40

50

60

70

Depth from surface (mm)Figure 11: Water content results in test pieces and members(left: 28 days, right: 56 days)
4. CONCLUSIONSThis study proposed a quality evaluation technique for on-site cover concrete
using the air permeability test. The conclusions of this study are as follows.

New Technologies for Urban Safety of Mega Cities in Asia

1) To reduce the influence of water content on the air permeability of coverconcrete, the curing and exposure method for test pieces should be the same
conditions as the actual structure.
2) Air permeability at the surface increases as the materials age. This tendency
differs depending on the type of member and height. It may be attributed tothe difference in drying speed, which in turn is caused by difference in quality.
3) The thickness has little influence on water content, which decreased over time.
Therefore, it is possible that drying influenced the increase in air permeability.
In the future, when the drying speed of test pieces and members are same, it isnecessary to be examined whether air permeability evaluates quality expressing
true pore structure.
ACKNOWLEDGEMENT
The authors would like to express their thanks to Mr. Michael W. Henry who
generously assisted.
REFERENCES
Torrent, R.J., 1992. A two-chamber vacuum cell for measuring the coefficient
permeability to air of the concrete cover on site, Material and Structures, Vol.25,
pp.358-365.

Evaluation method of cover concrete air permeability considering water content

A Research on Business Continuity
Management of Big Private Companies
in Japan—A case of the new influenza pandemic in 2009

Shohei BENIYA
Research Scientist, Disaster Reduction and Human Renovation Institution, Japanbeniyas@dri.ne.jp
ABSTRACT
A pandemic flu is one of the biggest risks for companies that are involved in
Business Continuity Plans. However, few studies explain risk management
techniques for a pandemic flu. In this study, we administered a questionnaire
survey mainly to the First Section listed companies listed in the TSE to assess thestatus of the formulation of a Business Continuity Plan (BCP) for a pandemic flu
from 2008 to 2010 and to clarify the countermeasures for the pandemic flu in
2009. As a result, we observed that a major portion of the companies made BCPs
and took advanced measures to counter a pandemic flu.
Key Words: Business Continuity Plan (BCP), Large Companies, New Influenza
Pandemic, Questionnaire Survey
1. INTRODUCTION
The sense of crisis as a result of various risks such as natural disasters andinfectious diseases has risen in enterprises, and the number of companies thathave made Business Continuity Plans (BCP) or other kinds of plans or manuals
for disaster prevention has increased in recent years. After the new H1N1
influenza pandemic in May 2009, new influenza has become one of the biggest
risks that encourage companies to make Business Continuity Plans.
Few studies explain the risk management systems in enterprises, especially as
far as an influenza epidemic or pandemic is concerned. An exception can be madein the case of Sashida (2008), who indicated the basic concepts and conditions fordamage prediction and countermeasures for the new influenza pandemic, andBeniya (2009), who clarified the current status of BCPs of companies for various
hazards including a new influenza pandemic. Despite this, it is important forcompanies to be aware of how to respond against such a pandemic.
The aim of this study was to identify the problems in, and to learn lessons froma case of the new H1N1 influenza pandemic in 2009. We also aimed to clarify thestatus of crisis management in large companies in Japan by comparing thesituations before and after the pandemic in 2009.

0ctober 2010, Kobe, Japan

2. METHOD
We conducted a questionnaire survey of the First Section listed companies in
the Tokyo Stock Exchange (TSE) in 2008 and 2010 to clarify the situations of theformulation of BCP for a pandemic influenza or natural disaster and to clarify thecountermeasures taken by the companies for the H1N1 pandemic in 2009.
Table.1 Outline of questionnaire survey for large enterprises

ObjectContent ofquestionsExecution
methodExecution
time

Five hundred and eighty-seven large companies that were listed in thefirst section of the TSE were chosen according to the ratio of industry
specification
1) Planning situation of BCP or disaster prevention plan/manual
2) Kind of assumed crisis in the plan/manual
3) Progress situation of measures against natural disasters or new
influenza4) Correspondence to the new influenza pandemic in 2009, etc.
Mailing distribution and mailing collection
1) The first investigation “the 2008 survey” in November and December
2008 (about half a year before the new influenza pandemic in 2009)
The collection rate was 26.6% (156 companies)
2) The second investigation “the 2010 survey” in March and April 2010
(about one year after the new influenza pandemic in 2009)
The collection rate was 27.9% (164 companies)

2. PLANNING STATUS FOR A NEW INFLUENZA PANDEMIC

Figure 1 shows the planning status of the BCP or disaster prevention plan in2008 and 2010. Most companies have recognized the importance of BCPs. The
ratio of enterprises with BCPs increased from 41.7% in 2008 to 54.3% in 2010.
Around 36.5% of the companies have a plan to make BCPs in addition to their
existing disaster prevention plans.
0%

10%

20%

30%

40%

50%
41.7%

Already have BCPs
Plans to make BCPs with disaster prevention plans

36.6%

Plans to make BCPs without disaster prevention plans

5.1%
2.4%

No plans to make BCPs with disaster prevention plans

3.8%
3.7%

Plans to make only disaster prevention plans

0.6%
2.4%

No plans to make either BCPs or disaster prevention
plans

2.6%
0.6%

60%
54.3%

45.5%

2008(156companies)
2010(164companies)

Fig.1 Planning status of BCPs or disaster prevention plans (Single Answer (S.A.))
Figure 2 shows the risk factors assumed in BCP. In the 2008 survey, the largest
risk assumed by the companies that had or were making BCPs was that ofearthquakes such as the “Tokyo Earthquake” (81.9%) and the “Tokai, Tou-Nankai,and Nankai Earthquakes” (70.1%). On the contrary, in the 2010 survey, the largest
risk was that of a “pandemic of an infectious disease like new influenza.” The
New Technologies for Urban Safety of Mega Cities in Asia

percentage of companies that indicated that “the largest risk is a pandemic of an
infectious disease like new influenza” was 86.9% in 2010, a 19.2 point increase
from 2008. It is believed that the number of enterprises that settled on BCP
assumed the new influenza as a risk that had been increased by the new influenza
pandemic since May 2009.

0%

10%

20% 30%

40%

50%

60%

70%

80%

90% 100%

70.1%
68.0%

The Tokai, Tou-Nankai, and Nankai Earthquakes

81.9%
76.5%

The Tokyo Earthquake
56.3%
54.2%

General Earthquakes
36.1%
39.9%
34.0%
30.7%

Storm and Floods
Industrial fire and explosion
18.1%
21.6%

Massive Blackout

30.6%
26.8%
18.8%
16.3%

Network fault and computer virus
Terror and obstructive tactics

2008 (144companies)

5.6%
7.2%
7.6%
5.9%

Trouble in manufacturing process
Scandal of a business person

2010 (153companies)

66.7%

Pandemic of infectious disease

86.9%

4.9%
2.0%

OthersFig.2 Risk factors assumed in BCP(Multi Answer (M.A.), companies that have or plan to make BCPs)
3. CONUNTERMEASURES FOR THE NEW PANDEMIC FLU IN 2009
3.1 Planning
Figure 3 shows the situation of the plans at the beginning of the pandemic in
2009. When the new H1N1 influenza pandemic occurred in May 2009, more thanhalf the enterprises had BCPs or similar plans that would enable them to deal with
the new influenza. Around 53.0% of the enterprises had plans for new influenza
with strong toxicity, such as the H5N1, while only 2.4% were prepared with aplan for a pandemic of a disease with weak toxicity, such as the H1N1.
0

10

20

30

40

50

2.4
37.2

Making plans for new influenza
5.5

No plans for new influenza
others%53.0

Plans for new influenza with strong toxicity
Plans for new influenza with weak toxicity

60

1.8

Fig. 3 Status of the plans for new influenza in May 2009
(S.A., 164 companies)
Figure 4 shows the application of the plans for the new influenza pandemic in
May 2009. Against the pandemic of the new influenza with weak toxicity in 2009,71.3% of the companies that had made plans for only those diseases with strong
toxicity applied “a part of the plan for strong toxicity influenza,” and 10.3% of
A Research on Business Continuity Management of Big Private Companies in Japan0ctober 2010, Kobe, Japanthese companies completely applied “all of the plans for strong toxicity
influenza.”
Around 71.4% of the companies that did not have plans for the new influenza
pandemic started to make these plans immediately after the pandemic of 2009,
and 21.4% of the companies applied their existing disaster prevention plans or
risk-management plans as substitutes that did not cover the new influenza
pandemic.
0%
All the plans for strong toxicity influenza

20%

1.4%

Disregard of the plan for strong toxicity influenza

1.4%

Making new plans after the pandemic

0%

Existing disaster prevention or risk management plans

0%others

60%

80%

10.3%

0%

Part of the plans for strong toxicity influenza

40%

71.3%
17.2%
71.4%
With plan only for the strong
toxicity(87 companies)
Making plan or withoutplan(70 companies)

21.4%

1.1%
4.3%

Fig. 4 Application of plans for the new influenza pandemic in May 2009 (S.A.)
3.2 Problems and Influences
Figure 5 shows the problems of the pandemic. The major problems indicated by
the companies are “insufficiency of information about the infection and toxicity”
and “difficulty in obtaining the mask or antiviral drug.”
0%10%Insufficiency of information about the infection andtoxicity

20%

30%

19.5%

40%

50%

60%

30.5%

7.3%

41.5%

Difficulty in obtaining the mask or anti viral drug
Difficulty in deciding about the cancellation of 3.0%
events, business trips, etc.
4.3%
Difficulty in applying the BCP or any other plan

36.0%

Treatment of the suspension of an infected 4.3%
employee

34.1%

34.1%

Insufficiency of existing manuals on steps against 4.3%
pandemics
Enforcement of the practice of hand washing among 4.3%

25.6%
17.1%

customers
enforcement of hand washing for the customers

2.4%

18.9%

4.9%

15.9%

2.4%

17.7%

Lack of information for public consultation services
Estimation of proper recovery of infected employee

1.2% 6.7%
Effect of harmful rumors

Big problem
Small problem

Fig. 5 Problems of the pandemic influenza in 2009
(S.A., 164 companies)
Figure 6 shows the effects of the pandemic on business.

New Technologies for Urban Safety of Mega Cities in Asia

The positive effects of the 2009 pandemic were seen in 63.4% of the companies,
which indicated an “increase in crisis consciousness among employees,” and in
62.2%, which indicated that the “pandemic is a chance to consider risk
management or BCPs.”
Negative effects of the pandemic were seen in 43.3% of the companies, whichindicated that “the working system was affected because some of the employeesor their family members had caught the disease.” Moreover, 51.8% of companies
indicated that “employees and their families were inconvenienced by thesuspension of social facilities such as schools.” This suggests that the closing of
public facilities such as schools has a significant impact on the employee morethan the direct effect of the infection on the employee or his/her family.
0

10

20

30

40

50

60

70%

Increase in crisis consciousness among employees

63.4

Chance to consider risk management or BCP

62.2

Inconvenience to employees and families withsuspension of social facilities like schools

51.8

Affected working system because of infection in
one employee or his/her family member

43.3

Impractical plan or manual for new influenza withstrong toxicity due to very strict rules

17.1

Increase in crisis consciousness among customers

17.1

Drop in sales due to conservative purchasing or
decrease in leisure activities

10.4

Increase in sales of products related to the
influenza pandemic

8.5

Others

6.1

Fig.6 Effects of the pandemic on business (M.A., 164 companies)
Figure 7 shows the effects on sales according to the industry sectors. Further,with regard to the influence on sales, there is a 10.4% decrease due toconservative purchases and 8.5% increase in products related to the influenza. The
sales of manufacturing companies tended to increase, while that of nonmanufacturing companies tended to decrease.
02

Drop in sales due to conservative purchases ordecrease in leisure activities
Increase in sales of products related to the
influenza pandemic
All (164 companies)

Manufacture(83 companies)

4

6

8

10

12

14

16
%

10.4
6.0

14.3
8.5

6.5

10.8

Non manufacture (77 companies)

Fig.7 Effects on sales due to the new influenza pandemic according to the industry
sectors (S.A.)A Research on Business Continuity Management of Big Private Companies in Japan0ctober 2010, Kobe, Japan

4. FUTURE COUNTERMEASURES FOR A NEW PANDEMIC WITH
STRONG TOXICITY
Figure 8 shows the progress of countermeasures against the pandemic of a new
influenza with strong toxicity. The ratios of “already in operation” increased
largely from 2008 to 2010 in every countermeasure for the new influenza
pandemic. Progress was seen in measures taken toward infection prevention, suchas “stockpile of mask and disinfectant spray,” “infection prevention training for
employees and their families,” and “forced stay-home program for infected
employees.”0%
Stockpile of masks and disinfectant sprays etc.

39.1%

Infection prevention training for employees and theirfamilies

36.5%

39.1%

Institutionalization to confirm infected employees in allcompanies

86.0%

19.9%

86.0%

Travel prohibition of employees to pandemic countries andregions

41.7%

84.8%

35.9%

Order to business travelers to return from pandemic areas
Stock of protective equipment like goggles, gloves, andaprons against infected employees

80.5%

19.9%

Information transmission of company situation or
countermeasures to employees

12.8%

Audio and Video conferencing systems to reduce face toface interactions

15.4%

Limitations against visitors’ entry and checking of bodytemperature

14.1%

Choice of important dealings in case of limited humanresources and facilities

10.9%

Decision about the importance level of the business ateach stage of the pandemic

8.3%

Information transmission to the society about company
policies and countermeasures

9.0%

Adoption of staggered or alternative commuting to avoid
public rush

11.5%

10.3%

Regular education and training

10.9%
5.8%
3.2%

Group alternation system for business continuity

2.6%

Support system to take care of employees at home

1.9%
6.7%

61.0%
59.8%
50.6%
48.2%
48.2%
42.1%
41.5%
39.6%

5.8%

Working in home to prevent infection

Financial treatment (financing/internal reserves)

91.5%
88.4%

Institutionalization of a task force and a chain-ofcommand structure

Collecting information about the infection and continuingbusiness with customers

92.7%

23.7%

Forced stay-home program for infected employees

Distribution of personnel according to pandemic stage

100%

10% 20% 30% 40% 50% 60% 70% 80% 90%

37.2%
29.3%
28.0%
28.0%
26.2%
24.4%

2008(156companies)
2010(164companies)

Fig. 8 Progress in countermeasures against the pandemic of new influenza withstrong toxicity (The ratios of “already in operation”)

New Technologies for Urban Safety of Mega Cities in Asia

Figure 9 shows the current problems of countermeasures against a pandemic of
new influenza with strong toxicity. The 2010 survey helped identify predictableproblems of new influenza with strong toxicity, such as “countermeasures of the
supply chain are insufficient” (51.8%), “the response plan, action plan, or BCP are
not arranged well” (43.9%), and “the prospect of vaccination of the pre-pandemic
vaccine is uncertain” (40.9%).
0%

10%

20%

30%

40%

50%

60%
51.8%

Insufficient countermeasures of the supplier chain
Response plan, action plan, or BCP are not wellarranged

43.9%

Uncertain prospect of vaccination of the pre-pandemic
vaccine40.9%

Difficulty to maintain working system due toemployees’ absence

36.0%

Insufficient education and training

34.8%
29.9%

Difficulty in obtaining antivirus drug
15.2%

Insufficient precautions for in-house infections
Insufficient in prevention plan for infection expansion

12.2%

Insufficient stock of masks, disinfectant sprays andprotective equipment

12.2%

Insufficient transmission of information and public
relations system

11.6%
1.8%

No problem in business continuity

6.7%

othersFig.9 Problems of countermeasures against a new influenza pandemic with strong
toxicity in March 2010 (M.A., 164 companies)
0%

10%

20%

If there is an infected person in the region, business would
drop or even stop.

17.1%

30%

34.0%
31.7%

Business would drop or stop after a consensus amongcustomers and stake holders.

17.9%
15.9%
30.8%

Receiving a request from a government without public support
Receiving a request from a government with public financial
supportothers

38.4%

8.3%
11.0%
3.8%

17.1%

Countermeasures would be examined in the future
No plan to examine the countermeasures

50%

21.8%

If there is an infected person in-house, business would drop oreven stop.

Business will be continued if possible, regardless of therequest from a government

40%

17.7%
1.9%
1.2%

42.9%

2008(156 companies)
9.0%

14.0%

2010(164 companies)

Fig.10 Conditions for downsizing or suspending the socially noncritical businessplace (M.A.)

A Research on Business Continuity Management of Big Private Companies in Japan0ctober 2010, Kobe, Japan

Figure 10 shows the conditions for downsizing or suspending the sociallynoncritical business place. According to the central governmental guidelines, thesocially noncritical business place would be downsized or suspended in the caseof a pandemic. In the 2008 survey, the most common answer was“countermeasures will be examined in the future” (42.9%). However, it decreased
to 17.7% in the 2010 survey, where the most common answer was “receiving arequest from the government” (38.4%). On the other hand, 17.1% of thecompanies believed that “If possible, business will continue, regardless of thegovernment’s request” in the 2010 survey.
5. CONCLUSION
5.1 Results
In this study, we administered a questionnaire survey to the TSE First Section
listed companies in 2008 and 2010 to compare the situation before and after the
pandemic of new influenza with weak toxicity in 2009. The main results are as
follows.
1) Attitudes toward the Business Continuity Management in large companies
were clarified. There were some differences between the attitudes in 2008 and2010. Given the H1N1 pandemic in 2009, the number of companies with
BCPs against new influenza increased. However, some problems remained,
such as “risk management in the supply chain,” “countermeasures for thevisitor,” “treatment of suspension from office and furlough,” and “support tothe employee who recuperates at home.”
2) The situations and problems of the companies during the weakly pathogenic
H1N1 pandemic in 2009 were clarified. The biggest problem indicated bymany companies was the lack of information on the infection and toxicity.
Employees needed to take care of their families because schools, nursery
centers, welfare facilities, and so on were closed. This gave the companies anopportunity to enhance the employee's consciousness of crisis, and to improvethe company’s crisis management.
3) The situations and problems of the measures were clarified for strong toxicity
new influenza in 2010. The problem was the lack of BCP and BCM for the
supply chains in all. Even if the influenza epidemic occurred, more companies
intended to continue their noncritical business. Compulsory requests of thegovernment for downsizing or suspension will be required to delay the
influenza pandemic.
5.2 Consideration
The new influenza virus is not an already special risk. It became a risk that was
generally assumed in the BCP of big enterprises after the new influenza pandemic
with weak toxicity occurred in 2009. In the near future, the small and mediumsized enterprises will be requested to make BCPs, irrespective of whether they are
big enterprises or government establishments.
There is a possibility that an optimized solution subject to the individual BCP
of such an enterprise and public facility will become a cause of social disorder. Ifschools, welfare institutions, or socially important businesses are suspended,
many employees would find it difficult to work. The larger the number of

New Technologies for Urban Safety of Mega Cities in Asia

enterprises that tend to continue socially noncritical businesses in the case of new
influenza pandemics, larger is the risk of infection.
The present actions taken to address the new influenza pandemic are defective.
Governments can not deal with the pandemic adequately as leaders because they
do not have sufficient authorities to control the social function. It is necessary toshare a grand design as a kind of “Social Continuity Plan” to maintain importantfunctions of the whole society and to establish laws like the Disaster
Countermeasure Basic Act that can integrate the countermeasures of varied
stakeholders.
REFERENCES
Tomohisa SASHIDA, The Pandemic Influenza : Public Sector Crisis Management
and Regional Safety, Proceedings of the Annual Conference of the Institute ofSocial Safety Science, No.23, 2008
Shohei BENIYA, Keisuke KUBOTA and Hiroaki MARUYA, A Research on theBusiness Continuity Plans of Big Private Companies for a Pandemic Flu or
Natural Disasters, Proceedings of the Annual Conference of the Institute of Social
Safety Science, No.25, 2009

A Research on Business Continuity Management of Big Private Companies in Japan

Collapse Analysis of RC Structures using
Improved Applied Element Method
Said ELKHOLY1, Mohamed GOMMA2and Adel AKL3
1
Assistant Professor, Fayoum University, Egypt
Sak00@fayoum.edu.eg
2
Ph.D. Candidate, Cairo University, Egypt
3
Professor, Cairo University, Egypt

ABSTRACTIn this paper, the Improved Applied Element Method (IAEM), which was
originally developed as an effective analysis technique of large-scale steel
structures up to complete failure under different hazard loads, has been
progressively developed to carry out modeling of the behavior of plane frame
reinforced concrete (RC) and composite structures. By adopting the fiber-beamelement model and the multi-layer-element model, which are developed for RC
and composite framed structures, the extreme nonlinear behavior of RC andcomposite structural elements can be accurately simulated. The technique is aneffective tool for the numerical evaluation of the behavior of structures under
extreme loading conditions and their collapse mechanisms. Moreover, theproposed model's high simulation capability for the cycle behavior under coupledaxial force-bending moment-shear force, the breakdown of structural elements at
ultimate states, and the contact between structural elements during the collapse
are demonstrated. Finally, the method is used to study the vulnerability of schoolbuildings in Egypt to progressive collapse by conducting a detailed dynamic
collapse analysis for an old school building. The analysis is carried out toinvestigate the cause of the collapse and the method that can be adopted toenhance the structure so that the collapse can be prevented.
Keywords: Progressive collapse, Improved Applied Element Method, Multi
Layered Element, School buildings, Retrofitting technique.
1. INTRODUCTION
Reinforced concrete is one of the most widely used modern building materials.
With the rapid growth of urban population, RC frame construction has been
widely used for residential construction in both the developing and industrializedcountries. One of the major causes of seismic vulnerability associated with RCbuildings is that, in the developing countries, a large number of the existing RC
frame buildings have been designed without engineering input and have been built
by inadequately skilled construction workers. This paper considers issues related
to earthquake induced progressive collapse of RC buildings in extreme events.
This paper concentrates on developing an efficient numerical technique based on
the IAEM. The IAEM is a newly developed method for structural analysis oflarge-scale steel framed structures (Elkholy and Meguro, 2003) It can trace the0ctober 2010, Kobe, Japan

behavior of steel structures up to the complete failure stage with high accuracy inreasonable CPU (Elkholy and Meguro, 2004). In IAEM, each structural member
is divided into a proper number of rigid elements connected by pairs of normal
and shear springs distributed on the boundary line between elements. Unlike theconventional AIM (Tagel-Din and Meguro, 2000), the element in IAEM has been
modified in order to use different thickness per each connecting spring to follow
the change of thickness of the cross-sectional width in the case of modeling nonrectangular cross-sections.
This research is concerned with the development of an efficient and accurate
numerical technique based on the IAEM to analyze the collapse of large-scale RC
and composite structures under hazardous loads, such as earthquakes andexplosions.
2. MODELING OF RC AND COMPOSITE STRUCTURES USING IAEM
In IAEM, each structural member is divided into several segments. Each segment
represents certain cross section properties. A new element type (multi-layered
element) is introduced to IAEM to simulate non-homogenous cross sections(Figure 1). This new element is composed of several layers. Each of these layers
has its own material properties. All identical layers in the nearby elements are
assumed to be connected to each other by sets of normal and shear springs
distributed on the boundary line. These sets of springs represent the microscopic
material properties of the layer. Moreover, each spring has its own thickness
according to the average thickness in the area represented by this spring and its
own shear and normal stiffness.

Figure 1: Modeling RC framed structures with the new element typeThe value of normal stiffness ( K ni ) and shear stiffness ( K si ) for each pair ofsprings in the Lth layer can be determined as:

New Technologies for Urban Safety of Mega Cities in Asia

Collapse Analysis of RC Structures using Improved Applied Element Method

E .d i .(T i )(K )L = L L n L
a
i
n

,

( )

G L .d Li . Tsi L(K )L =ais(1)where: the subscripts n and s refer to normal and shear springs, respectively; d Li isthe distance served by the ith spring in the Lth layer; a is the length of therepresentative area; EL and GL are the Young’s and shear’s modules of the Lthlayer, respectively; Tni and Tsi are the thicknesses represented by the pair ofsprings “i” for the normal and shear cases, respectively.
The corresponding condensed stiffness matrix of each element is obtained bysumming the effects of each spring pair at each layer that the element is composedof. This matrix is then transformed from the local (element) co-ordinate system tothe global (structure) co-ordinate system. Equation (2) shows the components of
the upper left quarter of the stiffness matrix. All used notations in this equation
are shown in Figure 2.

(2)

Figure 2: Contact points and DOF
2.1 Material Modeling
The Maekawa compression model for concrete is adopted in the IAEM (Figure3a). The tangent modulus is calculated according to the strain at the spring
location. In tension, the stress-strain curve for concrete is approximately linear
elastic up to the maximum tensile strength. After this point, the concrete cracks
and its strength decreases gradually down to zero. The steel I-beam and steel bars
are modeled as a classical elastic plastic material with strain hardening usingbilinear stress–strain relationship in both compression and tension (Figure 3b).
Finally, the stress strain relation of all types of FRP material is assumed linear up
to failure (Figure 3c).
Collapse Analysis of RC Structures using Improved Applied Element Method

0ctober 2010, Kobe, Japan(a) Concrete(b) Steel(c) FRP

Figure 3: Material Models used in IAEM
3. MODIFICATION IN DYNAMIC PROPERTIESThe general differential equation of motion, governing the response of thestructure in a small displacement range can be expressed as:[M ]{ΔU&&}+ [C ]{ΔU& }+ [K ]{ΔU } = Δf (t ) − [M ]{ΔU&& }(3)
G

where: [M] is mass matrix; [C] is the damping matrix; [K] is the nonlinear
stiffness matrix; Δf(t) is the incremental applied load vector; {ΔU&&} , {ΔU& } , {ΔU }and {ΔU&& } are the incremental acceleration, velocity, acceleration, and gravity
acceleration vectors, respectively.
G

Equation (3) is solved numerically using an implicit time-stepping method basedon the Newmark-Beta technique (Chopra, 2000). In this technique, thedisplacement, velocity and acceleration vectors at time t are used to obtain adisplacement vector after a time interval (Δt) based on the following equation.
⎡ 1
⎤
⎡ 1
⎤
⎡ 1
⎛ γ
⎞
γ
γ ⎤
− 1⎟⎟ΔtC ⎥U&&M+
C + K ⎥ ΔU = Δf + ⎢M + C ⎥U& + ⎢M + ⎜⎜⎢
2βΔtβ ⎦⎣ β Δt
⎝ 2β
⎠
⎣ 2β
⎦
⎣ β (Δt )⎦(4)

where the parameters β and γ define the variation of acceleration over a time-stepand determine the stability and accuracy.
Adopting the multi-layered element in the IAEM allows the user to definematerial specific weights for each layer, with which the distributed self-mass ofthe structure can then be obtained using the Materials and Sections facilities. The
individual structural mass matrix of each element is calculated assuming thatmasses lumped at the element centroid. The corresponding lumped mass in each
DOF direction is calculated by summing the effect of the small segmental massrepresented by each spring considering the change of the springs’ thickness.
Equation (5) represents the value of lumped mass in each DOF direction. In
addition, non-structural mass is added to the model to define any mass not
associated to the self-weight of the structure (e.g. slab, finishing, walls, etc).

(5)where: a and b are the element dimensions; ρ j is the density of material of the jthlayer considered; nlyr is the number of layers; nsp is the number of connecting
springs; mix and miy are the ith spring mass per unit area of the element in x and y
New Technologies for Urban Safety of Mega Cities in Asia

Collapse Analysis of RC Structures using Improved Applied Element Method

directions respectively; and t xj and t jy are the ith spring thickness at a certain levelin the jth layer in x and y directions respectively.
4 ASSESSMENT OF OLD EXISTING SCHOOL BUILDINGSThe vulnerability of schools and other educational facilities has been observed inevery recent destructive earthquake all over the world. The work in this section
aims to identify the causes of the collapse of one of the typical types of old
existing school buildings in Egypt to evaluate its seismic risk, to evaluate theefficiency of different retrofitting techniques, and to propose a national and public
policies to reduce the risk of this type of schools. In this section, the multi-layered
IAEM is applied to investigate the validity of the proposed method in simulating
progressive collapse of RC school buildings under hazardous load conditions. A
detailed analysis of the collapsing process of the selected structure with andwithout retrofitting under severe ground motion conditions is presented.
4.1 School buildings in Egypt
School buildings in Egypt are typically one to five-storey long narrow buildings
with an open corridor on the school courtyard side and classrooms on thelongitudinal side. The courtyard side of a classroom typically has large windows;
and the back wall is solid up to about 70 cm from the upper floors, where long andnarrow longitudinal windows are located to allow for ventilation and extra
lighting. School class blocks are often aligned in an L-shape or U-shape aroundthe school courtyard. The typical structure consists of a moment resistant concrete
frame in the longitudinal direction and a concrete frame with unreinforced
masonry infill walls in the transversal direction.
4.2

Structural modeling and verification

Figure 4 shows the concrete dimensions and reinforcement details of one of thetypical school buildings that were designed and constructed according to the
Egyptian specifications issued before the October 1992 earthquake. The structure
consists of a series of single bay, 3-story RC frames with a cantilever. Using themulti-layered element features, the school building was modelled using only 87
elements for the superstructure. Moreover, three retrofitting techniques for thistype are also investigated using the same number of elements (Figure 5).

columns

Figure 4: Concrete dimensions and reinforcement details

Collapse Analysis of RC Structures using Improved Applied Element Method

0ctober 2010, Kobe, JapanRC Jacketing 1st floor

CFRP warping

RC Jacketing all floors

Figure 5: The three proposed retrofitting techniques

Mode 1Mode 2Mode 3

ω = 6.422 (rad/sec)

ω = 22.207 (rad/sec)

ω = 43.608 (rad/sec)

ω = 6.25 rad/sec
2.693%

ω = 21.48 rad/sec
3.370%

ω = 40.66 rad/sec
7.264%

FEM

Multi-layered
IAEM

To evaluate the accuracy of the modelling, the frame is simulated both in IAEM
and SAP2000 (CSI, 2000). A modal analysis was performed to calculate thenatural frequencies of the structure. The first three modes are basicallycoincidentally close and a maximum difference of 7.26 % has been observed.
These three mode shapes are shown in Figure 6.

Difference

Figure 6: Comparison between the first three modes obtained by IAEM and FEM
4.3 Seismic response
After verifying the method, the inelastic dynamic collapse analysis has been
performed by introducing a displacement time history of three ground motion
records at the supports, as shown in Table 1. The acceleration time history and 5%
damping elastic response spectra curves of the selected ground motions with thebuildings fundamental periods illustrated on the curve by vertical lines are shownin Figure 7 which shows a distinctive difference among each ground motion. Each
record has been scaled up and down to different levels in order to determine thePGA value at which a certain building type can resist without collapse.
Table 1: Ground motions characteristics
Earthquake
Kobe
Northridge
Park fieldDate
16/1/1995
17/1/1994
28/6/1966

Component
KAK090
NWH090C02065

PGA (g)
0.345
0.583
0.476

PGV (cm/s)
27.6
75.5
75.1

PGD (cm)
9.6
17.57
22.49

A/V
1.247
0.772
0.634

New Technologies for Urban Safety of Mega Cities in Asia

Collapse Analysis of RC Structures using Improved Applied Element Method

Figure 7: Selected ground motions and their response spectrum
4.4

Analysis results

The main objectives of the assessment are to investigate the collapse mechanismof each model and to obtain the minimum value of the PGA of each groundmotion record used in this analysis that can produce the collapse. These minimum
values are used to evaluate the vulnerability of each model and to assess theefficiency of each retrofitting strategy. Figure 8 summarizes the results of theanalysis for the un-retrofitted and the retrofitted models. The figure demonstrated
that the un-retrofitted school building has a very poor performance in the short
direction (investigated direction). Therefore, even a small magnitude earthquake
posed a threat. It was also founded that retrofitting the columns by CFRP warpingincreased the seismic capacity by around 40%, however, using RC jacketing
increased the seismic capacity of the building by at least 80% to 150% based on
the height of the jacketing.

Figure 8: Minimum values of the PGA that produced complete collapse
Figure 9 shows the seismic collapse mechanism of the un-retrofitted school. The
figure shows that the collapse initiated at the mid of the ground floor column due
to combined actions of axial and flexural moments. The insufficient ductility ofthe members due to insufficient confinement, and low level of strength due toCollapse Analysis of RC Structures using Improved Applied Element Method

0ctober 2010, Kobe, Japan

Northridge earthquake (PGA = 0.233 g)

insufficient cross-sectional dimensions, longitudinal reinforcement ratio and low
strength of longitudinal bars were the main reasons of the failure.

(a) 10.05 (sec)(b) 10.20 (sec)(c) 10.25 (sec)(d) 10.30 (sec)(e) 10.35 (sec)(f) 10.50 (sec)(g) 10.55 (sec)(h) 10.60 (sec)Figure 9: Collapse mechanism of the building without repair
The rehabilitation using FRP

Figure 10 illustrates the enhancement in the columns capacity due to using CFRP
warping which increased the resistance capacity of the building. The FRP
composite materials do not significantly affect the initial stiffness of the concrete
members but improves the strength. Therefore the rehabilitation using FRP
warping for the columns does not significantly change the dynamic response of
the frame. FRP-strengthening significantly changes the damage location and thecollapse mechanism of the frame.
The rehabilitation using RC jacketing

The effect of using RC jacketing for columns in the first floor only is shown in
Figure 11. However, the seismic capacity of the building increased by more than
80%, Figure 11 shows one of the undesirable collapse mechanisms. Due to thesudden change of the cross-section of columns, the building had a non-ductile
soft-story collapse mechanism at the second floor level. The max story
deformation occurs at the second story and plastic hinges developed at the ends ofcolumns.
Finally the analysis shows that using the RC jacketing for all columns in all floors
improves the seismic performance of the structure (Figure 12). According to thefigure, the inelastic deformation demand and energy dissipation spread throughout
the structure. Beams commence yield before columns and a beam side-sway
mechanism occurred. Plastic hinges form at critical sections of all beams in theframe and the bottom of the first story columns.

New Technologies for Urban Safety of Mega Cities in Asia

Northridge earthquake (PGA = 0.292 g)

Collapse Analysis of RC Structures using Improved Applied Element Method(a) 9.50 (sec)(b) 9.60 (sec)(c) 9.85 (sec)(d) 9.95 (sec)(e) 10.50 (sec)(f) 10.70 (sec)(g) 11.00 (sec)(h) 11.50 (sec)Northridge earthquake (PGA = 0.758g)

Figure 10: Collapse mechanism of FRP Retrofitted building(a) 23.50 (sec)(b) 24.00 (sec)(c) 24.50 (sec)(d) 24.75 (sec)(e) 25.00 (sec)(f) 25.20 (sec)(g) 25.40 (sec)(h) 25.60 (sec)Figure 11: Collapse mechanism of the building with RC jacketing columns in the
ground floor only
5. CONCLUSIONSThe numerical method, IAEM, presented in this paper shows a good capability to
study the total behavior of RC and composite structural buildings from the earlystage of loading until the total collapse occurs. The analysis demonstrated theCollapse Analysis of RC Structures using Improved Applied Element Method

Northridge earthquake (140% PGA = 0. 0.816 g)

0ctober 2010, Kobe, Japan(a) 10.00 (sec)(b) 15.00 (sec)(c) 20.00 (sec)(d) 23.00 (sec)(a) 23.50 (sec)(b) 23.75 (sec)(c) 23.85 (sec)(d) 24.35 (sec)Figure 12: Collapse mechanism of building with RC jacketing in all floors
reliability of the new IAEM in modeling large scale RC framed structures using
the minimum number of elements. The validity of the developed code has been
demonstrated by a numerical example. Moreover, less computational effort and awider applicability for structural analysis have been observed than those of
conventional discrete element methods. The proposed method can provide a better
understanding of the failure mechanism of buildings due to severe groundmotions. Simple two-dimensional analysis tools such as that adopted in this paper
can be used to judge in a qualitative and quantitative manner the damage toleranceof buildings. Evaluation of the seismic performance of a sample of old existing
school buildings in Egypt is presented. Approaches to reduce the vulnerability ofthe building are also highlighted.
REFERENCES
Elkholy, S., H. Tagel-Din, and K. Meguro. Structural Failure Simulation due toFire by Applied Element Method. in The 5th Japan Conference on Structural
Safety and Reliability. 2003. Tokyo, Japan.
Elkholy, S. and K. Meguro. Numerical Simulation of High-rise Steel Buildings
using Improved Applied Element Method. in 13th World Conference on
Earthquake Engineering. 2004. Paper No. 930, Vancouver.
Tagel-Din, H. and K. Meguro, Applied Element Method for Simulation of
Nonlinear Materials: Theory and Application for RC Structures. StructuralEngineering and Earthquake Engineering, 2000. 17(2): p. 137-148.
Sap2000 v.12, Structural Analysis Program, Computers and Structures, Inc., CA.,
USA, 2000
Chopra, A.K., 2000. Theory and Applications to Earthquake Engineering. 2ndedition, ed. P.H. Education.: Prentice Hal

New Technologies for Urban Safety of Mega Cities in Asia

Influence of segregation with execution
for quality variation of cover concrete
Kenji HAYAKAWA1 Yoshitaka KATO2
Tokyu Construction Co. Ltd., Tokyo, Japan
hayakawa.kenji@tokyu-cnst.co.jp
2
ICUS, Institute of Industrial Science, The University of Tokyo, Japankatoyosh@iis.u-tokyo.ac.jp
1

ABSTRACTThe quality of cover concrete, which is affected by the execution conditions ofconstruction works such as casting and consolidation method, strongly influences
the durability of concrete structures. Currently, the quality of the structuralconcrete is confirmed by examining fresh concrete properties and the compressive
strength of test pieces, but these examinations do not evaluate the durability of thestructural concrete directly. It is more effective to directly evaluate the durability
index of cover concrete to ensuring the durability of structure. One of thesemethods is the non-destructive air permeability test which can be utilized in thefield, but it is not clear what effect the execution conditions of construction works
may have on the variations in cover concrete. The purpose of this study is toevaluate the influence of the execution condition of construction works on the
cover concrete quality. Causes of quality variation include the segregation of
fresh concrete, which occurs when the ratio of coarse aggregate and mortar
changes due to excessive vibrations or the blockage by steel-bar, and bleeding
after completion of casting. This study investigates the influence of vibration time,arrangement of steel bar, and change of mix proportions on quality variations.
Additionally, when the mix proportion is changed, the fresh performance such as
bleeding and air permeability after hardening is also examined. In this study,
quality of cover concrete is evaluated by the air permeability index, void content,
rebound number, and compressive strength. The results found that although thecompressive strength of concrete itself can be understood by the water-cement
ratio, air permeability index may vary even when the water-cement ratio is thesame. The bleeding ratio is influenced by the change in mix proportion, and ahigh degree of influence was observed for high slump concrete.
Keywords: cover concrete, execution, vibrating consolidation, segregation
1. INTRODUCTION
Durability of concrete structures depends on the mass transfer resistance of coverconcrete, which is a primary factor in deterioration due to chloride ion and carbon
dioxide, oxygen, water. Therefore, the quality of the cover concrete is very
important for ensuring the concrete structures’ durability. The quality of coverconcrete is influenced by factors other than the water-cement ratio, especially the
execution conditions of works such as the consolidation and curing method, and0ctober 2010, Kobe, Japanthe relative influence is different for constructive quality of fresh concrete such as
workability and consistency.
Currently, the quality of structural concrete is confirmed by examination of the
fresh condition, such as slump, and the compressive strength of test pieces.
However, these examinations do not evaluate the durability of the structuralconcrete directly, and the influence of execution condition of work is uncertain. If
the evaluation of quality of cover concrete, such as permeability, could be
conducted directly on the structures, it would be very effective for ensuring
durability (JSCE, 2007).
The purpose of this study is to evaluate the influence of the execution condition of
construction works on cover concrete quality. One of the causes for the quality
variations is the segregation of fresh concrete, which is affected by the ratio ofcoarse aggregate, mortar change by excessive vibrations, obstruction by steel-bar,and bleeding after casting completion. This study investigates the influence ofvibration times and arrangement of steel bar for quality variations in Section 2. In
addition, the fresh performance such as bleeding and air-permeability after thehardening at various mix proportions is examined in Section 3.
2. EXPERIMENTS WITH LARGE-SCALE SPECIMENS
2.1. Test procedure
Mix proportions are given in Table 1. In this study, ready mixed concretes which
satisfy JIS A 5308 were used. Two types of concrete with different slump were
investigated. The water-cement ratio of these mix proportions was set at 57.0%.
The slump for water unit weight of 180 kg/m3 was 18.0 cm, whereas the slump forwater unit weight of 159 kg/m3 was 8.0 cm. Table 2 shows the test results for
fresh conditions. The bleeding content and ratio of 24-18-20N is larger than thatof 24-8-20N.
Table 1 Concrete mix proportions

Air
W/C
s/a
Unit Weight(kg/m3)
No. Concrete Type
W
C
S
G
(％)
(％)
(％)
1
24-8-20N
4.5
57.0
46.6
159
279
858 1002
2
24-18-20N
4.5
57.0
49.3
180
316
866
906
※1：Strength-slump-Maximum Aggregate Size（Cement type）※2: AE water reducing agent

Table 2 Fresh conditions test results

Ad.
2.79
3.16

ConcreteType24-8-20N

Slump
cm
6.5

Air
%
4.9

ConcreteTemp.（ºC）
17.1

Bleeding Content（cm3/cm2）
0.074

Bleeding Ratio
（%）
1.85

24-18-20N

16.0

5.3

16.0

0.148

3.58

※Bleeding content and ratio(JIS A 1123: Bleeding of concrete)

New Technologies for Urban Safety of Mega Cities in Asia

Figure 1 illustrates the full-scale specimen dimensions and reinforcing steel bar
arrangement. Specimen dimensions are similar to the original structure at 0.9×
0.9×1.2m with reinforced (both form sides) and non-reinforced cases in order toinvestigate the influence of reinforcing steel bar on cover concrete quality. The
side surface was also investigated for some specimens.
D22 80mm ピッチ
D22@80mm

1200

D16125mm ピッチD16＠200mm
900

100

900

Figure 1 Full size specimen dimensions and rebar arrangement
Table 3 shows the construction works and specimen conditions. Concrete was castusing a concrete pump-piston and consolidated with a high-frequency vibrator of
φ50 mm. Vibration time is 15 seconds for standard construction works, and wasdetermined from experience and compressive strength. In addition to the standard
time, 45 seconds vibration case was also investigated to examine the most suitablevibration time for concrete quality of fresh condition. After curing specimens
were exposed to a warm outdoor environment unaffected by chloride ions.
Table3 Construction works and specimen condition
Casting speed
Vibration times
Curing times

Execution Condition and Parameter2 to 3 m/h
15 seconds(Standard vibration)
45 seconds(Excessive vibration)
5 days (removed form)

Table 4 shows the test items and methods. Air permeability was tested by the nondestructive Torrent method which can also be used in the field (Torrent, 1992).
This method uses a two-chamber cell, with an inner and outer chamber, based on
the guard-ring principle. The coefficient of air permeability by Torrent method(KT) is computed by following numerical formula.

Influence of segregation with execution for quality variation of cover concrete

0ctober 2010, Kobe, Japan(1)
KT：Coefficient of air-permeability-Torrent method(m2)V C ：Volume of inner cell system(mm3)
A：Cross-sectional area of inner cell（mm2）μ：Viscosity of air（Ns/m2）（2.0×10-5）
ε：Estimated porosity of the cover concrete(m3/m3）（0.15）
Pa：Atmospheric pressure(N/m2)⊿P：Times(s) at the end of the test(N/m-2)
T：Times(s) at the end of the test
T 0 ：Times(s) at the beginning of the test(=60s)

Testing of the full-scale specimens examined air permeability at the concretesurface. Void content and apparent density was measured for specimens by taking
drilled cores considering segregation in concrete materials. These examinations
were tested at each three points in the upper, middle, and lower areas of specimen.
Table 4 Tests items and method
Tests items
Air permeability
Apparent density
Void content

Test method
Torrent method (Torrent, 1992)
ASTM C 642
Weight method (Core specimens)

2.2. Test results and discussion
Figure 2 shows relationship between KT (the coefficient of air permeability)
results and specimen height. Comparing reinforced and non-reinforced results inthe case of slump 8cm, it can be seen that for reinforced specimens the airpermeability in all areas of the specimens are fairly similar, whereas for nonreinforced specimens measurements in the upper area tended to be larger than the
middle and lower areas. This is because the concrete is affected by consolidation
due to self-weight and bleeding. This effect wasn’t seen in the case of reinforced
concrete because the reinforcing steel-bar affected the self-load of the coverconcrete.
For the vibration times, vibrating for 45 seconds resulted in lower air permeability
than the 15 seconds standard vibration time used in real construction works. The
fact that air permeability at the concrete surface decreased for long vibration times
suggests that the vibration time appropriate for permeability is different than thatappropriate for compressive strength for the concretes used in this study.

New Technologies for Urban Safety of Mega Cities in Asia

120

120

100

100

試験体の高さ(cm)Height of specimen(cm)Whereas, in the case of 18cm slump, KT for both reinforcing and non-reinforcing
tended to be larger than those of 8cm slump, and upper areas are larger than
middle and low areas.

80
60
40
20
0

0.1

1

SL8-Vib15
SL8-Vib45
SL18-Vib45

80
60
40
20
10

0

0.1

1

10

KT（10 -16 m 2 ）Non-reinforcing
Reinforcing

12

14

16

18

SL8-Vib15
SL8-Vib45
SL18-Vib45

14

16

18

20

Voids content(%)

Heigtht of specimｅ
n(cm)

120
100
80
60
40
20
0

120
100
80
60
40
20
0
20 12

試験体の高さ(cm)

120
100
80
60
40
20
0

120
100
80
60
40
20
0
2.4 2.1

試験体の高さ(cm)Heigtht of specimｅn(cm)Figure 2 Relationship between KT and height of specimen(Tested at 91 days)

2.1

2.2

2.3

2.2

2.3

2.4

Apparent density(kg/ℓ)
Non-reinforcing
Reinforcing

Figure 3 Relationship between void content or apparent density
and height of specimen(Tested at 91 days)
Figure 3 shows relationship between void content, apparent density and specimen
height. The test results of void content and apparent density are similar to air
permeability in that for the reinforcing of 8cm slump the difference by specimen
height is small, and in the case of 18cm slump it is large.
In this study, since the condition of curing is same in all case, the change of void
content and apparent density was caused by the change of course aggregate
quantity by excessive vibrations, and pass through obstacle of steel-bar, and thebleeding after the casting completion.
Figure 4 shows between apparent density and ratio of unit coarse aggregate
weight, unit water weight by calculation of mix proportion. Here, the ratio = 1.0 is
Influence of segregation with execution for quality variation of cover concrete

0ctober 2010, Kobe, Japan

standard mix proportion, and under the condition that assume ratio of the othermaterial uniformity, it was changed unit weight of coarse aggregate or water. We
see from Figure 4 that for the density change, the influence of the coarse
aggregate change is large. Comparing the test results of apparent density and ratioof unit coarse aggregate, ratio of unit coarse aggregate in the each case appear in
Table 5. In the case of 8cm slump, the influence of excessive vibration against
segregation of coarse aggregate tended to be small, but in the case of 18cm slump
it was large. In general, since the decrease in quantity of coarse aggregate(increase of mortar quantity) influences void content, this relationship agreed withtest results.
Maximum amount of coarse aggregate（Solid content）

0.8
0.9

0
0.5

mortar
1

1
1.5

1.1
1.2
2.05

Change of unit water weigth
2.15
2.25
Apparent density（ｋｇ/ℓ）

2
2.45

2.35

Ratio of unit coarse aggregate

Ratio of unit water weight

Change of unit coarse aggregate

Figure 4 Relationship between apparent density and ratio of unit coarse aggregate
weight, unit water weight
Table 5 Test results of apparent densityand estimated results of ratio of coarse aggregate
Concrete
type24-8-20N
24-18-20N

Vibration
standard
excessive

Apparent density(kg/ℓ)
Measured value
standard(Test piece) Min Max Range
2.32
2.31 2.37
0.06
2.32
2.29 2.37
0.08
2.28
2.17 2.39
0.22

Ratio of coarse
aggregate
Min
0.93
0.86
0.43

Max
1.22
1.25
1.57

Range
0.29
0.39
1.14

As shown in Section 2.1., KT is calculated by the equation (1). In general, since
the accurate porosity (ε) of the cover concrete cannot be known at the time of
examination, εin the equation is calculated using constant value (0.15 ). Here,given that the porosity is determined by mortar in the concrete, the estimatedporosity can modify KT relative to standard mix proportions.
Figure 5 shows the relationship between modified KT and specimen height. If thereason why change of coefficient of air permeability is that mortar quantity ischanged, then this relationship should not change for specimen height. But also inthis case, the modified KT for upper area tended to be larger than middle and low
areas. The reason for this is that concrete quality is changing by influence of
bleeding, and may be influenced by segregation.

New Technologies for Urban Safety of Mega Cities in Asia

120

100

100

試験体の高さ(cm)Height of specimen(cm)

120
80
60
40
20
0

0.1

1

SL8-Vib15
SL8-Vib45
SL18-Vib45

80
60
40
20
10

0

0.1

1

10

Modified KT（10 -16 m 2 ）Non-reinforcing
Reinforcing

Figure 5 Relationship between modified KT and height of specimen

3. EXPERIMENTS ON COARSE AGGREGATE SEGREGATION
3.1. Test procedure
Mix proportions are given in Table 6. These mix proportions are intended toevaluate material segregation of mortar and coarse aggregate in the concrete,
therefore the quality of mortar is constant and the ratio of coarse aggregate ischanging from 0 (mortar) to 1.21 (standard is 1.0).
The concrete manufactured at 20 ℃ in a laboratory, and the slump, air andbleeding test of fresh concrete were examined. The test pieces cast were φ10×20cm (compressive strength, mortar: 5 × 10cm) and 15 × 15 × 15 cm (airpermeability at the concrete surface). These pieces were exposed to 20ºC and 60%
RH after sealed curing until 5 days, and the test for compressive strength and air
permeability was examined at 28 days.
Table 6 Concrete mix proportions
W/C

Air

s/a

%
%
%
55
7.1
100
55
5.2
57.8
55
4.5
46.5
55
3.9
38.3
Standard mix proportions

Ratio
of G
0.00
0.73
0.99
1.21

Unit Weight (kg/m3)
W
270
197
170
148

C
491
357
309
270

S
1294
949
821
716

G
0
705
963
1175

Ad.
1.23
0.89
0.77
0.68

3.2. Test results and discussion
Figure 6 shows the change in ratio of coarse aggregate and compressive strength
or coefficient of air permeability. In the figure, KT (modified porosity) was
modified estimated porosity following ratio of coarse aggregate. The compressive
strength tended to be constant without the influence of coarse aggregate quantity.
Here, the reason why in the case of change ratio 0 (mortar) the compressive
strength is a little larger than other case is that it seems to be influenced by the test
piece dimensions. On the other hand, in the case of coarse aggregate change, theInfluence of segregation with execution for quality variation of cover concrete

0ctober 2010, Kobe, Japan

50
45
40
35
30
25
20
15
10
5
0

10

1

compressive strangthKT
KT(modified porosity)
0.00

0.50
1.00
Ratio of coarse aggregate

1.50

Coeff.of air permeability
KT(m 2 )Compresive strangth（N/mm 2 ）coefficient of air permeability can be seen larger than those of standard concrete.
This relationship is similar in the case modified estimated porosity.

0.1

Figure 6 Relationship between ratio of coarse aggregate and compressive
strength, coefficient of air permeability
Figure 7 shows the bleeding test results. When changing the ratio of coarse
aggregate, the bleeding ratio tended to be larger than standard mix proportion. The
fact that this tendency is similar to coefficient of air permeability suggests that air
permeability is more easily affected by bleeding than compressive strength.

Bleeding ratio（%）

10
8
6
4
2
0

0.00

0.50
1.00
Ratio of coarse aggregate

1.50

Figure 7 Relationship between change ratio of coarse aggregate
and bleeding ratio
In general, in the case of non-segregation, the quality of cover concrete changes in
the height direction by bleeding of concrete by casting and vibration. In addition,
if the segregation of mortar and coarse aggregate occurred by construction process
such as excessive vibration, the quality of the fresh concrete changes bleeding
ratio. As a result, the change of the height direction may become larger than nonsegregation case. It should be noted that segregation such as aggregate settling
due to vibration occur for concretes with high slump which are consolidated byexcess vibration.

New Technologies for Urban Safety of Mega Cities in Asia

4. CONCLUSION
This study carried out an experimental investigation to evaluate the influence ofvibration and segregation on the quality of cover concrete for ensuring the
durability of structure concretes. The conclusions of this study are as follows:
1) For reinforced specimens, the changes of air permeability in height directionof the specimens are smaller than non-reinforced specimens. This is because
the concrete is affect by consolidation due to self-weight and bleeding.
2) For concrete with 8cm slump, the air permeability index tended to decreasefor vibration times longer than the standard method. However for concretewith 18cm slump, the air permeability index tended to increase with excessive
vibration due to segregation of coarse aggregate and mortar.
3) The compressive strength was not affected by segregation of coarse aggregate
and mortar. On the other hand, the air permeability of concrete was moreeasily affected by the segregation due to change of bleeding property ofsegregated concrete and mortar quantity.
ACKNOWLEDGEMENT
The authors would like to express their thanks to Dr. Michael W. Henry of
Katoyosh Laboratory, University of Tokyo who generously assisted.
REFERENCES
Torrent, R.J.,1992, A two-chamber vacuum cell for measuring the coefficient of
permeability to air the concrete cover on site, Materials and Structures, Vol. 25,
pp.358-365
Japan Society of Civil Engineers, 2008. Concrete engineering series80, Subcommittee on the verification system for surface quality and durability
performance of RC structures

Influence of segregation with execution for quality variation of cover concrete

Fatigue damage estimationof RC beams under cyclic loading
Mitsuyoshi TSUNEKUNI1, and Yoshitaka KATO2
1

Tokyo Electric Power Services Co., Ltd., Japan
tunekuni@tepsco.co.jp
2
International Center for Urban Safety Engineering,
Institute of Industrial Science, University of Tokyo, Japan
ABSTRACTIn Japan, the deterioration of some concrete structures constructed in 1960s is
beginning to be detected. In the future, maintenance costs for deteriorated
structures will steadily increase, so the quantitative evaluation of deterioration
degree will become an important task. In this study, the fatigue damage estimation
method of reinforced (hereafter referred to as “RC”) beams subjected to cyclicloading is discussed through loading tests of specimens in laboratory.
In the proposed method, the damage progress – the degradation of flexural
stiffness – is modeled by the correlation between increasing deformation due tocumulative cyclic loading and residual deformation caused by cyclic creep. The
deformation is represented by the curvature obtained by the measured strain of
extreme compressive fiber and reinforcing bar. Using the proposed method it may
be possible to carry out quantitative evaluation of safety for limit values, e.g.
yielding or compression failure.
Keywords: cyclic load, fatigue, cyclic creep, flexural stiffness

1. INTRODUCTION
A large number of concrete bridges were constructed since the era of higheconomic growth in Japan. The numbers of concrete road bridges, i.e., reinforce
and pre-stressed concrete bridges, with span length longer than 15m is about
71,000 (MLIT, 2002). Since most of the bridges constructed before the upgrade ofdesign load up in 1995, it seems that the number of deteriorated bridges may
increase owing to the increase of traffic and vehicle weight in recent years. So theevaluation of the soundness of existing concrete bridges will be becoming animportant task to decide whether a bridge is still in serviceable condition or not.
Currently, the maintenance of concrete road bridges is carried out mainly by
periodic visual inspections. On the basis of the inspection results, the degree ofdeterioration and the main cause of deterioration are determined. In this process,however, it is difficult to evaluate the safety, serviceability, and especially fatigue,
which are the criteria mentioned in Standard Specification for Concrete Structures(JSCE, 2002). So in this study, the quantitative estimation method related to the0ctober 2010, Kobe, Japanfatigue under cyclic loading is discussed for RC beam structures like bridge main
girders. To deal with this problem, the cyclic loading test in laboratory was
carried out to clarify the progress of fatigue.
2. LOADING TEST OF SPECIMENS IN LABORATORY
2.1 Outline of loading test
In order to clarify the estimation method and the measurement one in situ for
fatigue progress of RC beams, the cyclic loading test of specimens were carriedout in laboratory.
Details of specimens are shown in Figures 1 and 2. And outline of tension
reinforcement is summarized on Table 1. The beams were 3400 mm long, 200
mm wide and 300 mm thick and were simply supported over a span of 3000mm.
The flexural and shear reinforcement was designed to ensure flexural failure.
Stirrups of 10mm diameter were placed in the beam as shear reinforcement at
spacing of 200mm.There was a 40mm clear cover of concrete. The compressive
strength of concrete was 30.4 MPa whereas the yield strength of steel was
399MPa.
The tests were carried out using a 294 kN capacity hydraulic servo actuator as
shown in Figure 3. The actuator was operated under load control. And the load ofsin wave type was applied. Increasing the maximum value of load, the loading foreach the maximum was continued until the crack propagation converges, as
shown in Tables from 2 to 4.
Strains of reinforcement bar, concrete of extreme compressive fiber anddeflections at mid-span were recorded during testing.
400

ｃ
Ｌ

D16

1100
D10

200

D19
7＠200＝1400

200

Figure1:Details of test beam (unit：mm)
D1640Table1:Type of tension steel

300

D10

No.

TensionReinforcement

Tension Steel
Ratio (%)

1
2
3

2-D16
2-D19
2-D22

0.66
0.90
1.29

200

Figure2:Closs-sction of test beam
New Technologies for Urban Safety of Mega Cities in Asia

Tabel2: Loading of Specimen No.1
Maximum Load
(kN)
6.9
16.7
36.3
46.1
51.0

Number of Cycle
50,00050,00030,00061,00010,000

Table3: Loading of Specimen No.2

Loading Rate
(Hz)
1.5
1.0
0.5

Maximum Load
(kN)
6.9
16.7
36.3
66.6

Number of Cycle
6,000
30,00020,000100,000

Loading Late
(Hz)
1.0
0.75
0.50

Table4: Loading of Specimen No.3
Maximum Load
(kN)
6.9
16.7
36.3
75.5
85.3
91.2

Number of Cycle
20,000100,000
50,00080,0005000
10,223

Loading Rate
(Hz)
1
1
1
0.5
0.5
0.5

Figure3:Test set-up

2.2 Experimental Results

The state of cracks after test of each specimen is illustrated in Figure 4. The
number and spacing of cracks becomes grater with the amount of reinforcement.
The relation between residual and elastic deflection at mid span before the yieldof reinforcement shown is shown in Figure 5. In this diagram, the data of the firstcycle and the last of cycle for each the maximum load. And the elastic deflection
is defined as the division of increment deflection by the load for a cycle loading.
Due to crack growth, the deterioration of flexural stiffness occurs. As aconsequence, the deflection increased. Furthermore, the increase of residual
deflection was becoming greater than the increment of elastic deflection owing to
the damage in compression. The damage in compression is represented by the
relation between plastic and maximum strain as shown in Figure . The elastoplastic and damaging model (Maekawa et al.,2009) is also shown together bysolid line.

(a)No.1(b)No.2(c)No.3
Figure4: Cracks after test

Your paper title

4.0

Eauivalent Residual Strain(μ)

Residual Deflection(mm)0ctober 2010, Kobe, Japan

No.1
No.2
No.3

3.0
2.0
1.0
0.0
0.0

0.5

1.0

1.5

2.0

400
No.1
No.2
No.3

300
200

No.2
No.1

100
0
0

Elastic Deflection(mm/kN)

No.3

500

1000

1500

2000

Equivalent Maximum Strain(μ)

Figure5: Residua land elastic
deflection diagram

Figure6:Residual and total strain
at compression top fiber

3. FATIGUE DAMGE EVALUATION
3.1 Estimation of Cross Section Curvature
According to the analogy of the elasto-plastic and damaging model, in this study,
the fatigue damage of beams is evaluated by the use of the residual and the
maximum deformation. In order to evaluate the decline stiffness of members by
deformation, in general, both of load and deformation have to be observed
simultaneously. However, the load observation in situ seems to be expensive. To
avoid this problem, therefore, the curvature, which is one of the criteria of
deformation, under a certain constant strain in compression top fiber will beutilized in this study.
The curvature of the observed cross-section is evaluated using the strain ofcompression top fiber and reinforcement under in-place hypothesis as illustrated
in Figure 7.
Strain of compression fiber

Curvature

Crack

Strain of reinforcement bar

Figure7: Estimation of curvature
And the reinforcement strain is estimated using the crack width observed by
pai-gage as follows;w
εs =1.1 ⋅ l c
where,εs：strain of reinforcement bar
w：crack width
lc：crack spacing

New Technologies for Urban Safety of Mega Cities in Asia

Estimated reinforcement
strain(μ)

In view of simplicity of measurement in situ, the maximum crack width of all
cracks is adopted for the estimation of reinforcement strain in this study. The
comparison of the estimation results of reinforcement strain estimated by
maximum crack width with observed strain by strain gage at mid span is shown in
Figure 8. The gradient of regression line is different among specimens. However,
it is possible to adopt for the stiffness degradation estimate of each specimen,
because the linearity is held until the yield of reinforcement. The difference of thegradient seems to be mainly caused by the distance between strain gage on
reinforcement and crack. In other words, the fairly agreement may be obtained on
condition that the distance is zero. The distance is as follows; 29mm (16% of
crack spacing) in No.1, 104mm (similarly 50%) in No.2 and 60mm (similarly31%) in No.3.
For the purpose of evaluation of deterioration without observing of load, theincrease of curvature under a constant strain of compression top fiber is used inthis study. Figure 9 shows the diagram of curvature and compression strain at top
fiber of specimen No.3 as an example. It is noticeable that the linear relation ofcompression strain and curvature exists for every cycle and the gradient becomes
greater with cumulative cycle. Figure 10 shows the relation relative curvature andcyclic loading. The relative curvature is normalized with respect to the curvatureof 1000 times cycle of 16.7kN, As a result, it is possible to evaluate the stiffness
decline by the curvature for any constant compression strain.
2500

y=1.03x (No.1)
y=1.21x (No.2)
y=1.50x (No.3)

2000
1500
1000

No.1
No.2
No.3

500
0
0

500 1000 1500 2000 2500

Ovserbed reinforcement strain(μ)

Figure8: Observation result vs.
Estimation result
1.2

50

100

150

200

Top fiber compression strain(μ)

Figure9:Curvature vs.
Top fiber Compression strain

Your paper title

250

0.8

⊿εc=200μ
46
.1
×1

0

⊿εc=100μ

36
.3
×3
00
00

0

⊿εc=50μ

0.9

36
.3
×1

10

1.0

16
.7
×5
00
00

6.7kN
16.7kN
36.3kN
46.1kN

1.1

16
.7
×1
00
0

Rrative curvature-8(×10 1/mm)

No.1

20

-8

Curvature(×10 1/mm)

30

Load(kN)×Cycle

Figure10: Curvature vs. cyclic loading

0ctober 2010, Kobe, Japan

3.2 Degradation of Fatigue Damage
In this study, growth of fatigue damage is evaluated on the basis of relation
between maximum curvature and residual one as shown in figure 11. The
maximum curvature is the sum of residual curvature and elastic one. The elastic
curvature is the observation for a certain constant compression strain at top fiber(100μ in this case) as mention in previous section. It is noticeable that thedifference with the amount of reinforcement is small. Figure 12 shows thederivative of the residual curvature with respect to the maximum curvature(defined as “Rate of damage”). The damage rate gradually comes close to 1 withmaximum curvature growth. That is to say, the growth of residual curvature seems
to be distinguished with coming close to the yield of reinforcement.
Once more than two observations in situ will be obtained at an interval, it ispossible to calculate increment of residual and of maximum respectively. Then themeasurement rate of damage can be obtained by division the increment residual
curvature by the increment maximum curvature. Comparing the measurement rateof damage with the previously calculated damage rate, the fatigue damage ofstructure can be evaluated quantitatively. And the damage rate is obtained by theratio of residual and maximum curvature.
Residual is observation under no-loading.
1.2

No.1
No.2
No.3

6
4

Rate of damage-7(×10 1/mm)

Residual curvature

8

2

1.0
0.8
0.6
0.4
0.2
0.0

0
0

2

4

6

Maximum curvature(×10

-7 1

8
/mm)

Figure11: Residual curvature vs.
maximum curvature

0

2

4

6

Maximum curvature(×10

-7 1

8
/mm)

Figure12: Rate of damage

4. VERIFICATIONThe results of static loading test of same bar arrangement specimens were adopted
for verification of proposed method. The static tests were carried out to access thebearing capacity and determine cyclic loading way for each specimen in advancefor fatigue tests.
For specimen No.1 as an example, the relation between the load and top fiber
compression strain, and one between load and maximum crack width are shown in
Figures 13 and 14 respectively. In the test, 6 times repetitive load with different
maximum value was applied.
The relation between residual curvature and maximum one is shown in Figure 15．

New Technologies for Urban Safety of Mega Cities in Asia

And Figure 16 shows the relation of residual curvature increment and maximum
curvature increment on the condition that the 3rd cycle is initial value. The relation
seems to coincide with the results of fatigue tests, that is also illustrated together
by dash line, on the condition that the residual curvature of 0.638 and maximum
curvature of 1.50 is as initial values. That is to say, it is possible to evaluate
fatigue damage progress using both increments of residual and maximum
curvatures.
100

100
80

No.3

60

Load(kN)

Load(kN)

80
40

40

20

20

0

0
0

500

1000

No.3

60

0

1500

2

(5)

(3)

0
0

1

2

3
-7

Maximum curvature （×10 1/mm)

Figure15: Residual curvature vs.
maximum curvature

Incremant (3)～(4)Increment (3)～(5)Increment (3)～(6)(×10 1/mm)

(6)

1.0

-7

Increment of φp-7(×10 1/mm)

Rsidual curvature

1.5

2
(4)

8

Figure14: Load vs. crack width inspecimen No.1

Figure13: Load vs. compression
strain at top fiber in specimen No.1

1

6

Crack width(mm)Compression fiber strain(μ)

Fatigue Test
Static test

4

0.5
(φ p0,φ max0)=(1.50,0.638)

0.0
0.0

0.5

1.0

1.5

2.0

-7

Increment of φmax(×10 1/mm)

Figure16: Increment of φp vs.
Increment of φmax

4. CONCLUSION
In this paper, the quantitative evaluation method of fatigue damage by the use of
the relation between increasing deformation and residual deformation caused bycyclic creep due to cumulative cyclic loading is proposed. The deformation isrepresented by the curvature obtained by the measured strain of extreme
compressive fiber and reinforcing bar.
The following conclusions can be drawn:
a. The growth of fatigue damage is represented by the relation between
maximum curvature and residual one. It is noticeable that the difference of therelation with the amount of reinforcement is small.
b. If more than two observations are carried out in situ at an interval, it ispossible to calculate increment of residual and of maximum respectively.
Comparing the measurement rate of damage with the previously calculatedYour paper title

0ctober 2010, Kobe, Japan

damage rate, then, the fatigue damage of structure can be evaluatedquantitatively.
c. As a consequence of the verification utilizing the static loading test, it ispossible to evaluate fatigue damage progress using both increments of residualand maximum curvatures.
REFERENCES
Ministry of Laod, Infrastructure and Transport of Japan (MLIT), 2002. Annual
statistics report of road, Japan Highway Users Conference.
Japan Society of Civil Engineers (JSCE), 2002. Standard specification for
concrete structures “Structural performance verification”, 14-16.
Meakawa,K., ISHIDA,T., and KISHI,T.(2009). Multi-scale Modeling ofStructural Concrete, Taylor & francis.

New Technologies for Urban Safety of Mega Cities in Asia

The Time Change of Shape of Timber Bridge
Mikio KOSHIHARA
Associate Prof., ICUS, Institute of Industrial Science,
The University of Tokyo, Japan
kos@iis.u-tokyo.ac.jp
ABSTRACTThe timber bridge, “KINTAI-Kyo”, is located in Iwakuni City, Yamaguchi
Prefecture, JAPAN. It was built in 1673 and rebuilt several times until 2001 forwashed away or its deterioration.
In 2001 “KINTAI-Kyo” was rebuilt as same shape in 1953. It is marked by thebeauty of its five arches. The bridge length is 193m, every arch length is about
35m, its rise is about 5m and the wide is 5m. This bridge was made by somestructural elements, KYOROKU(timber beam), KURA-GI(timber bracing),
TASUKE-GI(timber parts), TAGA(iron hoop), KASUGAI(iron cramp),
DABO(timber shear connector), etc.
After rebuilt in 2002, the shape of bridge, temperature and humidity are measured.
The following results were provided by these measurements.
In the first year, the deformation at the center of bridge move 2cm downward forgaps between the structural elements. And there is a seasonal change of thedeformation at the center of the bridge. At the center of bridge it moves upward insummer and downward in winter. The range of seasonal change is about 2cm.
These changes are influences by temperature and humidity. In 2005 the irregularchange of shape was observed in the autumn because no.1 bridge was washedaway by the typhoon. These measurements have a possibility of safety diagnosis
for timber bridge.
Keywords: timber bridge, heritage, monitering

1.INTRODUCTION
Figure 1 shows an elevation of “KINTAI-KYO” bridge. The bridge consists offive timber ones and is supported on each stone pillar. The bridge is 193.3m longand 5m wide. Three bridges of the middle part, from No.2 to No.4, are 35.1m longand the rise is about 5m.
It was constructed first in 1673 of Edo era by a feudal lord of the time, Hiroyoshi
Kikkawa, to meet the transportation problems which the people faced every time
when the Nishiki River flooded. The structural idea of the bridge is said to havecome from a story of a Chinese priest of the Ming Dynasty who settled in Japan
about the arch-type stone bridges of China.
Unfortunately, the entire bridge was washed away by a flood in May, 1674. But it
was reconstructed in October, 1674. After that the bridges were often repaired and0ctober 2010, Kobe, Japan

reconstructed partially. Each bridge was repaired about every 12–15 years andreconstructed about every 20 years.

Figure 1: Elevation of “KINTAI-KYO” bridge [unit: mm]

Photo 1: “KINTAI-KYO” bridge

Figure 2: Detail of “KINTAI-KYO” bridge

The bridge we can see today was reconstructed from 2001 to 2004. This bridge isa replica of the original bridge reconstructed as the Edo design. Many Japanesetraditional timber structures are preserved with maintenance, repairing andreconstruction. Even if they are rebuilt, the replica is re-built with original styleand spilt of traditional timber technique. “KINTAI-KYO” bridge is composed of alot of members. The main structure is KYOROKU (girder). The KYOROKU is
composed of KETA (beam), KURAGI,TASUKEGI, HEIKINGI and ATODUME.
They are connected with DABO (dowels), KASUGAI (cramps), nails and
MAKIGANE (hoops), as shown in Figure 2.
There are past researches about the secular changes of “KINTAI-KYO”. The
properties of vibration are measured and static loading tests were conducted by
Waseda university[1]-[3] from 1953 with the interval of 5 years.
On the reconstruction of these bridges in 2002, investigation about deterioration
was conducted. In these investigation two greatly deterioration were found. One isthe decay of the bridges especially in the joint between the floor board and top of
HEIKINGI as shown in photo 2. This decay of timber was caused by the puddles
around the pegs. Other deterioration is the deformation of dowels between the
beams as shown in photo 3. The horizontal deformations of the dowels were about
2-4 mm as shown in Photo 3.

New Technologies for Urban Safety of Mega Cities in Asia

Photo 2: The Decay of the top of“HEIKINGI” (Photo by Kamiyama.)

Photo 3: Deformation of dowel
between beams

2. MEASUREMENT METHOD
The bridge shape and factors of secular change are being measured from 2003. In
this year the no.4 and no.5 bridges were completed and just one year was passed
from the no.3 bridge was completed. The no.2 and no.1 bridges werereconstructed in 2004 and there are the no.2 bridge passed about 50 years in 2001.
2.1 Shape
The shapes of the middle three bridges (no.2, no.3 and no.4) are being measured
with theodolite. 13 targets were measured on every one side of bridge and 26
targets were measured on every bridge. Target points are the rivets bottom of thebalustrades (Photo.4).
Measurements were started on March 14, 2003. In the first month the shape wasmeasured with the interval of one week and in next two months it was measured
with the interval of two weeks. After three month it was measured with theinterval of one month and it was measured every 3 month from August 1, 2005.
2.2 Temperature and Humidity
Temperature and humidity influence the water content and the strain of wood.
Especially wooden bridge is located in hard environment, above the river.

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0ctober 2010, Kobe, Japan

Photo 4: Target point of measurement

Photo 5: Thermo recorder
Temperature and humidity under the bridge are being measured with thermo
recorder, T & D’s TR72S, every one hour (Photo 5).
2.3 Live Load
For timber structure the creep deformation is one of the largest influences to thesecular change. In case of this bridge the continuous or repeating loads and isdead load, its weight, and live load, crossing person. For estimating the live load,
the number of sold tickets to cross the bridge was counted as the number of
persons crossing bridge. Actually this load is underestimating because there aremany not counting people with coupon tickets and group tickets.
3.RESULTS
3.1 Secular Change of the Bridge ShapeFigure 3 shows the deformation of the center of bridge. The horizontal axis shows
how many days passed from the completion of each bridge. No.3 bridge iscompleted in 2002, no.4 bridge is from 2003 and no.2 bridge is from 2004. In thefirst year, from 0 to 365 days, the deformation of center of all bridges went down
about 2 cm. But the deformation of no.2 was a little small. It is because this no.2
bridge has completed lastly and there is no construction after completion. Afterthe first year they go up in summer and go down in winter. The width of change is
0.005

no.2-upperno.3-upperno.4-upper
系列

deformation (m)0.000-0.005-0.010-0.015-0.020-0.025-0.030-0.035
0

120

240

360

480

600

720

840 960 1080 1200 1320 1440 1560 1680 1800 1920 2040
Day from completion

New Technologies for Urban Safety of Mega Cities in Asia

Figure 3: Deformation of the center of bridge (Upper part of a river)

2003/3/14
2007/2/1
2006/8/1

405

The deformation is magnified by 50 times
Figure 4: The deformation of no.4 bridge (Upper part of a river)

0.02

deformation(m)

0.01

405

405U
405D
2003

0.00
-0.01
-0.02
-0.03
-0.04
01 04 06 09 12 03 06 09 12 03 06 09 12 03 06 09 12 03 06 09 12 03 06 09 12
2002
2003
2004
2005
2006
2007
Month

Figure 5: The deference between the upper part and the lower part of the river inbridgeabout 1.5cm. The deformation of each point of no.4 bridge in the summer (Aug. 1,
2006) and in the winter (Feb. 1, 2007) are shown in Figure 4. The maximum
deformation of bridge is at the point of a third part of bridge.
The deference of the deformation between at the upper part and lower part of theriver in bridge is shown in Figure 5. This figure shows the deformation at the
point 405 shown in Figure 4. The deformation at the upper part of the river inbridge is larger than at the lower part of the river and its difference grows larger.
The deference is about 1cm in 500cm width.
3.2 Factors of Change
3.2.1 Temperature and humidity
Temperature and humidity were measured by thermo recorder every one hour.
The results are shown in Figure 6 and Figure 7. Both temperature and humidity
value are 7-day average before measuring the shape of bridges. The horizontal
axis shows how many days from every January 1.

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0ctober 2010, Kobe, Japan

Temperature changes cyclically. The highest temperature, about 30 degrees
Celsius, was recorded in August and the lowest temperature, about 5 degrees
Celsius, was recorded in February. Considering the change of relative humidity, it
is high because this bridge is located above the river. Especially it is over 90% in
35

2003
2004
2005
2006

Temperature (Cels.)

30
25
20
15
10
5
0
0

60
120
180
240
300
Day in 2003-2006 (from Jan. 1)

360

Figure 6: Change of temperature

Relative humidity (%)

100
90
80
70
60

2003
2004
2005
2006

50
40
0

60
120
180
240
300
Day in 2003-2006(from Jan. 1)

360

Figure 7: Change of relative humidity
every night and in every morning. But the change in the year is not cyclically and
it is different from every year.
3.2.2 Live load
The number of sold tickets to cross the bridge was counted. This ticket is roundtrip ticket, so the number of crossing the bridge is twice as this number. The
number of sold tickets in month is shown in Figure 8. About 80-240 thousand
persons cross the bridge every month. There are two peaks and over 100 thousand
persons cross the bridge in April and November. In April they enjoy the cherry
blossom on the bank of river and in November they enjoy autumn leaves. There issmall peak in August and this reason is summer vacation. There are two off-peakin July and December. In June and July is the rainy season in Japan and in
December it is cold in Iwakuni-city.
These numbers are reference value and maybe lower limit because there were thecrossing persons who did not buy the tickets
New Technologies for Urban Safety of Mega Cities in Asia

140000

the number of tickets

120000100000
80000
60000
40000
2003
2004

20000
0
0

60
120
180
240
300
Day in 2003-2004 (from Jan. 1)

360

Figure 8: The number of persons crossing the bridge
3.2.3 Gap of connectors“KINTAI-KYO” bridge is mainly composed of beams and these beams areconnected to the other beam with dowels. These dowels are deformed by the shear
force between beams. This deformation influences the shape of the bridges. By
the field experiments in 2003[4]-[5] it is cleared that the vertical deformation of
the center of bridge is 14.3mm if the gap between beams is 0.28mm and that
deformation is 27.39mm if the gap is 0.67mm.
3.2.4 Typhoon
On September 6, 2005, the column of the no.1 bridge was washed away by a flood.
The damage of no.1 bridge after typhoon no.14 is shown in Photo.5.

Photo 5: The damage of no.1 bridge after Typhoon
4. DISCUSSION
4.1 The Degree of the Influence to Secular Change
Timber bridge, “KINTAI-KYO” is changing its shape secularly and cyclically.
Considering the cause of secular change of wooden bridge, there is many factor
described in 3.2. In this chapter the degree of influence is considered.

A survey on residents’ response to earthquake early warning at the 2008….

0ctober 2010, Kobe, Japan0.000▲ no.2○ no.3
× no.4-0.005deformation[m]-0.010-0.015-0.020-0.025-0.030-0.035-0.0405101520
moisture content[%]

25

Figure 8: Relationship between moisture content and deformation
4.2 Temperature and Humidity
Temperature and humidity influence to the moisture contents of wooden members.
Fig.8 shows the relation between the deformation of center of bridge and the
moisture content. The moisture content of wooden member is calculated
according to the theory of Hawley, Keywerth, Kollmann et.al.
In the no.3 and no.4 bridge the correlation between the deformation and moisture
content, but in the no.2 bridge there is no correlation. In this figure the moisture
content is changing from 10% to 15%. If the moisture content of wooden member
is change from 10% to 15%, the change of length parallel to grain is about 0.15%
and length perpendicular to grain is about 1.5%.
4.3 Typhoon
The no.1 bridge was washed away by a flood. The other bridge were damaged bywashing away of no.1 bridge. The deformation of center of bridge was changed
irregularly as shown Figure 9
2003/10 2004/01 2004/04 2004/08 2004/11 2005/02 2005/05 2005/09 2005/12 2006/03
0.02

Deformation[m]0.01

2-Lower
3-Lower
4-Lower

0.00

-0.01
-0.02
-0.03
-0.04

TyphoonFigure 9: Change of deformation of the center of Bridge.
New Technologies for Urban Safety of Mega Cities in Asia

The no.4 bridge did not change as same as the no.2 and no.3 bridge. If thesechange can be monitoring, some damages can be found. These measurements
have a possibility of safety diagnosis for timber bridge.
5. CONCLUSION
After rebuilt in 2002, the shape of bridge, temperature and humidity are measured.
The following results were provided by these measurements.
In the first year, the deformation at the center of bridge move 2cm downward forgaps between the structural elements. And there is a seasonal change of thedeformation at the center of the bridge. At the center of bridge it moves upward insummer and downward in winter. The range of seasonal change is about 2cm.
These changes are influences by temperature and humidity. In 2005 the irregularchange of shape was observed in the autumn because no.1 bridge was washedaway by the typhoon. These measurements have a possibility of safety diagnosis
for timber bridge.
ACKNOWLEDGEMENTS
The author graciously acknowledges the financial support of these projects
granted from IWAKUNI-city, YAMAGUCHI prefecture.
REFERENCES[1]Takeshi SHINAGAWA: Report about reconstruction of “KINTAI-kyo”,
Iwakuni-city, 1955
[2]Kusuo AOKI: Report about static and dynamic tests of “KINTAI-kyo”, 1953
[3]Research Center, Science Faculty, Waseda: Report about the Load Test of“KINTAI-kyo”,1998[4]Mikio KOSHIHARA et al.: A study about “KINTAI-KYO” in Iwakuni Part 13, Summaries of technical papers of Annual Meeting Architectural Institute ofJapan. C-1, pp.277-283, 2002[5]Mikio KOSHIHARA et al.: A study about “KINTAI-KYO” in Iwakuni Part 46, Summaries of technical papers of Annual Meeting Architectural Institute ofJapan. C-1, pp.469-474, 2003

A survey on residents’ response to earthquake early warning at the 2008….

Climate and Disaster Resilience of Asian Cities
Rajib Shaw1, Yukiko Takeuchi2, Jonas Joerin3, Sunil Parashar4, Parvin Gulshan5
1: Associate Professor, Graduate School of Global Environmental Studies, Kyoto
University, Japan, (shaw@global.mbox.media.kyoto-u.ac.jp)
2: Assistant Professor, Graduate School of Global Environmental Studies, Kyoto
University, Japan
3: Graduate Student, Graduate School of Global Environmental Studies, Kyoto
University, Japan
4: Graduate Student, Graduate School of Global Environmental Studies, Kyoto
University, Japan
5: Post-doc Researcher, Graduate School of Global Environmental Studies, Kyoto
University, Japan

ABSTRACTOver years, due to several human and natural factors, cities are becoming
vulnerable to natural disasters. Climate change is imposing another additional
threat, and due to different constraints of resources, it is important to focus on thecity’s resilience to reduce the disaster impacts. In an attempt to focus on
enhancing resilience, Climate Disaster Resilience Index (CDRI) is developed tomake a comparative analysis of the cities. The index is developed based on fivevulnerability and resilience-based dimensions: natural, physical, social, economic
and institutional. The scope of this study is limited to climate-induced disasters,such as cyclone, flood, heat wave, drought and heavy rainfall induced landslide.
For each individual city case, resilience information is presented as overall
resilience, and separate physical, social, economic and institutional resilience.
Higher values of resilience are equivalent to higher preparedness to cope withclimate and disasters and inversely. Based on the results, policy points andrecommendations are suggested by the authors and provide encouragement of city
governments’ engagements in specific cist services, institution and capacity
building. Not only are outputs from this study useful for city governments, but theyalso provide valuable knowledge and information to other local and national
stakeholders having a similar target: the enhancement of community resilience.
The CDRI is a considered as process to develop capacity of local governments toundertake decisive actions at city level.
Keywords: climate related hazards, resilience, urban risk, capacity building, Asia

1. INTRODUCTION
Urban areas, where 65 to 90 percent of economic activities of most Asian
countries are concentrated, are experiencing ever increasing risk due to changing
climate. On one hand cities are expected to continue acting as backbone of thenation’s economy and on the other they also need to prepare to accommodate

0ctober 2010, Kobe, Japanlarger population because it is estimated that two out of three people on earth will
live in urban areas by 2030. According to the United Nations Human Settlements
Programme 2007, ‘there is a constant pressure to keep pace with, if not lead,change in regional and global economic development. This, in turn, can be a force
contributing to uncontrollable urban expansion and the generation of more
vulnerability to disasters’. Moreover, since Asia is the most disaster-prone region,
the incidences of climate-induced disasters are also high compared to otherregions. Past disaster trends suggests that high density population in Asian cities
increases the mortality and the number of affected people in a typical disasterevent, which in turn also result in increasing economic losses in the region. Thereis a serious concern that the targets of Millennium Development Goals may not beeffectively achieved if disaster risk reduction is not prioritized in development
planning in general and urban development in particular.
With growing confidence of scientific community, climate change and induced
impact on human life have become a burning issue not only for theenvironmentalists but also for the policy makers and world communities. Climatechange is occurring, accompanied by significant changes in precipitation,
temperature, and changes in the frequency and intensity of some extreme events.
These changes will affect natural and human systems independently or in
combination with other determinants to alter the productivity, diversity andfunctions of many ecosystems and livelihoods around the world. Yet these
impacts will not be distributed or felt uniformly, as those “with the least resources
have the least capacity to adapt and are the most vulnerable”.
Settlement on marginal or unstable land such as coastal areas, mountainous areas,
river basin and urban slums heightens their exposure to the impacts of climate
hazards. With limited capacities and resources at their disposal to respond to
stresses such as droughts, floods, typhoons and rainfall-induced landslides, theirability to meet basic needs and improve their lives is constrained. Climate change
impacts and variability, therefore, threaten to exacerbate existing vulnerabilities
and further entrench development disparities. Therefore, there is a need to build aresilient community that would be efficiently capable to face climate change andassociated disaster risk. For that, city governments need to be aware of current
and future potential risk and take more initiative in order to enhance the resilienceof the urban systems and communities.
Despite growing recognition of ‘building resilient communities and enhancing
adaptation to climate change’, Asian urban communities are not yet receiving
adequate attention. Most of the explosive growth is going on in developing
countries of Asia where already about half of the urban population live in slumareas. These large proportions of the people are also at higher risk from the effects
of climate change. Many urban dwellers have already started to face lifethreatening risks from the increased intensity of storms, flooding and landslides
that climate change is bringing. These and other impacts will also bring the threatof damage to their livelihoods, property, environmental quality and future
prosperity. [References: United Nations Human Settlements Programme, 2007;
IPCC, 2001; IISD, SEI, IUCN, Intercooperation, 2003; ID21, 2008; DFID, 2007;
IDS, 2007; UNHSP, 2003]
New Technologies for Urban Safety of Mega Cities in Asia

2. METHODOLOGYThis study recognizes that the scale of developmental concerns Asian cities are
expected to address in a very near future will be behemoth. Moreover, even thebest possible and technologically advanced resource provisions cannot ensure
elimination of threats which is already demonstrated through experience of
hurricane Katrina. Therefore, more attention needs to be paid to raise theresilience of both urban local organizations and communities to climate change
and associated disasters. This study looks at different dimensions of resiliencefrom the lens of urban communities. Understanding urban problems andrecognizing potentials within communities is of utmost importance to enhance
resilient to climate change risk and disasters. It attempts to measure the existinglevel of climate disaster resilience of urban communities. The scope of this study
is limited to climate-induced disasters (hydro-meteorological disasters), such as
cyclone, flood, heat wave, drought and heavy rainfall induced landslide andbuilding resilience against them.
In the attempt of building a resilient community, key questions that need to beanswered are:
• How to enhance resilience of the community?
• What are the indicators that need to be addressed to be able to characterize
and measure Climate Disaster Resilience?
• How can we create an effective index to assess the level of climate disaster
resilience of a vulnerable urban community?
This research is an attempt to seek answers to these queries by focusing on theurban communities of Asian cities. It aims to enhance community resilience after
evaluating the existing level of climate disaster resilience of a community using a
Climate Disaster Resilience Index (CDRI).
In this initiative, community resilience can be understood as:• Capacity to absorb stress or destructive forces through resistance oradaptation• Capacity to manage or maintain certain basic functions and structures during
disastrous events• Capacity to recover or ‘bounce back’ after an event.
This concept comprises the capacity of a community to absorb stress (hydrometeorological disasters), to manage it and to recover from it. It is assumed that if
a community can raise its climate resilience, it would enhance its disaster
resilience and finally these two resiliencies would enhance community’s
resilience to climate disaster risk.
3. RESULTS AND DISCUSSION
The community’s climate disaster resilience would be assessed considering thefollowing dimensions:• Natural: topography, disasters, natural environment degradation, hydroClimate and Disaster Resilience of Asian Cities

0ctober 2010, Kobe, Japan

•
•
•

•

meteorological situation
Physical: history, location, accessibility, infrastructure and utilities, housing
condition, land tenure, environmental degradation,
Social: population, health, education, knowledge and awareness, social
capital, conflict, crime,
Economic: income,
employment,
expenditures, assets,
access to financial
services,
financialcoping mechanism
Institutional: internal
andexternal
institutions,institutional
collaboration,
coordination
andFigure 1. Five dimensions of CDRI
cohesion

Based on these dimensions, a methodological approach is developed to determinea Climate Disaster Resilience Index (CDRI).
Briefly, outcomes of this study are:
• MethodologyofCDRI
development;• CDRI to measure community’s
climate disaster resilience;• Climate Disaster Resilience Map
for the identified communities;• Strength and weakness ofdifferent
sectorsof
eachdimensionof
CDRI
FigureResults of CDRI
(physical/social/economic/institutional/natural)of a2.community
so that local
authorities and development organizations can prioritize the sectors for policy
implication.
• Inputs for policy formulation process of development organizations for urban
communities risk reduction.
Climate and Disaster Resilience Index (CDRI) and the analysis are based on thequestionnaire survey, filled up by the city officials. The quality of results is verymuch dependent on the data quality, and proper understanding of thequestionnaires. Needless to say, these results are not absolute values, but broad
policy guidance and scope of improvements in selected sectors of the climate anddisaster related problems in the respective cities.
On the overall analysis, there are six graphs showing comparative nature of cities.
This comparison is made to highlight the positive side of city’s preparedness. One

New Technologies for Urban Safety of Mega Cities in Asia

graph shows overall city’s resilience, and five other graphs demonstrate city’s
resilience in terms of natural, physical, social, economic and institutional.
For each city, five graphs are presented: overall resilience (combination of all fivefactors), and physical, social, economic and institutional resilience. Higher thevalue of the resilience means higher preparedness to cope with climate anddisasters. Policy points are based on the results, and provide encouragement ofcity government’s engagements in specific city services and institution andcapacity building.
REFERENCES (including non-cited reference)
ADB, Managing Asian Cities: Sustainable and Inclusive Urban Solutions. (AsianDevelopment Bank, 2008)
The World Bank, World Development Report 2009. (The World Bank, 2008).
Retrieved
January
21,
2009
from
http://www.worldbank.icebox.ingenta.com/content/wb/bk17607/
IDS, Building Climate Change Resilient Cities, IDS in Focus Issue 02.6 (2007).
Available at www.ids.ac.uk
UN-Habitat, Global Report on Human Settlements 2007, Enhancing Urban
Safety and Security, United Nations Human Settlements Programme(UN-Habitat), (Earthscan, London, 2007).
J. T. Houghton, Y. Ding, D.J. Griggs, M. Noguer, P. J. van der Linden, and D.
Xiaosu (eds.), Climate Change 2001: The Scientific Basis, Contributionof Working Group I to the Third Assessment Report of theIntergovernmental Panel on Climate Change (IPCC). Cambridge
University Press: 944, (Cambridge, 2001).
IISD, IUCN, SEI-B, Intercooperation [International Institute for Sustainable
Development, IUCN–The World Conservation Union, Stockholm
Environment Institute–Boston Center], Livelihoods and Climate Change:
Combining Disaster Risk Reduction, Natural Resource Management andClimate Change Adaptation in a New Approach to the Reduction of
Vulnerability and Poverty. (Winnipeg, Canada IISD, 2003). Also
available at www.iisd.org/pdf/2003/natres_livelihoods_cc.pdf.
ADPC (Asian Disaster Preparedness Center), Building Disaster Risk Reduction in
Asia- A Way Forward ADPC Looks Ahead to 2015. (Bangkok Thailand,2004). www.adpc.net
A. Kreimer, M. Arnold and A. Carlin (eds.), Building Safer Cities: the Future ofDisaster Risk, Disaster Risk Management Series, 299pp (The World
Bank, Washington USA, 2003).
J. Twigg, Characteristics of a Disaster-Resilient Community; a Guidance Note,version 1 for field testing, for the DFID Disaster Risk Reduction
Interagency Coordination Group (Benfield UCL Hazard Research Centre,2007).
S. Huq, A. Rahman, M. Konate, Y. Sokona and H. Reid, Mainstreaming
Adaptation to Climate Change in the Least Developed Countries. IIED
(London, 2003).

Climate and Disaster Resilience of Asian Cities

0ctober 2010, Kobe, Japan

IPCC, Impacts, Adaptation & Vulnerability, IPCC Working Group-II, IPCC 4th
Assessment
Report,(IPCC,
2007).
Availableat
http://www/gtp89.dial.pipex.com/10.pdf
L. Briguglio, The Vulnerability index and Small Island Developing States. A
Review of conceptual and methodologies issues. (University of Malta,2003).
G. McGranahan, D. Balk and B. Anderson, Environment and Urbanization 19, 1,
7 (2007)
IPCC, Workshop on the Detection and Attribution of the Effects of Climate
Change. Working Group II Workshop Report. GISS (New York. USA,
2003)

New Technologies for Urban Safety of Mega Cities in Asia

The Community-based Planning andConsideration of Countermeasures throughWorkshop in "Below-Sea-Level City" against
Forthcoming Flood Disasters– Case in Katsushika City in Tokyo Takaaki KATO1, Hitoshi NAKAMUA2, Yuto SHIOZAKI3, Kinji ISHIKAWA4
1
Associate Prof. ICUS, Institute of Industrial Science,
The University of Tokyo, Japankato-t@iis.u-tokyo.ac.jp
2
Project Researcher ICUS, Institute of Industrial Science,
The University of Tokyo, Japan
3
Graduate School of Engineering, The University of Tokyo, Japan
4
Director, NPO “Ah! Safe and Amenity MACHIDUKURII”

ABSTRACT
There are high-density and broad urban areas below the sea level, we call
"BELLOW-SEA-LEVEL CITIES (BSLCs)". There are few safe facilities or areafor evacuation in case of flood disaster, therefore, huge amount of residents morethan two million in Tokyo have high exposure risk. Huge physical and humandamage is estimated in case of a wide-scale flood. Meanwhile, sea level risingand emergence of huge typhoons is estimated in the future according to IPCC
(2007). Some sort of countermeasure from the aspect of urban planning andarchitecture is needed in below-sea-level city in preparation for gradual flood
disaster risk rising. We have tried to study countermeasure with NPO andcommunity association in Katsushika City in Tokyo since 2006. In this paper, we
report a series of resident collaborative workshop.
Keywords: climate change, urban planning, community-based planning, residents
collaborative planning

1. INTRODUCTION
According to Ministry of Land, Infrastructure, Transport and Tourism (MLIT)
2005, a population living in areas under the sea level is said to be a total of morethan four million in three major metropolitan areas in Japan, i.e. Tokyo, Osakaand Nagoya metropolitan areas. We call these areas "BELLOW-SEA-LEVELCITIES (BSLCs)". BLSCs have been exposed to flood risk and the risk has been
increasing corresponding to climate change. However, recently, few floods haveoccurred in BSLCs because of the enhancement of flood-control. As a result, theawareness of flood risk has been declining and the preparation for flood cannot beenough.

October 2010, Kobe, Japan

These areas also have another risk to not usual flood but one following anearthquake. The probability of the conjunction of an earthquake and an extreme
weather causing flood may be negligible; however, the probability of theoccurrence of an extreme weather under repairs of damaged flood-control
facilities including banks will not be negligible because they have possibility to bedamaged by a huge earthquake and the recovery will need much time. If damagedbank was broken, wide spread built-up would be under water for a long time.
Revision of flood prevention law in 2005 has obligated municipalities to publish aflood hazard map which has information of flood hazard and evacuation areas.
However, municipalities in BSLCs have difficulty to make an understandable
hazard map for citizens because they have no safe evacuation areas in case offlood. For example, Katsushika city located in BSLC of Tokyo had no choice but
to induce more than 27 million people to evacuate for terraces on a hillside morethan 10km far away with no exposure to flood. For comparison, evacuation areas
against post-earthquake urban fire spreading are allocated to be less than 2 km for
all citizens. The evacuation will be difficult under the present condition in case ofwide scale flood.
At the present time, there is no perfect solution for BSLCs, therefore,
consideration of countermeasures and various kinds of planning including
mitigation and evacuation will be essential.
This paper reports a case of community-based planning and consideration ofcountermeasures against mega flood disasters. It is residents collaboration throughworkshops schemed by experts group and a non-profit organization (NPO) in
Katsushika City which is typical BSLC in the east of Tokyo. A total of sevenworkshops and 4 events have been implemented by collaboration from FY2006
until the present. In a series of the activities, there are several experiments oringenuities in this paper, we focus on them and discuss to share common problem
and our experience with readers.

2. OUTLINE OF CASE STUDY AREA
2.1 A Study Area
Our study area is located in the east of Tokyo and named North Shin-Koiwa
district. It is enclosed by three rivers: the Arakawa, the Shin-Nakagawa, and the
Nakagawa, on three sides (See Figure 1). The district has an area ofapproximately178 ha and has a population of 32,000 in 2004. It had been built up
with low-rise buildings.
This district has not experienced since flood disaster in 1947. The residents had
little interest in flood disaster.

New Technologies for Urban Safety of Mega Cities in Asia

Figure 1 Study Area (northern Shin-Koiwa District in Tokyo)
2.2 What Create BSLCs?
BSLCs were rural zone above sea-level before modernization. They have beencreated by artificially. A large amount of ground water pumping throughindustrialization caused subsidence in vast area of river plain. The Subsidence had
continued for approximately eighty years until regulations for ground water
pumping placed in 1970’. On the other hand, urbanization had expanded into
these areas rapidly since 1960’ although the subsidence was apparent. In fact,
BSLCs had been born by two failures: the overdue regulations and urban planningwithout a concept of risk management. At present, a population of approximately
two million lives in BSLCs (See Figure 2)

Area exposed to tidal flood risk: 254.6km2
Area under high tide sea level: 124.3km2
Area under low tide sea level: 31.5km2

Figure 2 BLSCs in Tokyo (Tokyo
Metropolitan Government)

3. COLLABOLATIVE ACTIVITIES IN BSLCs
3.1 Implementation Organizations
Concerned parties of the activities are three: NPO which have the base in the
district and act for creation of safe and amenity city, experts group who hasvarious kinds of specialties: urban planning, river engineering, municipal
administration and disaster prevention, and a community association which iscalled “CHOKAI”. Each party has different roles. The original sharing role is as
The Community-based Planning and Consideration of Countermeasures throughWorkshop in "Below-Sea-Level City" against Forthcoming Flood Disasters

October 2010, Kobe, Japanfollows: NPO and experts group play a role as project managers. NPO is total
coordinator, and experts group give various kinds of know-how needed. The
community association is participants of workshops. As mention later, the role
sharing has been changing by gradation.

Figure 3 Collaboration of three different kinds of organizations
3.2 Outline of Workshops for Planning and Consideration ofCountermeasures
The activities started from FY2006 and have succeeded up to present date. A totalof seven workshops and four events schemed by experts and NPO were
implemented and they have induced community association to take theircountermeasures by themselves. Administrative officers of the municipality haveparticipated in them as observers and supported from backward.
The activities can be classified into four stages. The stages cover from risk
communication to implementation of countermeasure. Especially, they were
designed to consider both short-term countermeasures such as evacuation
planning and long-term ones such as urban planning including creation of highland for evacuation.
The first stage had been implemented in FY2006. The objective was tounderstand risk and consider a scheme of countermeasures they should take. We
have two intents. The first is to promote discussion based on facts. We used not
only usual tools such as map exercise and field work, but outputs of analysis with
GIS including flood simulation. The participants confirmed that their houses weresinking, and could understand flood risk as their own. The second is to the balanceof short-term and long-term countermeasures. When people first realize risk, theynaturally weigh on short-term countermeasures in order to remove risk at hand
rapidly. As result, long-term countermeasures including drawing a vision of town
tend to be forgotten. In the program, we focused on the scheme and avoid detail
discussion of each countermeasure. The balance has continued to be kept up to thepresent date thanks to enough discussion of the scheme at that time.

New Technologies for Urban Safety of Mega Cities in Asia

The second had been implemented. The aim was to consider countermeasures we
can do. Two main issues were raised. They were evacuation plan as short-term
countermeasures and drawing a vision of their town as long-term ones. They
understood the difficulty to evacuate and intended to look for solutions. Especiallythey discuss practicable solution focusing on those who require support such as
elderly persons and disable persons. As for long-term countermeasure, they who
don’t have sense of urban planning are difficult to draw a vision; therefore, we
prepared a planning tool to inspire imagination. We use an amount of LEGO
blocks corresponding to an area of evacuation which residents need and put themon a map of their town. It facilitated building-up and sharing of spatial image
among the participants. They could two alternatives, creation of high-rise land inriverside or public facilities such as elementary schools. They shared the directionin the future.
The third stage is implementation phase. Independent implementation bycommunity had started in practical. They hold a workshop for risk communication,
which corresponds to the first workshop they had experienced, by themselves.
The most important problem at that time was that problems of a community wereshared among only the participants. Propagation for other residents who are notparticipants was a hot issue. The best way to do so was that the participants taught
non-participants. They had trained the operation of GIS before the workshop andthey operated GIS in front of the residents in a workshop. For reference, they weremore than sixty five years old, and have no skill at all. We can say that they hadmuch high motivation. The others were two drills: ones of long distanceevacuation and of preparation of meals outdoors as refugees. The role of NPO andexperts has been changing from as project manager to as supporter.
The newest stage has just started from FY2010. It has focused on a new theme,
long-term measures of making safe evacuation area in neighborhood andconsidered realization procedures with a view to revision of the existing
institution of redevelopment. NPO, community, experts and administrative
officers has collaborated.
In addition, there were two events and two symposium held. Two events wereintended to lead the change in thinking. Motivation of the participants might
decline because they cannot get a kind of fun in front of mega-risk. We think thata kind of fun is essential to keep motivation and continue activities. On the other,two symposiums were prepared as one of solution for a problem. Of course,
neighbor communities had same problem, and should share the problem
consciousness. We regarded a symposium as place to appeal for neighborcommunities. They invited leaders of neighbor community associations andadopted each declaration in a symposium involving them.

The Community-based Planning and Consideration of Countermeasures throughWorkshop in "Below-Sea-Level City" against Forthcoming Flood Disasters

October 2010, Kobe, Japan

Table 1 Outline of Collaborative Action
1st Stage: Consider countermeasure by yourselves. (FY2006)
1 Workshop
Understand problems as your own.
2nd
Confirm the structure of preparation for flood and clarify what a
Workshopcommunity and an individual should consider.
Consider the preparation which a community and an individualrd
3 Workshop
should implement.
st

1st Event

Board a boat :Boat handling training through boating in the seand

2 Stage: Start short-term countermeasures and consider long-term ones indetail (FY2006-2007)th
4 Workshop
Understand a hazard map with more realism
5th Workshop
Draw up the vision of town in the future
2nd Event
1st
Symposium

Observe our town from the river on a ship
Draw up the declaration of preparation for flood and climatechange as a town.

3rd Stage: Induce participants to implement self-motivated actions(FY2007-present)
Organize workshop of the community, by the community, for
6th Workshop
the communityth
7 Workshop
Select countermeasures which should be implement
Self-motivated Action of town resident association (FY2009 - )1 Action
Implement drills of long distance evacuationnd
2 Action
Implement drills of preparation of meals outdoors as refugees
to be continuedst

2nd
Symposium

Draw up the declaration of implementation of countermeasure
and climate change as a town.

4. CONCLUSION
The community-based planning and consideration of countermeasure for megaflood disaster will be new approach in Japan. Previously, the river administration
had entirely charge of flood control. Approach from urban planning or community
didn’t exist as a concept. However, it will be essential for mega-flood taking
climate change into consideration. This case can become the first case. In what
follows, we consider achievement and assignment.
4.1 Achievement of a Series of Activities
We can say that this case is best practice. The fact that community own activities
have been implemented naturally demonstrates it. We get standardization of
method for planning and consideration of countermeasures for mega-flood
disaster in BSLCs through a series of activities. In this regard, we need to pointout that the ability of facilitators determines the feasibility of workshop. Further
standardization will be needed.

New Technologies for Urban Safety of Mega Cities in AsiaAt the same time, it was demonstrated that the structure of organizations
constituted with NPO, experts and community is effective. In this case,administrative officers had stood backward as supporters. If they were membersof project managers, the residents would claim many countermeasures of which
the public sector takes the initiative and independent activities of community
would not be induced. On the other, administrative officers generally prepare
kinds of countermeasures when they show the citizens the risk information. The
structure of this case will be one of models of new public sector.
4.2 Next Challenges
There are many challenges left. People in the community who share common
understanding with the participants remain minority. Further propagation inside
the community will be needed. At the same time, neighbor communities share acommon destiny. They need to advance their activities for collaboration withneighbor communities. At present, the community is projecting workshop withjunior high school students which the participants have charge of facilitation.
NPO and the community implement traveling exhibition on mega-flood risk in
Katsushika city this year.
REFERENCES
Tokyo Metropolitan Governments: height of low land in Tokyo, Japan.
Ministry of Land, Infrastructure, Transport and Tourism, 2005.10, The present
situation of lowland area under sea-level, Japan
T.Kato, K.Ishikawa, and T.Ichiko, 2007.5, The Community-based Workshop to
Correct the Awareness of a Flood Damage and Discuss Measures, Proceedings ofInfrastructure Planning Japan
T.Kato, K.Ishikawa, and T.Ichiko, 2008.5, The Community-based Workshop to
Understand the Hazard Map and Discuss Long-Term Measures, Proceedings ofInfrastructure Planning JapanThe Community-based Planning and Consideration of Countermeasures throughWorkshop in "Below-Sea-Level City" against Forthcoming Flood Disasters

Climate-Resilient Development in Urban
Areas – A Perspective from Malaysia
1

Joy Jacqueline PEREIRA1 and T. F. NG2
Professor, Deputy Director, SEADPRI-UKM, Universiti Kebangsaan Malaysia
joy@ukm.my
2
Associate Professor, Geology Department, Universiti Malaya, Malaysia

ABSTRACT
Climate change mitigation and adaptation are generally played out in different
policy domains involving different stakeholders. Mitigation is driven primarily byagreements at the UNFCCC, which would require national responses. Adaptation
issues tend to be confined to affected entities at national, state, local andcommunity levels. In an effort to reconcile these differences, the Malaysian
Government has defined climate-resilient development as “development that takes
into account measures to address climate change and extreme weather in linewith national priorities”. Spatial planning responses provide an opportunity foradaptation-mitigation interactions. However, in the immediate term, the priority
should be on adaptation to minimize the impacts of climate change to reduce therisk of disasters. For this purpose, the ongoing terrain assessment approach has
to be expanded to include potential interaction with climate related stressors. The
priority should be to identify highly susceptible urban areas and delineate socioeconomic dimensions such as exposure, coping capacities and adaptive capacity.
Keywords: climate change, adaptation, hazards, vulnerability, spatial planning

1. INTRODUCTION
In order to achieve sustainable urban development, it is necessary to ensure thatthe planning process includes socio-economic considerations, management of
resources and suitability of land, taking into account potential hazards andenvironmental impacts. In addition, the planning process also has to take into
account the changing climate and its potential impacts so as to reduce
vulnerability and ensure resilience of any proposed socio-economic development
project. It would be more cost-effective to take adaptation measures early on,
especially for critical infrastructure with long economic life.
Changes in climate may be due to natural processes or to persistent anthropogenic
changes in atmosphere or in land use. The definition of climate change as used in
the United Nations Framework Convention on Climate Change (UNFCCC)
includes only those changes that are attributable directly or indirectly to humanactivity. There are two central actions associated with climate change, mitigation
and adaptation. Mitigation refers to actions taken to reduce greenhouse gas (GHG)
emissions and enhance sinks to tackle the causes of climate change. Adaptation

0ctober 2010, Kobe, Japanrefers to actions taken to help communities and ecosystems cope with actual or
expected impacts of climate change (IPCC, 2007).
This paper commences with a brief articulation of resilience as perceived in the
climate change and disaster risk reduction platforms, and its relationship toclimate-resilient development. The potential for both climate change adaptationand mitigation within the spatial planning processes is briefly alluded to in thissection. The subsequent focus of the paper is on climate change adaptation. This
is in light of the immediate intervention that is required to reduce vulnerability
and build resilience in a changing climate. Knowledge on hazards andvulnerability is highlighted. This is followed by a brief discussion on
circumstances in Malaysia, and the means of addressing them. The main aim is toaccentuate the possibility of expanding existing assessments to incorporate
elements to address climate change adaptation within the spatial planning
processes in Malaysia.
1.1 Climate-Resilient Development
Resilience in the context of the climate change discourse refers to “the ability of asocial or ecological system to absorb disturbances while retaining the same basic
structure and ways of functioning, the capacity for self-organisation, and thecapacity to adapt to stress and change” (IPCC, 2007). Resilience in the context ofthe disaster reduction community refers to “the capacity of a system, community
or society potentially exposed to hazards to adapt, by resisting or changing inorder to reach and maintain an acceptable level of functioning and structure”(UNISDR, 2005). The ability of the social system to learn from past disasters
would influence its capability to be better prepared to respond to future disasters.
The IPCC definition of resilience is generic in that it does not qualify the nature of
the “disturbance”. However, in the UNISDR definition, the nature of the“disturbance” is specified in the form of exposure to hazards. Furthermore, there
is emphasis on retaining “the same basic structure and ways of functioning” in theformer as distinct from “to an acceptable level of functioning and structure”. The
difference in the definitions from both these institutions is open to interpretation.
In the context of the climate change discourse, it could be interpreted that
resilience alludes to both climate change mitigation and adaptation. In the context
of the disaster risk reduction, the emphasis is only on climate change adaptation.
This is particularly pertinent with respect to the term “climate-resilient
development”. Generally, the term is widely used and tends to be associated withadaptation and the need to ensure that a social system has the capacity for selforganisation and ability to cope with the change. This inference is most likely
derived from the definition of resilience associated with the disaster risk reduction
community, which clearly confines the term “disturbances” to exposure to hazards.
However, “disturbances” could constitute more than threats posed by the physicalmanifestations of climate change such as sea-level rise, floods, etc. Disturbancecould also be interpreted as social and economic pressures to curtail GHG
emissions. Such pressures would require reallocation of development funds for

Climate-Resilient Development in Urban Areas – A Perspective from Malaysia

mitigation measures that may undermine socio-economic growth and distribution
efforts, particularly for developing countries.
Climate change mitigation and adaptation are generally played out in different
policy domains involving different stakeholders (Tompkins and Adger, 2005).
Mitigation is driven primarily by agreements at the UNFCCC, which would
require national responses. Adaptation issues tend to be confined to affected
entities at national, state, local and community levels. In an effort to reconcile
these differences, the Malaysian Government has defined climate-resilient
development as “development that takes into account measures to address climatechange and extreme weather in line with national priorities” (Government of
Malaysia, 2009). Issues associated with mitigation tend to have an explicit
economic orientation involving business and industry. Examples include carbon
offset schemes, financing and transfer of technologies related to energy efficiency
and renewable energy to promote GHG emission reduction and Reducing
Emission from Deforestation and Forest Degradation (REDD) to promote sinkenhancement. Adaptation issues are tend to be related to resource security withrespect to its depletion and community safety in relation to hazards and disasters.
The implication of the National Policy is manifold in several levels. Key actions
have been formulated to balance adaptation and mitigation in the quest forclimate-resilient development. Climate change responses to-date has been
implemented in a disjointed manner with emphasis on mitigation and mainly inthe federal government level. Actions to balance adaptation and mitigation will
now have to be implemented at all levels. This will be a very challenging task at
the state and local levels because land, forests, water and other resources comeunder the purview of the state government. State governments and local
authorities are generally constrained by limited knowledge, capacity and resources.
Urban areas under the management of local authorities pose the biggest challenge
as many are unaware of not only climate change issue, but also of existing hazards
that may undermine development in the near term.
There is much potential for both adaptation and mitigation through the spatialplanning process. Urban landuse planning at the local authority level results instructure plans and local plans, which takes into account several aspects. These
include economic needs, population density, existing land use and other factors
associated with the development process as well as environmental aspects such asconservation of wetlands and catchment areas. Conservation efforts willcontribute to natural carbon sequestration and this would constitute as a mitigation
measure. Initiatives for assessing such potentials are expected to commence
shortly, with implementation of the National Policy on Climate Change, which
advocates balanced adaptation and mitigation. However, the immediate focus
should be on climate change adaptation as climate change is very likely during the
21st century (IPCC, 2007). The projected change and increase ofhydrometeorological hazards is also likely to have consequences on certain
geological hazards (NAHRIM, 2006). Immediate intervention is required toreduce vulnerability and build resilience in a changing climate.

Climate-Resilient Development in Urban Areas – A Perspective from Malaysia

0ctober 2010, Kobe, Japan

1.2 Hazards and Vulnerability
Hazards are potentially disruptive physical events, substance, phenomena or
human activities that may cause the loss of life or injury, property damage, socialand economic difficulty or environmental degradation, including dormant
conditions that may represent future threats (UNISDR, 2004). Disasters areconsequences of such disruptive events, phenomena or human activities on human
life, properties and infrastructure within a specific geographic area in a given
period of time. Hazards have always played an important role in shaping socialand cultural development. They threaten humans and their properties andinfrastructure; and without any form of intervention, hazards always lead todisasters. Catastrophes are very severe disasters where almost all members of acommunity and their basic supply centers are disrupted and they cannot help eachother; making delivery of humanitarian aid difficult if not impossible.
Vulnerability refers to the conditions determined by physical, social, economic,
and environmental factors or processes, which increase the susceptibility of acommunity to the impact of hazards (UNISDR, 2004). Climate change is expected
to contribute to increasing the occurrence of natural disasters in the future (Cruz etal., 2007). In the context of climate change, vulnerability is the degree to which asystem is susceptible to and unable to cope with the adverse effects of changes, interm of the character, magnitude and rate of change, as well as the exposure,sensitivity and adaptive capacity of the system (IPCC, 2007). Adaptive capacity inrelation to climate change impacts refers to the ability of a system to adjust tochanges in climate to moderate potential damages, to take advantage ofopportunities, or to cope with the consequences.
Risk is generally viewed as the function of hazard levels and vulnerability of theelements exposed. Over the years, the concept of vulnerability has been mademore comprehensive to include susceptibility, exposure, coping capacity andadaptive capacity, as well as different thematic areas, such as physical, social,economic, environmental and institutional vulnerability (Birkmann, 2007). The
implication of the expansion of the definition of vulnerability is that the usage of“risk” becomes less useful in the context of hazards influenced by climate change
for a given area, with respect to the long-term changes associated with climatechange. It would be meaningful to assess risk for observed changes and current
drivers of change for a system in present conditions, and more so if it is related toa social decision (Tompkins and Adger, 2005). Any assessment of long-term risks
would entail a projection of future changes in physical conditions framed around
scenarios of social, economic, environmental and institutional set-ups, resulting inhigh levels of uncertainty. A vulnerability assessment is more useful in thiscontext, to come to a social decision.
Vulnerability assessments encompass current characteristics of a hazard and its
interaction with climate related stressors (susceptibility components), representing
the intrinsic weakness of a system, as well as socio-economic dimensions such as
exposure, coping capacities and adaptive capacity. This is particularly relevant toa developing country, which would have the opportunity for making spatialplanning responses as a form of policy intervention, in the present time to avoid

Climate-Resilient Development in Urban Areas – A Perspective from Malaysia

future exposure. It is also relevant for strengthening coping capacities andadaptive capacity. There are also economic advantages in this approach, as thecosts of remediation or application of adaptation technologies would be reduced.
In addition, the need for adaptation technologies could be identified more
effectively.

2. CURRENT CIRCUMSTANCESIn Malaysia, the most common hydrometeorological disaster is flooding. The
phenomenon has affected the greatest number of people over the last century(Liew, 2009). Urban areas are particularly affected by flash-floods. Between 1990
and 1996, over 100 incidents were reported in the Klang Valley alone, where
Kuala Lumpur is located (Pereira & Komoo, 2004). Flash-floods usually occur
with little or no warning after heavy rain and can reach peak level in a short time.
A number of reasons contribute to flash-floods in urban areas. These include
increased impermeability due to an increase in the built-up areas and increased
accelerated erosion from exposed surfaces resulting in sedimentation of rivers andstreams, which subsequently cause flash-flood along flat low-lying river channels.
Flash-floods in urban areas are also due to poor maintenance of drainage facilities(Jamaluddin, 1986).
Reports of disasters related to rock-falls and subsidence have been reported in theCity of Ipoh, coinciding with urban expansion into limestone terrain. Around
Kuala Lumpur and Penang, the onset of economic growth and expansion of thecity into hilly terrain have resulted in landslides and slope failures becoming moreprevalent. Such disasters have taken its toll on the urban population. Between
1990 and 1996, about 20 incidents were reported around Kuala Lumpur alone,with total fatalities amounting to 48 people (Pereira & Komoo, 2004).
Engineering approaches are the most common way to address hazards in urban
areas. There are many flood mitigation projects to address the flash-flood
situation, particularly around Kuala Lumpur. Such projects have served to lessen
flash flood disasters in limited parts of the city. Engineering solutions are also
commonly prescribed to remediate landslides and slope failures. In one particularcase, apartment blocks had to be abandoned after the structure was found to beunstable, causing much hardship to its residents.
In an effort to move away from remediation to prevention, the Minerals andGeoscience Department of Malaysia embarked on a systematic large-scale urban
mapping exercise. The geological terrain assessment involved systematic
segmentation of an area based on landform patterns, geology, drainage andsurficial processes (Chow& Ferdaus, 2000; JMG 2006). The GIS-based
assessment used a combination of information from remote sensing and field
mapping. A series of thematic maps on physical constrains, erosion and instability
were produced, to provide information on susceptibility of an area to floods,
landslides and subsidence. The end-product of the assessment is a construction
suitability map, to support planners and decision-makers in development of urban
areas.
Climate-Resilient Development in Urban Areas – A Perspective from Malaysia

0ctober 2010, Kobe, JapanThe Town and Country Planning (Amendment) Act 1995 (Act A933) exerts
primary control over the planning process in Malaysia. The Act has twocomponents and these are land use planning and development control. Local
authorities are empowered by this Act to incorporate elements of safety, healthand well-being as part of the development control process (Ismail, 1996). In somestates, local authorities have used information from terrain assessments toevaluate the suitability of a proposed development projects on a routine basis.
However, this practice is limited to very few local authorities. The majority of
local authorities have yet to apply this practice.
Efforts have been made to help planners and decision-makers to understand andappreciate terrain assessment and disaster reduction due to geological hazards.
This includes creating effective linkages between geologists, planners anddecision-makers to increase the awareness of the essential contribution of terrain
assessments to sound planning. Notwithstanding this, much more needs to bedone, especially to address the new challenges that are anticipated in the onset ofclimate change.

3. ADDRESSING FUTURE CIRCUMSTANCESIn Malaysia, localised climate projection indicate a substantial increase inmonthly rainfall over the North East Coastal region and decrease in monthly
rainfall in West Coast of Peninsular Malaysia may be expected by 2050
(NAHRIM, 2006). By end of the century, a more significant change in the annual
rainfall may be expected in the western regions of Sabah and Sarawak (Wan Azliet al., 2008). Simulations of future river flows in several watersheds in the east
coast of Peninsular Malaysia indicate increases in hydrologic extremes, i.e. higher
high flows and lower low flows when compared with historical levels (NAHRIM,
2006).
The number of disasters and people affected is anticipated to increase with theonset of climate change. Hydrometeorological and certain geological hazards areaffected by climate change. For example, landslides and subsidence are to acertain extent influenced by rainfall, which is in turn affected by climate change.
Higher and extreme run-offs may result in increased risk of flooding, which inturn heightens the risk of landslide disasters in urban areas. Increased flooding,particularly in areas previously not exposed to the hazards could lead to dispersalof contaminants and toxins into rivers where wastewater treatment plants are
overwhelmed. Such occurrences are already suspected in recent times and are
currently under investigation. The possibility of circulation of environmentallyhazardous substances in surface water where industrial sites and landfills areaffected cannot be ignored. The consequences could be disastrous if such risks are
not addressed.
The Town and Country Planning (Amendment) Act 1995 (Act A933) is the firstline of defense in terms of environmental protection, and it can be also be used asa planning response to climate change and disaster risk reduction. Development

Climate-Resilient Development in Urban Areas – A Perspective from Malaysia

control involves the regulation and control of planning for projects. This takes
into account consultation with and input from several technical departments, prior
to the concession of land conversion or planning permission. The local authority
consults several technical departments before permission is granted. In addition,
the Act requires the participation of the public in reviewing the plans that areformulated, making it suitable as a tool to enhance stakeholder engagement withrespect to climate change and disaster risk reduction.
The provision of appropriate and easily understood information regarding
vulnerable areas in the future will aid local authorities in making a decision
regarding an application for planning permission. Terrain assessment can support
planning tools such as the Guidelines on Integrated Environmental Sensitive
Areas (ESAs) to incorporate elements of climate change adaptation and disasterrisk reduction (Pereira et al., 2006; Halimaton et al., 2007). The use of terrain
assessment and Integrated ESAs will ensure landuse that supports the aspirationsof climate resilient-development, particularly when used in conjunction withexisting landuse planning mechanisms in urban areas.
In order for terrain assessment to be effective, the current information on
susceptibility, which represents the intrinsic weakness of a system, has to be
expanded. The assessment has to include potential interaction with climate related
stressors. The priority should be to identify highly susceptible on urban areas.
Based on this initial screening, socio-economic dimensions such as exposure,coping capacities and adaptive capacity have to be assessed. This is not currently
done by any organizations in the country. There are many aspects to be taken into
account at the assessment level, incorporation of findings into planning anddecision-making processes and subsequent implementation. These include
handling of uncertainties, harmonizing scale of information, governance withrespect to participatory planning and stakeholder consultation, education,awareness and communication of risks, emergency response and early warning aswell as limitation of resources, knowledge and technology. In addition to this,
there is the challenge of ensuring effective interactions between adaptation andmitigation.

4. CONCLUDING REMARKSThe National Policy on Climate Change and the National Policy on GreenTechnology accepted by the Cabinet of Malaysia in 2009. The establishment of
the National Green Technology and Climate Change Council, chaired by thePrime Minister of Malaysia has served to mainstream the issue of climate change
and bring about new institutional arrangements. The issue of balancing adaptationand mitigation can be addressed more effectively, to better serve the country. The
revitalized policy and institutional domains provides an opportunity address
climate change adaptation and mitigation at the macro and sectoral levels.
Spatial planning responses provide an opportunity for adaptation-mitigationinteractions. However, in the immediate focus should be on adaptation. Research
initiatives should be embarked upon that bridge the science-governance interface.
Platforms that link and create synergies between researchers, practitioners andClimate-Resilient Development in Urban Areas – A Perspective from Malaysia

0ctober 2010, Kobe, Japanother stakeholders should be strengthened. Concerted, systematic and purposive
efforts should be made to enhance education and awareness, in conjunction withstakeholders at the appropriate levels. All these efforts will make a significant
difference to the country in the context of climate-resilient development.

REFERENCES
Birkmann, J., 2007. Risk and vulnerability indicators at different scales.
Environmental Hazards (2007), doi:10.1016/ j.envhaz.2007.04.002
Chow, W. S. and Ferdaus, A., 2000. Geological inputs for the development of the
Payar Terubong – Relau area, Pulau Pinang. In: Teh, G.H., Pereira, J.J. and
Ng, T.F. (Eds.) Proceedings of the Annual Geological Conference 2000,
Geological Society of Malaysia, Kuala Lumpur, 249-260.
Cruz, R.V., H. Harasawa, M. Lal, S. Wu, Y. Anokhin, B. Punsalmaa, Y. Honda,
M. Jafari, C. Li & N. Huu Ninh, 2007. Asia. Climate Change 2007: Impacts,
Adaptation and Vulnerability. Contribution of Working Group II to the
Fourth Assessment Report of the Intergovernmental Panel on Climate
Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden &C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 469-506.
Government of Malaysia, 2009. National Policy on Climate Change. Ministry of
Natural Resources and Environment, Putrajaya.
Halimaton S.H., Pereira, J.J. and Komoo, I., 2007. Sustainable City Planning –Emphasis on Management of Environmentally Sensitive Areas. Journal of
the Malaysian Institute of Planners, 5, 61-76.
IPCC, 2007. Climate Change 2007: Impacts, Adaptation and Vulnerability.
Contribution of Working Group II to the Fourth Assessment Report of theIntergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani,
J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge
University Press, Cambridge, UK.
Ismail Ibrahim, 1996. Pindaan Akta Perancangan Bandar dan Desa dan Laporan
Cadangan Pemajuan [Revision to the Town and Country Planning Act andDevelopment Proposal Plan]. 11th Senior Officials Meeting of the Town andCountry Planning Department, Kuching, Sarawak, 2-5 October, 1996.
Organisers: Town and Country Planning Department of Peninsular Malaysia
and the Government of Sarawak.
Jamaluddin, M.J., 1986. Human Perception and Responses to the Flash-Flood
Hazards in Parts of Kuala Lumpur. In: Sham Sani (ed). A Study of the Urban
Ecosystem of the Kelang Valley Region, Malaysia, Vol. 1 - The Kelang
Valley Region: Some Selected Issues, 84-104.
JMG, 2006. Geological Terrain Mapping Manual. Department of Minerals andGeoscience Malaysia, Ministry of Natural Resources and Environment,
Kuala Lumpur. 69 pp.
National Hydraulic Research Institute Malaysia (NAHRIM), 2006. Study of the
Impact of Climate Change on the Hydrologic Regime and Water Resourcesof Peninsular Malaysia – Final Report. Ministry of Natural Resources andEnvironment, 184 pp.

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Pereira, J.J. and Komoo, I. 2004. Sustainable Management of the PhysicalComponent of Urban Ecosystems: The Malaysian Perspective. In: Miller, D.
& de Roo, G (Eds.) Integrating City Planning and Environmental
Improvement-Practicable Strategies for Sustainable Urban Development(2nd Edtn.). Ashgate Publishing Ltd., Aldershot, 115-126.
Pereira, J.J., Halimaton S.H. and Komoo, I., 2006. Management ofEnvironmentally Sensitive Areas. In: Halimaton, S.H. & Norliza, H. (Eds.)
Planning a Developed State-Development Planning for Sustainability.
Selangor State Government, Shah Alam, 13.1-13.13.
Tompkins, E. L. and Adger, W. N., 2005. Defining response capacity to enhance
climate change policy. Environmental Science & Policy 8, 562-571.
UNISDR, 2004. Terminology Basic Terms of Disaster Risk Reduction. In: Livingwith Risks: A Global Review of Disaster Risk Reduction Activities,
UNISDR, Geneva (Revised 2009).
UNISDR, 2005. Hyogo Framework for Action, 2005-2015. In: Building theResilience of Nations and Communities to Disasters, UNISDR, Geneva.
Wan Azli, W.H., S.Mohan, K. and S. Kumarenthiran, 2008. Climate Change
Scenario Climate Change Scenario and the Impact of Global Warming on
the Winter Monsoon. In the Second National Conference on Extreme
Weather and Climate Change: Understanding Science and Risk Reduction.
14-15 October 2008, Putrajaya, Malaysia.

Climate-Resilient Development in Urban Areas – A Perspective from Malaysia

Climate-related and other Hazard-related
Urban Risks in Coastal India – An Overview
on Specific Study Sites
Ramasamy R. KRISHNAMURTHY
Associate Professor, Department of Applied Geology, School of Earth &Atmospheric Sciences, University of Madras, Chennai 600 025, India
rrkrishnamurthy@gmail.com
ABSTRACT
Important coastal cities – Chennai and Mumbai are located on east and west
coasts of India, respectively, are witnessing the fury of climate change induced
disasters like cyclone and monsoonal floods especially from the year 2005.
Invariably all the coastal cities in both east and west coasts of India are having
the similar threat due to climate change and future sea-level rise and otherclimate change induced disasters like drought and monsoonal floods. Especially
due to unplanned urbanization and rapid developmental activities along thecoastline both cities are now witnessing erosion and accretion of their coastlines,
which is now being treated as a chronic disaster and the same is expected toaggravate in the future due to sea-level changes. This paper is aimed to review
the core issues and concerns related to urban risks in Chennai and Mumbai. .
Keywords: coastal urban centers, multi-hazards, chronic disasters, urban risk

1. INTRODUCTION
The coastal zone includes both land as well as the adjacent water part, which areusually dynamic in nature and strongly influenced by each other, and also more
susceptible to hazards induced by natural as well as man-made processes. Coastal
locations were some of the first settled in India and have always accounted for
population concentration as well as population explosion apart from the place for
future areas of expansion. Due to rich in biological diversity, coastal areas
housing large number of hot spots such as reserves forests, national parks andmarine biosphere reserves. Due to the rapid economic expansion expected indeveloping world cities, the highest asset exposure is projected to become moreconcentrated in Asian cities, with eight of the top 10 situated in this region:
Guangzhou, Kolkata (Calcutta), Shanghai, Mumbai (Bombay), Tianjin, Tokyo,
Hong Kong and Bangkok. Out of these ten cities, 2 are situated in coastal areas inIndia. Seventeen out of the 20 cities with the expected largest proportional
increase in asset exposure by 2070 are located in Asia. They comprise both megacities and current second-tier cities www.cat-risk.com. Since urbanization is an
irrecoverable process the reality of urban risks especially during floods are
witnessed in a majority of the coastal cities in India after 2004. However, the0ctober 2010, Kobe, Japaninfluence of biophysical factors like coastal landforms, land elevation, water ways,
wave and tide conditions etc are more in controlling as well as aggravating urban
risk due to natural and man-made disasters. Most of the coastal cities along east
coast of India are prone to climate-related disasters, which is mainly due to low
elevation, gently sloping topography, occurrence of water ways, backwaters,
estuaries and marsh land areas which provide scope for informal settlements /encroachments.
Urban economic imbalances especially the urban poor being forced to settle overmore vulnerable localities even by knowing the risk and other environment related
hazards. Due to the availability of limited space, coastal cities like Chennai areexpanding horizontally and new townships are emerging in the southern part ofthis coastal city. Also the natural beauty and location of the coastal belt attracts
multi-story buildings for both residential and commercial purposes, which are
now becoming prone for contamination of coastal aquifer due to theoverexploitation of subsurface ground water, which leads to incursion of sea waterin to coastal aquifiers. Even in normal and below normal rainfall scenarios,
Chennai and Mumbai will experience more droughts and scarcity of potable water
during the summer period.
The Bay of Bengal is one of the major centres of the world for breeding tropicalstorms while a few strike the west coast of India, mainly the Gujarat and North
Maharashtra coast. Out of the storms that develop in the Bay of Bengal, over 58
percent approach or cross the east coast during October – December. Cyclones
over the Bay of Bengal usually move westward, northwestward, or northward andcross the east coast of India or Bangladesh. Though the east coast of India is more
prone to cyclones, as natural barriers like coastal dunes and mangroves are morein east coast when compared to west coast. Severe alteration of these naturalbarriers especially in urban centres due to urbanization and industrialization
makes coastal areas more susceptible to climate induced disasters. Also the recent
study based on the integration of long-term daily rainfall dataset and highresolution gridded analysis of human population indicates a significantly
increasing trend in the frequency of heavy rainfall climatology over urban regionsof India during the monsoon season. Urban regions experience less occurrences oflight rainfall and significantly higher occurrences of intense precipitationcompared to non-urban areas (Kishtawal et al., 2010). Coastal urban areas inIndia are expected to face the risk due to monsoonal floods almost every year.
Therefore, every coastal city is now in a stage to make an attempt to strengthen its
infrastructure like storm water drainage system, desiltation and interconnection ofurban water bodies, evacuation modalities and shelters, institutional cooperation
mechanism, etc to meet the eventualities.
2. COASTAL URBAN RISK MANAGEMENT– ISSUES AND CONCERNS
2.1 Shoreline Changes
One of the major requirements of planning coastal protection work is to understandcoastal processes of erosion, deposition, sediment-transport, flooding and sea-levelNew Technologies for Urban Safety of Mega Cities in Asia

changes, which continuously modify the shoreline. Multi-date satellite data have beenused to study shoreline change and coastal landforms to understand coastal processes.
Shoreline is one of the rapidly changing landform along coastal India. The accurate
demarcation and monitoring of shoreline (long-term, seasonal and short-term changes)
are necessary for understanding of coastal processes. The rate of shoreline change
varies depending up on the intensity of causative forces, warming of oceanic waters,
melting of continental ice, etc. Shoreline erosion is being considered as a calamity
because it causes (i) loss of invaluable land areas and lives (ii) habitation displacement/ relocation (iii) loss of beaches and (iv) loss of transport network, infrastructure andother installations. This has been observed in northern part of Chennai coast, whereshoreline erosion is chronic and put in to stage for forcible migration of local
population. Earlier study (Krishnamoorthy et al., 2001) based on GIS analysis has
quantified that nearly 77 sqm of land area along north Chennai coast is being eroded
every year due to shoreline erosion, which make the fisher community lives in about
15 hamlets are forced to move from this part.

Figure 1: Shoreline erosion scenario in North Chennai
While considerable land part of this coastal zone is swallowed by the sea due toerosion, the resultant accretion leads to closure of important estuarine mouths inthis urban centre. This is an important environmental hazard being faced by thiscity during the last two decades and the State Government has given special focus
to prevent further erosion of this shoreline.
India is one of the pioneering countries in Asia to utilize the satellite imagery toassess the changes in land use / cover, environment and ecosystems including the
dynamics of its more than 7500 km length coastline since early 1970s. Due to theadvancement in remote sensing technology in the country especially the
improvements in both spatial and spectral resolution, more site specific studies
were carried out including micro level mapping for disaster prone areas. A
considerable amount of work has been carried out by various institutions /agencies especially the Space Applications Centre and National Remote Sensing
Agency to map the shoreline changes to quantify the rate of erosion and accretiondue to both natural as well as made impacts.

Climate-related and other Hazard-related Urban Risks in Coastal India – An Overview
on Specific Study Sites

0ctober 2010, Kobe, JapanThe changes in configuration of shoreline due to erosion and accretion lead to its
frequent oscillation, which will be treated as a benchmark line especially inzoning the coastal zone for the implementation of Coastal Regulation Zone (CRZ)
by the Ministry of Environment and Forests (MoEF). Now the MoEF is taking into the consideration of horizontal shifting of shoreline due to erosion andaccretion with reference to 1967 Survey of India topographical maps andmultidate satellite imagery.
2.2 Coastal flooding
After a decade of acute water scarcity in majority of coastal urban cities like
Mumbai and Chennai both these cities have experienced heavy rainfall eventswith increasing frequency of urban floods during South West Monsoon season
since 2005. Local governments have taken efforts in implementing rain water
harvesting programme through the participation of community to meet out thewater crisis. As these cities started growing uncontrollably especially during thelast two decades, the land use pattern changed drastically with more vacant areas
which have been converted for constructions and other infrastructure facilities.
This results in change of urban hydrology from gradual rising discharge to quicker
and higher peak flow. Many of the water storage areas have been encroached byhuman settlements and denudation of water ways during the drought years
aggravated the impact of urban floods both in Mumbai and Chennai since 2005.

Figure 2: Encroachments around water body in South Chennai
Mumbai is one of five cities included in the centrally sponsored Mega City
Scheme launched by the Government of India in the Eighth Five Year Plan. Like
most major urban centres in our country, Mumbai has grown tremendously in thelast few decades due to unabated migration from the smaller towns and rural areas.
This resulted in a haphazard fashion with little consideration for proper urban
planning. Also most areas of the city are lacking basic civic amenities. Slums are
considered vulnerable primarily because of their location and density, population
concentration and access to infrastructure. Slums are occupying hilltops, slopes,
nallahs, low-lying areas with tendency to flood during high tides and monsoon
seasons. Some projections state that Mumbai could overtake Tokyo as the world’s
largest city by 2050 (Shaw, 2008). Mumbai’s greatest stress bundle is related to
New Technologies for Urban Safety of Mega Cities in Asia

extreme rainfall and floods, such as the heavy flooding that occurred in July 2005.
A record of 994 mm rain within 24 hours marooned the entire Mumbai on 26th
July 2005. In some low-lying areas, the water was 10 to 15 ft deep. Open guttersand nallahs turned into raging rivers. Thousands of homes in the Mumbai’s
sprawling slums were either washed away or damaged beyond repair. The middle
and upper class were not spared either, with floodwaters entering and evencompletely submerging ground floor apartments in many areas (Conservation
Action Trust, 2006). Mumbai’s various characteristics of topography (flat),geology (unconsolidated fill material), numerous wetlands and flood-prone areas,
the city’s building conditions (not meeting building codes, squatter dwellings,
previously flood-damaged buildings), poor sanitation and poor waste treatment
and removal capabilities together create a particular bundle of stresses thatcollides with the set of socio-environmental conditions of Mumbai, such thatvulnerabilities emerge for the system (www.ihdp.org/publications). Climate
model forecasts indicate that extreme precipitation will happen over a large area,
particularly over the west coast of India and west central India (Rupa Kumar at al.,2006). Additionally, spatial distribution of temperature changes indicated asignificant warming trend which has been observed along the west coast, central
India, and interior Peninsula and over northeast India. However, cooling trend has
been observed in northwest and some parts in southern India (Gupta et al., 2009).
2.3 Coastal Flooding due to Extreme events - Tsunami
On 26 December 2004, as many as seven countries in Asia were devastated by the
Indian Ocean tsunami event, which resulted in more than 200,000 loss of life andseveral millions of families displaced and property damages of about US $ 10
billion. Among many areas destroyed were urban coastal areas with important
infrastructure and lifeline facilities. Chennai on the southeast coast of India is oneof the worst affected sites along Tamil Nadu coast. The wave height created bythis tsunami resulted in the inundation of urban areas bordering the sea, which not
only resulted in loss of life and property damage but also severe environmental
hazards due to flooding. Inundation mapping of this tsunami and also theincorporation of land elevation details together with administrative boundary
maps clearly brought out the quantitative details on coastal flooding due totsunami water. Though flooding due to tsunami waves is not an event due toclimate related disaster, the vulnerability assessment and the warning systemmodel are useful to study the impact of storm surges and monsoonal floods.
Important biophysical factors which influence the control of tsunami water
inundation are: (1) land elevation, (2) nearshore topography and (3) presence ofwater ways like estuary, back waters etc. Apart from these some of the man madestructures such as shoreline erosion control measures, harbor structures are also
reduced the impact of tsunami wave inundation on the urban coast.
2.4 Environmental hazards
Across India, urban citizens have access to only 105 litres per day of potable,
piped water supply, as compared to a minimum basic requirement of 150 litres.
Only 43 percent of the population has access to sewerage and septic tank facilities,
and only 30 percent of sewerage generated actually gets treated. McKinsey Global
Climate-related and other Hazard-related Urban Risks in Coastal India – An Overview
on Specific Study Sites

0ctober 2010, Kobe, Japan

Institute Report (2010) claims that this is true also for large cities like Mumbai,
which treats only 30-40 percent of its sewage today. Another key urban pressure
point is affordable housing. Nearly 80 million people live in slums across thecountry. This report forecast shows that all cities in the country are expected to
face the surging demand for civic services like water supply, sewage treatment
and solid waste management.
India could by mid-century, have both the largest national urban and rural
populations of the time. This will have an important bearing on global climate
vulnerability and the potential for mitigation and adaptation. Hence, the future
direction of Indian urbanization, is not only an important domestic concern, butwill be major international opportunity to demonstrate the viability of a moresustainable development. It is possible, that climate change induced drought andresource conflict may force the pace of rural-urban migration over the next few
decades. “Alternatively, severe stresses induced in urban areas due to a mix ofwater scarcity, environmental services breakdown, flooding and consequent water
borne disease and malaria-like epidemics combined with a rapid rise in healthexpenditures could maintain the low current level of rural-urban migration” (Revi,
2007, pp 209). “The risks to human settlements could be reduced if people andenterprises are encouraged to move away from the coast, or at least from the mostrisk-prone coastal locations (this would also reduce the pressures humansettlements place on coastal ecosystems). Experience after the Indian Ocean
tsunami of 2004, in which over 200,000 people lost their lives and millions moretheir homes, has demonstrated the profound difficulties involved in instituting
more restrictive coastal settlement policies without further undermining the lives
and livelihoods of the most vulnerable residents” (McGranahan et al, 2007, pp 21).
Tsunami vulnerability assessment also proved that there are certain areas of urban
coast in Chennai classified as unsafe (Krishnamurthy et al., 2009). Futureplanning and developmental activities in these vulnerable zones need to becontrolled including safe relocation of vulnerable community through a bottom-up
approach.
Sedimentary budget studies of coastal environments are one of the main tools
used to define the actual trend of coastal geomorphological evolution and for theevaluation of the impact of human intervention. Littoral sedimentary systems,
especially beach and dune areas, are dynamic environments which change
according to waves, water currents and the wind regimes that built them.
“Energetic events may cause a temporary state of disequilibrium but as long as theboundary conditions remain stationary, sediment can be reworked and adjusted
back towards the pre-disturbance morphology” (Alejo et al., 2005, pp 64).
However this may not be applicable in large scale intervention of human activities
like construction of port and harbors which alters the shoreline in an irrecoverable
stage. Additionally, this aggravates the erosion rate as well as deposition on theother part of the coast making the coast to undergo a chronic disaster, which
ultimately makes the people to migrate / relocate.
Recent studies on climate forecast also confirm that very heavy and extreme
rainfall events show increasing trends over both urban and rural areas, but thetrends over urban areas were larger and statistically more significant. According
New Technologies for Urban Safety of Mega Cities in Asia

to current forecasts, sea levels will gradually but inexorably rise over the coming
decades, and this will place large coastal urban populations under threat aroundthe globe. The Coromandel coastline is more cyclones prone, with 80 per cent of
the total cyclones generated in this region. Coastal wetland ecosystems, such as
salt marshes and mangroves, are especially threatened where they are sedimentstarved or constrained on their landward margin. Urban flooding risks indeveloping countries stem from a number of factors: impermeable surfaces thatprevent water from being absorbed and cause rapid run-off; the general scarcity ofparks and other green spaces to absorb such flows; rudimentary drainage systems
that are often clogged by waste and which in any case are quickly overloaded withwater; and the ill-advised development of marshlands and other natural buffers.
When flooding occurs, fecal matter and other hazardous materials contaminate
flood waters and spill into open wells, elevating the risks of water-borne,
respiratory, and skin diseases (Balk et al., 2009).
4. THE WAY FORWARD
The increasing frequency of natural disasters and their tremendous impact on poor
communities confirm that disasters continue to be one of developing world’s
unresolved problems and a major challenge for sustainable development throughpoverty alleviation. The first steps towards addressing disaster management in an
organized and coherent manner were taken with the passage of Disaster
Management Act 2005, and the establishment in 2005 of the National Disaster
Management Authority (NDMA). Many Indian states are now in the process of
formulating state and district disaster management plans. The country has thepotential to use remote sensing satellite imagery for mapping and monitoring
coastal areas through variety of sensors on board including making near real timeassessment of coastal hazards apart from having tsunami and storm surges
warning systems in place. All the maritime states are invariably entrusted the taskof preparation and implementation of Integrated Coastal Zone Management(ICZM) plan during the last decade. The right use of remote sensing and GIS
technology tools helped to prepare Coastal Vulnerability Index (CVI), forexample, the Orissa State on the east coast has already prepared CVI map(Srinivasa Kumar et al., 2010). As per this study 22 percent of Orissa coast ishighly vulnerable to natural as well as man-made hazards and disasters.
Similar studies with reference to Tsunami vulnerability has also been carried out
for Tamil Nadu, which considered the important physical parameters i.e land
elevation and near shore bathymetry along with inundation boundary. However,wave height will be an important physical parameter along with land elevationand ocean floor topography. Hence the national programme on establishment ofearly warning system for tsunami and storm surges has developed a wave model
based on these parameters to study the vulnerability of India’s coast morequantitatively (Krishnamurthy et al., 2010). Under the initiative of Kyoto
University, the Climate and Disaster Resilience Index (CDRI) for 12 Indian cities
located both on the coast and inland areas were carried out (India City Profile,2010). This initiative has brought out initial results on the resilience capacity ofthese cities with reference to climate related disasters. As a follow up under thisinitiative and one of the first attempts in India, Kyoto University prepared a first
Climate-related and other Hazard-related Urban Risks in Coastal India – An Overview
on Specific Study Sites

0ctober 2010, Kobe, Japan

consultation CDRI report for Chennai zones jointly with the Chennai Corporationand the University of Madras. Since there is a definite link between urban disasterand climate risks, the concept of climate resilience presented in this report aimed
to assess the urban disaster risks comprehensively in adopting a multi-stakeholder
approach in order to build resilience. This study takes an innovative attempt tomeasure the resilience of Chennai to climate-related disasters (floods, cyclones,
heat waves, droughts, etc.) by taking a truly multi-sectoral and developmental
approach. Based on five dimensions (physical, social, economic, institutional, andnatural), the focus in this study is to understand the capability and condition of theten zones of Chennai to cope with such events. In this approach, the belief is thatmicro-level analysis is best in addressing urban disaster risks adequately andcomprehensively in order to build resilience. The report provides the baseinformation that can help to build such resilience through taking appropriate
action (CDRI, 2010). Actual utilization of resilience study report in the field by
the local government needs to take it as an integral part of community
development, coastal management and disaster management domains. Also multistakeholders participation is important to take resilience study as a national
approach (US Indian Ocean Tsunami Warning Program, 2007). The efforts taken
towards the preparation of ICZM for maritime states will be used as a base for
DRR in coastal urban centres. It is note worthy that several coastal cities in the
country have taken field based activities in tackling climate induced disasters in
the form of storm water drainage, shoreline erosion protection measures, rainwater harvesting etc. Along with the recent initiatives on CDRI will be highly
useful in achieving DRR in the coming years (Figure 3).

Figure 3: The gap between ICZM and DRR

New Technologies for Urban Safety of Mega Cities in Asia

Among the coastal cities in India, Chennai is pioneering in implementing sciencebased people centred urban disaster risk reduction. Hence the Chennai
Corporation is committed to the Global Campaign of Making Cities Resilient,promoted by the United Nations International strategy for Disaster Reduction(UN-ISDR) for the period of 2010-2011. In this context the Chennai Mayor haslaunched the “Safer Chennai Campaign” with an aim to create awareness todifferent target groups by strengthening the cooperation and coordination of thecity’s institutional mechanism. Chennai is taking big efforts to become a rolemodel city under this campaign and the outcome of this effort is to better control
the climate related disasters in the future. Additionally, efforts are underway toprepare multi-hazard vulnerability mapping along with strategies for DRR. The
outcomes of these initiatives along with the strengthening of institutional
cooperation through the Safer Chennai campaign and CDRI studies are expectedto address the climate-related and other hazard-related urban risks in the near
future.
ACKNOWLEDGEMENT
The author would like to thank Mr. Joerin Jonas, Graduate School of Global
Environmental Studies, Kyoto University, Japan, for his review and suggestions
to improve this paper.
REFERENCES
Alejo, I.,Costas, S. and Vila-Concejo, A. (2005). “Littoral evolution as a response
to human action: the case of two sedimentary systems in a Galician Ría”, Journalof Coastal Research, SI 49, pp. 64 to 69.
Balk, D., Buettner, T., McGranahan, G., Montgomery, M.R., Small, C., Kim, D.,
Mara, V., Todd, M., Chandrasekhar, S., Baptista, S., and Dorelian, A. (2009),“Spatial Distribution and Risk for Urban Populations: An International Overview”,
pp. 1 to 40. Climate and Disaster Resilience Index (2010), “Chennai Zone Profile
Report”, jointly published by Kyoto University, Chennai Corporation andUniversity of Madras, 33pp.
Conservation Action Trust (2006) Mumbai Marooned: An Enquiry into Mumbai
Floods 2005, Mumbai.
Gupta, A.K., Nair, S.S. and Sehgal, V.K. (2009), “Hydro-meteorological disasters
and climate change: conceptual issues and data needs for integrating adaptation
into environment - development framework”, e-Journal Earth Science India, 2(II), pp. 117 to 132. India City Profile (2010) Climate and Disaster Resilience,
Consultation Report, Kyoto University.
Kishtawal, C., Niyogi D.,Tewari M.,Pielke R.A., Shepherd M. (2010),“Urbanization Signature in the Observed Heavy Rainfall Climatology over India”,
International Journal of Climatology, 30, published online Wiley InterScience(www.interscience.wiley.com) DOI: 10.1002/joc.2044.
Krishnamoorthy, R.,Bharathi, G.S.,Periakali G.S. and Ramachandran S. (2001),“Coastal zone hazards in India: Study based on remote sensing and GIS
techniques”, Observing our environment from Space: New solutions for a newmillennium, Begni (Ed), A. A. Balkema Publishers, pp. 79 to 86.
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on Specific Study Sites

0ctober 2010, Kobe, Japan

Krishnamurthy, R. R., Satheeshkumar, C. and Ilayaraja, K. (2009), “Post-tsunami
hazards along the Indian coast”, In: Disaster Management – Global Challenges
and Local Solutions (Rajib Shaw & R. R. Krishnamurthy, EDs), Universities
Press, pp. 86 to 100.
Krishnamurthy, R.R.,Mohana P.,Ilayaraja K.,Dhanasekari K. and Rajkumar J.
(2010), “Coastal Vulnerability Studies based on Modeling and Mapping ofTsunami and Storm Surges along Indian Coast”, Storm Surges congress, Hamburg,
Sept 2010 in press).
McGranahan, G.,Balk, D.,Anderson, B. (2007). “The rising tide: assessing therisks of climate change and human settlements in low elevation coastal zones,”
Environment & Urbanization, 19(1), pp. 17 to 37.
McKinsey Global Institute report (2010), “India’s urban awakening: Building
inclusive cities, sustaining economic growth”, 80 pp.
Shaw, R. (2008) “An Overview of Urban Risk of South Asia: Issues, Approaches
and Thoughts”, Journal of South Asia Disaster Studies, 1(1), pp. 69-84. Srinivasa,
K.,Mahendra T.R.S.,Nayak, S.,Radhakrishnan, K. andSahu, K.C. (2010), “Coastal
Vulnerability Assessment for Orissa State, East Coast of India, Journal of Coastal
Research, 26(3), pp. 523 to 534.
Revi, A. (2007), “Climate change risk: An adaptation and mitigation agenda for
Indian cities”, Environment and Urbanization, 20, pp. 207 to 229.
Rupa, K., K.,Sahai, A.K.,Krishna Kumar K.,Patwardhan S.K.,Mishra
P.K.,Revadekar J.V.,Kamala, K. and Pant, G.B. (2006), “High-resolution climatechange scenarios for India for the 21st century”, Current Science, 90(3), pp. 334
to 345.
U.S. Indian Ocean Tsunami Warning System Program (2007), “How Resilient isYour Coastal Community? A Guide for Evaluating Coastal Community
Resilience to Tsunamis and Other Coastal Hazards, U.S. Indian Ocean Tsunami
Warning System Program supported by the United States Agency for International
Development and partners, Bangkok, Thailand, 144pp. Accessedfrom http://apps.develebridge.net/usiotws/13/CoastalCommunityResilience%20G
uide.pdf on 6th Sept 2010.
www.cat-risk.com last accessed on 4th Sept 2010.
www.ihdp.org/publications last accessed on 4th Sept 2010.

New Technologies for Urban Safety of Mega Cities in Asia

Resilience and adaptation: Coping withclimate related urban risk of traditional urban
settlement of Bangkok’s agricultural fringe.
12Danai THAITAKOO , Brian McGRATH
Lecturer, Department of Landscape Architecture,
Chulalongkorn University, Bangkok , Thailand
danait@yahoo.com, danathai@gmail.com
2
Associate Professor of Urban Design,
Parsons the New School for Design, New York, NY, U.S.A.
1

ABSTRACTThis research suggests a radical shift in emphasis from the current solid state oflandscape urbanism, towards a more systemic approach to urban design based on
the dynamic liquid states of waterscape urbanism. Waterscape urbanism is
inspired by indigenous water-based cultural practices as well as emerging
scientific techniques of monitoring urban systems through watershed frameworks
and networked technologies.
The argument about the waterscape urbanism presents Greater Bangkok,
Thailand, as a critical case study. Bangkok is one of the most vulnerable and at
risk cities in the world already experiencing severe effects of unpredictableclimate change. It also presents a degraded, but still vibrant indigenous waterbased urbanism that remains a model of resilience and adaptability developed inconcert with the historical cycles of monsoon rains and wet rice cultivation.
The analysis and interpretation is that the indigenous methods and practices will
provide a good basis for resilience and adaptation for Climate Change
Adaptation and Disaster Risk Reduction. Filling up the lowland of the delta andrefusing to adjust to the fluctuation of water level in the delta is futile. Being apart of the water – adjusting local practices according to the level of water is amore reasonable approach.
Keywords: waterscape urbanism, resilience and adaptability, indigenous methods
and practices

1. INTRODUCTION: THE CHAO PHRAYA RIVER DELTA LANDSCAPE
The meandering river and an endless network of natural streams and manmadewaterways comprise a distributory rather than tributary geography in the Chao
Phraya delta. Bringing and retaining the water during the dry season and draining
the water during wet season the vast network of canals brought life to the delta.
The lower part of the Chao Phraya river delta, the geomorphologically younger
part of the Chao Phraya river delta, is a part of “the center of the geographical0ctober 2010, Kobe, Japanliving space” (Tanabe 1977). This view was built upon the capability of thelandscape to provide functions or potentials (Zonneveld 1988) for humaninhabitation and exploitation, such as the capacity to produce foods and resources,
the capacity to build human’s habitat and places, a self-regulated environment,
based on the resilience of the landscape’s ecosystem and the capability to linkwith aesthetic, scientific, cultural and other interest of human kind.
The landscape of Chao Phraya River delta has been through the processes ofmodification and transformation becoming early in the 20th century a major partof the world’s rice bowl and the undisputed world leader of rice production forexport. By the end of the 20th century through conversion and replacement by
urbanization and export manufacturing, its inhabitants also have been throughlong periods of adaptation and resilience in dealing with various kinds of change.

Figure 1: The Lower Chao Phraya River Delta and the city of Bangkok: Watery
Bangkok sprawls over an urban agricultural landscape dominated byfruit orchards to the west, rice fields to the east, shrimp farms along thecoast and fish farms in the lowlands.

New Technologies for Urban Safety of Mega Cities in Asia

2. THE CITY OF BANGKOK AND LANDSCAPE CHANGES
Bangkok, the capital of Thailand, is situated in a slight deltaic high amidst a
predominantly low lying, flat terrain of the lower Chao Phraya River delta. The
area was first urbanized during the Ayutthaya period, as a vast network of mixed
fruit orchards and market towns planted within a harsh marshland(Tachakitkachorn, 2005). The rapid development of the lower delta for export ricecultivation affected the rapid urbanization of the city of Bangkok (Takaya 1987).
In the early years, many canals were constructed and functioned as highways(Takaya 1987). The canals radiated outward from the center of the city, providing
access to the city center. Along the canal banks were homes and shop houses. The
lands in between were fruit orchards and rice paddies. The early residents relied
upon canal and river water for their basic needs (Jarupongsakul and Kaida 2000).

Figure 2: Bangkok circa 1890 (left) and 2004 (right): Bangkok’s urban
morphology follows the pattern of water-based rice and fruit framing
and the wandering Chao Phraya River
During the beginning period of city establishment (1782-1900), Bangkok grew
rather slowly. The city's rapid urbanization and increase in population started after
the Second World War (BMA 2004). These rapid changes brought the number ofland based infrastructure and other constructions that resulted in a rapid increasein built up area (BMA 2004) at the expense of cultivated land and thehydrological matrix. The swift expansion of Bangkok's industry and suburban
development occurred in the late 1960s and 1970s. Consequently, the growing
demand for housing sprawled eastward into the paddy fields (Jarupongsakul andKaida 2000). The rapid urbanization also affected the city's unique vast canal
network which became secondary to the construction of roadways through therapid urbanization. The network once considered a lifeline has been neglected andabandoned, yet still fragility persists in many areas. The major mechanism thatkeeps the delta habitable and prolific has been damaged (Jarupongsakul 2000).
__________________________________________________________________
Resilience and adaptation: Coping with climate related urban risk of traditional urban
settlement of Bangkok’s agricultural fringe

0ctober 2010, Kobe, Japan

Many canals were filled up for developments or replaced by the construction of
new roads, while many others became stagnant and non navigatable, reduced todrainage ditches and open sewers.

Figure 3: Since 1950, road building has far out-paced the canal digging which was
the dominant transportation infrastructure for the previous centuries ofdelta inhabitation.(adapted from Sternstein 1982) The result is a twolevel transportation network where the land-based infrastructure
dominates and comprises the ability of the hydrological network to
operate. In rainy season, the opposite is often the case as annual floods
slow and stop traffic in much of Bangkok.

3. THE LANDSCAPE AND THE PEOPLE
Along the 14th parallel, day and night oscillate neatly between predictable twelve
hour divisions and months pass with little change in temperature barely affectedby the earth’s axial tilt. However between May and October, a shift in
atmospheric currents brings monsoon rains from the Indonesian archipelago northto the mountain ranges ringing northern Thailand whose runoff feeds the Mae
Nam Chao Phraya River Basin - and Bangkok sprawling across its flat, silted tidaldelta. Seasonal cycles of precipitation rather than temperature extremes of winterand summer bring rhythm to life just above the equator, putting into motion
human cycles of planting, harvest and migration, as well as shaping Thai beliefs
and rituals.
Early settlements along the bank of rivers, canals and flood plain areas were
subjected to flooding and draught every year. This settlement characteristic was
the result of cultural, topographical and hydrological characteristic of the delta.
The vast agricultural settlement benefited from flooding without serious problem
or flood damage. Flood, a natural process, was a part of life and considered as
life’s nourishment. People adapted to the rhythm of the natural process bybuilding their living environment according to flooding and draught characteristic
without any action against the course of the natural process.

New Technologies for Urban Safety of Mega Cities in Asia

The alteration of the land and waterscape overtime through the course ofurbanization and modernization has turned the effect of flooding into a negative
impact, especially in urban areas. Flooding has become a natural hazard andconsidered life and property threatening, although several factors contributing tourban flood are the consequences of human activities. Engineering solutions(structural control) to prevent flooding were introduced at great cost. Unforeseen
consequences due to the limitation of structural control have changed thelandscape and natural process that have affected the way of life for people to agreat degree. Moreover, when the structural control fails, it causes greater damage(Jarupongsakul 2000).

4. THE THREAT AND THE RISK
Lying on the low-lying of the lower Chao Phraya Delta, Bangkok encountersperiodic floods every year. As an agricultural settlement in the past, flood, anatural process, was a part of life and considered life’s nourishment. Historicallypeople lived in concert with the natural process of flooding as essential to the wet
rice growing economy, while the modern city depends on the immediate releaseof excess rain water, upstream runoff and tidal surge through elaborate
technologies of flood control dikes and gates, which too often remain closed towater flows and discharge.
Dictated by the tropical monsoonal climatic conditions and coastal tidal dynamics,
the low-lying flat terrain of Bangkok’s land-based urbanism is now under the
threat of flood during the height of the rainy season. The combination of theexcessive flow generated by the rainfall in upland watershed of the Chao Phraya
River and the excessive runoff created by the rainfall in Bangkok and vicinity
often puts many parts of Bangkok under water. Compounded with the high tidethat slows down the flow of the river, the draining of excessive runoff isimpossible without the help of modern technology such as floodwalls andpumping stations. The landscape of the area is greatly dominated by these threehydro-ecological characteristics which given the symbolic name of Bangkok as“the city of three waters” (Jarupongsakul 2000). The question and risk Bangkok
faces is which way of perceiving these three waters can insure an adaptable andresilient urbanism in the face of the uncertainty of climate change?
The plight of climate change compounds an already complex ecosystem withmany conflicts between delta and the city dynamics. More hot days, longer
summers, higher rain intensity, more water, and sea level rise (SEA START RC
2007) are among the main concerns in the Bangkok metropolitan area and vicinity.
These changes would be compounded by the increasing threats of urban heatisland phenomena, periodic flood during rainy season, drought during dry season,
loss of coastal land due to coastal erosion, industrialized prawn production, andland subsidence due to industrial ground water withdrawal. The delta and the citypresents threats to each other due to a lack of both recognition of naturalhydrological processes and the indigenous and traditional knowledge of living inconcert with natural cycles of wet and dry seasons. The dynamic of space-time__________________________________________________________________
Resilience and adaptation: Coping with climate related urban risk of traditional urban
settlement of Bangkok’s agricultural fringe

0ctober 2010, Kobe, Japan

relationships of human and nature has failed to recognize the importance of thehydro-ecology of the landscape of the city.
The vanishing views of natural processes and the vanishing land and waterscapethat reflect the relationship between human and natural processes are clearlyvisible in the Bangkok metropolitan area. These views are also reflected in the
recent transformation of agricultural areas to built-up areas in the urban fringe ofthe metropolitan area. As consequences of these different views, the roles andfunctions of natural processes and the landscape are perceived differently. These
different values play a major role in dictating different changes in the land andwaterscape and land and water use.

5. THE FUTURE IN THE PAST: THE INDIGENOUS METHODS
Today, the Chao Phraya River Basin is managed by a vast network of hydroelectrical and draught control dams and reservoirs by ministries in Bangkok rather
than tributary kingdoms. Modern dams and huge reservoirs replaced cities aslocally controlled and maintained water retention systems modeled on the
Tennessee Valley Authority with World Bank and American assistance during theCold War. Water and floods were thought to be technologically controllable andmanageable in a system that is more ideologically aligned with techno-rationalmodels than with the complexities of indigenous Thai socio-hydrology andurbanism.
Thai urbanity and domesticity evolved from intimate association with climatic,
topographic and hydraulic conditions. River, canal and lagoon based garden cities
retained six months of rainwater for the following six dry ones, staging
ceremonies and rituals in sync with attentive observation of hydrological cycles
and variations.
The contemporary Bangkok in the context of Thai waterscape urbanism: a premodern, locally controlled, human ecosystem watershed model structured andsustained Thai cities for centuries. An animist tradition combined with an
inherited Hindu-Buddhist cosmological framework created a tributary culture fora locally managed, forest and agricultural production society with a Dhamma
King, as the symbolic Lord of Life symbolized through water. A reassessment of
how river and water flows that have been engineered to pass around and under
cities rather than through them is critical in order to create new dynamic designmodels of urban ecosystems. The understanding of historical resilience andadaptability of living with water of indigenous and traditional methods would be
crucial for dealing with future uncertainty. This is not just a historical model, butcontemporary urban ecosystem designs around the world are looking for ways toretain water in cities (McGrath, 2008). The discipline of landscape and urban
planning and design is being added to this framework in order to create new
dynamic planning and design models of urban ecosystems. Contemporary urban
ecosystem science and Thai urbanism both point to the creation of cities as water
retention systems not dams – for socio-cultural as well environmental reasons.

New Technologies for Urban Safety of Mega Cities in Asia

6. CONCLUSION
The urban hydro-agricultural complex of the Chao Phraya River Delta wasradically transformed as a result of Bangkok's rapid and expansive urbanization
over the last fifty years. While the delta and the city are now in conflict, they wereonce entangled in a highly resilient absorbent agricultural matrix in concert withclimatic cycles of monsoon and dry seasons.
We suggest a radical shifting in emphasis from the current “solid state” oflandscape urbanism, towards a more systemic approach to urban design based on
the dynamic liquid states of waterscape urbanism. This shift in language also
represents a shift in thinking about urban design in the age of rapid climate change.
Instead of the design of cities thought of as permanent, stasis, solid land based
environments, liquid perception is based on change, adaptation and the continuous
reproduction of locality as an embedded and evolving cultural practice.
Waterscape urbanism is inspired by the philosophical concept of liquid perception(Deleuze, 1986), indigenous water-based cultural practices as well as emerging
scientific techniques of monitoring urban systems through watershed frameworks
and networked technologies.
Our argument about the liquid perception of waterscape urbanism presents
Greater Bangkok, Thailand as a critical case study. In addition to Bangkok’s
status as one of the most vulnerable and at risk cities in the world, alreadyexperiencing severe effects of rapid and unpredictable climate change, it alsopresents a degraded, but still vibrant indigenous water-based urbanism thatremains a model of resilience and adaptability developed in concert with the morepredictable historical cycles of monsoon rains and wet rice cultivation. Combing
new ways of seeing the world, new ecosystem science and the case study of
Bangkok liquid perception will contribute to an argument about making aredefined concept of waterscape urbanism central to addressing the social andenvironmental challenges and risk of climate change.
It would be important for architects, landscape architects and urban designers tounderstand the difference between these two land and water based models to
critically analyze current trends in landscape urbanism. While landscape urbanism
has developed an argument around North American post-industrial cities and thecreation of large parks as islands in these cities, we suggest the exploration in
depth the watershed approach as a new model for urban design, allied with the
new modes of perception Deleuze calls for, waterscape urbanism.

Figure 4: Solid and Liquid Perception and Practices
A. A flood wall and water gate blocks an old house from the canal.
B. Traditional houses can be periodically raised above rising flood levels.
C. A new house is constructed on raised landfill and behind a protective
wall.
D. A house raising in progress, finding a higher living level.
E. A city trunk canal with reinforcing concrete beams across the canalpreventing navigation.
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Resilience and adaptation: Coping with climate related urban risk of traditional urban
settlement of Bangkok’s agricultural fringe

0ctober 2010, Kobe, Japan

F. An urban fringe canal with a walk way and a fish trap.
G. A city canal and a city street in a business district.
H. An urban fringe canal with waterside shop houses.

New Technologies for Urban Safety of Mega Cities in Asia

Table 1. Solid and Liquid Perceptions and Practices
Solid perception
Rigid flood protection structures
inhibit the natural flow of water.

Liquid perception
Flexible and open traditional
structures allow the natural flow ofwater.

Life behind the flood protection
barriers will be static and stagnant
because the structure separates the life
behind the wall from the dynamics
and nutrient flow of water.

Cultural and social life is tied to the
dynamics of water. Social andeconomic patterns adjusted according
to the dynamic level of water.

Resists any changes of water level orquantity.

Resilience and adaptation evolve
through time with the seasonal flow ofwater.

Incoherence between land and water.

Coherence between land and water.

Water is a hazard and need to beeliminated /mitigated.

Water is a part of vulnerability and it
is manageable.

Disjointed – separation among landwater-human.

Joined, linked, connected land-waterhuman.

ACKNOWLEDGMENTS
The authors would like to thank the Chulalongkorn University Centenary
Academic Development Project, Chulalongkorn University, Parsons The New
School for Design and the U.S. National Science Foundation Biocomplexity andBaltimore Ecosystem Study of Long-Term Ecological Research program for theirsupport of this research.

REFERENCES
BMA 2004: Bangkok Metropolitan Administration, General Information Website:
http://www.bma.go.th/bmaeng/body_general.html#geography, December, 2004.
Deleuze, G. 1986: Cinema 1: The Movement Image, Minneapolis, University of
Minnesota Press, 1986.
Jarupongsakul, T. and Kaida, Y. 2000: The Imagescape of the Chao Phraya Delta
into the year 2020, Proceedings of the International Conference: the Chao Phraya
Delta: Historical Development, Dynamics and Challenges of Thailand's Rice
Bowl: 12-15 December 2000, Kasetsart University, Bangkok, Thailand.
__________________________________________________________________
Resilience and adaptation: Coping with climate related urban risk of traditional urban
settlement of Bangkok’s agricultural fringe

0ctober 2010, Kobe, Japan

Jarupongsakul, T. 2000: Chapter 2: Geomorphology Aspects Affecting the
Occurrence of Floods and influencing the Drainage in the Lower Central Plain,
Thailand, in The Analysis and Preparation for Flood-risk map in the Lower
Central Plain, Thailand, Jarupongsakul, T. edited. Center for Disaster and Land
Information Studies, Chulalongkorn University, Bangkok, Thailand.
McGrath, B., V. Marshall, M. L. Cadenasso, J. M. Grove, S. T. A. Pickett, R.
Plunz, and J. Towers (eds.).
2007.
Designing Urban Patch Dynamics.
Columbia University Graduate School of Architecture, Planning and Preservation,
Columbia University, New York.
SEA START RC 2007: South East Asia START Regional Center: A Decade of
Climate Change Research in Thailand, South East Asia START Regional Center,
Chulalongkorn University, Bangkok, Thailand.
Sternstein, L. 1982. Portrait of Bangkok, Bangkok: Bangkok Metropolitan
Administration, Bangkok, Thailand.
Tanabe, S. 1977: Historical geography of the canal system in the Chao Phrayadelta from the Ayutthaya period to the fourth reign of the Ratanakosin Dynasty,
CSEAS, Kyoto University, Japan.
Takaya, Y. 1987: Agricultural Development of a Tropical Delta: a Study of the
Chao Phraya Delta, translated by Peter Hawkers, Monographs of CSEAS, Kyoto
University, Japan.
Tachakitkachorn, T. 2005: A comparative Study on the Transformation Process of
Settlement Developed form Orchards in the Chao Phraya Delta, Doctoral
Dissertation Kobe University.
Zonneveld, I.S. 1988: Landscape Ecology and its Application, in Landscapeecology and Management, Proceedings of the First Symposium of the CanadianSociety for Landscape Ecology and Management: University of Guelph, May,
1987, Polyscience Publications Inc., Montreal, Canada.

IMAGES SOURCES
Figure 1: The Global Land Cover Facility (GLCF), University of Maryland(http://glcf.umd.edu/)
Figure 2: Bangkok circa 1980 Map: Sternstein, 1982. Portrait of Bangkok (page88)
Bangkok circa 2004 ASTER VNIR image: The acquisition of ASTER
data was supported by a research project, ‘Investigation of Rapid
Urbanization Processes Using ASTER, MODIS, and Landsat Data, by
Dr Philip Christensen, Principal Investigator, NASA Grant number:
EOS/03-0000-0502.)
Figure 3: Adapted from Sternstein (1982) (page 89)
Figure 4: Danai Thaitakoo

New Technologies for Urban Safety of Mega Cities in Asia

The rapid urban transition in Viet Nam:
Challenges for sustainable development in
the face of climate change
Phong TRAN
Faculty of Economic and Development Studies,
College of Economics, Hue University, Viet Nam
ABSTRACT
Urban transition in Viet Nam poses great challenges for sustainable developmentin the face of climate change. The growing urban vulnerabilities contribute toincreasing urban risks in the face of which natural hazards coupled with thepossible impacts of climate change are compounded into frequent disasters. Many
recent major disasters have occurred in densely populated human settlements in
big cities such as Hanoi and Ho Chi Minh City leading to high levels of human,economic, social and environmental loss with a consequent severely negative
impact on national and regional development. This paper will present urban
environmental risks in terms of urban governance, housing and shelter, urban
poverty, infrastructure and natural environment and draw the lessons learned
toward a climate resilient city in the context of urban transition in Viet Nam.
Keywords: climate change, sustainable development, urban risks

1. INTRODUCTION
Viet Nam’s economic growth has the potential to catch up the ‘tigers’ in East Asiaand other Asian developing countries. Nevertheless, Viet Nam entered a period ofindustrialization and modernization with a range of unresolved environmental
problems, particularly due to polluting industries, inadequate infrastructure to
manage waste, and worsening natural hazards (Douglass et al. 2002). Along witheconomic growth, urban transition in Viet Nam also poses great challenges forsustainable development, as the country is considered as one of the ten countries
most prone to the impacts of climate change. The growing urban vulnerabilities
along with rapid urbanization contribute to increasing urban risks in the face of
which natural hazards coupled with the possible impacts of climate change arecompounded into frequent disasters. Many recent major disasters have occurred indensely populated human settlements in big cities such as Hanoi and Ho Chi Minh
City leading to high levels of human, economic, social and environmental loss
with a consequent severely negative impact on national and regional development.
This paper will present urban environmental risks and draw the lessons learned
toward a climate resilient city in the context of urban transition in Viet Nam.

0ctober 2010, Kobe, Japan

2. URBAN ENVIRONMENTAL RISKS
The major environmental risks facing Viet Nam’s urban areas include
contamination by residuals of industrial processes, disposal of domestic andindustrial waste, and changing consumption patterns, and natural disasters leading
to new types of urban risks in the face of increasing impacts of climate change.
Even in its relatively early stage of industrialization, the face of the cities and theindustrial zones has already changed very quickly. These changes and theirenvironmental impacts are most acutely observable in major cities like Hanoi and
Ho Chi Minh City (HCMC).
2.1 Solid waste
Solid waste collection and management represents a crucial issue in many major
cities, particularly in Hanoi and HCMC, the two cities with the largest generationof solid waste in Viet Nam. The volume and types of wastes generated in urban
and rural areas have changed over the past decades. This change reflects a major
cultural-shift taking place in Viet Nam; the shift from a low consumption, thrift
based society whose products were largely derived from organic materials to ahigh consumption society whose products are largely inorganic materials andcome from industrial processes. The shift of waste generation is extremely
important since it has many impacts on environmental management, health issues,and often breaks down inherited waste management practices based on symbiotic
rural-urban exchanges and uses of organic wastes.
Up to the mid-1980s, waste treatments in urban and rural areas of Viet Nam weresimilar in many ways. Most waste was organic and treated as livestock food, fuel,or was simply buried on house plots. Small fractions of wastes that had value (e.g.
waste paper, scrap metal, glass bottles, and bicycle tires) were retained for sale toitinerant junk buyers. In urban areas, sanitation companies were responsible forthe collection and disposal of the remaining fractions of solid waste throughregular street sweeping and transport to open dumps (which generally former clay
pits and fishponds within the urban boundary). Since the early 1990s, this systemof waste management has been forced to deal with new type of wastes generated
by the growth of an unevenly affluent; consumption oriented, and industrializedsociety.

Figure 1: Solid waste in Hue City

New Technologies for Urban Safety of Mega Cities in Asia

Transitions in both rural and urban lifestyles have increased waste loads,
increased the need to segregate waste, and increased the need to improve waste
treatment. So far, there has always been a gap between solid waste generation andthe collection process. However, urban solid waste generation, which mainly ismunicipal solid waste, has increased at a higher rate, widening the gap between
waste generation and collection rates.
2.2 Deforestation and land degradation
The loss of forestland in Viet Nam is a very serious problem for a number ofreasons. Forests prevent soil erosion, regulate natural water sources, regulate aregion’s climate, and provide numerous and valuable sources of plants andanimals. As a result of the degradation of Viet Nam’s forest lands, there has been
an increase in flooding and drought, rivers and irrigation channels are silting
faster, the country is losing bio-resources, and lands are becoming too degradedfor agricultural, with wastelands expanding. The depletion of Viet Nam’s tropicalforests is changing rainfall patterns since there are now less trees participating in
the transpiration and evaporation processes, which return moisture to theatmosphere. Most of these problems are being felt most severely in the highlands,
but they will eventually affect the lowlands: as rivers silt up, this affects
croplands in the lowlands that depend on these waters. Flooding of cities andmetropolitan regions will become more pronounced.
Among the sources of the loss of forest coverage in Viet Nam, many have clear
association with the urban transition. While urbanization brings the potential
benefits of new markets, commodities and technologies to the usually more
remote forested regions, it is also a process that results in quantum increases indemand for natural resources to support the physical building of cities andinfrastructure. The extraction of timber and other resources for energy, making
cement, supplying water and hydroelectricity to cities all represent profoundassaults on rural regions. The city rarely pays the costs of these externalities.
However, nor are the costs simply calculable in terms of the loss of trees, butrather are registered in terms of severe ecological disruption, undermining of local
food and agricultural systems, and increasing poverty.
In the case of Viet Nam, the rural-urban linkages related to deforestation havebecome more complex due to past government policies to stem migration to andreduce the population of large cities – especially Hanoi – by resettling people
living in very densely-settled regions and cities into the highlands. The
government policies outlined above had a number of ancillary goals. One was toreduce the size of southern cities. Second, the encouragement of North-South
movement was thought to reduce the overcrowding of the northern regions ofAnnam and Tonkin, and particularly the Red River Delta. These plans also
included the objective of moving settlers from the lowlands to the highlands,
including mountainous border regions. In addition to decreasing the population ofViet Nam’s cities, the government sought to urbanize the countryside by creating
agro-industrial communities.

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0ctober 2010, Kobe, Japan

2.3 Regional flooding
The prolonged flooding of the Mekong River Delta is an important issue for all
regions adjacent to the Mekong River. The rever provides the larger regional
context for what is undoubtedly the core urban region of highest economic andpopulation growth for the nation. Guiding urban expansion in concert withmanaging the water system of the Delta is one of the most formidable problems
faced in the urban transition. Catastrophic flooding has recently hit HCMC andother Southern provinces. This region is a densely settled area that is growing
rapidly due to increasing population in the communes and also in-migration.
Unlike Hanoi and its surrounding urban areas, cities and towns in the Mekong
Delta are currently less well connected to HCMC. However, this region is likely
to experience a rapidly booming population in the next few decades and willinvariably begin to try to link up more fully with HCMC in terms of transportationof agricultural commodities and access to seasonal and part-time employment aswell as to higher order services and government functions. Without more
attention given to managing the incipient rural-urban linkages across the Mekong
Delta, the type of disasters now being experience will surely magnify.
For decades, the floods along the Mekong River have been a way of life formillions of Southern Vietnamese; floods arrive each year with the summer's
monsoon rains. Often referred to as the Greater Mekong Subregion (GMS), theMekong river system is a direct part of the livelihoods of approximately sixty
million people, providing “food, water, transport and economic sustenance” (IRN,
2001). The flood-borne sediment provides the food that maintains one of theworld’s most diverse fisheries in Cambodia, and also serves as a natural irrigation
system for the region’s “rice bowl”, which is responsible for half of all the rice
grown in Viet Nam. For centuries, farmers, fishermen, and others have made theriver and its vast delta their home. A majority of the floodwater discharges into
the South China Sea through the Tien River and the Hau River, the two branchesof the Mekong River in Viet Nam. Along the path of the Mekong River throughCambodia and Viet Nam to its delta is a maze of seasonally flooded pastures,
woodlands and natural flood reservoirs known as bengs. These act like natural
flood regulators, absorbing part of the monsoon floods and, equally important,increasing the dry-season flows of the river (Gujja, 2001).
The Mekong River’s functions have been hindered by extensive deforestation in
the region. Deforestation increases the severity of flooding as rainfall on
deforested areas washes quickly into river ways instead of being partiallyabsorbed by forests. These 'quick-rising' big floods pose risks to farmers whoplant rice and vegetables on the banks of rivers in anticipation of beneficial siltladen 'slow rising' floods. The UN Economic and Social Commission for Asia
concluded that rampant deforestation in the Mekong Delta has resulted in
reduction forest cover from 70 percent in 1945 to 25 percent today. In addition,
as previously noted, natural forests are constantly shrinking in Viet Nam as awhole. The fear is that, in the context of the low capacity in the past to prevent
serious deforestation, an acceleration of unfettered market-driven economic
development will worsen such disasters.
New Technologies for Urban Safety of Mega Cities in Asia

Figure 2: Floods in Ho Chi Minh City and Hanoi,
source photo AFP/Getty Images
The flooding in 2000 has caused a great deal of suffering for the inhabitants of the
Mekong River Delta in southern Viet Nam. The floods have submerged 214,800
houses, nearly one third of which have collapsed, and floodwaters have prevented
237,000 students from attending school. Even worse, floods have claimed 149
lives (including 128 children); tens of thousands of families are now in urgent
need of food and evacuation. In addition, 100,000 ha of rice paddies have been
flooded and 28,000 homes damaged. Total losses caused by the floods are
estimated at more than US $ 30 million (People in Flooded Mekong Provinces
Need Help, 2001). This flooding is acknowledged to be the worst disaster inrecent decades in Viet Nam.
Beginning in the Tibetian Himalayas, the Mekong is the largest river in Southeast
Asia. Viet Nam is the last country through which the Mekong River flows before
it ends its 4,200 km journey to the South China Sea. Since the transboundarywatershed area is shared by numerous countries, whatever happens along the flow
path of the Mekong will affect the livelihood of communities downstream. One
mounting concern is global climate change that contributes to the seasonal settingof hydrological trends. Specifically, the warming global temperatures can lead tofaster snow melt along the headwaters of the Mekong in the Tibetian Plateau,triggering flash floods.
So far, the construction of dams has been proposed as a method to control thisdevastating flooding. Dams are thought to mitigate floods and provide adequate
supplies of water during droughts. In addition, the Mekong River has also long
been viewed as a potential source of hydropower. Hence, dam construction along
the Mekong has the additional purpose of producing electrical power, which will
be increasingly needed as cities expand and industrialization proceeds. This isperceived as a commodity, which could even be sold to other nations to add tonational income. However, the entire Mekong project has been the subject ofhigh controversy for decades. For Viet Nam, the dams may bring numerous
environmental consequences to downstream areas, including changes in the flow
regimes of the river and erosion or siltation problems. The downstream countries,
Cambodia and Viet Nam, are the most vulnerable ‘victims’ of these changes, as
fisheries and agricultural yields in these countries are largely dependent on thenormal water flow cycle of the Mekong.
The rapid urban transition in Viet Nam: Challenges for sustainable development in theface of climate change

0ctober 2010, Kobe, JapanAt the same time, intensive logging has been implemented to clear the area thatwill be submerged in the dam reservoir. Studies show that river catchment areasthat are largely deforested or wetlands that have been drained create very differenthydrological regimes (Gujja, 2001). When this factor is added to the climatechange, as already discussed, it appears to be affecting the timing and pattern of
the rainfall. Eventually, the rainfall may become more erratic. In this regard, thetiming and volume of expected flooding are becoming more unpredictable. In
addition, dams are often built without adequate spillways to cope with extreme
floods. In some cases, expected floods were greater than those that the dams had
been built to discharge over their spillways.
As a result of all these factors, severe flooding is a serious environmental risk
confronting communities in the Mekong Delta, and the severity of flooding has
increased in recent decades. The increases in the unpredictability, frequency, andmagnitude of floods have been responsible for high human and material costs inthe delta. As part of the many risk transitions underway in Viet Nam, natural
disaster has been added to the lists of unresolved environmental and healthproblems accompanying economic development. As with many of the great urban
regions in the world, the economic and political logic of the growth of Viet Nam’slargest urban region is confronting an environmental reality that defies quick oreasy solutions. While much effort has gone into inhibiting migration to HCMC
proper, this does not anticipate the larger process of urbanization that will takeplace in the Mekong Delta. There is thus a need to look more realistically at thelikely rather than contained growth of this region to better manage urbanizationand environmental management together.
2.4 Air quality
The major source of air pollution in Viet Nam is from industrial emission andvehicular traffic. Hanoi and Ho Chi Minh City (HCMC) are the two largest andmost densely populated cities in Viet Nam. Industrial zones are concentrated andemerging in and around Hanoi and to an even greater extent in HCMC. Formerly,
many enterprises and plants were located away from population concentrations.
Due to the expansion of cities into urbanizing peripheries, however industrial
zones are now situated among densely populated areas and cause serious air
pollution in neighboring communities. For example, the Thuong Dinh industrial
zone, the biggest old industrial zone in Hanoi, was initially located far frominhabited areas. Today, densely populated areas have grown up in areas near theplants such as Thanh Xuan Bac, Thanh Xuan Nam, Kim Giang and so forth. The
enterprises are mixed with residential areas and thus inhabitants are threatened bymore severe exposure to poor air quality (Douglass et al. 2002).
Indicators of poor air quality in Hanoi and HCMC include dust, particularly fromconstructions and industrial processes; sulfur dioxide (SO2), which mainly comesfrom coal as one of Viet Nam’s major sources of fuel; nitrogen oxide (NOx),carbon monoxide (CO), and particulates, which are generally emitted from the
motorized vehicles’ engines during the combustion processes.

New Technologies for Urban Safety of Mega Cities in Asia

The spreading construction processes, traffic, and many industrial processes havebeen generating high levels of dust in the air. Levels of suspended dust pollution
in the air that are just equal to or lower than the permitted norm have only been
noted in places located far from cities, industrial zones or traffic axes. In addition,as many new industrial zones are developed, the amount of noxious gases in theatmosphere of cities is increasing as a consequence of the greater industrial
processes.
Transportation is another major source of air pollution in Hanoi and HCMC.
Although in comparison with other countries, the density of vehicles in both cities
is not high, vehicles use is increasing rapidly. In the late 1980s, roads in Hanoi
and HCMC were filled with bicycles, pedicabs, and occasionally by trucks orother motorized vehicles. This situation began to change in the early 1990s when
the number of motorcycles on city streets began to increase and replace thenumber of bicycles.
2.5 Water quality and supply
In terms of sufficient water supplies that meet quality standards and sustain
human life, livelihood, and for ecosystem balance, Hanoi and HCMC are moving
towards a crisis point. These two cities have varied modes of water resources,
such as rivers, lakes, groundwater, and springs. However, water sources are being
degraded through four main sources: agricultural chemicals, urbanization,industrial waste, and poorly managed dumpsites. While some impacts are clearlyurban or rural, many occasions of water quality degradation occur acrossenvironmental settings due to flows of water above and below ground, thelocation of urban landfills, and the increasing need for urban areas to draw watersupplies from distant sources.
The increasing number of urban inhabitants also increases human settlement
waste and contributes to water quality degradation. This waste has been the major
source of wastewater in Hanoi and HCMC, and adds more than 80 percent of thetotal wastewater. Industrial waste and waste from hospitals and schools also
contribute waste, but at a relatively lower percentage. Most of the urban
population is not served by sewerage systems, and alternatives such as septic
tanks have not prevented the disposal of waste into urban waterways. In addition,
there have been changes in consumption patterns, in terms of consumption levels
and the variety of consumed products, which not only increase the volume andvariety of domestic waste, but also change waste characteristics from organic tomore inorganic wastes. Thus, relying on the carrying capacity of waterways toreceive and safely dissolve pollutants and contaminants is no longer a sufficientsolution for either the growing amount of already existing pollutants or themounting ‘new types’ of wastewater.
Rapid industrialization, notably water intensive light industries such as textiles or
chemical intensive production such as footwear or ‘high technology’ computer
chip fabrication, would add substantially to the degradation of an alreadyoverburden water system. Even now, while new industries have emerged in
Hanoi and HCMC, most industries in either city, including those financed throughThe rapid urban transition in Viet Nam: Challenges for sustainable development in theface of climate change

0ctober 2010, Kobe, Japan

foreign investment, have not implemented any sufficient treatment plants. Viet
Nam has inherited old industrial complexes, built at a time when environmental
concerns were minimal and were using technology dating back to the 1950s.
These problems have become worse since the development of new Industrial
Zones (IZs) and Export Processing Zones (EPZs). Viet Nam has currently
developed IZs, EPZs, and hi-tech parks in 28 provinces and cities across thecountry. The IZs were designed to house new factories and re-house thosefactories and production lines found to be causing pollution in the inner city.
However, IZ management boards face even tougher challenges due to the wornout and outdated equipment used by most of the factories. Moreover, mostowners of these factories fail to buy modern equipment or to pay to have theirwaste treated. Since the level of occupancy in these IZs only reached around 30
percent in 1999 (Le Huong Vong, 1999), IZ management boards may seek toattract new industries and keep current industries by any means possible, which inother countries has meant a reluctance to impose environmental laws or standards.
Considering the outdated technology owned by many factories, IZ boards are
rarely able to manage an industrial zone as it designed, which would facilitate
waste management. They are frequently required to expedite permitting,including environmental impact assessments (EIA).
In addition to above issues, lakes and ponds in Hanoi have been serving as
reservoirs of storm water, wastewater, and places for the natural purification ofwastewater. The worsening untreated wastewater quality and persistent chemical
substances that last in water for many years threaten these lakes; they may
become simply wastewater reservoirs. In fact, all of the city’s ponds and lakes,
with the exception of Hoan Kiem in the city center, have been used for wastewater
treatment and aquaculture.
In the case of HCMC, generally most of the waterways are heavily polluted byhuman settlement waste, industrial wastewater, and solid waste dumped into thecanals. The current conditions of these canals illustrate a health risk for people
living along the canal. These conditions also threaten paddy field and fish-ponds
at the lower stream areas, which is similar to problems around Hanoi.
As mentioned above, water pollution will likely occur across rural and urban
environmental settings due to the flows of water. This can be very dangerous insome cases, for example with agricultural chemical pollution, such as pesticides
and fertilizers. Pesticides are dangerous to the ecosystem because of their
persistent toxic organic compounds. These chemical compounds will persist innature for a very long time.
Another concern in managing water resources in Viet Nam is how to sustain water
quality to adequately meet standards for human use – as drinking water - and forecosystem balance. A high rate of urbanization and increasing urban populations
will lead to substantial increases in the demand for clean water in urban areas.
Viet Nam’s clean water supplies come from both surface water and groundwater.
Viet Nam has abundant water resources but two thirds of these come fromexternal rivers. The distribution of water in Viet Nam is very uneven with
New Technologies for Urban Safety of Mega Cities in Asia

variations greatly depending on both differences among regions as well as seasons.
However, clean water problems are not merely about matching water quantitywith expected demand, but also about how to provide sufficient water that meetsclean water standards and contains a proper and efficient distribution system.
Land subsidence due to excessive groundwater extraction has also begun to occur
in some areas such as Tuong Mai, which sink at an average rate of 40 mm per
year. Ha Dinh, Vong, and Van Dien, meanwhile, are sinking at the average rateof 20 mm per year (Francisco & Glover, 1999). Figure 4.5 shows the location ofpotential-risk points of severe land subsidence in Hanoi. Most of the areas shownin the map are industrial areas. Since water demands from industries are muchhigher than residential demands, groundwater will be overly extracted unlessenvironmental risk-costs are internalized.
One extreme example of land subsidence has occurred in Bangkok. Due to theover pumping of the aquifer layer, Bangkok’s land levels at certain areas havebeen reduced by more than 60 cm in the last 50 years (White, 1994:123). As aresult, Bangkok’s susceptibility to flooding has increased. Flooding occurs almost
every year, during the months of October and November, and has resulted in agreat misery for residents, as well as enormous economic costs due to damaged
roads, telephones, cars, etc. It is very important therefore, that Viet Nam
recognizes the early warning signs of this problem and strives to avoid theshortcoming of other countries.
Infrastructure development is another important aspect of water supplies. Viet
Nam, like almost all other Asian countries, lacks sufficient water supply service
for its cities. The coverage in urban Viet Nam reaches 60 percent of its target
with 50 percent Unaccounted-For-Water – (UFW) (ADB, 2001). In many other
Asian cities, this condition has resulted in large numbers of un-served urban
inhabitants and also decreased revenues for water providers. While still in the
beginning of the urban transition, 80 percent of Viet Nam populations still live inrural area. The latest survey shows that only 15-40 percent of rural populations
have access to clean water, and only a small percentage of these people haveaccess to sanitary latrines. Shortages of safe water and polluted rural
environments have caused many outbreaks of contagious waterborne diseases.
The lack of public water supply services has been compelling people to seek othersources to meet their water demands. This increases the uncontrolled extractionof groundwater by both households and industries. Excessive withdrawal ofgroundwater will, in turn, create future negative impacts on the city itself as
mentioned before. In addition, as people’s awareness of the importance of cleanwater increases, there is a trend of an increasing demand for bottled water, whichis said to be processed from springs by private enterprises). Nearly one-third of
Hanoi and HCMC inhabitants consume bottled water on a daily basis. Investors
have already recognized the potential market for this product, and there have beenfour companies that are ready to establish this business in Viet Nam (Cohen,2001).

The rapid urban transition in Viet Nam: Challenges for sustainable development in theface of climate change

0ctober 2010, Kobe, JapanThe trend of an increased use of bottled water presents two important aspects tobe considered. First, an increasing demand will lead to an increase in the use of
input materials, which in this case are springs as a reliable water source. There isa risk that these companies will over-utilize the resources simply for the sake of
their profits, unless resources-costs are internalized in their production. Second,
this shift of consumption pattern will adversely contribute to the increase of solid
waste generation in urban Viet Nam. Third, as found in the U.S. and Europe
where bottled water was not uncommonly below standard levels of safety, such
water sold by large and micro enterprises alike requires a routine system ofmonitoring, presumably by a public entity, which will add costs to water delivery.
The combination of water supply and quality problems forms a list of difficult
challenges for Vietnamese society. There is possibility that Viet Nam will repeat
the pattern of some other Asian countries; the pace of environmental management
and progress lag behind that of economic growth. Since water plays importantroles in development processes (e.g., a basic necessity for human beings, andcritical for many industrial uses), a sufficient water resource management systemshould be a prime concern in spatial planning in Viet Nam. This, in turn, will
have tremendous economic (e.g. lower costs for public water treatment process)and health benefits for the nation.
3. SPATIAL DIMENSIONS OF URBAN ENVIRONMENTAL RISKS
The accelerated urban-industrial growth that is underway in Viet Nam is bringing
new wealth and higher incomes for many people. An unintended effect of thisdevelopment is the danger that they are bringing new environmental as well as
economic risks, making the future of living conditions in the main urban areas aswell as rural regions uncertain. In major cities, the rapid growth of the urban
population, traffic congestion, unplanned land use changes, uncollected solid
waste, and polluted water sources are the most visible signs of the manyenvironmental management problems that are worsening, often at alarming rates.
The changes embedded in the urban and economic transition can be seen as
involving a shift in environmental risks from those associated with a largely
small-scale agricultural based society to a more modernized, urban-industrial
society. The shift involves new sources and quantitative leaps in energy use,
notably fossil fuels; transformations from organic to chemical inputs inagriculture; and increasing amounts of non-biodegradable wastes along with toxic
wastes -- in sum, forms of air, water and ground pollution never before
experienced.
As industries and commerce begin to play larger economic roles in societies thatformerly relied heavily on agriculture, forestry and fisheries, life style andconsumption patterns change. Along with these changes, society begins toencounter many new types and mixes of risks. As discussed previously, these
new risks (e.g. respiratory disease due to industrial air pollution) will add to still
existing old and well-known risks (e.g. waterborne disease due to poor sanitarysystem).

New Technologies for Urban Safety of Mega Cities in Asia

Viet Nam today has entered the most perilous phase of its environmental andhealth risks. Old risks remain serious or are becoming even worse, and new risks
are rapidly appearing. All of these have a pronounced regional pattern of mixes
and need to be addressed as such on a regional basis. Some regions continue toface more traditional forms of environmental risk, while more urbanized ones areexperiencing the more modern ones. At the same time, the sources of the risks do
not necessarily or even primarily come from the localities experiencing.
Deforestation of the uplands, which might result in the need for new kinds of fuelfor cooking, is often done by distant commercial interests; similarly the
introduction of plastic bags that replace organic materials for wrapping, e.g., food,can reach from the city to the most distant outpost. In other words, while thespecific mix of risks is particular to each locale, the ways in which risks aretransmitted are all part of the spatially integrative processes attending the urban
transition.
Many traditional institutions to cope with risks have developed through time inViet Nam. Rural society in northern and central Viet Nam was characterized byvery high levels of risks to individual survival, including threats associated with
the natural environment. Responding to these risks, strong social institutions were
established to help individuals and communities cope with the frequent disasters
that challenged them. Furthermore, it is argued that the “closed corporate”
peasant villages of the Red River Delta, in which individual households are tightly
integrated into largely autonomous self-managing communities, can be seen as an
adaptation to an unpredictable environment characterized by frequent natural
disasters (e.g. flood, drought, crop failures), and intense competition for land andother scarce resources.
In contemporary Viet Nam, many of traditional natural hazards still threaten
villagers. In some cases, natural disasters had been a part of the villagers’ life for
decades (e.g. flooding, drought). However, since natural cycles have been
influenced by modified methods of managing nature, devastating catastrophes
have occurred recently. Flooding in the Mekong River Delta, for example, is aperennial phenomenon. Local societies evolved ways of coping with this annual
cycle by implementing a method for “living together with the flood”. Houses
were often constructed in a certain way to be easily dismantled and transported tosafe areas in years of deep floods. Floodwaters also quickly drained away throughthe vast network of streams and canals that were available in the flood prone area.
In recent years, however, the expansion of the road network has created barriers todrainage. In addition, the conversion of flood retention basins to agricultural use
has made the impact of floods more serious and longer lasting (Tran and Shaw2007). Changes of housing in this area into a modern style of masonry structures
have also threatened communities; modern style masonry structures mean shelters
may be lost to flooding, since they cannot be moved.
In addition to these old and modified traditional risks, modern risks are appearing
at a disquieting rate. Many of these new ‘modern’ risks are discussed above andinclude increases in amounts and types of air, noise, and water pollution; exposure
to agricultural chemicals; and workplace hazards. In the early stage of the urban
transition, Viet Nam is also entering a phase of congested risks. Traditional
The rapid urban transition in Viet Nam: Challenges for sustainable development in theface of climate change

0ctober 2010, Kobe, Japancustomary practices break down in many cases, while ‘new’ practices are not fully
ready to respond to the emerging environmental and health risks. Viet Nam’s
related institutions have already been having a hard time coping with traditionalrisks. Today, these institutions are still poorly equipped and have to face
additional challenges from emerging modern risks.
In general, Viet Nam’s current worsening environmental and health problems are
the outcome of the interaction of many different factors, including: the natural
setting, historical legacies, cultural values, and institutional structures. These
factors provide a backdrop for the more recent rapid environmental changebrought about by the expansion of the market economy, population pressure,urbanization and industrialization, inappropriate or poorly implemented policies,
and lack of adequate knowledge and understanding of the environment. Past
policies to control urban growth, such as the restriction of migration, planned
decentralization of industry, and the development of NEZ in the periphery, arebecoming ineffective and have even exacerbated some problems; they have now
largely been abandoned. These conditions foster the rapid growth of cities, which
overwhelm existing infrastructures and exacerbate environmental problems.
However, these challenges are not merely concerns for urban inhabitants, but also
confront households in many communes which are partly industrialized or where
localized urbanization is taking place.
4. ENVIRONMENTAL RISKS IN THE URBAN TRANSITION
The economic and urban transition that is underway in Viet Nam is manifest in ashift of the consumption pattern to a higher level and more varied patterns that are
acknowledged to represent an increase in wealth and general welfare of society.
Today higher order goods such as televisions and motorcycles can be found invery large shares of households. Despite the positive impact of economic growth,
there are questions about the increasing trends of urban risks. In general,
environmental stress is related to industries, industrial processes and urbanization;
all contribute to a sense of cities being overwhelmed by looming crises, withmounting problems exceeding capacities to manage them.
Viet Nam has recently been entering a critical phase, when traditional risks remain
serious or even worse, but new risks are rapidly appearing. Before, Viet Nam
already had wisdom and social institutions to cope with traditional risks (e.g. stilt
houses in flood areas of Mekong delta). But with the shift of risks incontemporary Viet Nam, these customary practices have broken down in manycases. For example, wastewater management methods still follow ‘old customs’and discharge waste directly into canals. This waste exceeds the water’s carrying
capacity to proceed with the natural degradation process. Hence, customary
practices do not currently work and at the same time, new methods to deal withthe ‘more modern’ problems have yet to be materialized. This phenomenon not
only happens in urbanizing rural areas, but also in the cities where mosthouseholds and industries are not equipped with sufficient waste treatment
technologies.

New Technologies for Urban Safety of Mega Cities in Asia

Hanoi and HCMC demonstrate that environmental deterioration is worsening
along with the increased urban populations and economic growth. Environmental
issues tend to be seen as an outcome of the rapid pace of industrialization andmodernization. Thus, environmental management attempts are reflexive rather
than anticipatory, falling behind rather than moving ahead of the problems being
generated. Implementation problems also appear to be increasing with the scaleof the impacts. How to meet current management needs and also scale up
environmental management capabilities to reach the level and pace ofenvironmental degradation is a central question in the urban transition.
Economic growth alone has not been able to ameliorate environmental problems,
although to some extent it can shift industrial processes towards cleaner
technologies and less polluting sectors of production. However, if energy
consumption and resource use is still highly inefficient, and are accompanied by
failures to internalize environmental costs, then energy and resource consumption
will keep increasing as will the production of waste.
Reviewing the trends of economic and urban growth, there have been signs thatthe two largest cities, Hanoi and HCMC, are continually expanding along with thegrowth of population and infrastructure developments. Moreover, there have been
many spots settlement around these cities that are experiencing local-urbanization
and are now becoming densely populated areas. As these ‘urban-like’ areas
experience rapid increase in population, they are likely to have the same types ofenvironmental and health problems as those of the urban areas. However, it isimportant to note that these ‘urban-like’ areas lack the environmental
infrastructure and services afforded to the cities. In addition, the customary
practices that are still widely implemented in the high density settlements inenvironmentally sensitive zones are furthering environmental risks in these areas.
A spatial perspective reveals important dimensions of environmental issues. The
more obvious insight is that the specifics of these issues vary greatly over space,
and thus call for localized capacities to respond to them. Beyond this observation
are the many insights from understanding how transformations occurring in one
region are resulting from the integration of localities into an expanding urban,
regional and global spheres of influence and change. Just as deforestation in thehighlands is not taking place in isolation from urban demands for timber,migration from one region to another, and the push for export crop production, thedifficulties in sustaining traditional systems of environmental management inlowland areas and cities are not simply a problem of too many people in theselocations, but are instead an outcome of gross increases in degree and type ofenvironmental problem linking to broader processes over space. The same is true
for the livability of the built environment of cities, including civic and open
spaces and housing.
REFERENCES
Asia Development Bank (ADB). (2001). Financing and Developing
Environmental Infrastructure in Vietnam: The case of water supply andwastewater treatment. ADB-VRM News Release
The rapid urban transition in Viet Nam: Challenges for sustainable development in theface of climate change

0ctober 2010, Kobe, Japan

Cohen, M. (2001, September 27). The trials and tribulations of a springwaterbottler in an unpredictable frontier market. Far Eastern Economic Review.
Douglass, M., DiGregorio, M., Pichaya, V., Boonchuen, P., Brunner, M.,
Bunjamin, W., Foster, D., Handler, S., Komalasari, R., Taniguchi, K., 2002. The
Urban Transition in Vietnam, Department of Urban and Regional Planning,
University of Hawai’i at Manoa, UN Center for Human Settlements, Fukuoka and
UNDP.
Francisco, H. & Glover, D. (1999). Economy and Environment: Case studies inVietnam. EEPSEA.
Gujja, B., 2001. Dam accused of role in flooding: Research Paper: “Dams andFloods”, World Wide Fund for Nature.
International Rivers Network (IRN), 2001. The Asian Development Bank:
Financing Destructive Development in the Greater Mekong Subregion.
People in flooded Mekong provinces need help. (2001, October 2). Nhan Dan[On-line]. Available: http://www.nhandan.org.vn/english/today/ouropinion.html
Tran P, Shaw R (2007) Towards an integrated approach of disaster andenvironment management: A case study of Thua Thien Hue Province, Central
Viet Nam. Environmental Hazards
White, R. (1994). Urban Environmental Management: Environmental change andurban design. John Wiley & Son. Inc.

New Technologies for Urban Safety of Mega Cities in Asia

Effect of mix proportions and construction
conditions on permeability properties
of surface and internal concrete
1

Shinichiro MATSUZAKI1, Takeshi IYODA2, and Taketo UOMOTO3
Graduate Student, School of Eng., Shibaura Institute of Technology, Japan
m509090@sic.shibaura-it.ac.jp
2
Assistant professor, Shibaura Institute of Technology, Japan
3
Professor, Public Works Research Institute, Japan

ABSTRACTReinforced concrete is exposed to environmental conditions which may lead tocorrosion of reinforcing steel due to carbonation or salt damage. Durability
against these factors is determined by the permeability properties of the concrete.
It is generally believed that permeability properties are constant for both surface
and internal concrete, but in reality the permeability may vary due to watercement ratio, cement type, and curing conditions, so it is necessary to understandthe effect of these variables on the permeability properties of surface and internal
concrete. In this research, a new method for evaluating permeability properties byvacuum pump was developed. This method determines the permeability property
based on concrete absorption area and change of weight. The results clarify theeffect of the research variables on the permeability property. It was found thatcuring significantly affects the permeability of surface concrete, and the internal
permeability increases as the water-cement ratio increases. For Portland blast
furnace slag cement, the importance of curing period for improving the concrete
permeability was clarified. Utilizing this examination method may allow for
estimation of concrete mix proportions and construction conditions.
Keywords: permeability property, cement type, water-cement ratio, curing period
1. INTRODUCTION
In recent years durability of concrete structures has become more important for
reducing life cycle cost. Generally, the diffusion coefficient, an indicator of
durability and permeability of concrete, is considered constant in a concrete
structure. However, it is believed that the diffusion coefficient at the surface isdifferent than that inside concrete because surface and internal concrete properties
differ depending on the water-cement ratio, bleeding property and drying
conditions due to curing period. To improve durability against carbonation andsalt damage, the influence of these durability factors should be understood.
There are some suggestions for concrete durability evaluation tests; however,those methods are not able to understand the difference between surface andinternal conditions. Therefore, a method for easily evaluating the durability on
both the concrete surface and interior is necessary. This research aims at the0ctober 2010, Kobe, Japanestablishment of a permeability evaluation method for the concrete structure andtries to understand the influence of the factors mentioned above. The process of
this research is as follows. From the first test, the influence of curing period onwater-cement ratio on concrete permeability property was examined. Next, theinfluence of permeability property considering the difference between concretesurface and interior was evaluated. Finally, using these results the permeability ofconcrete exposed at a construction site was measured.
2. EXPERIMENTAL OUTLINE
2.1 Permeability test for uniform specimens (Step 1)
Table 1 shows the concrete mix proportions for the permeability test on uniform
concrete. To understand curing period suitable for kind of cement, Portland
cement and Blast-furnace slag cement which have many shares in the country
were used. Materials for mixing were prepared and stored at 20℃ for 24 hours
before casting. The test pieces were 100×100×50 mm beams. Figure 1 shows
the curing method and period, and the total curing period was 28 days. The periodof sealed curing was decided according to the Japan Standard Specifications forConcrete Structures (JSCE, 2007).
Table 1: Mix proportions (air permeability and Slump test)
W/C

3

s/a

Amount of unit(kg/m )

SL

Air

(cm)

(%)

cementOPC

BB

AE waterreducing agent

(%)

(%)

W

C

BFS

S

G

55

47

172

313

0

855

982

C*0.25% C*0.02%

12.0

4.2

45

45

172

382

0

792

987

C*0.25% C*0.02%

14.5

3.9

30

42

172

573

0

672

946

21.5

5.8

55

47

172

156

156

850

976

C*0.25% C*0.02%

17.5

4.0

45

45

172

191

191

786

979

C*0.25% C*0.02%

18.5

4.3

30

42

172

287

287

663

933

64×62

4.6

AE

SP

C*0.9％

C*0.9％

Figure 1: Relationship between curing method and curing period

New Technologies for Urban Safety of Mega Cities in Asia

2.2 Influence of depth in the permeability test (Step 2)
Concrete mix proportions are same as given in Table 1, and the specimens werecylinders φ 100 × 200mm. The specimen forms were removed after curing(Figure 1) to understand the relationship between permeability property and depth
from surface of concrete. Tests were conducted 28 days after casting.
2.3 Method of permeability test
Figure 2 shows the method for the developed permeability test. After curing,
specimens were dried in oven for one day and specimen sides were sealed byaluminum tape to protect from water penetration under vacuum conditions. These
specimens were set in a container, and water was poured to half the specimen’sheight. Specimen containers were placed in a desiccator and vacuum conditions
were applied by vacuum pump, which draws water up through the specimens.
These specimens were then split in compression and the permeability wasevaluated as the ratio of area which absorbed water. In Step 1, the permeability
property was calculated as the ratio of water absorption area per all cross sections.
In Step 2, it was calculated as the ratio of water absorption area per unit area inwhich all cross sections were divided into 1-cm segments.

Figure 2: Method of permeability test
Effect of mix proportions and construction conditions on permeability properties of
surface and internal concrete

0ctober 2010, Kobe, Japan

3. RESULTS AND DISCUSSION
3.1 Permeability test results for Step 1
Figures 3 and 4 show the results from the new permeability test. For both cement
types, permeability property tends to decrease as water-cement ratio increases. In
case of high water-cement ratio, the water which is not necessary for hydration
increases, so the permeability property was greatly affected by outside conditionof concrete. In the blast-furnace slag cement, the permeability property was higher
than cement when the curing period was one day. However, permeability
properties of both cement types showed a similar result when the curing period
was seven days. It is believed that the pore structure changed due to the hydration
velocity of the blast-furnace slag cement, which is slower than the Portland
cement. These result showed that curing period is important to improve
permeability property of surface concrete.

Figure 3: Relationship between permeability property and curing period(Portland cement : N )Figure 4: Relationship between permeability property and curing period( Blast-furnace slag cement : BB )New Technologies for Urban Safety of Mega Cities in Asia

3.2 Permeability test results for Step 2
Figures 5 and 6 show the results of the permeability test for Step 2. Similar to theprevious results, permeability property of both cement types tends to decrease as
water-cement ratio increases. In addition, the permeability property of both endsof these specimens showed a tendency to become higher by drying from surface.
The inflexion point at which the permeability property stopped changing isregarded as the curing influence area; this area (the shaded areas in the figures) for
both cement types was about five centimeters. The difference in permeability inthe flat area was regarded as the influence of the water-cement ratio because it is
not affected by the external conditions. In both figures, the permeability property
at both ends (the shaded areas in the figures) was different. It is believed that thisdifference is due to the difference between casting direction and watertransportation direction.

Figure 5: Relationship between permeability property and depth from surface ofconcrete (Portland cement : N )Figure 6: Relationship between permeability property and depth from surface ofconcrete (Blast-furnace slag cement : BB )Effect of mix proportions and construction conditions on permeability properties of
surface and internal concrete

0ctober 2010, Kobe, Japan

4. Application of the permeability test to on-site concrete
The results of Steps 1 and 2 were arranged in Figures 7 and 8 to examine therelationship between permeability property and the water-cement ratio, and thepermeability of concrete exposed at a construction site was evaluated using thesefigures. The concrete information known before examination is as follows. The
specimen was cast in φ100×200 mm framework in a tunnel as shown in Figure
9. The upper end of the specimen was exposed on-site where it was located 30
meters from the tunnel entrance, and it was examined 30 days after casting. The
specimen cement was blast-furnace slag cement. However, information such as
the water-cement ratio and curing period w
was
as unknown, so these were predictedusing the permeability test.. Figure 10 shows the result of permeability test and an
estimate of the water-cement ratio and curing period.

Figure 7: Relationship between permeability property and water-cement ratio(Portland cement : N )Figure 8: Relationship between permeability property and curing period(Blast-furnace slag cement : BB )Firstly, the permeability property of internal concrete was compared with a test
result of the potential (Step 2) and the water-cement ratio was estimated to beabout 53% by the intersection point. Next, the permeability property of surface
New Technologies for Urban Safety of Mega Cities in Asia

concrete was compared with the test result of S
Step
tep 1, and the curing period wasestimated to be between one and five days. After finishing the permeability test,
the actual concrete information was received from the contractor. The watercement ratio was 52.5% and curing period was two days, which demonstrates that
this result showed that the permeability test can estimate these factors.

Figure 9: Tunnel where the specimen was cast

Figure 10: Result of permeability test and estimation method for water-cement
ratio and curing period
5. CONCLUSION
This research aimed to establish a method for evaluating the permeability property
of concrete structures, and also tried to understand the influence of durability
factors. The conclusions of this study are as follows.
1. It was confirmed that the water-cement ratio and curing period had an
influence on permeability property of surface and internal concrete.
2. It was clarified that the permeability property was greatly influenced by curing
period. In this research, the original concrete properties could be estimatedand the permeability property could be evaluated using the results from Steps
Effect of mix proportions and construction conditions on permeability properties of
surface and internal concrete

0ctober 2010, Kobe, Japan

1 and 2, which examined the influence of curing time and difference between
surface and internal properties. However, this estimation was only verified
with one on-site specimen at this time.
3. In the future, it will be necessary to examine other types of cement and curingmethods, and to increase the number of specimen in order to improve theprecision of the method.
ACKNOWLEDGMENT
The authors would like to express their thanks to Dr. Michael W. Henry for his
assistance.
REFERENCES
JSCE, 2007. Japan Standard Specifications for Concrete Structures, 122-124.
Y. Dan, T. Iyoda, Y. Ohtsuka, Y. Sagawa, H. Hamada, 2009, The relationshipbetween curing condition and durability on concrete using blast-furnace slag
cement, Journal of the Japan Society of Civil Engineers E, Vol.65 No.4, 431-441,
Japan. (in Japanese)
H. Suzuki, S. Matsuzaki, T. Iyoda, 2010, A durability test of the surface concrete
using a core sample, Journal of the Japan Society of Civil Engineers-kanto, Japan.
(in Japanese)
S. Okazaki, T. Yagi, T. Kishi and T. Yajima, 2006, Difference of sensitivity due tocuring condition on strength and permeability, Cement Science and Concrete
Technology, NO.60, 227-234, Japan Cement Association. (In Japanese)
T. Iyoda, Y. Dan, Y. Sagawa, H. Hamada, 2008, The effect of curing period on the
durability of concrete usingBlast-furnace sag blended cement, The 3rd ACF
International Conference-ACF/VCA 2008

New Technologies for Urban Safety of Mega Cities in Asia

Effects of nutrient concentration on
microbial cementation in Toyoura sand
Makoto HOSOO1, Reiko KUWANO2
1
Graduate school of Engineering,
The University of Tokyo, Japanhosoo@iis.u-tokyo.ac.jp
2
Associate Prof., ICUS, Institute of Industrial Science,
The University of Tokyo, Japan
ABSTRACTA new technique of ground improvement using microbial function has been
recently proposed, as more eco-friendly technique than conventional one.
Metabolic function of microbes produces carbon dioxide, which helps to generatecalcium carbonate in soil. In this study, a series of trial test was conducted inorder to evaluate the degree of soil cementation generated by those function in
Toyoura sand specimens filled in a syringe. It was found that the cementation insoil can be roughly estimated by monitoring the change of the calcium ion
concentration in the pore liquid. The concentration of nutrient affected theamount of precipitated calcium carbonate in sand.

Keywords: Microorganisms, Urea , Calcium Carbonate

1. INTRODUCTION
Some researchers reported that urease enzyme from “Bacillus Pasteurii” could be
used to add cementation in sand (Dejong et al., 2006; Whiffin et al., 2010). In thisstudy, a series of trial test was conducted in order to evaluate the degree of soil
cementation generated by those microbial functions in Toyoura sand.
Bacillus Pasteurii helps to precipitate calcium carbonate through the chemical
process (Eq.1, 2, 3). Precipitated calcium carbonate on a soil grain and/or between
soil particles seem to contribute to stiffen and strengthen the ground.
CO(NH 2 ) 2 +2H 2 O → 2NH 4 + +CO 3 2CO 2 +H 2 O→CO 3 2-+2H+
Ca 2 ++CO 3 2-→CaCO 3 ↓

(1)
(2)
(3)

0ctober 2010, Kobe, Japan

2. MATERILS AND METHODS
Toyoura sand was filled in a 50ml plastic syringe to prepare a specimen of
29.5mm in diameter and 48mm in height. 17ml Nutrient solution which contains
Calcium and carbon source, and 3ml Pasteurii (2x106 cells/ml) was put in asyringe in advance. Toyoura sand was pluviated through the solution to relative
density of approximately 90 %.
In test series 1, two types of nutrient were used, Case A and B, as shown in Table
1. 20ml nutrient solution was poured into a specimen from top surface of a
specimen and the same amount (20ml) was drained from the bottom at one day
and two days later.
In test series 2, three kinds nutrient were used as shown in Table 2. Concentrationof Case C is same as Case A (Table 1), Case D is twice, Case E is three times ofthat of Case C. Nutrient solution was supplied one day and two days after for only
Case C.
For the evaluation of degree of cementation in a sand specimen, penetration tests
were conducted. The penetration needle of 3mm diameter is shown in Fig.2.
Penetration test was conducted at a rate of 10mm per minute up to a depth of
45mm. The calcium concentration and the pH of the pore liquid were alsomeasured. After the test, enough amount of distilled water was flushed through thespecimen in order to remove the remained nutrient solution and dry weight ofspecimen was measured. For all test cases, two specimens were tested for thesame condition in order to check the repeatability of the test. In addition to thatmeasurement, the strongly cemented portion from one of Case A specimen wasobserved by scanning electron microscopy (SEM) and energy dispersive
spectroscopy (EDS) was performed using JEOL JSM-5600.

Injection
direction

Pinch cockFigure.1: A specimen in a syringe

New Technologies for Urban Safety of Mega Cities in Asia

3mm

Figure.2 Penetration needle and tip shape
Table1: Composition of nutrient
solution, Test1 (g/L)

Table2: Composition of nutrient
solution, Test2 (g/L)

Case
Bacto nutrient broth
Urea
CaCl2・2H2O
NH4Cl
NaHCO3

Case
Bacto nutrient broth
Urea
CaCl2・2H2O
NH4Cl
NaHCO3AB
3.5 0.35
35 3.582 8.2
12 1.2
2.4 0.24

C
3
30
70
10
2

D
E
6
9
60 90
140 21020 30
46Depth (mm)Depth (mm)3. RESULTS AND DISCUSSION
Penetration Resistance (N)
3.1 TEST 1
18
150
120
90
60
30
0
0
Penetration resistance is shown in
Figures 3 and 4. Comparing with
CaseA 2day
dense/loose saturated Toyoura sand,
15 CaseB,
it is clear that microbial cemented
Toyoura sandsoil indicated larger resistance. The
CaseA 1day
effectiveness of Pasteurii wastherefore confirmed. Distinctive
30
difference was shown between
Case A and Case B due to different
CaseA 3day
nutrient concentration. When three45
days passed, 3N was measured inCase B while 130 – 150N was Figure.3: Penetration resistance in Case A
measured in Case A.
Variation of Calcium concentration
Penetration Resistance (N)
0
1
2
3
4
5
and pH is shown in Figure.5.
0Values of pH were 7.3 to 8.0 for
both cases A and B, It is almost
CaseB 1day
neutral that is appropriate for the15
CaseB 2day
CaseB 3day
calcium carbonate precipitation.
Calcium concentration decreases
greatly in Case A day by day. Case30
B was decreased from 1st day toDense Toyoura sandthe 2nd day. Afterwards, it was
Loose Toyoura sandsimilar value.
45 ※ Pore liquid within dashed line of Case B 3day was drained during penetration
The increment ratio of dry weightof the specimen before and after Figure.4: Penetration resistance in Case B
Effects of nutrient concentration on microbial cementation in Toyoura sand0ctober 2010, Kobe, Japan

30

9

pH

2+

2+

Efficiency (%)

increased dry weight / initial dry weight (%)

Calcium ion concentration (g/L)

the test is plotted in Figure.6.
CaseB pH
25
Case A Ca
Assuming that all remained nutrient
were flushed in the washing process
20
8after experiment, weight increment is
15thought to be the calcium carbonate
CaseA pHprecipitation. The maximum value
10
7
drawn in the short dashed line
5
Case B Ca
indicates the case in which all theadded calcium ion precipitate as
0
6
0
1
2
3
calcium carbonate. Plotted open
elapsed time (day)symbol indicates calculated value
based on the measured calcium ion in
the pore liquid, assuming that a Figure.5: Calcium concentration and pH
consumed
calciumion
was
7
precipitated as calcium carbonate.
6
Maximum weight
Weight increases day by day in Case
Measured weightA, and its increment is about 5% in
Calculated weight5
three days. Case B was increased
CaseA
4
0.5%. It almost corresponds to the3
ratio of the amount of calcium source
given to the specimen. When calcium
2
CaseB
ion in pore liquid reacts completely,1efficiency reaches 100%. Efficiency
0of Case A reaches around 80% with230
1
elapsed time (day)both measured and calculated weightin two days. Efficiency of Case B
sometimes exceeded 100%, which Figure.6: Increment ratio of dry weight ofindicates some errors involved in thethe specimen before and after the test
measurement due to its low
concentration.
150
Images of SEM and compositional
CaseB
mapping by EDS were provided in
Figure.8. It is obvious that100
precipitated stuff adhere to the
CaseA
particle surface and pore in the partthathascementedstrongly
50(Figure.8(a)) Furthermore, the resultof compositional mapping shown in
Measured value
Calculated value
Figure.8 (b and c) indicates that0precipitated stuffs mostly contains
12
30
elapsed time (day)Calcium. Remarkable increase ofpenetration resistance in Test 1 wasthought to be caused by particle Figure.7: Efficiency of calcium carbonate
precipitation
bonding or friction increase due toprecipitated calcium carbonate.

New Technologies for Urban Safety of Mega Cities in Asia

20μm

(a)
(b) Ca(c) SiFigure.8:Images of SEM and compositional mapping by EDS

0

0

50

Penetration Resistance (N)100150

Depth (mm)Case C 2day

20

Case C 3day

15
Case D , E
Toyoura sand

30

45
0
0

Case C 1day

10

20

30

40

Depth (mm)Case D 1day
Case D 2day

15

Case D 3day

30

45
0

Dense Toyoura sand
LooseToyoura sand

0

5

10

Case E 1day

Depth (mm)

3.2 Test 2
Penetration resistance is shown in
Figure.9. Distinctive difference wasalso shown between Case C, D and E
due to nutrient concentration. When
three days passed, 10N was
measured in Case E, 30N was
measured in Case D while 150 –200N was measured in Case C.
Specimen that has the higher initialnutrient concentration indicateslower penetration resistance.
Variation of Calcium concentrationand pH is shown in Figure.10. Lower
values of pH were shown in casewith higher concentration of nutrient.
Substantial
calciumion
wasconsumed day by day in Case C. In
contrast, it was consumed 1/2, 1/3 ofinitial calcium ion in Case D ,E. The
increment ratio of dry weight of thespecimen before and after the test isplotted in Figure.11. Maximum value
was calculated by same method asshown in Figure.6. A weight in CaseC increases steadily. It reached 6%
in three days, and got close to
maximum value. Case D wasincreased 2%，Case E was increased
1%.
The efficiency of calcium carbonate
precipitation is plotted in Figure.12.
Efficiency of Case C reaches around
90% in three days. Case D was 60%
Case E was 25%. The result of thisexperiment shows that higher initialconcentration of nutrient prevent

15

Case E 2day
Case E 3day

30
Dense Toyoura sand45

Loose toyoura sandFigure.9: Penetration resistance in Case
C(a), D(b), E(c)Effects of nutrient concentration on microbial cementation in Toyoura sand0ctober 2010, Kobe, Japanchemical reaction. From the result of Test 2, it is concluded that inject nutrient bysuitable concentration frequently is more reasonable.
8
Case C pH

50
Case D pH

40

7
Case D Ca2+

30
Case E pH

20

6
Case C Ca2+

100Case E Ca2+

pH

Calcium ion concentration (g/L)

60

0

5
3

1
2
elapsed time (day)Figure.10: Calcium concentration and pH

Effectivity(%)

100

50

Figure.11: Increment ratio of dry
weight of the specimen before and after

Measured value
Calculated value

Case C

Case D
Case E0012elapsed time (day)3

Figure.12: Efficiency of calcium carbonate
precipitation

New Technologies for Urban Safety of Mega Cities in Asia

3.3 Relationship between calcium carbonate content and degree of
cementation
Relationship between maximum penetration resistance and increment ratio of dry
weight is presented in Figure.13. Specimen with a larger resistance exhibitedheavier tendency. Amount of calcium carbonate and penetration resistance shows
good agreement, which implies that consumption of calcium ion in the pore liquid
can be reasonable indication to evaluate the degree of cementation.

Penetration resistance (N)

200

150

100

50

0

0

Case A
Case B
Case C
Case D
Case E642increased dry weight / initial dry weight (%)

8

Figure.13: Relationship between maximum penetration resistance and increment
ratio of dry weight

4.SUMMARY
The microbially cemented soil using urease enzyme from Bacillus Pasteurii
exhibited success of cementation corresponding to nutrient concentration. The
exsistence of a large amount of calcium carbonate on the Toyoura sand was also
confirmed by the observation using SEM-EDS. When total amount of added
calcium and nutrient is same, it is more effective that nutrient is injected
separately and frequently.However, specimens in this test series show partial
cementation. More effective nutrient concentration, injection interval and method
for uniform cementation should be examined in the future.
REFERENCES
Jason T. DeJong, Fritzges, M.B. and Nüsslein, K.(2006), “Microbially induced
cementation to control sand response to undrained shear.” Journal of
Geotechnical and Geoenvironmental Engineering, Vol.132, No.11, pp.1381-1392.
Marien P. Harkes, Van Paassen L.A., Booster J.L., Whiffin V.S., Van Loosdrecht
M.C.M. (2010), “ Fixation and distribution of bacterial activity in sand to induce
carbonate precipitation for ground reinforcement.” Ecological Engineering,
Vol.36, Issue2, pp.112-117.

Effects of nutrient concentration on microbial cementation in Toyoura sand

Fundamental study of permeability changearound buried structures in sandy ground
Mari SATO1, Reiko KUWANO2
1
Graduate student of the University of Tokyo, Japan,
msato@iis.u-tokyo.ac.jp
2
Associate Prof., ICUS, Institute of Industrial Science,
The University of Tokyo, Japankuwano@iis.u-tokyo.ac.jp

ABSTRACT
Many cave-in accidents occur and sometimes injure people. Expansion of anunderground cavity and loosening causes cave-in accidents. Some accidents
supposed to be caused by soil outflow from broken parts of sewer pipes in shallow
ground. However, the mechanism of a cavity and loosening generation is notclear. It is so hard to prevent cave-in accidents before a cavity and loosening
expand to the ground surface.
Recent researches show that a boundary between a basement structures and theground may be one of the important factors of causing cave-in accidents. It is
supposed that water pathway expands through the gaps between a buried
structure and the ground due to a change of the water level. Then water pathwaycauses soil drainage which makes expansion of a cavity and loosening.
In order to study the effect of permeability at the boundary, constant head
permeability test which has the contact plane between the ground and the acrylic
cylinder was conducted.
Keywords: cave-in, water pathway, permeability test, buried structure,
1. INTRODUCTION
Many ground cavities and loosening are found in the ground close to undergroundstructures nowadays. It is a serious problem in urban cities because cavities andloosening sometimes leads to cave-in accidents which injure people. One factor of
expansion of cavities is distinct spots of soil outflow like broken parts of sewer
pipes, as shown in Figure 1. Kuwano et al. (2006) conducted model test
simulating how a cavity is generated due to the broken parts of sewer pipes.
However, specific spots of soil outflow are seldom found near to cavities. The
reason why cavities and loosening are generated and expanded around theunderground structures without visible spots of soil outflow is not clear. In thisresearch, it is suggested that boundary between the ground and buried structures
has water pathway which cause soil outflow. Figure 2 schematically represents
such kind of situation. This paper attempts to investigate permeability changes

October 2010, Kobe, Japandue to the existence of gaps between the basement structures and the ground. In
the concrete, constant head permeability test which insert an acrylic cylinder was
conducted.

RainfallRise of ground water level
Loosening

CavitySoil outflow

Figure 1: A Cavity and loosening formed above the defective buried pipes

Figure 2: Situation of expansion of a cavity and looseningaround a buried structure

2. TEST APPRATUS AND PROCEDURE
Concept of our experiments is shown in Figure 3. Apparatus of constant head
permeability test is adopted. A photograph of the test apparatus is shown in Figure
4. Diameter of the soil chamber is 10cm. Hime gravel is put as a filter above thetested material. Acrylic cylinder is placed at the center of this soil chamber andsoil is compacted by Air Pluviation, AP. Figure 5 represents the situation how to
prepare the soil chamber. The boundary between acrylic cylinder and the soil aresupposed to be the boundary between buried structures and the ground.

New Technologies for Urban Safety of Mega Cities in Asia

After finishing preparation of soil chamber, soil chamber is inserted into a waterchamber and water is poured into the soil chamber. Each water level of the soilchamber and the water chamber is constant during the permeability test. The
amount of penetrated water in 180 second, head difference between soil chamber& water chamber and water temperature were measured. Calculated coefficient of
permeability is corrected as that at 15 degrees Celsius.

Figure 3: Concept of the permeability test placing a cylinder

Figure 4: Situation of conducting permeability test

Fundamental study of permeability change around buried structures in sandy groundOctober 2010, Kobe, Japan

Figure 5: Preparation of the soil chamber
3. TEST CONDITIONSTest conditions are shown in Table 1. Tested materials, density, diameter of anacrylic cylinder, surface form of a cylinder were changed. Three sandy materials
are used– Toyoura sand, Silica sand no.5 and Silica sand no.8. Figure 6 represents
the particle size distribution of three materials. Both Toyoura sand and Silica sandno.5 are clean uniform sand, but average particle size of Silica sand no.5 is larger
than that of Toyoura sand and Silica sand no.8. Silica sand no.8 contains fines
around 15%. Surface form of an acrylic cylinder was changed by putting panels
made by plastic tapes as shown in Figure 7. Size of each panel is about 10mm ×15mm and thickness of the panel is about 0.2mm. These panels cause surface ofan acrylic cylinder uneven. In this research, this uneven cylinder is named as“rough cylinder” and normal cylinder is named as “smooth cylinder”.

Figure 6: Particle size distributions of three materials

New Technologies for Urban Safety of Mega Cities in Asia

Table 1: Test conditions
Material
Toyoura sandToyoura sandToyoura sandToyoura sandToyoura sandToyoura sandToyoura sandToyoura sandToyoura sandToyoura sandToyoura sand
Silica sand no.5
Silica sand no.5
Silica sand no.5
Silica sand no.5
Silica sand no.5
Silica sand no.8
Silica sand no.8
Silica sand no.8
Silica sand no.8
Silica sand no.8
Silica sand no.8

State of a cylinder(diameter, rough orsmooth)No cylinder
No cylinder
No cylinder
5cm smooth
5cm smooth
5cm rough5cm rough7cm smooth
7cm smooth
7cm rough7cm roughNo cylinder
5cm smooth
5cm rough7cm smooth
7cm roughNo cylinder
No cylinder
5cm smooth
5cm smooth
5cm rough5cm roughRelative
Density
(%)
30
39
79
30
78
36
71
34
77
34.5
70.5
72
74
74
72
62
40
70
34
72
34
71.5

Figure 7: Appearance of ” rough cylinder”

Fundamental study of permeability change around buried structures in sandy groundOctober 2010, Kobe, Japan

4. TEST RESULTS
4.1 Test results of Toyoura sandRelationship between relative density and permeability coefficient is shown in
Figure 8. Square symbols dots represent the result without a cylinder, which isregarded as result of normal constant head permeability test. Figure 8 refers thatsmooth (normal) cylinder doesn’t have much influence on permeability. On theother hand, rough cylinder (uneven surface) cause increasing of permeability anddiameter of a cylinder is not so important for permeability in loose sand.
Permeability of a cylinder with 7cm diameter is larger than that of a cylinder with
5cm diameter in dense sand. Conditions of rising permeability are different
between loose sand and dense sand.

Figure 8: Permeability coefficient of Toyoura sand
4.2 Test results of Silica sand no.5
Results of permeability test of Silica sand no.5 are shown in Figure 9. Figure 9
indicates that cylinder with 5cm diameter makes permeability increase. It can besuggested that roughness of a cylinder with 5cm diameter isn’t significant forpermeability because permeability coefficient of rough cylinder is similar to thatof smooth cylinder. In contrast, the result of a cylinder with 7cm is different fromthe result of a cylinder with 5cm diameters. Rough cylinder doesn’t cause
increasing of permeability.

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Figure 9: Permeability coefficient of Silica sand no.5
4.3 Test results of Silica sand no.8
Results of permeability coefficient of Silica sand no.8 are shown in Figure 10.
Permeability test placing a cylinder with 7cm diameter wasn’t conducted in Silica
sand no.8. It is proposed from Figure 10 that smooth cylinder let permeability
increase in loose sand, and rough cylinder let permeability increase in dense sand.
This tendency can be also stated that permeability change between loose sand anddense sand is largest with smooth cylinder, and smallest with rough cylinder.

Figure 10: Permeability coefficient of Silica sand no.8

Fundamental study of permeability change around buried structures in sandy groundOctober 2010, Kobe, Japan

4.4 Influence on the direction of surface unevenness of a cylinder
Referring to the results of Toyoura sand (4.1), it can be suggested that surface
uneven of a cylinder (rough cylinder) makes permeability increase especially inloose sand. To investigate which direction of unevenness is most critical toincrease permeability coefficient, three kinds of rough cylinder were installed.
Each of three cylinders has different direction of roughness – normal, horizontal
and vertical. These cylinders are prepared by putting plastic panel (0.2mm
thickness) as Figure 11 is shown. Normal rough cylinder is same as roughcylinder it has been defined in previous chapters. Test procedure was same asprevious one (referring to chapter 2). Table 2 represents test conditions.

Figure 11: Three different types of rough cylinder
Table 2: Test Conditions
Material
Toyoura sandToyoura sandState of a cylinder(diameter, direction ofroughness)
5cm vertical rough5cm horizontal roughRelative
Density (%)
30
39

Permeability coefficients of three rough cylinders are shown in Figure 12. Figure
12 is also plotted results of other conditions of Toyoura sand, which has been
already explained in 4.1. Figure12 suggested that horizontal direction ofroughness is the most sighnificant for increasing permeability.

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Figure 12: Permeability coefficient of vertical & horizontal rough cylinder
5. CONCLUSIONS
If permeability increases due to installing a cylinder, it can be proposed thatboundary between a cylinder and soil cause water pathway. In this research,permeability putting a cylinder is often higher than normal permeability especiallyin loose sand. This result suggested that loose sand has larger gaps and makes
water pathway easier than dense sand. Direction of unevenness is also importantfor making water pathway. Horizontal roughness (Referring to 4.4), which isregarded as vertical uneven direction to water penetration, has some influence on
causing water pathway. Why material difference affects permeability is not clear,but particle size or fines may have some effect of forming gaps. This researchsuggests existence of water pathway between buried structures and the ground inparticular conditions.
REFERENCES
Kuwano, R, Yamauchi, K., Horii, T. and Kohashi, H. 2006. Defects of sewer
pipes causing cave-in’s in the road, Proc. of 6th International Symposium on New
Technologies for Urban Safety of Mega Cities in Asia, Phuket, November 2006.

Fundamental study of permeability change around buried structures in sandy groundMechanical properties and seismic behaviorof soil walls using rammed earth technique
Hiroyuki ARAKI1, Jina LEE2,
Takeshi SATO , Tsutomu NAMIKAWA4, Junichi KOSEKI5
1
Ph.D. student, University of Tokyo, Japanaraki-h@iis.u-tokyo.ac.jp
2
Formerly master student, University of Tokyo, Japan
3
Technical Director, Integrated Geotechnology Institute Ltd., Japan
4
Associate Professor, Kobe City College of Technology, Japan
5
Professor, Institute of Industrial Science, University of Tokyo, Japan
3

ABSTRACT
Rammed earth is a traditional construction technique to build soil structures bycompacting clay, sand, gravel and, if needed, cementitious materials. The rammed
earth walls are frequently seen in historic heritages in Japan. Furthermore, therammed earth walls have been also applied to modern architecture due to theiradvantages of using natural soil materials in recent years. However, themechanical properties and the seismic resistance of rammed earth walls have notbeen fully investigated. In this study, therefore, the shear and tensile properties oframmed earth materials made of a mixture of soil, lime and water, were evaluatedby conducting a series of compaction test, unconfined compression test,
unconfined tension test and drained triaxial test. Moreover a finite element
analysis based on an elasto-plastic model that can describe the mechanicalproperties of rammed earth material was conducted in order to clarify the seismic
behavior of rammed earth walls.
Keywords: Rammed earth, soil walls, lime mixed soil, laboratory test, FEM

1. INTRODUCTION
Rammed earth is a traditional architectural technique, and soil walls using thistechnique are frequently seen in historical heritages. The soil walls surrounding
Horyu-ji temple, Nara (Fig. 1a), Taikou-bei in Sanju-sangen-do temple, Kyoto(Fig. 1b) and Ohneri-bei in Nishinomiya shrine, Hyogo are famous rammed earth
walls in Japan. Effective conservation and repair methods need to be establishedin order to pass on these cultural heritages to next generations.
In recent years, the rammed earth is getting a rising interest in construction
projects of individual housing, since it is with some advantages which include
temperature and humidity control performance, fire resistance performance,
potential for recycling and low negative impact on the environment of natural soilmaterials (Hall, 2007; Morel et al., 2001). However, mechanical properties andseismic behavior of rammed earth walls have not been clarified sufficiently.

0ctober 2010, Kobe, Japan

Evaluation of seismic safety of a rammed earth wall is required in conducting anappropriate design of a newly built wall in earthquakes-prove countries like Japan.
In this study, seismic behavior of a rammed earth wall was evaluated by a finite
element analysis. It was carried out employing an elasto-plastic model that can
describe the mechanical properties of a lime-mixed soil which is often used as arammed earth material in Japan. In addition, the mechanical properties of limemixed soil were obtained on some laboratory tests.
b)a)Figure 1: a) Rammed earth walls surrounding Horyu-ji temple, Nara and b)
Taikou-bei in Sanju-sangen-do temple, Kyoto, Japan.

2. EVALUATION OF MECHANICAL PROPERTIESIn order to obtain mechanical properties of a rammed earth material, unconfinedcompression tests, triaxial compression tests and unconfined tension tests werecarried out.
2.1 Specimen of lime-mixed soil
As a rammed earth wall material, a lime-mixed soil that was composed of silty
sand, poorly graded sand and quicklime was prepared. Mixing proportion isshown in Table 1. Specimens were prepared by compacting the material in layersof 1 cm-thick under the optimum water content. The compacting energy was 2700
kJ/m3 which is equivalent to the modified Proctor test. The shape of specimens forunconfined compression tests and triaxial compression tests is a cylinder with adiameter of 50 mm and a height of 100 mm. The shape of specimens forunconfined tension tests is a dog-bone with a maximum diameter of 50 mm and aheight of 140 mm and the diameter at the middle height is trimmed down to 45
mm.
Specimens after curing for 28 days were used for all the tests. All specimens were
cured in air without sealing under atmospheric pressure and room temperature.

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Table 1: Mixing proportions to prepare tested material
Volume ratio
4
0.5
1
2

Silty sandPoorly graded sand
Quicklime
Water

Weight in percentage (%)
53.8
8.8
14.2
23.2

2.2 Test result and discussion
The axial strain rate of unconfined compression and triaxial compression tests was
set to 1 %/min, and that of unconfined tension test was 0.01 %/min. The triaxial
compression tests were carried out under drained condition with a confiningpressure of 20 kPa, 50 kPa and 100 kPa.
The results of unconfined compression and tension tests are compared in Fig. 2 interms of the stress-strain relations. The average values of the mechanicalproperties are shown in Table 2. The stress-strain relationships in tension test
show that stress reduces sharply after the peak strength. The tensile strength
values are very low and represent only 5% of compressive strength ones. The
tensile strength of lime-mixed soil are lower than those found by Koseki et al.
(2008) on cement-treated sands (mixing proportions for cement/water/sand being
similar to those of lime/water/soil) after a curing period of 7 days, which ranged
from 20 to 30% of the unconfined compression strength for a shorter curing
period. For a curing period in this study four times higher than that of the cementtreated sands, the tensile strength for the lime-treated soil is three to six times
lower.
5000b) 200

4500

180

4000

160

3500

140

3000

Stress(kPa)Stress(kPa)

a)

2500
2000
1500

L23Stress
L24stress
L2Stress
L3stress

120
100
80
60

1000

40

500

20

0

0

-500
0

1

2

3

Strain(%)

4

5

6

0.0

0.1

0.2

0.3

0.4

0.5

Strain(%)

Figure 2: Stress strain relationships of a) unconfined compression test and b)
unconfined tension test. (The axial strain was measured with an externaltransducer, respectively.)
The cohesion and the internal friction angle were obtained by drawing the Mohr
circle at the peak stress state of the results of the triaxial compression tests, as canbe seen in Table 2. In addition, the secant modulus, E50 for the unconfinedcompression tests, unconfined tension tests and triaxial compression tests at aconfining pressure of 20 kPa are shown in Table 2. These values were used to

Mechanical properties and seismic behavior of soil walls using rammed earth technique0ctober 2010, Kobe, Japandecide a numerical elasto-plastic model of lime-mixed soil for a finite element
analysis in this study.
Table 2: The results of mechanical properties of lime-mixed soil
Unconfinedcompression test
Unconfined tension
test
Triaxial compression
test

Compression strength (kPa)
E50 (MPa)
Tensile strength (kPa)
E50 (MPa)
Peack angle of internal friction, φ (°)
Cohesion, c (kPa)
E50 (MPa)

3098
240
154
173
35.3
983
656

3. EVALUATION OF SEISMIC BEHAVIOR
The seismic behavior of rammed earth wall section is investigated using a twodimensional finite element analysis, while incorporating experimentally obtained
properties of the lime-mixed soil in the unconfined compression tests, unconfinedtension tests and triaxial compression tests.
3.1 Finite element mesh and seismic wave
The prototype model analyzed is shown in Fig. 3. It reflects the cross section of asoil wall in a certain temple. The height of the wall is 2400 mm, the top width1100 mm and the bottom width 1400 mm. It is composed of 8400 elements ofaround 20*20 mm2 and 8591 nodes.
The boundary at the base row is fixed in the horizontal and vertical directions. A
damper was added at this boundary so that the seismic waves are not trapped in
the soil wall and can be dissipated into the ground. Roof load was modeled byplacing a beam element at the top of the wall, with a self weight that is equivalent
to an intensity of 3.31 kPa using a small elastic modulus (E = 10 MPa).
The N-S component of the recorded earthquake motion at Kobe JMA (Japan
Meteorological Agency) station during the 1995 Hyogoken-Nanbu earthquake
was used as the base input motion (Fig. 4). This input motion was applied in thehorizontal direction and the duration of the excitation was 20 seconds. The input
motion was modified by rescaling the maximum acceleration from 200 gal to1000 gal.

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800
Acceleration (gal)

600
400
200
0
-200
-400
-600
-800

Time = 5.5 sec
Acceleration = 820.57 gal

-1000
0

Figuer 3: Prototype model of arammed earth wall

2

4

6

8 10 12 14 16 18 20
Time (sec)Figure 4: Original input motion of JMA-Kobe
wave

3.2 Constitutive model and parameters of a soil wall material
An elasto-plastic model developed by Namikawa and Mihira (2007) that can
describe the non-linear shear and tensile behaviors of cement-treated soils wasused in this study. Two failure criteria are employed to express tensile and shear
failure characteristics observed in the experimental results of the cement-treatedsands. It can model strain-hardening and strain-softening responses in both failuremodes. In the strain softening rules, the smeared crack concept is used and acharacteristic length is employed to avoid the issue of mesh-size dependency. The
details of the model are not explained in this paper and can be found in Namikawa
and Mihira (2007). This model was successfully used to simulate the tensile andshear behavior of cement-treated sand in the laboratory tests (Namikawa andKoseki, 2007).
The elastic modulus, E, the tensile strength, Tf, the angle of internal friction, φ andcohesion, c were deduced based on the laboratory tests results (Table 2), as can beseen Table 3. Elastic modulus and tensile strength were assigned as 200 MPa and150 kPa, respectively, in a conservative approach. When necessary, Tf was
modified from 150 kPa to 300 kPa in order to obtain information about the
influence of tensile strength.
The parameters listed in the second part of Table 3 are assigned based on relevant
references (Namikawa and Koseki, 2006; Namikawa and Mihira, 2007; Koseki etal., 2008). The hardening parameters, a and ey are linked the strain-hardening
response of cement or lime-treated soils. The fracture energy, Gf is a parameter
dominating the tensile strain-softening behavior. The parameters er and Dc are
related to the shear fracture energy and to the dilation during the shear strain
softening process, respectively. ts0 is related to the size of strain localization zone
and is assumed to be 0.6 mm, and lc is determined from the mesh size, i.e. around
20 mm.

Mechanical properties and seismic behavior of soil walls using rammed earth technique0ctober 2010, Kobe, Japan

Viscous Rayleigh damping was employed as the damping. C= α M+ β K where M,
C and K are the mass, damping and stiffness matrices, and α and β are thedamping parameters. As the damping matrix C functions depend on the frequency,
these parameters were obtained by an eigen value analysis while assuming themodal damping factor of the Rayleigh damper hr = 1/2 (α / wr + β wr) = 0.02 at thefirst and second dominant frequencies of the wall (f1 =11 Hz and f2 =37 Hz).
Table 3: The results of mechanical properties of lime-mixed soil
Experimentally deduced parameters
Elastic modulus
E (MPa)200
Tensile strength
Tf (kPa)
150
Angle of internal friction
φ (°)
35.3
Cohesionc (kPa)983
3
Densityρ (g/cm )1.70
Assumed parametersνPoisson's ratio
0.33
Hardening parametera
1.05
Hardening parameterey
0.0002Fracture energy
Gf (N/m)
37.5
Softening parameterer
0.40
Dilatancy coefficientDc-0.4
Localization size
ts0 (mm)
0.6
Characteristic lengthlc (mm)20.0
2.10
αDampingcoefficients
β0.000133

4. RESULT OF SEISMIC RESPONSE ANALYSIS
By inputting the properties presented above, the walls failed: numerical analysis
could not be successfully completed as the number of iterations increased
significantly, where many elements failed for the duration of the strong motion.
Therefore the tensile strength Tf and the maximum acceleration Amax of the input
motion were varied in order to evaluate the seismic response of the soil wall.
4.1 Stress state in the soil wall
The maximum values of the minor principal stress in tension, σ3, mobilized at theleft bottom corner of the wall (Element 1, Fig. 3) are plotted versus the maximum
acceleration Amax in Figure 5. In the case with Tf of 150 kPa, the relationshipbetween |σ3| and Amax is linear when |σ3| is smaller than 150 kPa. When Amax
exceeded 525 gal, |σ3| does not increase even if Amax increases. When Amax waslarger than 650 gal, the analysis could not be completed. In other words, partial
failure occurred when Amax is between 525 gal and 650 gal, and it was followedby overall failure that took place when Amax was larger than 650 gal. A similar

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Maximum value of |σ3 in tension| (kPa)trend could be observed in other cases where the value of Tf is 200 kPa, 250 kPa
and 300 kPa.
350
Tf = 150 kPa
Tf = 200 kPa
Tf = 250 kPa
Tf = 300 kPa

300
250
200
150
100
50
0
0

200

400

600

800

1000

Amax (gal)Figure 5: Maximum values of minor principal stress in tension
The time histories of the minor principal stress and the maximum shear stress,
τmax in the case with Tf = 150 kPa and Amax = 650 gal are shown in Fig. 6. The
distributions of σ3 and τmax when Amax occurs are shown in Fig. 7. The maximum
value of τmax is mobilized at the right bottom corner of the wall and its value is153.4 kPa. The shear failure could not be observed because the maximum value ofτmax was smaller than the cohesion of 983 kPa. On the other hand, the maximum
value of σ3 in tension is mobilized at the left bottom corner of the wall, and its
value is -156.5 kPa. Tensile failure occurred at this element because |σ3| exceeded
the tensile strength of 150 kPa. Therefore, not the shear failure but the tensile
failure would occurs in the soil wall in the event of an earthquake.
180
Maximum shear stress (kPa)

Minor principle stress (kPa)

60
30
0
-30
-60
-90
-120
-156.5

-150

153.4
140
100
60
20
-20

-180
0

2

4

6

8 10 12
Time (sec)

14

16

18

20

0

2

4

6

8 10 12
Time (sec)

14

16

18

20

Figure 6: Time histories of the minor principal stress and the maximum shear
stress (Tf and Amax are 150 kPa and 650 gal, respectively.)

Mechanical properties and seismic behavior of soil walls using rammed earth technique0ctober 2010, Kobe, Japan

a)

b)
[kPa]
150

[kPa]
180

-150

0

153.4 kPa

-156.5 kPa(Scale ｘ50)

(Scale ｘ50)

Figure 7: Distribution of a) the minor principal stress and b) the maximum shear
stress (Time is 5.5 sec. Tf and Amax are 150 kPa and 650 gal, respectively.)
4.2 Displacement of the soil wall

1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0

Tf = 150 kPa
Tf = 200 kPa
Tf = 300 kPa

y = 0.0008x - 0.0002
R2 = 1.0000

0200

400 600 800 1000
Amax (gal)Horizontal ｄisplacement (mm)Vertical displacement (mm) .

The maximum values of the vertical and the horizontal displacement at the left top
corner of the soil wall (Node 12001, Fig. 3) are plotted versus the maximum
acceleration Amax in Figure 8. The displacements are very small compared to thedimensions of the wall. Moreover, they exhibit a linear relationship with the
maximum acceleration, even when partial failure occurs. These observations
suggest that the wall response is more like a rigid body.
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0

Tf = 150 kPa
Tf = 200 kPa
Tf = 300 kPa

y = 0.0034 x - 0.0018
R² = 1.0000

0200

400 600 800 1000
Amax (gal)Figure 8: The maximum values of the vertical and the horizontal displacement infunction of Amax
The time histories of the vertical and the horizontal displacement in the case with
Tf = 150 kPa and Amax = 650 gal are shown in Fig. 9. The distributions of thevertical and the horizontal displacement when Amax occurs are shown in Fig. 10.
The maximum vertical displacement and the maximum horizontal displacement
are 0.55 mm and 2.20 mm at 5.5 sec, respectively. The distributions of both
displacements show rocking motion of the soil wall. The risk of overbalancing of
the soil wall is increased when the rocking motion occurs severely as the result of
the tensile failure at the bottom of the wall. In order to restrain the large horizontal
displacement, tensile strength should be evaluated correctly, and the tensile failure
should be prevented.
New Technologies for Urban Safety of Mega Cities in Asia

Horizontal displacement (mm)Vertical displacement (mm)

0.8
0.55

0.6
0.4
0.2
0.0
-0.2
-0.4
-0.6
-0.8
0

2

4

6

8

10

12

14

16

18

20

2.5
2.0
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-2.5

2.20

0

2

4

6

8

10

12

14

16

18

20

Time (sec)Time (sec)Figure 9: Time histories of the vertical and the horizontal displacement (Tf andAmax are 150 kPa and 650 gal, respectively.)
Verticaldisplacement[mm]

Horizontal
displacement
[mm]

0.5

2.0

-0.5

-2.0

(Scale ｘ50)

Figure 10: Distributions of the vertical displacement and the horizontal
displacement (Time is 5.5 sec. Tf and Amax are 150 kPa and 650 gal)

5. CONCLUSION
In this study, mechanical properties and seismic behavior of a rammed earth wall
made of a lime-mixed soil were evaluated. Finite element analyses of the seismic
behavior of the wall were carried out employing an elasto-plastic model that can
describe the mechanical properties of the lime-mixed soil which were obtained bysome laboratory tests.
⋅
The tensile strength of lime-mixed soil are very low and represent only 5% ofcompressive strength ones.
⋅
In the case where the tensile strength of lime-mixed soil is 150 kPa, partial
failure occurred at the bottom of the wall when Amax is between 525 gal and
650 gal, and it is followed by overall failure that took place when Amax islarger than 650 gal.
⋅
Not shear failure but tensile failure would occur in the soil wall in the eventof an earthquake.

Mechanical properties and seismic behavior of soil walls using rammed earth technique0ctober 2010, Kobe, Japan⋅⋅The wall response is more like a rigid body. The deformations of the wall
exhibit rocking motion.
In order to decrease the risk of overbalancing of the soil wall, the tensile
strength should be evaluated correctly, and the tensile failure should be
prevented.

REFERENCESHall M. R. (2007): Assessing the environmental performance of establishedreamed earth walls using a climatic simulation chambar, Building andenvironment, 42, 139-145.
Koseki J., Tsutsumi Y., Namikawa T., Mihira S., Salas-Monge R., Sano Y. andNakajima S. (2008): Shear and tensile properties of cement-treated sands and theirapplication to liquefaction mitigation, Keynote Lecture, Proc. of 4th International
Symposium on Deformation Characteristics of Geomaterials (IS-Atlanta 2008), 1,
27-50.
Namikawa T. and Koseki J. (2006): Experimental determination of softening
relations for cement-treated sand, Soils and Foundations, 46(4), 491-504.
Namikawa T. and Koseki J. (2007): Evaluation of tensile strength of cementtreated sand based on several types of laboratory tests, Soils and Foundations,47(4), 657-674.
Namikawa T. and Mihira S. (2007): Elasto-plastic model for cement-treated sand,International Journal for Numerical and Analytical Methods in Geomechanics, 31,
71-107.
Morel J. C., Mesbaha A., Oggerob M., Walkerc P. (2001): Building houses withlocal materials: means to drastically reduce the environmental impact ofconstruction, Building and Environment 36, 1119-1126.

New Technologies for Urban Safety of Mega Cities in Asia

Interaction between degradation and selfhealing behavior in high strength mortar
exposed to high temperatures (up to 500℃)
Tae-Ho AHN1, Michael Henry2
Yoshitaka Kato2, Toshiharu KISHI1
1
Department of Human & Social Systems, Institute of Industrial Science,
The University of Tokyo, Japan
than@iis.u-tokyo.ac.jp
2
International Center for Urban Safety Engineering (ICUS)
The University of Tokyo, Japan
ABSTRACT
Recently, many researchers have been reported on the repair of fire-damaged
concrete structures. These researches generally suggest that the repair process
involve the removal and replacement of weakened layers of concrete with fresh
concrete. However, no detailed examination of the interaction between the
degrees of deterioration on various deterioration zones by heating and its rehydration behaviors has been reported. Moreover, a few past studies indicatedthat the deteriorated concrete could regain its strength, without repairing, if
properly recurred in water or a moist environment. In this paper, a comparative
study of the degradation behavior of various zones, such as the dry anddehydrated zone, the drying and dehydrating zone, and the initial-state zone of
cement paste close to surface area, of high-strength mortar is presented in orderto clarify the self-healing behavior of high-strength mortar after damage byheating.
Keywords: Self-healing, Degradation, Pore pressure, fire-damaged concrete

1. INTRODUCTION
Concrete generally demonstrates good resistance to high temperature exposurecompared with other building materials, and has been widely used for hightemperature applications. However, it does undergo a loss of performance, such as
decreased strength and spalling, depending on exposure time and temperature.
Explosive spalling in particular has been observed inconsistently in laboratory
tests due to the large number of variables which potentially affect its mechanism 1),
as well as a lack of general guidelines for fire testing to provide a unified
approach for measuring the effects of these variables. Kalifa et al. 2) proposed adegradation mechanism involving both thermo-mechanical processes related tothermal dilation gradients in the mortar and thermo-hydral processes due to masstransfer (air, vapor, and liquid water) in the pore network. The build-up ofpressure in concrete under heating exposure is illustrated in Fig. 1. As heat flux

0ctober 2010, Kobe, Japandrives water vaporization, the surface becomes a dry/dehydrated zone – a brittle
layer composed of sintered material which cannot undergo re-curing. In thedry/dehydrating zone, evaporation of free and chemically-bound water isoccurring but the material has not yet sintered, and the quasi-saturated zone
contains water under heating. Degradation of high-strength concrete has beenfound to be more severe than normal-strength concrete due to increased loss ofstrength and higher occurrence of explosive spalling, which may be attributed to
the low permeability of low water-cement ratio concretes and leads to increased
pore pressure and thermal stresses. Build-up of pore-pressure is driven by“moisture clog spalling,” in which water vapor migration under heating generates
pore pressure which, when combined with thermal processes, results in spallingwhen the tensile strength of the matrix is exceeded.
Dry/dehydrating zone

Initial state

HeatingDry/dehydrated zone

Quasi-saturated zone
Pressure
Temperature

Distance from heated faceFig. 1: Dehydration zones under heating (adapted from Kalifa et al.2))
Repair of fire-damaged concrete is necessary to restore degraded performance andcommonly involves the removal of damaged areas and their replacement withfresh concrete or a patching material. However, past research has found that recuring fire-damaged concrete in water can restore strength and durability throughthe re-growth of hydration products, development and filling of pore structure,and healing of cracks. High-strength concrete was also found to have betterrecovery under re-curing due to its dense microstructure 3); however, as discussed
earlier, the degradation of high-strength concrete is more severe due to thermohydral and thermo-mechanical mechanisms, which may significantly reduce therepair effect due to re-curing. Therefore, the interaction between degradation andself-healing behavior under re-curing conditions should be clarified to further
understand the potential for re-curing as a repair method.

New Technologies for Urban Safety of Mega Cities in Asia

In this paper, a study on the degradation behavior is presented in order to clarify
the self-healing behavior of fire-damaged high-strength mortar during re-curing.
Mortar was selected for this investigation to focus on the microstructure behavior
and self-healing in the cement mortar matrix. The first part investigates thedegradation behavior by examining the surface microstructure of zones withdifferent dehydration levels and considers the deterioration mechanism in terms ofsolid-state-sintering of entrained pores. The behavior of entrained air formed by
the usage of admixtures and the local stress incompabilities between the cement
paste and aggregates are also investigated by microscopy. The second part deals
with self-healing behavior of fire-damaged high-strength mortar under watersupply considering the differing dehydration zones. The self-healing behavior isthen connected to recovery of strength and porosity as observed in an additional
study.
2. EXPERIMENTAL PROGRAM
2.1. Mortar specimens
High-strength cement mortar was prepared using ordinary Portland cement (Japan
Type I) at a water-binder ratio of 0.35 and Fujigawa river sand, with a maximum
particle size of 4.75 millimeters, at a sand-cement ratio of 1.8. Air-entraining andsuper plasticizer admixtures were also utilized to satisfy workability requirements.
Beam specimens (40mm×40mm×100mm) were demolded 24 hours after castingand placed under water for 14 days at 20°C, then air-cured at 20°C and 60%
relative humidity (RH) until high-temperature exposure at 28 days. Compressive
strength at 28 days was 66.9 MPa.
2.2. Fire exposure and post-fire re-curing conditions
Specimens were exposed to high temperatures using an electric furnace. As thisfurnace does not have a control mechanism for the rate of heat increase, thefurnace was preheated to the target temperature before beginning exposure. The
temperature was set at 500°C for one hour in order to clarify the shrinkage of
cement paste and local stress behavior by mass loss of Ca(OH) 2 as well as freewater, and was selected based on past research which found that damage attemperatures beyond 500°C cannot be fully recovered. Specimens were allowed
to cool at room temperature and conditions for one hour after exposure, and thenre-cured in water-submerged conditions.
2.3. Estimation methods of transport properties
Fig. 2 shows the size of pores in concrete and their methods of measurement. This
investigation is focused on super plasticizer-entrained air, which falls between 10
nanometers to several millimeters, so microscopy was selected for observation.
SEM (scanning electron microscope) with EDS detector were utilized toinvestigate the morphology and shape of fire-damaged specimens and the size ofthe rehydration products in order to clarify the degradation mechanism and selfhealing behavior. Three-dimensional (3D) digital microscopy images were alsoacquired using 3D visualization software in order to identify connected pores inentrained air. Thermo-gravimetric differential thermal analysis (TG-DTA) wasused to analyze the mass transport of cement paste according to degradation area,and mercury intrusion porosimetry (MIP) was conducted to clarify the selfInteraction between degradation and self-healing behavior in high strength mortar
exposed to high temperatures (up to 500℃)

0ctober 2010, Kobe, Japan

healing behavior. All specimens were analyzed during the healing process ofcracked mortar specimens, and observations were performed at each location byfollowing the paste-aggregate bond zones and cracks.
Type of Pore

Size of Pore

Pore by water

Measure Method
Adsorption of N2 gas- Gel pore

MIP test- Capillary Pore
Entrained air by AE

Microscopy- Small size entrapped air- Big size entrapped Air

X-ray CT
1nm 10100 1μm 10 100 1mm 10

Fig. 2: Concrete pore types, sizes and associated measurement methods
3. RESULTS AND DISCUSSION
3.1. Degradation behavior of cement paste on surface area
Fig. 3 shows the surface morphology of deteriorated high strength mortar after
500°C exposure. Degradation occurred at the surface due to shrinkage of thecement paste, similar to the solid-state-sintering effect, and the specimen surface
could be divided into dry/dehydrated or dry/dehydrating zones. The deteriorated
surface of the dry/dehydrated zone after heating is shown in detail in Fig. 4. This
zone was almost entirely sintered, and various phenomena were observed, such as
solid-state-sintering, pore shrinkage, and volcano effect driven by increasing porepressure. Mass loss in this zone may be attributed to the reduction of Ca(OH) 2 andevaporation of free water in the system within the one-hour heating period.
Pore shrinkage by dehydration of combined water such as solid-state-sintering
was also observed (Fig. 5). In general, the solid-state-sintering on the surface due
to heating affects the grain size and shape and pore size and shape, and is driven
by a reduction in surface energy. Densification occurs as excess free energy builds
up on the surface of cement paste, and the release of built-up surface energy leads
to the formation of coarse grains which increase in size under heating.
Fig. 6 shows the sintered and combustion traces by EDS analysis in thedry/dehydrated zone. Many coarse grains can be seen at the surface, and theirchemical composition is similar to 3CaO•SiO 2 due to dehydration of the cement
paste at the surface.

New Technologies for Urban Safety of Mega Cities in AsiaDry/dehydrated
zone

Thermo-hydral(pore pressure)

Thermo-mechanical(local shrinkage)Dry/dehydratingzone

0.3 mmFig. 3: Surface morphology of deteriorated mortar

0.25 mm
Solid-state-sintering

Pore shrinkage

Volcano effectFig. 4: Deteriorated surface of dry/dehydrated zone in detail
Sintering shrinkage

Material transfer (mass flow)ρx

Increase of local shrinkage stressr
Dehydrated
materials (mass loss)

After heating:Densification of surface
Decrease of pore size
Increase of pore pressure

Fig. 5: Pore shrinkage by solid sintering in dry/dehydrated zone

Interaction between degradation and self-healing behavior in high strength mortar
exposed to high temperatures (up to 500℃)

0ctober 2010, Kobe, Japan

CaO 70.47%
SiO2 19.02%

C
Ca
Si
Al
S

Fig. 6: X-ray spectrum of sintered mortar surface after heating

Fig. 7: Surface image and 3D visualization of surface degradation

Formation of grains leading toshrinkageTensilestressHeating

Evaporation of surface (moisture loss)
Increase inpore pressure

Degradation

Exposure of dry/dehydrating zone
(1st degradation zone)
Dry/dehydrated zone Dry/dehydrating zone

Fig. 8: Surface degradation phenomenon leading to exposure of dehydrating zone

New Technologies for Urban Safety of Mega Cities in Asia

The dry/dehydrating zone was partially exposed after degradation of cement paste
in the dry/dehydrated zone as observed visually in Fig. 7, and the mechanism is
illustrated in Fig. 8. The depth of the dry/dehydrated zone was measured at 0.08 to
0.1 millimeters, but this depth is dependent on heating time and temperature.
Densification of the surface layer led to a thermo-hydral degradation process(volcano effect) caused by incremental increase of pressure within entrained air.
This phenomenon will be discussed in detail in the following section.
3.2. Volcano effect of entrained air by pore pressure
Observation of the mortar surface layer found deterioration of the cement paste toa depth of 0.1 millimeters. Densification of the surface through solid-statesintering based on dehydration led to a reduction in vapor flow, causing an
incremental increase of internal pore pressure within entrained air andcontributing to demolition of the dry/dehydrated zone – similar to the eruption ofa volcano. This volcano effect may be affected by pore size, shape, and degree ofmoisture content within the pore; most entrained air between 0.3 and 1.0
millimeters under this heating exposure showed volcano effects.

1. Initial stage(sintering of surface)

2. Demolition ofdry/dehydrated zone

3. Initial demolition ofdry/dehydrating zone

0.35 mm

4. Accelerated
demolition ofdry/dehydrating zone

5. Final demolition ofdry/dehydrating zone

Final Stage

Fig. 9: Demolition process at the mortar surface by pore pressure

Interaction between degradation and self-healing behavior in high strength mortar
exposed to high temperatures (up to 500℃)

0ctober 2010, Kobe, Japan

Connected
pore

Connected
pore

Fig.10: Surface images and 3D visualizations of volcano effect in connected pores
The demolition process of the dry/dehydrated and dry/dehydrating zones is
illustrated in Fig. 9 through microscopy images, which show the degradation fromsurface sintering and demolition of the dry/dehydrated zone to demolition and of
the dry/dehydrating zone. The volcano effect may also occur in conjunction withadjacent entrained air, where built-up pore pressure in the smaller pore exceeds
the matrix strength and a connecting passageway is formed between the two pores.
Pressure first drops due to larger space then increases again under heating untilthe volcano effect occurs at the surface, exposing both the entrained air pore aswell as the adjacent, connected pore. The exposed connected pore can be clearlyseen in both the surface images and 3D visualizations in Fig. 10 for two different
locations where the volcano effect was observed. This section and the preceding
section discussed the degradation of mortar under heating exposure and examined
the mechanism considering the progress of the dry/dehydrated anddry/dehydrating zones and the build-up of pore pressure in entrained air. The
following section will move towards the next step, the repair of fire-damaged
mortar, by examining the self-healing behavior under water supply.
3.3. Self-healing behavior of high-strength mortar
Sintered materials lose their self-healing capability due to the sintering effect; thisis clearly seen in Fig. 11, in which 28 days re-curing in water shows no effect on
the sintered material. On the other hand, the dry/dehydrating zone is not yet
sintered but in the dehydrated condition, indicating there is potential for re-curing
if water is supplied to this zone. Fig. 12 shows that the self-healing effect occurs
in the dry/dehydrating zone even after one day of re-curing, and by 28 days thecrack was almost entirely self-healed.

New Technologies for Urban Safety of Mega Cities in Asia

1 day28 days (under water supply)

Fig. 11: Loss of self-healing capability by sintering in the dry/dehydrated zone

0.31 mm(a) 1 day(b) 3 days(c) 7 days(d) 28 days

Fig. 12: Observed self-healing behavior in dry/dehydrating zone (I)The self-healing phenomenon also occurred in the entrained air structures for the
dry/dehydrated, dry/dehydrating, and quasi-saturated zones. In the dry/dehydrated
zone, it was found that self-healing behavior did not occur due to the poresintering effect. For the dry/dehydrating zone, there was partial self-healing
although sintering was also observed. In the quasi-saturated zone, almost
complete self-healing occurred after 28 days. This demonstrates that there is highpotential for fire-damaged mortar and, by extension, concrete to recovermechanical properties if re-cured under appropriate water supply conditions.
3.4 Strength and porosity recovery
A complementary investigation on self-healing under water curing was conductedby the authors but with a water-cement ratio of 0.3 and exposure temperature of
550°C. The compressive strength and porosity were examined before heating,after 1 hour of water cooling, and after 28 days re-curing, with the relationshipbetween strength and porosity shown in Fig. 13.

Interaction between degradation and self-healing behavior in high strength mortar
exposed to high temperatures (up to 500℃)

120

0.00

100

0.05

80

0.10

60

0.15

40

0.20
Strength
Porosity

20
0

Porosity (ml/ml)

Comp. strength (MPa)0ctober 2010, Kobe, Japan

0.25
0.30

Before fire

1 hour after fire

28 days recuring

Fig. 13: Change in strength and porosity after heating and water re-curing

Pore volume (ml/ml)

0.020

Before fire
1 hour after fire
28 days re-curing

0.016
0.012
0.008
0.004
0.000
1

10

100
1000
Pore diameter (nm)10000

Fig. 14: Change in pore distribution after heating and water re-curing
Recovery of both properties can be clearly observed, but strength only recovers to
72% of its original value whereas porosity is observed to completely recover after
28 days water re-curing. This discrepancy between the strength and porosity
behavior may be explained by self-healing behavior observed for similar
specimens in the previous section; specifically, although full crack self-healing
was observed to occur after 28 days of re-curing in water (Fig. 12), the stability ofthis new, self-healed interface is unknown and may contribute to the lack of fullstrength recovery. In addition, while the porosity completely recovers by 28 days,
the pore distribution is slightly different, as can be seen in Fig. 14. Pores less than
11 nanometers in size occupy a greater volume than they did before heating, withpores greater than 11 nanometers in size occupying less volume after re-curing
than before heating, suggesting that re-curing in water after heating may lead to anincrease in gel pores and a decrease in capillary pores relative to the pre-fired
conditions.
4. CONCLUSION
In this paper, the degradation and self-healing behavior of fire damaged highstrength mortar was investigated in order to support concrete recycling and todevelop a new repair method for fire-damaged concrete. Key findings are as
follows:

New Technologies for Urban Safety of Mega Cities in Asia

-

Degradation behavior of the cement paste on the mortar surface could be
related to thermo-hydral and thermo-mechanical processes under heating.
Solid-state-sintering due to dehydration, pore shrinkage, and volcano
effect were observed by microscopy. The volcano effect was proposed to
explain degradation at the mortar surface. This phenomenon is driven by
the build-up of vapor pressure in entrained air which leads to demolition of
the dry/dehydrated zone. It was observed that this occurred both in single
pores and connected pores near the mortar surface.
- Self-healing behavior was observed in both cracks and in entrained air inthe dry/dehydrating and quasi-saturated zones, which demonstrated thepotential for self-healing behavior in fire-damaged high-strength mortar.
No self-healing behavior was found to occur in the sintered dehydrated
zone, which may limit recovery capability depending on the extent of
exposure.
Secondary degradation may occur due to the weak bond between thedry/dehydrated and dry/dehydrating zones. In order to reduce this effect, thedevelopment of a chemical bonding agent for a water-based re-curing process
could lead to the practical development of a new repairing method.
ACKNOWLEDGEMENTS
The authors would like to thank Grants-in-Aid for Scientific Research from JSPS
(Japan Society for the Promotion of Science) for their financial supports.
REFERENCES
1)

2)
3)

V. Kodur, Fiber reinforcement for minimizing spalling in high strength
concrete structural members exposed to fire, in: ACI SP-216, Innovations inFiber-Reinforced Concrete for Value, ACI, Farmington Hills, 2003, pp. 221236.
P. Kalifa, F.D. Menneteau, D. Quenard, Spalling and pore pressure in HPC
at high temperatures, Cement and Concrete Research 30 (2000) 1915-1927.
T.H. Ahn, Development of self-healing concrete incorporating geomaterials: a study on its mechanism and behavior in cracked concrete, Ph.D.
dissertation, Dept. of Civil Engineering, The University of Tokyo, Tokyo,
2008.

Interaction between degradation and self-healing behavior in high strength mortar
exposed to high temperatures (up to 500℃)

Impact of Climate Change on Waste Water
Reticulation System:
A Case study in Drouin, Australia.
JOSEPH P DANIEL and DUSHMANTA DUTTA
School of Applied Science and Engineering,
Monash University, Australia
dushmanta.dutta@ monash.edu
ABSTRACT
Australia being an island continent is highly vulnerable to infrastructure damage
due climate change. The sewer reticulation systems are not an exception.
Research needs to be carried out to quantify the impacts of climate change anddesign criteria be reviewed, to mitigate or adapt to the impacts of climate change
in the waste water reticulation system. Although much of Australia is expected todry because of climate change, due to decrease in total rainfall, increase in
extreme rainfall events are still expected in many regions. This will affect thesewer reticulation system in many ways.
The aim of the research is to quantify the impacts of climate change on a sewer
reticulation system in urban areas of the Gippsland region, Victoria. The specificobjectives are to simulate the impacts of climate change in a working calibrated
sewer model and to analyse, understand and quantify the impacts in an existing
waste water reticulation system based on the modelling. The model is used tosimulate various scenarios individually and collectively to assess the impacts ofclimate change and quantify them. The simulated outputs give us a chance toquantify the impacts of the possible effects of climate change on the catchments
and their characteristics. Drouin, a regional township in the Gippsland region,
has been selected as the case study area for quantification of climate change on
the wastewater reticulation system.
The paper presents the detailed outcomes of the case study. The results
demonstrate that there will be significant effects of climate change at several
locations of the selected systems including reduction of inflow to the system. The
reduction in inflow would result in the reduction of the velocity of flow, which inturn would reduce the self cleansing velocities. These results would help the waterauthority to prepare adaptation measures and in designing the sewer reticulation
systems in future to cater for the impacts of climate change.
Key Words: Waste Water Reticulation Systems, climate change, impacts andadaptation.

1. INTRODUCTION

Climate change manifests itself through an elevation in average temperature,
variation in rainfall patterns or an increase in sea level and thereby poses a
significant risk to infrastructure and its owners, managers and long-term operators.

0ctober 2010, Kobe, Japan

According to the Fourth Assessment Report (AR4) of the Intergovernmental Panelon Climate Change (IPCC), the 100-year linear trend (1906-2005) of average
global temperature rise of 0.74°C [0.56 to 0.92]°C is larger than the corresponding
trend of 0.6°C [0.4 to 0.8]°C (1901-2000) given in the Third Assessment Report(TAR) (IPCC, 2001 and 2007).
Australia being an island continent is highly vulnerable to infrastructure damage
due climate change. Australia’s average temperatures have already risen byaround 0.7°C over the last century. Victoria has warmed by 0.6°C since the 1950s
and the last ten years have been hotter than average, with 2007 being the hottest
year on record. By 2030 warming in Victoria is likely to range from 0.6°C to
1.2°C on 1990 temperatures and by 2070 from 0.9°C to 3.8°C. There will be more
hot days and fewer cold days. Widespread decreases in atmospheric moisture arelikely over Victoria. Increases in extreme daily rainfall are likely, but decreases
are also possible in some regions and seasons. An increase in fire-weather risk islikely. Relative to 1990, sea level may rise by 3 to 17 cm by 2030 and 7 to 52 cm
by 2070 (Howe et al., 2005, Atkinson et al., 2007, Holper et al., 2007). Thesechanges will have impacts on the urban infrastructure including the waste water
systems.
The Victorian Government’s ‘Victorian Greenhouse Strategy Action Plan
Update’ (Victorian Government, 2005) acknowledged the need of appropriate
decisions to ensure that the outcomes of those decisions were robust enough tocope with, or adapt to, changing climatic conditions in the future for various key
areas including urban infrastructure. A research, commissioned by Victorian
Government to study the risk exposure to key aspects of climate change of somekey areas of Victoria including infrastructure, found that the water and wastewater
infrastructure sector is exposed to the highest risk due to climate change (Holper
et al., 2007). The main risks associated with climate change are the potential forincreased frequency of extreme daily rainfall events, affecting the capacity andmaintenance of storm water, drainage and sewer infrastructure. There are likely to
be significant damage costs and environmental spills if water systems are unable
to cope with extreme events or multiple events in a season. Acceleration of thedegradation of materials and structural integrity of water supply, sewer andstormwater pipelines may occur through increased ground movement and changes
in groundwater. Water shortages may occur due to greater demand for waterassociated with increased temperatures, reduced available moisture and increased
population. A decrease in annual rainfall in catchments would affect water supply.
In several parts of Victoria, especially in rural towns, it has been alreadywitnessed that flows into the sewer treatment plants have been affected due to thewater restrictions, more efficient water-using appliances and recycling of water inhomes and on farms in the past few years Managing director of agriculturalresearch consultancy Arris Pty Ltd, Dr Daryl Stevens, reportedly stated that"flows into most Australian sewage treatment plants are declining dramatically,
especially in drought-affected country towns". He says water restrictions, more
efficient water-using appliances and recycling of water in homes and on farms are
all contributing, and Australia's sewage system may struggle to cope with waste

New Technologies for Urban Safety of Mega Cities in Asia

(Grant, 2009). The amount and volumes of water have decreased 10% to 30%
going in to some sewage treatment plants. The whole sewage system is designed
on a certain volume of water flushing through it to carry all the solids that are
mixed up in the water. This has resulted in less waste water in the pipes as drains
and sewers dry up. This is an example of how climate change alters the
behavioural patterns and water usage of people.
There is a critical need for research to develop comprehensive understanding andfor quantification of the impacts of climate change on water and wastewater
infrastructure for appropriate adaptation measure and retrofitting of existing
infrastructure and designing new infrastructure to withstand the climates of today
and the future. The solutions may vary from , “Do nothing”, or increase the slopeof the pipes, or change the material of the pipe, increase or decrease the diameterof the pipes, Increase the capacity of the wet well and or emergency storage,
special odour control systems etc.
This study was undertaken as an attempt to quantify the impacts of climate change
on a sewer reticulation system in urban areas of the Gippsland region, Victoria.
The paper presents the outcomes of the project with a case study application inDrouin Township in the Gippsland Region of Victoria.
2. CASE STUDY AREA

Central Gippsland Region Water Corporation trading as “Gippsland Water” (GW)
provides water and sewer reticulation systems services for the town Drouin.
Figure 1 shows the catchment areas and the townships served by GW including
Drouin. The township of Drouin is located about 90 kilometers east of Melbourne
cantered along the Princes Highway.
The Drouin sewerage catchment contains approximately 61 kilometers of sewer,
and covers a gross area of 246 hectares serving a population of approximately
5,815 persons. The catchment is entirely situated in the local government area of
Baw Baw Shire and is predominantly residential, with some commercial,industrial and public use areas. Approximately 76% of the pipes within the Drouin
Catchment are 150mm in diameter or less, 14% are 225-300mm in diameter, 6%
are 375-525mm in diameter, while the remaining 4% are pressure pipes. A
majority of the existing catchment is situated in close proximity to Princes Hwy.
Approximately 80% of Drouin is residential. The main commercial and industrial
areas are within or in close proximity to the town centre. The sewerage catchment
drains towards the trunk sewers running parallel to Princes Hwy where the flows
travel westward to the Drouin Wastewater treatment plant (WWTP). After
treatment the treated effluent is discharged to Shillinglaw Creek under the GW
amalgamated EPA (Environmental Protection Agency) discharge license.
There are no emergency relief structures within Drouin. There are six sewerage
pumping stations operated by GW contained within the Drouin Sewerage
Catchment Area Plan SCAP, of which Hopetoun Road Sewer Pump Station (SPS)
is the only major pump station. The Drouin SCAP is serviced by approximately
61km of sewers and 1,170 manholes.

Impact of Climate Change on Waste Water Reticulation System: A Case study in Drouin, Australia.

0ctober 2010, Kobe, Japan

Figure 1: Gippsland Water general Operations (Wilbraham, 2007)

The existing reticulation systems have been designed initially using the guidelinesof Water Services Association of Australia (WSAA) and Gippsland water’s
Wastewater Systems Design Performance Criteria. This has been developed basedon the experience and the observed results over the years. GW’s Engineers over
the years have formulated these guidelines and are still improvising them as
required.
In a Greenfield situation, GW follows the Water Services Association of Australia(WSAA) guidelines to design its reticulation system. WSAA estimates the design
flow using the formula (WSAA, 1999):
Design Flow = PDWF+ GWI+ IIF
Where,PDWF = Peak Wet Weather FlowGWI = Ground Water Infiltration
IIF = Inflow Infiltration

New Technologies for Urban Safety of Mega Cities in Asia

However like most of the water authorities, GW has its own “Wastewater Systems
Design Performance Criteria” as mentioned above. The assumptions are to betested in conjunction with the impacts of climate change and there is a need forfurther research in this area.
The basic assumptions Gippsland Water’s Wastewater Systems Design
Performance Criteria are:• Average Dry Weather Unit flow = 650L/Lot/d• Ip (Permanent Infiltration)= 500L/ha/d• Is (Storm dependant infiltration)= 25,000L/ha/dThese assumptions are revisited as the climatic conditions and the usage patterns
have considerably changed in the recent years. Further to achieve this, a calibrated
model (Info works) has been used to simulate the impacts of climate change on
the existing systems and sub catchments to verify the assumptions.
GW engaged Montgomery Watson Harza (MWH) to install flow meters and rain
gauges at various locations in the above mentioned catchment and to record thereadings in five minute intervals for four months continuously. These readings
were used to calibrate the model (Info works) used by GW. The flow meterreadings were used to analyse the various parameters like Average Dry Weather
Flow (ADWF), Peak Wet Weather Flow (PWWF), Storm water Infiltration (Is)and Dry weather Infiltration (Ip).
Five flow monitors were installed by ADS for the temporary monitoring of theDrouin Sewer Catchment. The flow meter locations can be seen in Figure 2.
Manhole M/A defines the outlet of the Drouin SCAP which discharges to theDrouin WWTP. The Drouin SCAP boundary is defined by flow monitor DR1.
The remaining temporary monitors define each of the sub-catchments within theDrouin Catchment.
From the flow meter readings for four months for Drouin catchment wereanalysed and it was found that the values were different for different subcatchments. For example at Drouin, Table 1 shows the Average dry weather unit
flow per lot per day which is less than the assumed flow of 650L/Lot/day in the
GW’s Wastewater Systems Design Performance Criteria. This clearly shows thatthe conservation and reuse of water by the people is eminent.
Table 1: Average Dry weather unit flows for Drouin catchment
StationResidential Generation Rate
Non Residential Rate
Flow Meter Location
ASF/Lot/Day
L/connection/day
DR1
630
630
DR2
390
390
DR3
620
620
DR4
420
420
DR5
520
520
There is a wide range of differences between the above catchments. The
catchment DR 5 is almost fully developed and is mostly residential. The
catchment DR 1 still has provision for 55 residential connections and has 80 non-Impact of Climate Change on Waste Water Reticulation System: A Case study in Drouin, Australia.

0ctober 2010, Kobe, Japan

residential connections connected. DR3 has the potential for an additional 32
connections as Drouin Town ship is not fully developed.

Figure2: Drouin Sewerage Catchment Plan (adopted from Theodorlis, 2006)

New Technologies for Urban Safety of Mega Cities in Asia

3. INFO WORKS MODELING SOFTWARE

Info works Wallingford sewer modelling Software CS has been used for this study.
This model was developed in UK and is now used worldwide as one of the mostreliable models. The model has the features to simulate and run different scenarios
and the predicted impacts of climate change are being applied to the calibrated
model and the results are analysed. The model has been calibrated by MWH for
Gippsland Water and GW has given the 1st author permission to use thiscalibrated model for the research. Quantity analysis of the data was done by
MWH and it was found that 99% of the data recorded were good. For eachcatchment waste water generations were created separately for residential and non
residential profiles. Specialist profiles have been created for Schools, Hospitals,
Parks
The current hydraulic model was calibrated in Info Works CS 5.0 for dry and wet
weather conditions using data obtained from five (5) flow monitors, and two (2)rain gauges collected over a nine week period. Info works CS Fixed Runoff model
coupled with groundwater infiltration module was utilised to calibrate the model
to wet weather conditions due to the extensive wet weather response recorded in
the system. Dry and Wet weather system performance for existing (design)loading conditions was assessed using the calibrated hydraulic model.
The sub-catchment boundary is defined by the extent of the contributing areas
which exist between an Upstream and downstream flow monitor. The differencein flow between monitors represents the flow attributed to each sub-catchment.
The GW’s model requirements specify the following tolerances as given in
Table.2.
Table 2: GW’s requirements for dry and wet weather modeling
Wet weather model
requirements±10% for peak discharge;

Dry weather model requirements·±10% for daily flow volume;±5% for daily flow volume;

Peak timing ±30 minutes;

Peak timing ± 30 minutes;±20% for depth of flow; and±15% for depth of flow; andShape representative of observed
flow pattern

Shape representative of observed flow pattern±5% for peak discharge;

Climate Change Scenarios for simulation
One of the major impacts of climate change to the sewer reticulation system isreduction of inflow in the waste water reticulation systems due to water
restrictions, water saving devices and grey water reuse. GW is alreadyexperiencing this as the population is increasing but the inflow in to the waste
water treatment plants are decreasing. Figures 3 and 4 shows the increase in
Impact of Climate Change on Waste Water Reticulation System: A Case study in Drouin, Australia.

0ctober 2010, Kobe, Japan

population of different towns within the GW catchment and the reduction of water
usage by the GW customers in the recent years. This is mainly due to the use ofwater saving water efficient devices, grey water reuse, use of rain water tanks,
water restriction and the mindset of the people.
Population growth in Towns
8000

7206

7000

Population

6000

6452
5625

5383

4831

5000
4000

2872

2617

3000
2000

1314

1880
1239

1000

240

149

0
Morwell

Churchill

Towns

Yinnar
1981

1986

Moe
1991

Warragul
1997

2002

Drouin2006

Figure 3: Increase in Population in various towns.

Figure 4: Decrease in Water consumptions leading to decrease in inflow to the WWTPs

It has been predicted that the reduction in the waste water inflow to the Waste
water treatment plants would range from 10% to 30%. The calibrated Info works
model for Drouin was simulated for the scenarios of reduction in inflow by 10%,20% and 30 % and the changes in depth in the pipe, velocities in the pipe and theflow were analysed.
4. RESULTS AND DISCUSSION
New Technologies for Urban Safety of Mega Cities in Asia

Reduction in Velocity in pipe due to reduction in inflow
Table 4 presents the simulated maximum, minimum and average velocities offlow in the sewer network in DR1 due to the reduction in inflow by 10%, 20 %and 30 %. The results show that the reduction in minimum velocity is highly
significant with about 20% reduction due to the reduction of inflow by 30%. Thisis going to have impacts on self cleansing velocity of the system. The flow
velocity in the sewers should be such that the suspended materials in sewage do
not get silted up; i.e., the velocity should be such as to cause automatic selfcleansing effect. The generation of such a minimum self cleansing velocity in thesewer, at least once a day, is important, because if certain deposition takes placeand is not removed, it will obstruct free flow, causing further deposition andfinally leading to the complete blocking of the sewer.
Table 4: Change in velocity due to change in inflow at DR1.
Sensitivity
Normal DS
Simulated DS Velocity (m/s) – Difference
Analysis
Velocity (m/s)
10% reduction in inflow
in %
Max
0.26
0.25
2.99
Average
0.18
0.17
6.29
Min
0.11
0.10
6.05
Normal DS
Simulated DS Velocity (m/s) – Difference
Velocity (m/s)
20 % reduction in Inflow
in %
Max
0.25
0.22
13.28
Average
0.18
0.15
12.73
Min
0.11
0.10
13.27
Normal DS
Simulated DS Velocity (m/s) – Difference
Velocity (m/s)
30 % reduction in Inflow
in %
Max
0.25
0.21
18.93
Average
0.18
0.14
19.31
Min
0.11
0.09
20.37
Reduction in flow depth in pipe due to reduction in inflow
The depth of flow in the sewer is a major factor responsible for the sewertransport. The sewer consists of solids and liquids and if the depth of flow in thesewer is very less, it leads to settlement of solids to the bottom of the pipes anddue to the nature and the texture of the waste; it starts to build up and ultimately
blocks the sewer. A sensitivity analysis has been carried out and the results havebeen tabulated in Table 5. It is found that that the depths of flow in the sewer
system were reduced as the inflow reduced. .the maximum water depth in the pipe
is reduced from 0.32 m to 0.3m due to 30% reduction in inflow .The depths play avital role in the transport of sewer in the pipes. The reduction in depth will haveits impact on the self cleansing velocities in the sewer system. Previous researchon self cleansing velocities state that reduction in depth in the sewer flow to morethan 0.5 of the pipe would result in considerable amount of deposition andreduction in the shear force required to cleanse the system. Self cleansing
velocities also depend on the diameter of the sewer pipe (Nalluri et al., 1994). It isclear that a reduction in 20% of the inflow to the reticulation system affects thehydraulics of the system considerably. In reality we have seen from reports thatthe inflow to the waste water treatment plants are already reducing by 25 to 50%.
Impact of Climate Change on Waste Water Reticulation System: A Case study in Drouin, Australia.

0ctober 2010, Kobe, Japan

Table 5: Change in depth due to reduction in inflow at DR01
Depth in Pipe
Depth in Pipe 10 %Difference
Category
Normal DWF
reduction in inflow
in %
Max
0.32
0.32
0.92
Average
0.29
0.28
1.50
Min
0.26
0.26
1.08
Depth in Pipe
Depth in Pipe 20 %Difference
Category
Normal DWF
reduction in inflow
in %Depth in Pipe
20 % reduction in
Normal DWF
inflow
Max
0.32
0.31
4.10
Average
0.29
0.28
3.04
Min
0.26
0.26
2.33
Depth in Pipe
Depth in Pipe 30 %Difference
Category
Normal DWF
reduction in inflow
in %Depth in Pipe
30 % reduction in
Normal DWF
inflow
Max
0.32
0.30
5.83
Average
0.29
0.28
4.63
Min
0.26
0.25
3.54
Reduction in flow in pipe due to reduction in inflow
The model was simulated to run for a period of three days during the dry weather
flows. The results were confirming that the Downstream Flow, velocity and depth
are decreasing proportionally as the inflow was reduced. Table 6 displays thesensitivity analysis with the maximum, minimum and average changes for the
reduction of 10, 20 and 30 percent reduction of inflow to the down stream flow.
Table 6: Change in Downstream Flow due to Reduction in inflow at DR01
Sensitivity Normal DS
10 % less Inflow –Difference
Analysis
Flow (m3/s)
Simulated DS Flow (m3/s)
in %
Max
0.03
0.03
4.17
Average
0.02
0.02
8.19
Min
0.01
0.01
7.39
Normal DS
10 % less Inflow –Difference
Flow (m3/s)
Simulated DS Flow (m3/s)
in %
Max
0.03
0.03
17.90
Average
0.02
0.02
16.40
Min
0.01
0.01
16.06
Normal DS
10 % less Inflow –Difference
Flow (m3/s)
Simulated DS Flow (m3/s)
in %
Max
0.03
0.02
25.08
Average
0.02
0.02
24.56
Min
0.01
0.01
24.32

New Technologies for Urban Safety of Mega Cities in Asia

5. CONCLUSIONSThe paper presented the outcomes of a case study conducted to analyse theimpacts of climate change in the waste water reticulation system in Drouin
township of Gippsland Region using an established mathematical model. It isevident that the impacts of Climate change would affect the waste water
reticulation system and the various parameters. The reduction in inflow would
result in the reduction of the velocity of flow, which in turn would reduce the self
cleansing velocities. The depth of the flow is also reduced due to the reduction in
the inflow to the reticulation systems.
REFERENCES
Atkinson, N., P. Brait, L. Murphy and N.Rogers (2007), Victorian Local Government
Greenhouse and Climate Change Case Studies Report, Municipal Association of Victoria
2007, 80 pages.
Grant R., 2009. Increased water recycling leaves sewers struggling to flush retrieved
from http://www.abc.net.au/rural/news/13/02/2009 viewed on 01/12/2009.
Holper, P., S. Lucy, M. Nolan, C. Senese and K. Hennessy (2007) (ed). Infrastructure andclimate change risk assessment for Victoria, Report to the Victorian Government, March
2007 Prepared by CSIRO Maunsell Australia Pty Ltd, Phillips Fox, 177 pages.
Howe C., Jones R.N., Maheepala S., Rhodes B., 2005. Implications of Potential Climate
Change for Melbourne’s Water Resources Melbourne Water Climate Change Study,
Australia, 2005.
IPCC (2007). Climate Change 2007, 4th Assessment Report (AR4) of theIntergovernmental Panel on Climate Change (AR4), United Nations.
IPCC (2001). Climate Change 2001: Impacts, Adaptation and Vulnerability. Contributionof Working Group II to the Third Assessment Report (TAR) of the Intergovernmental
Panel on Climate Change (IPCC). Cambridge University Press, Cambridge, UK
Nalluri C., and Dabrowski W., 1994. Need for New Standards to Prevent Deposition in
Wastewater Sewers. Journal of Environmental Engineering, Vol. 120, No. 5, pp. 10321043, September/October 1994.
Sewerage Code of Australia WSA 02-1999. Standards Australia, Melbourne.
Theodorolis S., 2006. Churchill- Boolarra- Yinnar Sewage Catchment Hydraulic
Modeling. Engineering Report. Vol 1, August, 2006 Gippsland Water
Victorian Government (2005) Victorian Greenhouse Strategy Action Plan Update.
Victorian Government Department of Sustainability and Environment, Melbourne,
http://www.greenhouse.vic.gov.au/images/VicGreenhouse-ActionPlan.pdfWatson
R.,
Zinyowera M.C., and Moss R.H., 2008. Technologies Policies and measures for
mitigating climate change. Technical Report.
Wilbraham D., 2007. Gippsland Water’s Catchment Area.Gippsland Water World Series
Poster, Gippsland Water, Australia.

Impact of Climate Change on Waste Water Reticulation System: A Case study in Drouin, Australia.

CLIMATE DISASTER RESILIENCE INDEX(CDRI) IN
CHENNAI, INDIA
Jonas JOERIN1, Rajib SHAW2, Yukiko TAKEUCHI3, and 4Ramasamy
KRISHNAMURHTY
1
PhD Student, GSGES, IEDM, Kyoto University, Japanjoerin.jonas@ks2.ecs.kyoto-u.ac.jp
2
Associate Professor, GSGES, Kyoto University, Japan
3
Assistant Professor, GSGES, Kyoto University, Japan
4
Associate Professor, Department of Applied Geology, University of Madras,
India

ABSTRACTDue to the rising pressures on Chennai, India, to provide the rapidly growing
population (urbanisation) adequately with urban services (water, electricity, solid
waste collection, etc.), the local government and communities are key actors inshaping the resilience of the city to climate-related disasters. Proposing a tool
named Climate Disaster Resilience Index (CDRI), it shall understand thevulnerabilities and capacities (resilience) of physical, social, economic,
institutional, and natural aspects of Chennai at the micro-level (zone-level). The
key aim of this CDRI is to provide local governments with a planning tool inorder to make the city resilient to climate-related disasters. This shall trigger thedevelopment of appropriate and feasible disaster risk reduction measures, or socalled sound practices.
CDRI results from the ten administrative zones of the city of Chennai
highlight zone-wise the differences in terms of becoming resilient to climaterelated disasters; however, do not confirm that urbanisation is necessarily
negative for a city to become resilient, especially with regards to the physicaldimension (provision of urban services and infrastructure quality). The outcome
provides all the ten zones with individual results to the five aspects mentioned
above. In addition to individual zone-based results, the CDRI allows crosscorrelations between different parameters, for instance, high income levels of
people is closely related to higher levels of material wealth (household assets).
The CDRI engages different stakeholders from local government, academia, tocommunities and may well represent the local conditions.
Keywords: urban disaster resilience, climate change, disaster risk reduction

1. INTRODUCTION
This paper shall address the ongoing pressures resulting from trends ofurbanisation and projected future climate change impacts in Chennai, India.
Chennai being located at the south-eastern coast of India along the Bay of Bengal

0ctober 2010, Kobe, Japanis not only experiencing rapid population growth rates since many decades(Chennai Master Plan, 2008), but may also become susceptible to predicted more
frequent and severe climate change related hazards (IPCC, 2007) in the form ofintense rainfall events leading to flooding, storms from cyclones formed over the
Bay of Bengal mostly between October to December and potential heat waves anddroughts during the dry period between April and June (Revi, 2008). While
climate change impacts are not yet visible or statistically proven to become more
intense or frequent, the population of Chennai has already risen significantly overthe last decades by 1-3 percent per year, and demonstrates a serious risk driver. At
current, the population growth rate lies around the global average (1.76 percent
per year) for urban areas (UNDESA, 2010) at 1.72 percent per year; however,with large variations within different zones of the city (Chennai Master Plan,
2008).
The approach taken in this paper is to understand impacts of various risk
drivers (e.g. urbanisation) on the provision of urban services, like water,electricity or solid waste disposal, just to name a few. Put it in other words, how
the different sectors of a city are likely to sustain or bounce back in case an
occurring climate-related hazard (shock) turns into a disaster. The perception of
the city being more than just the social fabric or a physically defined entity(Godschalk, 2003: Vale and Campanella, 2005) is crucial in understanding the
adopted Climate Disaster Resilience Index (CDRI) where physical and social
aspects of a city are added by economic, institutional and natural issues related toclimate-related disasters.
Ultimately, the CDRI aims to unveil the sectors which are more or lessresilient to climate-related disasters; additionally, which areas among the tenzones of Chennai are likely to cope better during such disasters. This approach
follows the main goal to make cities – in this case Chennai – safer todisasters ,which is also emphasised through the Hyogo Framework for Action(HFA) 2005-2015 (UNISDR, 2005, 2007, 2010), and gains now even more
importance as Chennai is actively taking part in the 2010-2011 World Disaster
Reduction Campaign: Making Cities Resilient. The aim of this campaign issimilar to what the CDRI stands for which is raising the awareness among local
governments/institutions to embark on a new way of thinking that action needs tobe taken where disasters actually occur which is at the most local level. Thereby,
the CDRI offers a tool to understand the strengths and weakness of a city, like
Chennai, in order to address those adequately in future planning decisions.
This paper is structured as follows: firstly, a short theoreticalunderstanding to the CDRI is given; secondly, the characteristics of Chennai andits ten zones and the results of the undertaken CDRI-study are given; thirdly, a
conclusion gathers the key points of this paper.

2. UNDERSTANDING THE CDRI
2.1 Disaster resilience in urban areas
The term resilience used for the understanding of disaster resilient urban areas has
its theoretical origin from the field of ecology where Holling (1973) described thepersistence of different ecological systems to cope with disturbance and still
New Technologies for Urban Safety of Mega Cities in Asiamaintain the same relationships between populations and state variables. In otherwords, what is the impact of a disturbance let’s say lack of nutrition or changing
environment on a particular species. Is it capable to bounce back from this
disturbance and to what extent? This is how resilience may be understood. During
the following decades several contributions (Manyena, 2006) enriched the term
and began to link it to social systems, like the disaster resilience of communities(Adger, 2000; Twigg, 2007). Less specific solely on communities, Carpenter et al(2001, pp. 766) defined the resilience of a socio-ecological system as: “the amount of change the system can undergo and still remain within thesame domain of attraction;
 the degree to which the system is capable of self-organization;
 and the degree to which the system can build the capacity to learn andadapt”.
Merging the different approaches and understandings of resilience allows defining
the resilience of a city in relation to climate-related disasters. While the change(Carpenter et al., 2001) or disturbance (Holling, 1973) may be replaced by clearly
defined disasters (floods, storms, droughts, etc.) the system may be characterisedby a complex amalgamation of different actors (communities, institutions, etc.)
embedded in a physically, socially and naturally defined geographical area. Since
the resilience of communities (Twigg, 2007) is defined by the cultural and social
integrity of its members, a city is larger and includes more aspects than just theability of a well-defined population to cope in the event of a disaster.
2.2 The CDRI
The previous section made clear that understanding the resilience of climaterelated disasters in urban areas may be a difficult task: firstly, because resilience isunderstood differently depending on the source (Cutter et al., 2008) and has aclose connectivity to the term vulnerability (Berkes et al., 2003); secondly, thecomplexity of an entire urban system to be explained in relation to resilience is
cumbersome as it unavoidably must include different aspects. The World Bank
(2009) has also taken an approach to offer scientific findings that cities need to
become safer to disasters, but adopts a vulnerability assessment where different
sectors of a city are evaluated and does not include the ability of communities in
influencing the overall city’s ability to respond to a disaster. This is where the
CDRI fundamentally deviates from The World Bank’s (2009) approach as it
regards the ability of communities in shaping the resilience of a city to disasters as
crucial because the ultimate aim of making cities more resilient is not just limited
to the physical or infrastructural setting, but also to reduce losses in terms ofhuman lives. Therefore, communities, or households, as it is often referred to in
the CDRI, are key actors and need to be taken into account in measuring theoverall resilience of a city to disasters. Similarly, the institutional ability of a city
influences, as well as the natural and economic setting of a city, how a city islikely to perform in the event of a disaster. Another key difference between the
CDRI and the hot-spot assessment from The World Bank (2009) lies in theconceptual and theoretical understanding of how a city’s capacity can beevaluated; whereas, the hot-spot assessment uses the vulnerability approach, the
CDRI uses the term resilience to identify how good a sector is performing.

Your paper title

0ctober 2010, Kobe, Japan

Table 1: Dimensions, parameters (25) and variables of the CDRIDIMENSIONSPARAMETERS AND VARIABLESPHYSICALElectricity (access, availability, supply capacity, alternative capacity)
Water (access, availability, supply capacity, alternative capacity)
Sanitation and solid waste disposal (access to sanitation, collection of waste: treated, recycled,
collection of solid waste after a disaster)Accessibility of roads (% of land transportation network, paved roads, accessibility during flooding,status of interruption after intense rainfall, roadside covered drain)
Housing and land‐use (building code, buildings with non‐permanent structure, buildings above water
logging, ownership, population living in proximity to polluted industries)
Population (population growth, population under 14 and above 64, population informal settlers,
population density at day and night)
Health (population suffer from waterborne/vector‐borne diseases, pop. suffer from waterborne
diseases after a disaster, access to primary health facilities, capacity of health facilities during adisaster)
Education and awareness (literacy rate, population’s awareness about disasters, availability of publicawareness programmes/disaster drills, access to internet, functionality of schools after disaster)Social Capital (population participating in community activities/clubs, acceptance level of community
leader (in ward), ability of communities to build consensus and to participate in city’s decision‐making
process (level of democracy), level of ethnic segregation
Community preparedness during a disaster (preparedness (logistics, materials, and management),
provision of shelter for affected people, support from NGOs/CBOs, population evacuating voluntarily,
population participating in relief works)
Income (population below poverty line, number of income sources per household, income derived in
informal sector, % of households have reduced income due to a disaster)
Employment (formal sector: % of labour unemployed, % of youth unemployed, % of women
employed, % of employees come from outside the city; % of child labour in zone)
Household assets (households have: television, mobile phone, motorized vehicle, non‐motorized
vehicle, basic furniture)
Finance and savings (availability of credit facility to prevent disaster, accessibility to credits,
accessibility to credits for urban poor, saving practice of households, household’s properties insured)
Budget and subsidy (funding of DRM, budget for DRR sufficient, availability of subsidies/incentives forresidents to rebuild houses, alternative livelihood, health care after a disaster)
Mainstreaming of DRR and CCA (mainstreaming of CCA and DRR in: zone’s development plans, ability(manpower) and capacity (technical) to produce development plans, extent of community participationin development plan preparation process, implementation of disaster management plan)
Effectiveness of zone’s crisis management framework (existence and effectiveness of an emergency
team during a disaster: leadership, availability of evacuation centres, efficiency of trained emergency
workers during a disaster, existence of alternative decision‐making personnel)
Knowledge dissemination and Management (effectiveness to learn from previous disasters,
availability of disaster training programmes for emergency workers, existence of disaster awarenessprogrammes for communities, capacity (books, leaflets, etc.) to disseminate disaster awarenessprogrammes (disaster education), extent of community satisfaction from disaster awarenessprogrammes)
Institutional collaboration with other organisations and stakeholders, during a disaster (zone’s
dependency to external institutions/support, collaboration and interconnectedness with neighbouringzones, zone’s cooperation (support) with central corporation department for emergency management,cooperation zone’s ward officials for emergency management, zone’s institutional collaboration with
NGOs and private organisations)
Good governance (effectiveness of early warning systems, existence of disaster drills, promptness ofzone body to disseminate emergency information during a disaster to communities and transparencyof zone body to to disseminate accurate emergency, capability of zone body to lead recovery process)Intensity/severity of natural hazards (floods, cyclones, heat waves, droughts (water scarcity),
tornados)
Frequency of natural hazards (floods, cyclones, heat waves, droughts (water scarcity), tornados)
Ecosystem services (quality of city’s: biodiversity, soils, air, water bodies, urban salinity)Land‐use in natural terms (area vulnerable to climate‐related hazards, urban morphology, settlementson hazardous ground, amount of Urban Green Space (UGS), loss of UGS)
Environmental policies (use of zone level hazard maps in development activities, extent ofenvironmental conservation regulations reflected in development plans, extent of implementation ofenvironmental conservation policies, implementation of efficient waste management system (RRR),
implementation of mitigation policies to reduce air pollution)

SOCIALECONOMIC

INSTITUTIONAL

NATURAL

The reasons lie in a different understanding on how different sectors (see table 1)
can contribute to making a city resilient. For instance, if 95 percent of the citizen

New Technologies for Urban Safety of Mega Cities in Asia

have access to electricity at home they are more likely to be informed through anearly-warning information from an approaching hazard, provided they have also aradio or television, which would ultimately increase their ability to respond during
a disaster. These 95 percent have to be regarded as more resilient compared to theremaining 5 percent and the goal should be to provide electricity for every citizen
to reach full resilience. Now, why is the use of the term vulnerability not very
useful? While vulnerability is defined through the sensitivity and exposure of asystem (Pelling, 2003), the outcome of a study based on the ‘negative’ aspects ofa city may fail to adequately address and link the different linkages between the
aspects. In other words, looking at the only 5 percent who have not access toelectricity may fall short of looking at the potential of the much bigger number ofcitizen who actually are connected and are likely to respond in favour of the 5
percent during a disaster. And finally, the CDRI only includes climate-related
disasters.
Thus, the CDRI consists of five dimensions which are again defined by 5parameters each, total 25, to define the resilience of climate-related disasters inurban areas. Table 1 shows not only the five dimensions (physical, social,economic, institutional, and natural) but also their defining parameters andvariables. The parameters are again consisting of five variables each to define it inmore detail.
The selection of all these dimensions, parameters, and variables is basedon extensive literature review and lessons learned from previous disasters andshall not be discussed further in this paper. However, concepts originating from
Wisner et al. (2004), like the PAR-model, or linkages drawn among thecommunities and the city they live in provided by Pelling (2003), apart fromearlier mentioned authors such as Adger (2000), Carpenter et al. (2001), Cutter etal. (2008), Godschalk (2003), Holling (1973), Klein et al. (2003), or Twigg (2007),served in developing the CDRI.

3. ADOPTING THE CDRI AT THE MICRO-LEVEL IN CHENNAI
3.1 Characteristics of Chennai
Chennai is located at the Bay of Bengal in the south-eastern part of Chennai andshall be seen as a coastal city which was hit hard during the Asian tsunami in2004. Most parts of Chennai lie just a few metres above sea-level and in someareas the ground-water level even reaches the surface hampering the draining-off
of rainwater, particularly after heavy rainfall events. The city is, however,experiencing only a few such events and mostly during the post-monsoon period
between October and December (Revi, 2008). Also, the occurrence of heat waves
and droughts are rare and if they take place then during the dry season from April
to June. Nevertheless, in view of the likely change of the climate leading to more
frequent and intense climate-related hazards (IPCC, 2007), the city may become
more vulnerable over time to such hazards demanding adequate and wise planning
decisions for the future.
As climate change is likely to become a factor which cannot anymore beneglected in planning decisions, the population growth over the last decades haschanged Chennai into a city where the infrastructure, ecosystem and quality of lifeYour paper title

0ctober 2010, Kobe, Japanare reduced. Particularly, after reaching independence in the late 1940s Chennai
grew rapidly and due to this, urban poor settlements began to mushroom along
canals and rivers of the city (Chennai Master Plan, 2008). As a result, in 2001
around 18.9 percent of the population lived in slums.
Since the population growth has largely taken place in the central andcoastal parts of the city area during the previous decades, the population is now
rising in the urban fringe. This is particularly relevant for understanding theresults followed by the CDRI study assessing the ten administrative zones ofChennai; whereby, zones 2, 3, 6, and 7 form the old part of the city and theremaining six zones the new part within the total 176 sq/km of the city area.
Accordingly, the old part is currently experiencing population growth rates of
0.48 percent per year compared to 2.54 percent in the newer parts (Chennai
Master Plan, 2008). In 2001, the population was around 4.2 million, but is likely
to have risen up to 5.5 million by today. It is expected that Chennai will become
almost a megacity (9.9 million) by 2025 (UNDESA, 2010).
3.2 Methodology and approach
Table 1 shows the content of a comprehensive questionnaire which consisted of
total 125 variables equally divided into parameters and dimensions, as mentioned
earlier. In order to include the local context certain variables were slightly
adjusted to the conditions in Chennai. The CDRI questionnaires were thendistributed to all the ten administrative zones to be filled-out between January andFebruary 2010. Due to the simple structure of the CDRI where each dimension,
parameter, and variable consist of the number five, a simple formula named
weighted mean was adopted to also include weightings given for each variables
and parameters, see figure 1 showing the calculation of a parameter:
Weighted Mean:∑ni= 1 wixi=
∑ni= 1 wi

w1x1 + w2x2 + w3x3 + w4x4 + w5x5
w1 + w2 + w3 + w4 + w5

Figure 1: Formula – Weighted Mean for calculating a score of a parameter
Scaling-up this calculation for a single parameter up to the dimension-level theoverall resilience scores can be derived which is between 1 (low resilience) and 5(high resilience).
3.3 Results
The results are shown in figure 2 and depict that the northern part (zones 1-3) ofChennai is overall less resilient than the southern or western parts of the citywhich is due to lower economic and natural resilience scores. The northern partssuffer disproportionally from low employment opportunities and also have toabsorb the environmental impacts from solid waste disposal facilities, a large
coal-fired power plant and the port. The benefits from these installations is turningout to be rather negative and lowering the resilience of the northern part of

New Technologies for Urban Safety of Mega Cities in Asia

Chennai. The highest or most resilient zone is number 7 which is also the centre
for commercial activities besides of large residential areas.
Overall CDRI

PhysicalSocial

I
IV

I
IV

III

I
IV

III

II
V

II

V

V

VI

VII

VI

VII

VIII

VIII

< 2.75

3 – 3.2< 2.5

2.75 ‐ 3

3.2 – 3.4

2.5 – 3IX

3 – 3.25

X

3.5 – 4

> 3.5

> 3.8

>4

Institutional

Natural
I

IV

III

I
IV

III

II

II

V

V

VI

VI

VII

VIII

VI

VII

VIII

X

III

II

V

IX

3 ‐3.5X

3.6 – 3.8

I

VII

IX

3.4 ‐3.6

X

3.25 – 3.5

Economic

IV

VI

VII

VIII

IX

III

II

VIII

< 2.5

3 – 3.25<2

2.5 – 33.25 – 3.5

2 – 2.5

3 ‐3.5IX

X

3.5 ‐3.75

IXX

2.5 ‐3

3.5 – 43.75 – 4

3 – 3.5

>4

>4

> 3.5

Figure 2: CDRI Results
The southern and western part form the newer part experiencing not only larger
population growth, but also in terms of economic development compared to theolder part, as big companies ranging from the IT sector to car manufacturing havesettled in these areas. The results of this change are visible in a higher economic
and overall resilience of the southern and western parts of Chennai. The
institutional resilience is the strongest dimension among the five and also the one
with smallest variations between the zones resilience scores. This is not surprising,
but rather confirms the administrative purpose of the zone to carry out public
works at a lower institutional level than the central Corporation administration.
The social resilience is not showing a clear picture whether certain areas are morestronger than others, this is again not surprising since the land-use of Chennai(Chennai Master Plan, 2008) is quite mixed and does not have only industrial,commercial or purely residential areas.
The interpretation of the results is obviously not final after these
explanations above, but shall point out some of the key findings and the potentialof the CDRI. To add one more feature of the CDRI, the equal weighting of eachYour paper title

0ctober 2010, Kobe, Japan

parameter allows ranging the strongest and most resilient down to lowest/least
resilient, as table 2 shows.
Table 2: Average city-wide CDRI scores of all 25 parameters, highest to lowest
Electricity
Institutional collaboration
Accessibility of Roads
HealthCrisis Management
Good governanceHousehold assets
Mainstreaming
Community preparedness
Finance and savings
Housing and land‐use
Education and awareness
Water
Knowledge dissemination
Intensity/severity of hazards
Employment
Budget and subsidy
IncomeEnvironmental policies
Social capital
Sanitation and Solid Waste Disposal
Land‐use in natural terms
Ecosystem services
Population
Frequency of hazards

4.87
4.09
4.05
3.89
3.86
3.64
3.54
3.45
3.44
3.43
3.43
3.33
3.24
3.24
3.21
3.20
3.17
3.15
3.15
2.88
2.77
2.73
2.65
2.60
2.49

Table 2 emphasises that since electricity is centrally provided and at a full level
for all citizens it is also close to fully resilient, unlike the population parameter,
for instance, which ranks at the second-last position due to the ongoing rapid
urbanisation in the newer parts of the city and the densely populated character ofthe city where in many zone more than 30,000 people live per sq/km.
The results from the zone-wise applied CDRI can be summarized, as
follows: firstly, resilience to disasters is varying from zone to zone and is not
uniform throughout the city; secondly, population growth does not correlate
negatively to the physical condition of the city, as many newer parts have highresilience.

4. CONCLUSIONThe CDRI offers an ideal tool for the local government and associatedstakeholders to look at the weakness and strengths of the city regarding theresilience to climate-related disasters. It offers a micro-level analysis highlighting
differences in resilience levels depending on the population density of an area,
current population growth, economic opportunities, natural condition, etc. This isparticularly relevant to target the identified 25 key sectors at the most local levelas suggested by various authors to reduce the risk of disasters (Satterthwaite et al.,
New Technologies for Urban Safety of Mega Cities in Asia

2007; UNISDR, 2010). Furthermore, action and planning decisions can betargeted specifically for a particular area and sector. And this is also the nextchallenge followed by this CDRI study, which offered a baseline assessment of
the city’s resilience related to different dimensions, to identify solutions
enhancing the resilience to climate-related disasters. For this, a second study is
ongoing where all the 155 Councillors of the city are requested to decide on thefeasibility and appropriateness of pre-defined resilience enhancing actions. Since
the Corporation of Chennai is about to enlarge its city area up to 426 sq/km by
2011 this study may lose its significance, however, it may serve as an indicating
study from which the new added areas may benefit. On the other hand, crosscutting studies are again needed to see how the new areas are going to merge withthe current parts of Chennai along the urban fringe.
Finally, this study may also serve the Corporation of Chennai’s efforts tomeet some of the ten essentials defined in the 2010-2011 World Disaster
Reduction Campaign: Making Cities Resilient to which it has formally committed
itself.

REFERENCES
Adger, W.N. (2000) ‘Social and Ecological Resilience: Are They Related?’.
Progress in Human Geography. 24(3). pp. 347-364.
Berkes, F., Colding, J., Folke, C. (2003) Navigating Social–Ecological Systems:
Building Resilience for Complexity and Change. Cambridge University Press.
Cambridge.
Carpenter, S., Walker, B., Anderies, J.M., and Abel, N. (2001) ‘From Metaphor to
Measurement: Resilience of What to What?’. Ecosystems. 4. pp. 765-781.
Chennai Metropolitan Development Authority (CMDA) (2008) Second Master
Plan For Chennai Metropolitan Area, 2026. CMDA, Chennai.
Cutter, S.L., Barnes, L., Berry, M., Burton, C., Evans, E., Tate, E., Webb, J.
(2008) ‘A place based model for understanding community resilience to natural
disasters’. Global Environmental Change. 18. pp. 598-606.
Godschalk, D.R. (2003) ‘Urban Hazard Mitigation: Creating Resilient Cities’.
Natural Hazards Review. 4(3). pp. 136-143.
Holling, C.S. (1973) ‘Resilience and Stability of Ecological Systems’. Annual
Review of Ecological Systems. 4. pp. 1-23.
Intergovernmental Panel on Climate Change (IPCC) (2007) ‘Summary for
Policymakers’ In: Climate Change 2007: The Physical Science Basis.
Contribution of Working Group I to the Fourth Assessment Report of theIntergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning,
Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge
University Press. Cambridge.
Klein, R.J.T., Nicholls, R.J., and Thomalla, F. (2003) ‘Resilience to natural
hazards: How useful is this concept?’. Environmental Hazards. 5. pp. 35-45.
Manyena, S.B. (2006) ‘The concept of resilience revisited’. Disasters. 30(4). pp.
433-450.
Pelling, M. (2003) The Vulnerability of Cities: Natural Disasters and Social
Resilience. Earthscan. London.

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Revi, A. (2008) ‘Climate change risk: an adaptation and mitigation agenda for
Indian cities’. Environment and Urbanization. 20(1). 207-229.
Satterthwaite, D., Huq, S., Pelling, M., Reid, H., and Romero-Lankao, P. (2007)
Adapting to Climate Change in Urban Areas: The Possibilities and Constraints in
Low- and Middle-Income Countries. Human Settlements Climate Change andCities Discussion Series 1. IIED. London.
The World Bank (2009) Climate Resilient Cities: A Primer on Reducing
Vulnerabilities to Disasters. The World Bank. Washington.
Twigg, J. (2007) Characteristics of a Disaster-resilient Community: A GuidanceNote. DFID Disaster Risk Reduction Interagency Coordination Group. Benfield.
United Nations (2010) World Urbanization Prospects: the 2009 Revision. United
Nations Population Division, Department of Economic and Social Affairs(UNDESA). United Nations. New York.
United Nations International Strategy for Disaster Reduction (UNISDR) (2005)
Hyogo Framework for Action 2005-2015. United Nations. Geneva.
United Nations International Strategy for Disaster Reduction (UNISDR) (2007)
Words into Action: A Guide for Implementing the Hyogo Framework. United
Nations. Geneva.
United Nations International Strategy for Disaster Reduction (UNISDR) (2010) A
Guide for implementing the Hyogo Framework for Action by Local Stakeholders.
United Nations. Geneva. Consultation version.
Vale, L., and Campanella, T. (2005) The resilient city: How modern cities recoverfrom disaster. Oxford University Press. New York.
Wisner, B., Blaikie, P., Cannon, T., Davis, I. (2004) At Risk: Natural Hazards.
People’s Vulnerability and Disasters. MIT Press. Cambridge.

New Technologies for Urban Safety of Mega Cities in Asia

CLIMATE DISASTER RESILIENCE OF DHAKACITY CORPORATION- A MICRO LEVEL ANALYSIS
Gulsan Ara PARVIN1, Rajib SHAW21
JSPS Postdoctoral Fellow
International Environment and Disaster Management
Graduate School of Global Environmental Studies
Kyoto University, Japanniruurp@yahoo.com, parvin.g@at7.ecs.kyoto-u.ac.jp
2
Associate Professor
International Environment and Disaster Management
Graduate School of Global Environmental Studies
Kyoto University, Japan

ABSTRACT
Along with the threat of climate change and its induced disasters, rapid urban
growth is leading to unplanned urbanization, high population density andenvironmental degradation of Dhaka. Already the severity of climate disaster,
especially flooding is increasing. Also it is forecasted that among the coastal
mega-cities Dhaka would be the most vulnerable to climate change. In this context
this research intends to measure the existing level of climate disaster resilience of
Dhaka City Corporation by assessing the problems and potentialities in different
sectors.
Climate Disaster Resilience Index (CDRI) of 10 different zones of Dhaka City
Corporation has been measured by this research. Results imply that the CDRI
scores ranges from 2.4 to 3.1 in a 5 point rating scale. Out of 10, 7 zones haveobtained medium level of score in CDRI. The planned residential areas haverelatively higher level of climate disaster resilience; while, old parts of the cityand densely populated low income areas have low level of resilience than otherareas. It is expected that by utilizing CDRI results in future policy formulationand development plan disaster risk and challenges could be minimized anddevelopment opportunities could be enhanced and finally these would lead to havea resilient city in future.
Keywords: Dhaka, climate, disaster resilience

1. INTRODUCTION
Explosive growth and high density of population, low stages of economic growthand poor state of environment in many developing countries are contributing toaggravate cities vulnerabilities, enhancing disaster risk and thus reducing theirclimate disaster resilience (Razafindrabe et. al, 2009 and Roy, 2009). Present
context of urban growth and development trend of Dhaka is a real reflection of

0ctober 2010, Kobe, Japanthese circumstances. For being the distinct primacy in the national urban hierarchy,
Dhaka is the hub of administrative, political, economic, industrial, cultural,
educational and research activities of Bangladesh. But unfortunately, among thecoastal mega-cities Dhaka, the capital of Bangladesh would be the mostvulnerable to climate change (Worldwide Fund for Nature 2009).
On the other hand, with an urbanization rate of over 2.5 % Dhaka is
considered as one of the fastest growing cities in the world in recent decades(Roy, 2009 and Hossain, 2006). It is noticed that the recent rapid
urbanization of Dhaka is taken place in lowlands, which serve as retention
ponds during flooding seasons and most of the natural drainage and canals
that used to drain excessive water are encroached (Rahman, 2010 and
Dewan, 2004). It is claimed that urbanization has marked effects on global
and local environmental conditions including climate change (Grimm, 2000,
cited in Dewan et. al. 2009). In case of Dhaka already flooding has become
a common environmental problem and its severity is increasing. In fact,
Dhaka is historically located on the flood plain with a large number ofcanals and rivers bounded and crossed away. Therefore, by virtue of its
topographical condition along with rapid urbanization Dhaka would be oneof the worst victims of climate related disasters, especially flood. In thesecircumstances, for the overall economic growth and development of thecountry it is needed to manage these problems efficiently and enhance
Dhaka’s climate disaster resilience.
Initiatives aim to enhance climate disaster resilience of a city require detailand careful assessment of its current level of vulnerabilities and resilience.
During such assessment and initiatives it is important to bear in mind that
there are large differences in risk and vulnerability within urban areas(Satterthwaite, Dodman and Bicknell, 2009). It is natural that a city,
especially a larger city like Dhaka, covers a large and often
physiographically heterogeneous area, with different exposure andsusceptibility to hazards. Furthermore, population of a city and the condition
under which they live are diverse. For instance, out of 10 administrative
zones of Dhaka, some are old settlement with densely populated, located in
the low-lying flood prone areas, some are newly developed areas. Similarly,
land uses of some zones are dominated by commercial uses and some areresidential. Therefore, some parts and people of a city may be more
vulnerable than others (Klein et. al., 2004). In fact, city forms different micro
climates within it due to the variation of land use, settlement pattern,functions, density, characteristics of residential areas and the communities
live their. All these diversities contribute to disaster risk and which in turnaffect human development and resilience of different parts of the city (ISDR).
Recognizing the diversity within a city and its impact onvulnerabilities and resilience, it is a foremost requirement to assess thestrength, weakness, opportunities and threats of micro zones of a city.
It is advised that for well governed urban center it is necessary to know
the location specific, place specific needs through strong local
information (Satterthwaite, Dodman and Bicknell, 2009). But there
New Technologies for Urban Safety of Mega Cities in Asia

are a number of studies and initiatives addressing different aspects of
Dhaka’s resilience and climate, disaster vulnerabilities considered thewhole city as a single unit; while, neglecting the issue of zone level
diversities and its implication to resilience. However, Hyogo
Framework for Action has emphasized to recognize the importanceand specificity of local risk pattern and trends (ISDR, 2007) before any
attempt of disaster risk reduction. In this context, this paper is anattempt to depict the micro level variations of climate-disaster
resilience of Dhaka through Climate Disaster Resilience Index (CDRI).

2. METHODOLOGICAL APPROACHES OF CLIMATE DISASTERRESILIENCE INDEXING
2.1 Questionnaire/Data Collection Sheet
The questionnaire used for data collection to assess the level of climate
disaster resilience is comprised of five different dimensions named Physical,
Social, Economic, Institutional and Natural. Under each dimension there are
five different parameters (e.g. under physical dimension, electricity, watersupply, accessibility to roads etc. are parameters) and each parameterconsists of five different variables (questions). Therefore, the questionnaire
is treated as 5x5x5 matrix. There are total 125 questions to assess climate
disaster resilience (CDR). Answer of each question is limited within the
choice of 1 to 5, which means 5 point rating scale has been used to assess theresilience level, where 1 means the worst situation and 5 means the best.
2.2 Approach of Data Collection and Analysis
Data has been collected from each of the micro level administrative andfunctional unit of Dhaka City Corporation. This unit is known as zone. For
data collection the researchers directly approach to the officials (generally
higher level, relevant officials) working at the zone level of City Corporation.
Through direct interview of relevant officials (sometimes individual official
and sometimes group of officials in a mini workshop) answer of 125
questions were collected and also the weight to the parameters and variables
were assigned. Data analysis and formulation of Climate Disaster ResilienceIndexing have been done using Excel software.

3. DHAKA CITY CORPORATION: BASIC FACTS
3.1 Location and History
Dhaka City is located at the center of Bangladesh. It is placed between 24040’ N
to 24054’N latitudes and 90020’ E to 90030’ E longitudes. In 1864, Dhaka wasestablished as Municipality. After the independence of Bangladesh in 1971, it was

Climate Disaster Resilience of Dhaka City Corporation- A Micro Level Analysis

0ctober 2010, Kobe, Japandeclared as the capital of Bangladesh. In 1978, Dhaka Municipality was awarded
as the status of Corporation and finally in 1990 Dhaka Municipal Corporation was
renamed as Dhaka City Corporation (DCC). At that time DCC was divided into
10 zones to decentralize its administrative and functional duties (DCC website,2010). During the period of a history of over 400 years Dhaka has experienced not
only a number of dramatic historical events but also continuously faced dynamicchanges in its physical, social, economic, institutional and natural environments.
3.2 Area, Population and Population Density
Different sources have different estimation regarding the area, populationand population density of Dhaka City Corporation (DCC). The website of
DCC shows that the area of DCC is 360 km2, which accommodate 8 million
people (estimated in 2004) with a density of 22222 persons per km2.
Bangladesh Bureau of Statistics (BBS, 2001) estimated the area of DCC as
276 km2 with a population of 5.3 million and the population density is 19,
286 per km2. It is said the population density of DCC is more than double ofthe mega city average.
4. DISASTER RISKS OF DHAKA
Dhaka, being the primate city of the country, has dominance in terms of
population share, economic contribution, trade and commerce, politics,
administration and even environmental degradation. Eventually, the city is
continuously facing different challenges and opportunities. In addition withnumerous environmental problems and challenges, recurrent natural
disasters, especially annual flooding is one of the most concerning issues of
Dhaka. The main cause of floods in Dhaka city is the rise in water levels of
the rivers bordering the city during monsoon season (Faisal, et. al, 2003).
Dhaka is surrounded by distributaries of two main rivers, the Brahmaputra
and Meghna. All sides of Dhaka city are bounded by rivers and cannels;
river Buriganga is on the south, Turag on the west, Tongi Khal (cannel) on
the north and the Balu and Shitalakhya rivers on the east (Hossain, 2008). In
addition with the rise of river water, internal drainage congestion and incoordinated operation of flow regulation structures make the flood situation
worse. Since rainfall intensity is increasing, the extreme event such as
floods, drainage congestion and water logging becoming a regularoccurrence in rainy season. The severity of such occurrence is increasing
year on year due to climatic change and change in human activities. Rapidand unplanned urban growth of Dhaka city causing serious encroachment of
natural drainage and retentions areas and eventually worsening the natural
flow of water and causing serious water logging and flooding almost every
year in recent decade. Infrastructures, utilities, livelihood, trade andcommerce and public health all sectors are badly affected and vulnerable torecurrent flooding and water logging of Dhaka (Alam and Rabbani, 2009).
Scholars claim that beside, floods/drainage congestion, Dhaka will beaffected through heat stress due to climate change. Dhaka may face‘heat island’ problem because the temperatures of the city are a few
New Technologies for Urban Safety of Mega Cities in Asiadegrees higher than the surrounding areas. Vehicle exhaust emission,industrial activities, increase of built up areas, loss of open spaces andincreasing use of air conditioning are contributing to heat generation of
Dhaka and this situation will continue in future (UNEP, 2005, Alamand Rabbani, 2009).
Since rapid pace of urbanization, compounded with ever-increasing
population burden significantly increase urban vulnerability to natural
disasters, Dhaka’s disaster risk is remarkably increasing. Therefore,
reduction of disaster risk and eventually building climate disaster resilienceof Dhaka is an urgent need for the development and prosperity of the wholecountry.

5 CLIMATE DISASTER RESILIENCE OF ZONES
After being familiar with Dhaka City Corporation (DCC) by knowing about
its location, area, population, environmental challenges and disaster risk (insection 2 and 3), now in this section the status of climate disaster resilienceof DCC would be presented. This section highlights the level of climate
disaster resilience of DCC from overall and from physical, social, economic,
institutional and natural perspectives. This section also identified thedifferent development sectors and issues (parameters/variables) that are
significantly correlated with each other. Furthermore, the development
sectors (parameters) and issues (variables) that have been prioritized toenhance climate disaster resilience of each zone have been listed here.
5.1 Overall Resilience
Climate disaster resilience scores of each of 10 zones have been presented as
Climate Disaster Resilience Index (Overall CDRI) in Fiureg.1. This Overall
CDRI is the average of the scores that each micro level area (zone) has
obtained in physical, social, economic, institutional and natural dimensions.
Climate Disaster Resilience Index (CDRI) from overall perspective reveals
that among the 10 zones CDRI scores range from 2.4 to 3.1. Since 5 is thehighest score, these scores of Overall CDRI denote the low/poor to medium
level of resilience. It is interesting to notice that the planned residential areas(Zone No. 6, 9 and 10) have relatively higher level scores in climate disaster
resilience index; while, old parts of the city (except Zone No.2) and densely
populated low income areas located in the fringe areas have low level ofresilience scores than other areas.

Climate Disaster Resilience of Dhaka City Corporation- A Micro Level Analysis

0ctober 2010, Kobe, Japan

Overall-CDRI of 10 Zones

Zone 1
5
Zone 10

Zone 2

4
3

Zone 9Zone 3

2
1

Zone 8Zone 4

Zone 7

Zone 5
Zone 6

Figure 1: Climate Disaster Resilience of 10 Zones from Overall Perspective(CDRI scores)
In the overall CDRI assessment only 3 zones (no. 2, 6 and 9) have obtained
the scores that are considered as good in Climate Disaster Resilience Index(CDRI). Though these three zones are part of Dhaka City Corporation andmany characteristics are similar to other zones there are few features that has
made these zones identical. For instance, zone 2 is the smallest zone is DCC(3 sq. km.) but accommodates the highest number of people per square
kilometer. The density of this area is 125423 per sq. km., which is extremely
high. In spite of having high density, being old part of city, zone 2 has
obtained relatively higher score in overall CDRI. In fact this zone is locatedin high land, free from flooding; it is place of old residents of the city andalso place of rich traditional business man of the city. As a result, relatively
higher scores in physical, social and economic dimensions have lifted thiszone to good position in overall CDRI. On the other hand, it is reallyinteresting to notice that Zone No. 6, which is the location of National
Parliament and residential areas of parliament members and Zone No. 9,
which is the diplomatic zone and location of all embassies have relatively
higher score in physical, economic, institutional and natural dimensions andeventually have obtained higher scores in overall CDRI.
5.2 Resilience in Five Different Dimensions
Dhaka:CDRI-Five Different Dimensions
5

CDRI Values

4

PhysicalSocial3

Economic
2

Institutional
Natural10Zone 1

Zone 2

Zone 3 Zone 4

Zone 5

Zone 6

Zone 7

Zone 8 Zone 9

Zone
10

Figure 2: Climate Disaster Resilience Levels of 10 Zones in Five Different
Dimensions
New Technologies for Urban Safety of Mega Cities in Asia

10

10

Physical CDRI

Overall

N

8

8



N


7

7

9

6

6

Poor

Poor

Medium

4

5

9

5

Good

3
2

10

2

7

Economic

N

N





8

7

9

6

Poor

9

6

Poor

Medium4
5

4

Medium

5

Good

3

Best

1

10

Social

8

Good

3

Best

1

Medium

4

3

Good

2

2
1

1

Best

10

Institutional

10

Best

Natural CDRI

N

N



8

7



8

7

9

6

9

6

Poor

4

Poor

4

5

5

Medium

3

Good

2
1

Medium

3

Good

2
1

Best

Best

Figure 3: Dhaka City’s Map Showing the Resilience Level of Different Zones in
Different Dimensions.
Note: Here CDRI scores 1-2=poor, 2.1-3 = medium, 3.1-4= good and 4.1-5 = best
resilience level

Climate Disaster Resilience of Dhaka City Corporation- A Micro Level Analysis

0ctober 2010, Kobe, Japan

Physical CDRIIn Dhaka, Zone No. 9, 10 and 5 which are planned residential for higher
income group have relatively better condition in almost all variables ofphysical dimension and achieved higher score in Physical-CDRI. Main part ofzone 6 is the planned residential area for middle and higher income people.
Besides this, national parliament and the residential area for parliament
members are located in zone 6. Therefore, physical conditions, likeaccessibility of roads, land use and housing and electricity and water supply
conditions are relatively better in zone 6 and thus it assessed as good inphysical resilience against climate disaster. In fact, following building codeand house with ownership, accessibility of roads is higher in all these planned
areas. For being diplomatic area, zone 9 does not face interruption inelectricity and water supply, which is most common in other areas. So, zone 9
got the highest score (4.03) in physical dimension. It should be noted that thisscore is the highest among all the CDRI scores in all dimensions. In the caseof zone 2 and 7 though these are not planned areas they have considered as
good in physical resilience (score 3.14 and 3.47 respectively). Rather
electricity and water supply, housing land use and accessibility of road havecontributed to this score. These areas, houses are not constructed by followingbuilding code but houses with ownership, houses above the flood level andfree from polluted ground are higher, which contributed to have relatively
higher scores in physical CDRI.
Interruption in electricity and water supply is severe in zones that have lowscore in physical CDRI, especially zone no. 4 and 8. Further, most of thebuildings are constructed without building code.
Social CDRI
Social CDRI scores ranges from 2.2 to 3.6, which denote medium to goodlevel of climate disaster resilience in social perspective. Out of 10 zones only
4 zones have been considered as good and rest 6 zones are medium. Zone No.
7 has got the lowest score and Zone No. 5 has the highest score. Contrastingwith physical dimension, the social CDRI scores are relatively higher in theZone No. 1, 2, 3, which are densely populated old parts of Dhaka. In the caseof Zone No.1, 2 and 3, among different factors, social capital like community
participation, acceptance of community leader and ethnic interlink are playing
role in availing higher score in social dimension of CDRI. Similarly
community’s support during emergency and relief works, supports from
NGO/CBOs and religious group are also better in these zones and it hascontributed to their social resilience. In fact, these are the old parts of city,where a large number of residents are living for a long time and they havestrong community feelings. Unlike Zone 1, 2 and 3, in case of Zone No. 5
social issues like health, education and awareness have contributed much to
be good in social CDRI. Besides these, compare to the other planned
residential areas zone no. 5 is relatively old area established in 1950s.
Therefore, this zone has higher level of community participation and ethnic
interlink.
New Technologies for Urban Safety of Mega Cities in Asia

Zone No. 4 and 7 are poor in the score of social CDRI. Here also social capital,
community preparedness and health status playing role for their low score.
Zone 4 is the principal central business district of Dhaka and Zone 7 is mixedof residential and commercial areas. Due to flood (in zone 4) and water
logging (in zone 7) about one fourth of the population of these two zones
suffers from water borne diseases, which is less in other areas.
Economic CDRI
CDRI scores in economic dimension implies medium to good level ofresilience against climate disaster. These scores varies from 2.1 to 3.4 andout of 10 zones only two have been found as good and rest 8 are medium ineconomic CDRI. In economic dimension also Zone No. 9 and 10 haveobtained the higher scores (3.11 and 3.41 respectively). It is said earlier thatthese are planned residential areas for higher income group. So from income,
employment and household assets perspectives these zones are in a good
position. This is very identical to inform that in both of these zones about
40% of the households have motorized vehicles, which is very low in otherzones. Furthermore, in these two zones slum population is very low, which isabout 10 %. In contrast, Zone No. 1 and 3, which got the lowest scores (2.1
and 2.4 respectively) are the most densely populated poor areas of Dhaka.
Most of the slums are located here and more than 40% of the population
lives below the poverty line. Here, income, employment and household
assets are the prime factors for their low scores in CDRI Economic.
Institutional CDRI
In the institutional perspective all zones are assessed as having medium levelof climate disaster resilience, except Zone No. 7. Institutional CDRI scores
ranges from 1.8 to 3, which reveal poor to medium level of resilience. Hereit should be noted that only zone 7 got institutional CDRI score less than 2,
which denotes poor resilience. In the institutional dimensions of CDRI, Zone
No. 6 and 9 present themselves as better position compare to rest other zones.
Though these zones are also in the group of medium level of resilience they
have obtained the scores 3 and 2.8 respectively. In contrast, Zone No. 7 and
10 assess themselves as in the lower position among the 10 zones. In fact,
the mainstreaming of disaster risk reduction and climate change and theoverall management of disaster are handled centrally by City Corporation. In
spite of this, in the aspect of effectiveness of zone’s crisis management
framework, knowledge dissemination, institutional collaboration and good
governance some zones evaluate them as medium to good position and somezones (like 7 and 10) as poor. This assessment has ultimately determined the
CDRI score in institutional dimension.
Natural CDRI
Among the all five dimensions of CDRI assessment, natural dimension has
the lowest scores in case of all zones. Natural CDRI scores vary from 1.8 toClimate Disaster Resilience of Dhaka City Corporation- A Micro Level Analysis

0ctober 2010, Kobe, Japan

2.8 that mean poor to medium level of resilience. These scores show that
Zone 1 and 3 are in the poor condition and rest 8 zones are in medium levelof resilience. Zone 1 and 3 are the place of poor communities of the city.
More than 50 % areas of these two zones are very vulnerable to climate
related hazards. Both of these zones face severe flood and water logging
almost every year. Apart from this, the air, soil and water quality is
considered as poor in these zones. Zone No. 3 is the place of tannery
industries and zone 1 is a place of city bus terminal, water terminal anddifferent types of small industries. Therefore, overall environmental
condition is poor in these zones. Moreover, high density, poor housing
condition and very low level of green spaces have made these zones poor innatural dimension of CDRI. Here it should be noted that though other zones
are treated as medium in the natural CDRI during rainy seasons water
logging condition is severe in some zones, especially Zone No 4 and someparts of 9. Ecosystem and environmental condition are also not so sound in
all over Dhaka city.

6. CONCLUSION
Climate Disaster Resilience Index (CDRI) analysis of Dhaka City
Corporation (DCC) measures the capacity of city’s infrastructure andservices to withstand against disasters and evaluates how the communities
and institutions within a city are expected to deal with such an event. By
examining the problems, potentialities, strengths and weakness of 10
different zones of City Corporation this study assesses the ability of eachzone to absorb, maintain and recover (bounce back) from a hazardous
situation.
Assessment results reveal that climate disaster resilience score of different
zones ranges from 2.4 to 3.1 out of 5, which imply poor to medium level ofresilience. It has been noticed that the planned residential areas, which is theplace of medium to higher income groups and relatively new part of the city(zone 9, 10 and 6) have the higher scores in overall climate disaster
resilience. These zones also have higher scores in physical and economic
dimensions of climate disaster resilience, while climate disaster resilience insocial perspective is comparatively lower than the old part of the city. Zone
1, 4 and 7 have obtained overall CDRI scores ranges from 2.4 to 2.5, which
are the lowest. Zone 1 and 4 are the two most densely populated areas of
Dhaka and place of a large number of slums and squatters. These two zones
are also highly vulnerable to flooding and water logging. In contrast, though
the population density of zone 7 is lower than zone 1 and 4, it is also
vulnerable to water logging. The institutional dimension of this zone isscores the lowest. Coupled with this lowest level of institutional resilience,
low scores in social, economic, natural dimensions of climate disaster
resilience contributed zone 7 to be the least one in CDRI assessment.
This CDRI assessment shows that different zones have different level ofclimate disaster resilience. Since zones differ from locational and functional
New Technologies for Urban Safety of Mega Cities in Asia

characteristics, their problems, vulnerabilities and potentialities are different.
Eventually, the resilience level differs from zone to zone. Therefore,
different zones need to have zone specific development plan, programs anddifferent sectoral priorities to enhance their climate disaster resilience. But
the regretting fact is zone has neither any power nor the ability to prepare
development plan addressing their local problems and needs. However, in1990 Dhaka City Corporation was divided into 10 zones with a view todecentralize the administration. Every zone has an office for administrationand there are about 10 sub departments to operate and manage
administration and development activities within the zone. But there is nocell or department to handle or manage disaster risk. Any sort ofdevelopment plan and program formulation is solely done by the central
authority of City Corporation. Even though, at the central level too there isno specific plan for disaster management. Since the Standing Order ofDisaster (Govt. order) has the provision of constitution of Disaster
Management Committee at City Corporation level, DCC has formed thiscommittee and these committee has some prescribed duties to perform
before, during and after any disaster.
It is claimed that from the perspective of climate change fast growing cities
pose difficult challenges for local Government (Roy, 2009). Therefore,
recently Government of Bangladesh has published the National Plan for
Disaster Management 2008-2015 and this plan recommend for the
preparation of City Corporation Disaster Management Plan for each city. So
it is expected that in near future DCC will prepare its disaster management
plan. This Disaster Management Plan of Dhaka City Corporation shouldincorporate zone specific disaster management plans, where this CDRI
analysis would be an important guideline. It is expected that CDRI
outcomes would facilitate to formulate location specific, need and problem
specific future policy, hazard mapping, disaster management plan andbudget allocation and finally overall development plan implementation. Thus
climate disaster resilience of each zone would be enhanced, which would
lead to have a resilient city in future.

REFERENCES
Alam, Mozaharul and Rabbani, Golam, MD., 2009. Vulnerabilities andResponses to Climate Change for Dhaka. in Satterthwaite, David, Dodman,David and Bicknell, Jane (editors), Adapting Cities to Climate ChangeUnderstanding and Addressing the Development Challenges, Earthescan,
London. 93-110.
BBS, 2001. Statistical Year Book of Bangladesh, Bangladesh Bureau of
Statistics, Ministry of Planning, Government of Bangladesh.
Dewan, Ashraf, M. and Yamaguchi, Yasushi, 2009. Land use and land coverchange in Greater Dhaka, Bangladesh: Using remote sensing to promotesustainable urbanization. Applied Geography, Vol. 29, Elsevier Ltd. 390-401.
Dewan, A.M., Nishigaki, Makoto and Komatsu, Mitsuru, 2004. DEM based
Flood Extent Delineation in Dhaka City, Bangladesh, Journal of the Faculty

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0ctober 2010, Kobe, Japanof Environmental Science and Technology, Vol. 19, No.1. Okayama,
University, Japan. 99-110.
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Faisal, I.M., Kabir, M.R. and Nishat, A., 2003. The Disastrous Flood of1998 and Long Term Mitigation Strategies for Dhaka City. Natural Hazards,
Vol. 28, Kluwer Academic Publishers, Netherlands. 85-99.
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Hossain, Shhadat, 2006. Rapid Mass Urbanization and Its Social
Consequences in Bangladesh: The Case of The Megacity of Dhaka. Paper
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ISDR, 2007. Hyogo Framework for Action 2005-2015: Building theResilience of Nations and Communities to Disasters, International Strategy
for Disaster Reduction, United Nations, Geneva.
Klein, Richard J.T., Nicholls, Robert, J. and Thomalla, Frank, 2004.
Resilience to Natural Hazards: How useful is this concept? Environmental
Hazards, Elsevier Ltd. 35-45.
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Disaster Management Bureau, Ministry of Food and Disaster Management,
Government of the People’s Republic of Bangladesh.
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Management News, Vol. 16, No. 1, Asian Disaster Preparedness Center.6-7.
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Change-Understanding and Addressing the Development Challenges,
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Climate Vulnerability Ranking of Major Coastal Cities in Asia, WWF
International, Switzerland.

New Technologies for Urban Safety of Mega Cities in Asia

CLIMATE AND DISASTER RESILIENCE OF
DELHI, INDIA
Sunil Kumar PRASHAR
1st Year PhD Student, Graduate School of Global Environmental Studies, Kyoto
University, Yoshida Honmachi, Sakyo-Ku, Kyoto 6068501, Japan
sunilparashar111@gmail.com
Rajib SHAW
Associate Professor, Graduate School of Global Environmental Studies, Kyoto
University, Yoshida Honmachi, Sakyo-Ku, Kyoto 6068501, Japan
Yukiko TAKEUCHI
Assistant Professor, Graduate School of Global Environmental Studies, Kyoto
University, Yoshida Honmachi, Sakyo-Ku, Kyoto 6068501, Japan
ABSTRACTThe study addresses disaster risk of Delhi through resilience approach. The
Climate Disaster Resilience Index (CDRI) tool is used to assess resilience level ofthe city against climate related hazards. The city resilience level is assessed
through various dimensions: physical, social, economic, institutional, and natural.
The study is community based and was conducted in all nine revenue districts ofDelhi. They are: Central Delhi, North Delhi, South Delhi, East Delhi, North East
Delhi, South West Delhi, New Delhi, North West Delhi, and West Delhi. The data
was collected from district disaster management cells across all nine districts ofDelhi. The result shows that New Delhi is the most resilient district due to its
physical, social and economic factors, whereas East Delhi is the least resilient
district due to physical and natural factors. The limitation of the study is exclusionof geological and biological hazards. Moreover, the questionnaire contains somesubjective assessment. The study only considers climate related hazards to assess
resilience score. However, the approach is distinct in itself by showing thestrength and weakness of districts by assessing their resilience level against
climate related disasters.
Key words: climate related hazards, disaster risk, resilience, assessment, anddistricts
1. INTRODUCTION
India is one among the most vulnerable country to natural hazards like floods,
droughts, cyclones and earthquakes. According to National Disaster Management
Authority of India, 40 million hectares of land is prone to flooding, 18.6 million ofland flooded annually, 18% percent of total area is prone to drought, 60% of sown
area is drought prone, and approximately 50 million people are annually affectedby drought (NDMA, 2009).

0ctober 2010, Kobe, Japan

Since 1981, more than 300 disasters have occurred in India (EM-DAT, 2010).
Most of them are hydrometeorological in nature like storms, floods, mass
movement (wet), extreme temperature, droughts, and wild fire. Followed bygeophysical disasters like earthquake, volcano, mass movement (dry), and finally,
Biological disasters such as epidemics, insects, infection and stampede. The
number of people killed due to hydro meteorological disaster is also higher thangeophysical and biological disasters. The total number of persons killed is115,342. Out of this 12% percent were killed due to biological disasters, 43%from geophysical and remaining 49% killed from hydrometeorological disasters.
However, over 98% of people are affected by hydrometeorological disasters and
2% affected by geophysical disasters (EM-DAT, 2010). This shows that the
impact of hydrometeorological disaster caused heavy damage to people and theirproperty in the recent past.
The urban centers in India are often characterized with “rapid population growth,high densities, poverty, and high differentials in access to housing, public services
and infrastructure” (Revi, 2008). These characteristics are the main factors that
increase the vulnerability to natural and man made hazards in cities. Moreover, theimpact of disasters in city is unevenly distributed. For example, people from upperand middle income groups cope well with disasters and recover faster due tostable employment, insurance, credit and assets. On the other hand, people from
low income group or poor in the same city are severely affected due to fewer
assets, lack of insurance, few diversity income and sources (Vatsa, 2004). The
main reason for this uneven distribution of impact of disasters is rapid pace ofurbanization, which often leads to increase in the population of the city due toheavy influx of migrants. The urban poor are considered as migrants, who come tocity due to push factors like unemployment, low standard of living and also due topush factors like better economic opportunities and education (Niebergall et al.,2006). Most cities mainly grow in hazard prone areas like in the river bed or nearcoast areas. This makes poor settlements at risk. They are at risk not due theirlocation near hazard prone areas, but also due to their socio-economic conditions
like poor housing, poor education, low standard of living, and mainly engaged in
informal sectors (Sherbinin et al., 2007). They are the most vulnerable whendisaster strikes (Benson and Clay, 2003). They are the mostly frequently killed,injured or lose their house after any disaster (Albala-Bertrand, 2003). It is also
believed that the impact of climate change will further shrink their coping capacity
to withstand against the climate related disasters.
The study aims at addressing disaster risk of Delhi through resilience approach. It
is community based approach and data is collected from District Project Officers(DPOs) and Project Coordinators (PCs) across all nine districts of Delhi. The city
is highly populated and vulnerable to climate related hazards like, heat waves,cold waves, floods, and drought (water scarcity).
The first section describes the challenges of disaster risk in Delhi. The second
section focuses on how disaster risk is addressed in Delhi and why Climate
Disaster Resilience Index (CDRI) approach is effective for dealing with disasterrisk. The third section describes analysis of the study, which was conducted in
Delhi using CDRI approach. Finally, the last section describes the significance ofthe outcome.

New Technologies for Urban Safety of Mega Cities in Asia

2. DISASTER RISK IN DELHI – CHALLENGES
After independence the city has grown up in a haphazard way. It is among thecities with million plus population. The rapid pace of urbanization leads tomassive growth of slums followed by misery, poverty, unemployment,
exploitation, inequalities, degradation in quality of life. The city is vulnerable tonatural and man made disasters: Flood, Earthquake, fire, epidemic diseases andterrorist attack. This section discusses the overall challenges, which increases
disaster risk in Delhi.
2.1 Rapid urbanization
The city is experiencing rapid urbanization. According to 2001 Census, 93 percent
of Delhi’s population lives in urban areas (Ministry of Health and Family Welfare,2007). The population increased from 0.7 million in 1947 to 13.7 million in 2001.
It is expected to double by 2026 (Ministry of Health and Family Welfare, 2007).
Migration is considered as one of the main reason for urban population growth.
The city experienced large scale migration from north eastern states of India. As
per census 2001, 0.2 million migrants move into Delhi every year. The reason forhigh migration is the pull and push factors. These factors force them otherwise
attract them to come to the city for employment. The rapid increase in the
expansion of industry created huge employment opportunities. In 1951, there were8160 small scale industries, which increased to 129000 in 2001 (Government ofDelhi, 2006). The rapid migration created huge pressure on basic amenities, which
led to inequality in living standard. For example, housing shortage; inadequate
water and sanitation services; poor solid waste management; pressure on public
transportation; power failure; air, water, and noise pollution. The next section
discusses the environment degradation.
2.2 Environment degradation
The environment condition in Delhi is very poor. The last three decades led tochange in the land use pattern. There is increase in the built up area. In 1990-91,
the built up area was 742 sq. km, which was 50% of geographic area of Delhi. It
increased to 897 sq. km (60.5%) in 2000-2001 (Government of Delhi, 2006). Thiswas due to the huge expansion of industries, which attracted large migrants to city
for jobs. High rate of urbanization and migration in the past has deteriorated theenvironment condition of the city. Environment was degraded due to change inthe land use, explicit use of ground water, discharge of waste affluent in the river,high density, water pollution, air pollution and noise pollution. The condition ofwater and sanitation is very poor. In 2001, 25% of households had no access to
piped water supply and faced shortage of 200 Million Gallon Daily. Yamuna riveris considered as one of the most polluted river in the world (Rahman et al., 2007).
Similarly, air pollution and noise pollution have contributed to environment
degradation.

Climate and Disaster Resilience of Delhi, India

0ctober 2010, Kobe, Japan

2.3 Climate related hazards
The city is vulnerable to climate related hazards like floods, heat waves, and water
scarcity. In the recent past, Delhi has experienced flooding. Floods are mainly
caused due to river and local flooding. Since 1900, floods took place in 1924,
1947, 1976, 1978, 1988 and 1995. High magnitude floods occurred in 1977, 1978,
1988 and 1995 (DDMA, 2009). These floods have caused heavy damage to lifeand property. In 1977 flood, crop damage was close to one million rupees.
Similarly in 1988 flood, 8,000 families were affected (DDMA, 2009).
2.5 Increase in the slums, and squatter’s population
As per 2001 census, the slum population of the city was 15.7 percent of total
population, which was 1.85 million (Government of Delhi, 2006). It increased to 3
million in 2004. The number of housing units are 0.6 million, which accommodate
3 million population. That means more than three persons living in one room.
Apart from this, there are 50,000 to 70,000 persons, who are homeless(Government of Delhi, 2006). The living condition in slum areas is very poor due
to absence of basic services such as street light, sanitation, water and road network.
These situations often threaten health. Approximately 25 percent of slum
settlements have access to drainage system and only 30 percent have toilets andbath facilities. The problem of inadequate access to water supply is very common
in slum areas. These type of population remain in high risk not due to their poorsocio – economic condition but also due their settlement in vulnerable locations
like near sea coast, low lying area etc. The next section discusses the approach foraddressing disaster risk.
3. ADDRESSING DISASTER RISK IN DELHI

3.1 Existing approach
The existing approach to for addressing disaster risk is based on hazards andvulnerability analysis (DDMP, 2009). The disaster risk of each districts is
calculated using formula (i.e. Risk = Hazard * Vulnerability). This approach is far
better than approaches, which were centered only on the hazard aspects. Here, thevulnerability aspect considers physical, social, and economic conditions, which
are important in risk creation. The current approach analyzes vulnerability fromthe weakness or limitation of the system or group, which is essential but incapable
to show the ability or capability. According to Westgate and O’ Keefe 1976,
vulnerability can not measured without referring to the capacity of the population
to absorb, respond and recover from the impact of the event. In other word, theexisting approach does not recognize the positive aspect of population in
calculating the risk.
3.2 Current adopted approach for this study
The study uses approach that addresses risk from the resilience concept.
Resilience is capacity of population to absorb, respond, and recover from the
New Technologies for Urban Safety of Mega Cities in Asia

impact of events or disasters (Westgate and O’ Keefe, 1976). The concept ofresilience is applied to urban area. The concept of resilience was first evolved in
ecology and used by Holling in 1973. Thereafter, the concept received hugeattention and used in the many fields, including hazards and disasters.
Timmerman was probably the first, who use “the concept of resilience to in
relation to hazard and disaster” (Klein, 2003).
Climate Disaster Resilience Index (CDRI) tool is used to assess the resiliencelevel of Delhi’s districts against climate related natural hazards. The tool consistsof five dimensions, namely physical, social, economic, institutional and natural.
Each dimension contains five parameters. For instance, Physical dimension
consist of five parameters, such as electricity; water; sanitation and solid waste
disposal; accessibility of roads; and housing and land use. Each of theseparameters consists of five questions/variables. Therefore all in all, there are 125
questions and resilience level of district is assessed based on 125 questions. Thisapproach is holistic in nature and by no mean is an exhaustive assessment. In
addition, after end of parameters and dimensions, the respondent is asked to rankor assign weight to each parameter and dimension in order to reflect the priority ofthe districts. The collected data is analyzed using Weighted Mean Index (WMI)and Aggregate Weighted Mean Index (AWMI) to compute the resilience score foreach parameter and dimension respectively. The resilience score varies from one
to five. One shows very poor resilience score and five shows very high resilience
score. High resilience score reflects higher preparedness to cope with climate
related disasters and vice versa. Finally, the total score will show the strength andweakness of the districts.
3.3 Disaster Resilience of Delhi - About the study and outcome
The study was conducted in nine revenue districts of Delhi. They are: Central
Delhi, North Delhi, South Delhi, East Delhi, North East Delhi, South West Delhi,
New Delhi, North West Delhi, and West Delhi. The data collection was doneusing Climate Disaster Resilience Index (CDRI) questionnaire. The data wascollected from district disaster management cell across all nine districts of Delhi.
The respondents were District Project Officer (DPO)s and Project Coordinator(PC)s who look after the disaster management activities in their districts. The
study assesses resilience level of each district on the basis of five importantdimensions: physical, social, economic, institutional, and natural. The following
section discusses the outcome of the study for each dimension.
3.3.1 Physical resilience of nine districts of Delhi
The physical resilience of nine districts is assessed on the basis of five variables
including electricity; water; sanitation and solid waste disposal; and housing andland use. The physical resilience shows that New Delhi district is most resilient
district among all nine districts, where as East Delhi district is the least resilience
district (Fig 1). The main reasons for very low resilience is due to poor sanitationand solid waste disposal, then low level of housing and land use, and water.
Approximately, 463 tons of solid waste is produced every day and out of which
299.36 is disposed properly (Rahman et. al, 2007). District high population is alsoa major factor for huge solid waste generation. The district is also characterized by

Climate and Disaster Resilience of Delhi, India

0ctober 2010, Kobe, Japanpoor housing and land use. Most of the houses are without ownership. Almost 80
percent of district area suffers from interruption in water supply.
On the other hand, Electricity, water and accessibility of road are the threeimportant factors that makes New Delhi most resilient district. The district has
separate municipal body, which mange civic services. The interruption in thewater and electricity is very less in comparison to other districts. The district roads
are broad and accessible during normal flooding. All roads have roadside covereddrain. Entire district has pave roads. The district is characterized with parliamenthouse, Supreme Court, central government ministries, Delhi high court, and union
service public commission.
3.3.2 Social resilience of all nine districts
The social resilience of nine districts is assessed from five variables including
population; health; education and awareness; and social capital. Over all, theresilience level of all nine districts is between medium to good. However, New
Delhi is the most resilient districts among all nine districts (Fig. 1). The
population density of this district is lowest among all districts, which is 5117 per.
Sq. km in 2001 (Planning Department, 2009). Similarly, the total population is
also lower than other districts, which 171806 in 2001 (Planning Department,2009). Moreover, there are other factors that are reason for high resilience
including health, community preparedness, social capital, and education andawareness. Therefore, people suffer less from water and vector born diseases
every year. On the other hand, North east district is the least resilient district
among all districts (Fig. 1). The population density is highest among all nine
districts, which is 29, 468 persons per sq. km. in 2001 (Planning Department,2009). More over, the population growth rate annually is also highest among all
districts, which is more than 6% in 2001. (Planning Department, 2009). The highdensity also reflects on health aspect. Certainly, due to high density of population,
the health aspect is between poor to medium. Population, health, and social capitalare three most prominent factors responsible for low resilience of North East
district.
3.3.3 Economic resilience of all nine districts
The economic resilience of nine districts is evaluated from five variable factors
namely income; employment; household assets; finance and savings; and budget
and subsidies. The most resilient district is New Delhi (Fig. 1). The main factors
responsible for high resilience level are: income, employment and household
assets. The district is a mix of commercial activities as well as institutional areas
where government offices are situated. Most of them living in this district are
engaged in formal jobs. Due to better income, people are well equipped withhousehold assets. The residences in this district are better off in finance and saving.
Central Delhi is the least resilient district among all nine districts (Fig. 1). The
main factors responsible for low resilience are: income, employment, and financeand saving. Most of the working population in this district is engaged inhousehold industries. The working population is 35% of the total population(DDMPa, 2009). The dependency ratio is 1.88. There are certain areas in this
district, where dependency ratio is 2 (DDMPa 2009). Many household have only
one earner. According to 2001 census, up to 70 percentage of population ofcentral Delhi lives in slums area (Ministry of Health and Family Welfare, 2007).
New Technologies for Urban Safety of Mega Cities in Asia

The resilience scores for budget and subsidy is same in all nine districts. Equal
budget is distributed among all districts for disaster risk reduction related
activities.
PhysicalNaturalCentral Delhi
5
West Delhi
North Delhi
4
3
2
North West Delhi
South Delhi
1
New Delhi

Central Delhi
5
West Delhi
North Delhi
4
3
2
North West Delhi
South Delhi
1
New Delhi

East Delhi

South West Delhi

North East Delhi

East Delhi

South West Delhi

New Delhi

North East Delhi

West Delhi
North West Delhi

Central Delhi
5
North Delhi
432South Delhi
1

New Delhi

Central Delhi
West Delhi
North West Delhi
New DelhiSouth West Delhi

5
4
3
2
1

South West Delhi

East Delhi

South West Delhi

Overall

Institutional

SocialCentral Delhi
5
West Delhi
North Delhi
4
3
2
North West Delhi
South Delhi
1

North East Delhi

Economic

East Delhi
North East Delhi

North Delhi
South Delhi
East Delhi
North East Delhi

West Delhi
North West Delhi

Central Delhi
5
North Delhi
432South Delhi
1

New DelhiSouth West Delhi

East Delhi
North East Delhi

Figure 1: CDRI graph of all nine districts of Delhi
3.3.4 Institutional resilience of all nine districts of Delhi
The institutional resilience is measured by five variables including mainstreamingof disaster risk reduction and climate change adaptation; effectiveness of crisis
management framework; knowledge dissemination and management; institutional
collaboration with other organizations and stakeholders; and good governance.
The institutional setup is common for the nine districts. All districts follow
common guidelines laid down by the National Disaster management Authority(NDMA) and Delhi Disaster Management Authority (DDMA). The resiliencelevel of all districts is between medium to good (Fig. 1). However, themainstreaming of disaster risk reduction and climate change adaptation is not
visible in all nine districts. All districts use some common platform and tools fordisseminating information about disaster preparedness. For example, books,
leaflets, manpower and campaign etc. All districts have same collaboration withstate organization, Municipal bodies, and with other districts. The district bodies
are dependent on each other as well as on urban local bodies at state level. The
early warning system clearly disseminates all information related to disaster to allnine districts.
3.3.5 Natural resilience of all nine districts
The natural dimension is evaluated from five variables: intensity and severity ofclimate related hazards; frequency; eco system services; land use in natural terms;
and environmental policy. New Delhi is the most resilient district in natural terms(Fig. 1). There are three most prominent factors that are responsible for highresilience: intensity and severity of climate related hazards, frequency, and land
use in natural terms. The district is not vulnerable to flood. Moreover, it is lessvulnerable to heat waves and water scarcity. The frequency of heat waves andwater scarcity is once in a year. The land use in natural term is good. The district
land has no settlements located on hazardous ground. The district has well

Climate and Disaster Resilience of Delhi, India

0ctober 2010, Kobe, Japan

maintained gardens, trees etc. The least resilient district is east Delhi (Fig. 1). The
main factors contributing towards low resilience are: intensity and severity ofclimate related hazards, eco system services, and land use in natural terms. The
district is highly vulnerable to flooding due to its location near Yamuna River.
The land use pattern shows that the district area is mostly occupied with densly
populated area. There is no green space left. The air and water quality in the lakes
and river is very poor due to poor solid waste management.
3.3.6 Overall resilience of all nine districts
The overall resilience of nine districts is assessed through overall resilience scoreof each district. New Delhi is the most resilient districts among all nine districts(Fig. 1). The factors responsible for high resilience score is physical, social andeconomic factors. The physical resilience is high mainly due to better electricity,water and sanitation services. The district has its own Municipal body thatmanages civic services in the district. The main factors responsible for high social
resilience are population, health and social capital. The district population is least
among all nine districts and density is below 5000 person per. Sq. km. The healthcondition is better due to hygienic environment condition and better healthfacilities. The residential area in this district include large bungalow, foreign
mission/ state guest houses, government colonies and private colonies.
East district is the least resilient among all nine districts (Fig. 1). The mostprominent factors responsible for low resilience are: physical and natural factors.
The district has low physical resilience mainly due to poor solid waste
management, then housing and land use, and water. Due to high population
density, the district produces large amount of solid waste, which is not often
properly disposed regularly. The housing condition is very poor mainly because alarge number of population lives in the proximity to polluted industries anddumping ground. The condition of water is also very poor. More than 60% of the
district is affected by the interruption in water supply. The other reason for low
resilience is natural factor. Due to proximity to Yamuna River, the district isvulnerable to flooding. More, than 90% of district area is densely populated. The
land use in natural term is very poor. There is no green space due to built area,
which is more than 90% of total district area.
4. CONCLUSION AND WAY FORWARD
The study is a significant approach in assessing disaster risk at micro level. The
outcome clearly shows the strength and weakness of districts. It further throws
light on the factors that are responsible for low and high resilience. For example,
the important factors for low resilience for east district are: physical and natural
factors. Similarly, New Delhi is the most resilient district manly due to economic,
physical and social factors. Based on the above outcome, the policy points can berecommended to encourage government officials to enhance the capacity of their
specific institutions, which are less resilient. The policy points aim at disaster risk
reduction and received high attention at the Hyogo convention in 2005. The policy
points are Hyogo Frame work for Action (HFA) task. HFA tasks include: making
disaster risk reduction a priority, improving risk information and early warning,building a culture of safety and resilience, reducing the risks in key sectors, and
New Technologies for Urban Safety of Mega Cities in Asia

strengthening preparedness for response. The above mentioned policy points
encompass all important area to strengthen the resilience level.
4.1 Significance of the outcome
The outcome of the study helps policy or government officials as well as otherstakeholders in understanding the strength and weakness of their districts. The
approach is community based. So it facilitates stakeholders in assessing andenhancing the resilience of the community. It helps in reviewing their work
progress. The following section discusses on outcome significance.
4.1.1 District Project Officer (DPOs) and national stakeholders
The district project officer can very well use result of this study. They study cancontribute in making disaster management plans document for their district. The
district plan highlights disaster risk and vulnerability of their respective area.
Therefore, the study can be well incorporated into the district disastermanagement plan. The study also highlights key sectors or area, which requires
more attention from the officials. It can also help in monitoring the effectivenessof the activities by district project officers, which are related to disaster risk
reduction. For example, activities those are related to disaster preparedness,
mitigation and prevention.
The outcome of the study is also useful for the local organization as well as
national level organization who work in the community. For example, thedevelopment planner at national or local level can use the outcome of this study
while making the development plans. The outcome is also useful for the Non
government organization, in understanding the resilience level of the community,
where they work.
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Sherbinin, A., Schiller, A., Pulsipher, A., 2007. The vulnerability of global cities
to climate hazards. Environment and Urbanization Vol. 19, No.1, April 2007
Vatsa, K.S., 2004. Risk, vulnerability, and asset-based approach to disaster risk
management. International Journal of Sociology and Social Policy Volume 24
Number 10/11 2004
Wisner, B., Blaikie, P., Cannon, T., and Davis, I., 2003. At risk - natural hazards,
people's vulnerability and disasters. Routledge press

New Technologies for Urban Safety of Mega Cities in Asia

Status of natural hazards in the Asia-Pacificregion and impacts of climate change
Manzul K. HAZARIKA1, Sahdey SINGH2,
Md. Shahab UDDIN3, Lal SAMARAKOON1
1
Geoinformatics Center, Asian Institute of Technology, Thailand
manzul@ait.ac.th
2
Alternatives International, Thailand
3
DPMM field of study, Asian Institute of Technology, Thailand
ABSTRACTThe Asia-Pacific region is prone to a wide variety of disasters caused by natural
hazards. According to the EM-DAT database, between 1975–2006, while theregion experienced 37% of number of world's disasters and 44% of economic
losses, it suffered more than 57% of total number of global mortality and 88% of
the affected populations. Unfortunately, this trend has continued in subsequent
years and in 2008 alone, out of the 10 worst disasters in terms of total humanlosses nine occurred in the Asia-Pacific region and consequently 98% of people
killed by disasters worldwide were from Asia. The same year witnessed two
disasters of historical dimension, Cyclone Nargis in Myanmar and the Wenchuan
earthquake in China, both in Asia, causing large-scale death and destruction.
Asia-Pacific region is particularly prone to climate-sensitive hydrometeorological disasters such as floods (35%), windstorms (28%) and waterinduced landslides (8%). The global distribution shows that Asia-Pacific region is
accounted for more than 45% of the world’s water-related disaster fatalities
during the period from 1980 to 2009, and 90% of all water-related casualties.
Based on the limited available data of last three decades, it is statistically difficult
to quantify and isolate the exact impact of climate change on frequency ofoccurrence and magnitude of disaster events, considering the time dimension andrandomness involved in both the climate and disaster processes. However, while
comparing earthquakes and climate sensitive hydro-meteorological disasters in
the region for the time period 1980-2009 using EM-DAT, it was found that theincrease in the number of climate sensitive disasters is much higher than thenumber of earthquakes. While IPCC and UNEP present the global climate change
scenarios and their implications, though scattered, there is an emerging body ofevidence from the Asia-Pacific region that highlights the possible linkages
between climate change and its impacts on natural hazards of the region.
Keywords: natural hazard, disaster, EM-DAT

1. INTRODUCTION
Natural hazards have always been part of human existence and will remain so infuture, but by themselves they do not cause disasters until combined with anOctober 2010, Kobe, Japan

exposed, vulnerable and ill prepared population or community. Based on available
data and information for the past 30 years (1980-2009), this presents the status ofdisasters and natural hazards causing them in the Asia-Pacific region. Issues
related to generally improved disaster reporting mechanisms as well as neglected
and unreported disasters were also examined to identify the need for review andimprovement of the existing data sources and information sharing platforms atregional level. Low-intensity but high-frequency hazards have a significant
overall impact on human life, livelihoods and economic assets in many
developing countries of the region, but usually they are not adequately prioritizedin national DRR programs as compared with the more visible or widely reported
major disasters that attract international attention.
The paper is intended to serve as a rational basis for adopting a morecomprehensive approach to various socio-economic and technical aspects ofdisaster risk reduction in the face of (i) gradually mounting evidence of climatechange impacts on natural hazards, (ii) increasing human population, economic
assets and infrastructure in disaster prone areas, and (iii) uneven economic
development within countries (rural vs. urban) and across the region (low,medium and high income countries). Some mega-disasters overwhelm smaller
countries both in terms of physical damage and economic losses, and therefore,such countries can benefit significantly from a regional platform for DRR throughbetter sharing of data, information, and knowledge.
1.1 Regional overview of disasters, deaths, and damages
Cumulatively, the number of disaster events recorded around the world between
1900 and 2009 was over 17,000 affecting over 6 billion people, with more than 38
million fatalities. While in the year 1900 only 6 disaster events were recorded
globally (ICHARM, 2009), the number of the recorded disasters in 2009 increased
to 328 (EM-DAT). While 2009 appears a relatively quiet year, the number may
increase further based on most recent trends as the annual average for 2000-2009
is 392. Over the period 1991-2005, disaster related economic losses were over
US$ 1 trillion. The estimated financial loss due to disasters caused by natural
hazards in the 1970’s decade was US$75.5 billion, whereas the estimated loss
during the period from 2000 to 2009 was staggeringly above US$750 billion, aten-fold increase. Even if, inflation, purchasing power parity and other timesensitive financial parameters are considered, almost a 1000% increase in justtwo decades does underscore the rising magnitude of disaster related damage.
While sharp rise in disaster events can be attributed to several factors, including
better reporting mechanisms and possibly climate change effect on existing
natural hazards, the corresponding increase in impact is most probably due toincreasing human population and associated high-value economic assets andinfrastructure as well as their increasing exposure to natural hazards.
The Asia-Pacific region is prone to a wide variety of disasters caused by natural
hazards. According to the EM-DAT database, between 1975–2006, while theregion experienced 37% of number of world's disasters and 44% of economic
losses, it suffered more than 57% of total number of global mortality and 88% of
the affected populations. Unfortunately, this trend has continued in subsequent
New Technologies for Urban Safety of Mega Cities in Asia

years. In 2007, 37% of disasters caused by natural hazards recorded by the EMDAT database (EM-DAT, 2010) occurred in Asia alone accounting for 90% of all
the reported victims and 46% of economic damage. In 2008, out of the 10 worst
disasters in terms of total human losses nine occurred in the Asia-Pacific region
and consequently 98% of people killed by disasters worldwide were from Asia.
The same year witnessed two disasters of historical dimension, Cyclone Nargis in
Myanmar and the Wenchuan earthquake in China, both in Asia, causing largescale death and destruction (see Box 1). No mega-disasters occurred in 2009, theevent ranking highest in death toll was the earthquake in Indonesia which killedover 1,100 people, followed by a series of typhoons and floods that caused many
deaths, making Asia once again the most affected continent (CRED, 2010). In fact,
six of the top ten countries with the highest number of disaster-related deaths werein Asia. The long-term disaster trends cannot be based on a single year data,considering the disastrous losses caused by the earthquakes in Haiti and China in
the early 2010.
Longer-term data on disaster occurrence and impacts in the Asia-Pacific region
demonstrate continuous upward trend in the moving annual average of primarydisaster statistics over the last three decades (Figure 1.1.1), and it seems there is asignificant jump following mega-disasters (see red line in the graph) that haveoccurred in recent years (Box 1). The long term averages indicate that the AsiaPacific region accounts for 42% of the world's disasters caused by natural hazards
and 65% of their victims and therefore, unsurprisingly, the region occupies the top
spot in the list of world's regions for most of the disaster related indicators. For
example, during the last three decades, the Asia-Pacific region had the highest
average number of reported deaths per million inhabitants due to disasters.

Figure 1: Asia-Pacific trends of disasters, victims, and damages(Data source: EM-DAT)All sub-regions of the Asia-Pacific get their share of the disasters caused bynatural hazards and related impacts (Table 1.1.1). South and South-West Asia had
most disasters (1,283) over a 30 year period (1980-2009), followed by South-East
Asia (1,069)), and, consequently, these two sub-regions experienced greater

Status of natural hazards in the Asia-Pacific region and impacts of climate changeOctober 2010, Kobe, Japanfatalities. However, East and North-East sub-region suffers more economicallyand in terms of number of affected people. It should be noted that to some extent
the 2004 Indian Ocean Tsunami does spike the disaster statistics of South-East
Asia (see Box 1). Considering the smaller size of the Pacific sub-region, therelative loss of human life and economic damage are significantly high.
Table 1: Disasters and impacts in Asia-Pacific sub-regions over 1980-2009
Asia-PacificSub-region
East and North-East Asia
South-East Asia
South and South-West Asia
North and Central Asia
Pacific
Asia-Pacific (Total)

Events(Number)
908
1,069
1,283
297
406
3,963

KilledAffected(Thousand) (Thousand)
162,804
2,567,214394,687272,777
566,423
1,914,696
34,644
17,231
5,425
19,126
1,163,983
4,791,044

Estimated
Damage(million$)
578,60248,220141,506
15,636
39,078823,042

Among the world’s one thousand most fatal disasters between 1900 and 2006,
floods, windstorms and droughts accounted for up to 88.5%. Over the last three
decades, 76% of all disaster events were hydro-meteorological or climatologicalin nature; and these accounted for 45% of the deaths and 79% of the economic
losses caused by natural hazards. Asia-Pacific is prone to water-related disasters
such as floods (35%), windstorms (28%) and mass movement (8%) as shown in
Figure 1.1.2. The global distribution shows that Asia-Pacific region is accounted
for more than 45% of the world’s water-related disaster fatalities during the period
from 1980 to 2009, and 90% of all water-related casualties.

Figure 2: Distribution of disasters in the Asia-Pacific region during 1980-2009(Source: EM-DAT)New Technologies for Urban Safety of Mega Cities in Asia

Using EM-DAT database, Table 1.1.4 and Figure 1.1.3 compare the number ofannual events and moving averages for two categories of disasters – earthquakes
vs. climate sensitive hydro-meteorological disasters such as floods, drought,storms, extreme temperature, and landslides – for the Asia-Pacific region for thetime period 1980-2009. It can be clearly seen that increase in the number ofclimate sensitive disasters is much higher when compared with the number ofearthquakes. For example, in 1980, there were 11 reported earthquake disasters
compared to 55 climate sensitive disasters (a difference of 44), whereas in 2009,15 earthquakes vs. 124 climate sensitive disasters (a difference of 109). The trends
demonstrated by moving average (M.A.) lines in Figure 1.1.3 also confirm a much
faster increase in the number of climate sensitive disasters, with a difference of 83
in annual average of the two categories of disasters based on 30-year data. It
should be clearly noted here that these trends take into account both the improved
reporting mechanisms and increased exposure due to population growth, as these
are at same levels for both categories of disasters under consideration.
Table 2: Comparison of decadal and 30-year (1980-2009) average annual numbersof earthquake and climate sensitive disasters for the Asia-Pacific region
Time Interval
1980 – 1989
1990 – 1999
2000 – 200930-yearaverage

Average Annual
Number ofEarthquakes
(A)
10
15
19
15

Average Annual Number of
Climate sensitive Hydrometeorological disasters
(B)
64
94
136
98

Difference(B – A)
54
79
117
83

Figure 3: Comparison of moving averages of numbers of earthquakes and climate
sensitive disasters for the Asia-Pacific region over the period 1980-2009 (climate
sensitive hydro-meteorological disasters include floods, droughts, storms, extreme
temperatures, and wet landslides, Data source: EM-DAT)

Status of natural hazards in the Asia-Pacific region and impacts of climate changeOctober 2010, Kobe, Japan

1.2 Neglected and unreported disasters in the Asia-Pacific region
The Asia-Pacific region, perhaps like any other region in the world, experiences asignificant number of smaller disasters that go unreported by EM-DAT andsimilar international data capturing systems. Most of these are low-intensity, highfrequency disasters that often do not make headlines in international press or
publications, but actually inflict serious damage to highly vulnerable populations
and their livelihoods on a constant basis. Ironically, many local communities takethese as an integral part of their existence and learn to live with them with varying
degree of success. However, on the positive side, these long-term experiences
have helped them develop indigenous knowledge and practices which need to bebetter documented and shared among DRR communities.
Let alone the community-based extensive disaster risk identification and reduction,
many of the developing countries simply do not have modern technical andadequately qualified human resources for community level disaster monitoring
programs, particularly in the rural areas where majority of the region’s population
lives, and hence it never became a function of local government bodies to identify
potential local hazards, map them and develop rescue, recovery and reconstruction plans accordingly. The other part of the problem lies withinternationally accepted individual disaster definition and reporting
methodologies which are based on absolute number of deaths and economic
damages due to single disaster event, ignoring the frequency of such events andtheir sustained impact on local communities. The aggregate impacts of suchdisasters are difficult to quantify based on the available data. Some examples arepresented below to highlight this issue of neglected and unreported disasters andto draw attention of various DRR stakeholders for review of existing
methodologies and data collection and reporting protocols and procedures at local,
national, sub-regional and regional levels.
1.2.1 A comparison of EM-DAT and Desinvetar Databases
EM-DAT and Desinventer databases were examined to compare the number ofdisaster events from Indonesia (1998-2009) and Sri Lanka (1980-2008). In case ofIndonesia, Desinventer data are available from 1998 only. Four disasters, namely
floods, landslides, cyclones and droughts were considered for the analysis.
Earthquakes and tsunamis were not considered, those being generally catastrophic
events and well captured by both Desinventer and EM-DAT.
Table 3: Comparison of Desinventer and EM-DAT data in Indonesia (1980-2009)
No. of Events
Disasters

EM-DAT

People Killed

People Affected

Flood

63

Desinvent2,296

EM-DAT

Desinventer

EM-DAT

Desinventer

2,826

1,233

3,525,309

11,862,147

Lanslide

29

735

1,115

1,273

332,330

17,699Cyclone

2

680

4

109

3,715

147,778

Drought

1

1,149

0

0

15,000

0

Total

95

4,860

3,945

2,615

3,876,354

12,027,624

New Technologies for Urban Safety of Mega Cities in Asia

In case of Sri Lanka, the total numbers of recorded disaster events in Desinventer
database were 3,076 from 1980 to 2008, whereas only 49 events were recorded in
EM-DAT database for the same period (Table 1.2.2). The reported number offlood events during the period was 2,210 and 39 in Desinventar and EM-DAT
respectively. However, the reported the number of casualties due to flood in EMDAT is nearly 3 times higher than that of Desinventer. Further investigations
show that a large number of deaths (325 casualities) were reported in EM-DAT in
1989. A significant difference were also found in people affected by the disasters
in these two datasets, but it is not as severe as in the case of Indonesia.
Table 4: Comparison of Desinventer and EM-DATA in Sri-Lanka (1980-2008)
No. of Events
Disasters

EM-DAT

People Killed

Desinvent

EM-DAT

People Affected

Desinvent

EM-DAT

Desinventer

Flood

39

2,210

933

317

9,283,426

8,445,805

Lanslide

1

293

65

490

130

52,543

Cyclone

3

41

14

9

433,000

861,235

Drought

6

532

0

0

6,006,000

7,804,286

Total

49

3,076

1,012

816 15,722,556

17,163,869

Both in case of Indonesia and Sri Lanka, the number of events reported in
Desinventar is very large in comparison to EM-DAT. On the contary, the reported
number of people killed in Desinventar is lower than the EM-DAT. Desinventar
has reported nearly 50 times more numbers of disasters in case of Indonesia and60 times more in case of Sri Lanka. This shows that with the present criteria in
EM-DAT for data capturing does misses quite a big numbers of disaster events.
Secondly, reporting of higher number of casualties in EM-DAT (although thereported number of disaters events are very low) highlights that data varification
is an issue to which attention should be paid.
1.2.2 Disasters in Pacific Island Countries
Pacific Island Countries (PICs) are vulnerable to a range of natural hazards, suchas cyclones, volcanic eruptions, earthquakes, floods, tsunamis, landslides anddroughts. The small, highly dispersed land areas and populations, and changing
nature of life in the Pacific, intensify this vulnerability. Official statistics suggestthat natural hazards have a considerable economic impact on development in the
Pacific. (SOPAC, 2008). The real total impact of disasters caused by natural
hazards, including long-term impacts on the living conditions, livelihoods,
economic performance and environmental assets of Pacific Island Countries, islikely to be much larger (SOPAC, 2008). In addition, due to the small populations,
economies and land areas of many Pacific Island Countries, unreported disasterrelated damages that are small relative to the damages elsewhere in the world canhave a large impact relative to the country’s total GDP and population.
Many small islands are affected by random cyclonic events, which are a major
problem for communities, often causing significant storm damage and flooding.
Storm surges have often inundated land, caused loss of life and severely damaged
Status of natural hazards in the Asia-Pacific region and impacts of climate changeOctober 2010, Kobe, Japan

infrastructure in some small islands, for example, atolls in Tuvalu, the MarshallIslands, Federated States of Micronesia and the northern Cook Islands. During
these events, freshwater lenses may receive considerable inputs from land
inundation by seawater and subsequent infiltration, and many months may pass
before they return to a potable condition. The frequency of tropical cyclones has
been related to the ENSO cycle (SOPAC, 2002).
The unfortunate reality is that disasters caused by natural hazards can have adebilitating impact upon Pacific island economies. According to the World Bank
(2006), disasters in the Pacific have reportedly directly affected more than 3.4
million people and led to more than 1,700 reported deaths in the region (excluding
PNG) since 1950. In the 1990s alone, reported disasters cost the Pacific Islands
region US$2.8 billion in 2004 terms (World Bank, 2006). However, it is only at
the national level that the true impact of disasters on the economy are visible. Thisis because, compared to developed countries with larger reserves to draw on intimes of disaster, the small size of most Pacific island states means that disastercan have a disproportionately high impact on their economy. Accordingly:• During major disaster events, Samoa reported average economic disaster costsof 46 percent of annual GDP. (World Bank, 2006);• The 2007 earthquake and accompanying tsunami that hit the Solomon Islands
cost the country around 90% of the 2006 Government Budget (ADB, 2007);• Cyclone Heta which hit Niue in 2004 effectively completely wiped out thenational GDP, with immediate losses in 2004 amounting to over five times
that of the GDP (SOPAC, 2008).
These are only the direct estimates of the costs of disasters and are based in
immediate losses such as the destruction of infrastructure and crops. However,disasters also indirectly impact economic growth further by removing access to
infrastructure such as inability to get produce or producers to markets andlowering economic capacity such as loss of educational opportunities.
As there has been relatively little research on broader disaster impacts in the
Pacific, the true costs continue to be underestimated, creating problems in alerting
policy makers and international donors to the serious economic consequences ofnatural hazards and the imperative for integrating comprehensive DRR into
national development planning (SOPAC, 2008). Despite the serious negative
impacts of disasters caused by natural hazards in the Pacific, there is no
systematic collection of comprehensive data on these effects. The understanding
and documentation of these effects are vital to the development of long-term
policies for reconstruction, mitigation and preparedness. The lack of data also
limits the scope for conducting cost-benefit analyses of DRR measures (SOPAC,
2008).
1.2.3 Tornadoes in Bangladesh
Bangladesh lies between the Himalayas to the north and Bay of Bengal to thesouth, and geographically characterized by an intricate river system, complex
coastal configuration, and shallow bathymetry. This unique geography provides

New Technologies for Urban Safety of Mega Cities in Asia

cold heavy air from the north and warm moist air from the south, leading tofavorable conditions for severe thunderstorms which spawn tornadoes or otherstrong winds during pre-monsoon (March-May) and post-monsoon (OctoberNovember) seasons. Tornadoes are identified as one of the unpredictable localizedhazards in Bangladesh which result in significant deaths and disabilities, loss of
income, and destruction of resources. In recent decades, they have drawn little
attention, as the emphasis on disaster management has been dominated by floods
and cyclones. The frequency of tornadoes in Bangladesh is similar to that of thecentral United States, and is among the highest in the world. More than 10,000
deaths have been attributed to tornadoes during the period 1961 to 1996 (IAWE,
2009). Based on the number of casualties and overall impact on national
economy, tornadoes and thunderstorms are now considered as one of the major
hazards and exceeded only by cyclones and floods in Bangladesh. Bangladesh ismaking efforts to reduce the impact of such neglected localized disasters within
the larger context on national disaster risk reduction and management (IAWE,
2009).
1.3 Conclusions
1) Last 30 years data demonstrate a continuous rise in occurrence of disasters
caused by natural hazards in the Asia-Pacific region, economic
losses/damages, number of people affected and in some cases number ofpeople killed. The trends are more or less similar in all the sub-regions of the
Asia-Pacific. Probable factors behind these upward trends include improved
disaster reporting mechanisms, increase in human population, rapid economic
development, and impacts climate change on hydro-meteorological processes.
2) The underlying factor for the increasing trend of casualties and damage is thehigh levels of absolute and relative exposures to natural hazards in all subregions of the Asia-Pacific.
3) Among the different types of disasters, hydro-meteorological disasters are themost frequent, causing a greater loss of human life, livelihoods and economic
damages in Asia-Pacific as compared to the past. Last 30 years data confirm amuch faster increase in the number of climate sensitive disasters – such as
flood, drought, cyclone, extreme temperature and wet landslides – comparedto the number of earthquakes which is the main geological disaster in theregion. It is worth noting that these trends take into account both the
improved reporting mechanisms and increased exposure due to population
growth and urbanization, as the influence of these factors are same for bothcategories (hydro-meteorological and geological) of disasters.
4) Some countries in the Asia-Pacific region suffer significantly from neglecteddisasters such as tornadoes/cyclones in Bangladesh and the Pacific Island
countries. A significantly large number of small but frequent disasters fromIndonesia and Sri Lanka go unreported in official database such as EM-DAT,
highlighting the need for review of existing diversity in disaster reporting
mechanisms at national and international levels.

Status of natural hazards in the Asia-Pacific region and impacts of climate changeOctober 2010, Kobe, Japan

REFERENCES
ADB, 2007. Rehabilitation and Reconstruction Program for Disaster-affected
Areas of Solomon Islands, draft.
EM-DAT (Raw Data Source www.emdat.be as accessed in May 2010)
IAWE, 2009. Proceedings of International Forum on Tornado Disaster Risk
Reduction for Bangladesh - To Cope with Neglected Severe Disasters.
International Association of Wind Engineering (IAEW).
ICHARM, 2009. Global Trends in Water-Related Disasters: an insight forpolicymakers. The United Nations World Water Assessment Progr amme:Side publications series.
SOPAC, 2002. The Pacific Dialogue on Water and Climate: Synthesis Report.
Published by South Pacific Applied Geoscience Commission (SOPAC).
SOPAC, 2008. Disaster Risk Management in the Pacific: Economic Analysis andAdvocacy by Paula Holland, SOPAC Secretariat, Fiji Islands.
CRED, 2010. CRED CRUNCH, Vol. 19. (www.cred.be)World Bank, 2006. Not If But When: Adapting to Natural Hazards in the PacificIslands Region: A Policy Note.

New Technologies for Urban Safety of Mega Cities in Asia

Sustainable Concrete for
Urban Infrastructural Application
Kiang Hwee TAN1, Hongjian DU2
1
Professor, Department of Civil Engineering
National University of Singapore, Singapore
cvetankh@nus.edu.sg
2
PhD Candidate, Department of Civil Engineering
National University of Singapore, Singapore
ABSTRACTThe scarcity of natural resources and concern for environmental protection has
necessitated the exploration of alternative concrete materials to sustain thedevelopment and maintenance of urban infrastructure. Towards this end,
research is being carried out on concretes made without natural sand or withsand replaced by waste glass at the National University of Singapore. The fresh,mechanical and durability properties of such concretes were investigated andpresented in this paper. Sandless concrete was found to possess similar
mechanical properties as normal concrete. Reduced drying shrinkage andimproved resistance to chloride penetration were observed in sandless concretewith cement replaced by fly ash. The mechanical properties of waste brown glass
concrete were comparable to normal concrete even with sand totally replaced bywaste glass particles. Also, mortar bar tests to ASTM C1260 on mortar screened
from fresh waste glass concrete indicated no active aggregate-silica reaction.
Keywords: concrete, durability, mechanical properties, waste glass

1. INTRODUCTION
Urban infrastructure plays an important role in supporting the social and economic
activities of mega-cities. Traditionally, concrete has been used as the mainmaterial for both new construction and rehabilitation works. However, thescarcity of natural resources and the need for environmental protection has
necessitated the exploration of alternative concrete materials. As a result,numerous research works have been carried out globally on the use of
manufactured sand and aggregates, and industrial by-products such as fly ash andblast furnace slag as replacement of cement, sand and coarse aggregates, which
form the main ingredients for the production of concrete.
In view of the scarcity of concreting sand on the one hand and the low recycling
rate of household waste in the city-country of Singapore, a research has been
initiated at the National University of Singapore to develop concretes madewithout natural sand or with sand replaced by waste glass. The properties of suchconcretes have been investigated and are reported herein.

0ctober 2010, Kobe, Japan

2. “SANDLESS” CONCRETE
The term “sandless concrete” is used herein to refer to concrete made without
natural sand. There are concretes that do not contain fine aggregates, such as nofines concrete and pervious concrete; however, such concretes have highpermeability, low unit weight and low strength, and are used mainly in minor
structures or in pavements.
The present study was aimed at producing sandless concrete with a cube
compressive strength of at least 30 MPa, which is required for use in reinforced
concrete members. First, the mixture design was determined to achieve a densely
packed concrete with minimal porosity. The water-cement ratio was then varied
to produce concretes of different strengths, and the fresh properties, mechanicalproperties and durability of these sandless concretes were investigated.
2.1 Mixture Design
In order to produce a workable sandless concrete, the cement paste has to bind andlubricate the coarse aggregates adequately. From the economical point of view,
the paste should be minimal, which requires the coarse aggregates to be densely
packed. Thus, it was decided to use two coarse aggregate sizes of 10- and 20-mm
in the mixture proportion so as to reduce the void content in the concrete. The
voids in the aggregates for different combinations of 10- and 20-mm aggregateswere determined following ASTM C29.
Figure 1(a) shows that a void content of less than 0.31 could be obtained if thevolume fraction of 20-mm aggregates is between 60 and 100%. The ratio of 10to 20-mm aggregates was thus selected as 40:60 in this study, and thecorresponding aggregate size distribution is shown in Figure 1(b), which satisfies
the ASTM C33 grading requirement for size 67 aggregates. The paste volume
was taken to be about 10% more than the void volume, or 341 L/m3.

(a) Void content(b) Aggregate size distribution

Figure 1: Void content and aggregate size distribution
As shown in Table 1, four groups of sandless concrete with w/c ratios of 0.40,
0.45, 0.50 and 0.55 were investigated.
For comparison purpose, four
New Technologies for Urban Safety of Mega Cities in Asia

corresponding groups of normal concrete containing natural sand were also
included. The ratio of natural sand to coarse aggregates was 1:2 by mass, with theratio of 10-mm to 20-mm aggregates remaining at 40:60 as in sandless concrete.
At the same w/c ratio, both the sandless concrete and normal concrete mixes had
the same cement and water content. Furthermore, for each sandless concrete
mixture, Class F fly ash was used to replace cement at 0, 10, 20, 30, 40 and 50%.
Table 1 : Mix proportions for normal and sandless concrete
Content, kg/m3
Mixture10-mm
20-mm
Designation* Cement Water
Sand w/c
Coarse Agg. Coarse Agg.
M0.40-N
478
191
457
685
571 0.40
M0.40-S
478
191
683
1024
— 0.40M0.45-N
444
200
457
685
571 0.45
M0.45-S
444
200
683
1024
— 0.45
M0.50-N
417
209
457
685
571 0.50
M0.50-S
417
209
685
1028
— 0.50M0.55-N
393
216
457
686
571 0.55
M0.55-S
393
216
686
1028
— 0.55* N : normal concrete; S : sandless concrete
2.2 Fresh Properties
No bleeding or segregation was observed in each concrete mix. The target slump
was 50 mm, and a polycarboxylate-based superplasticizer was added for thispurpose. The dosage of superplasticizer was limited to 2% of the total weight of
cement and fly ash so as not to cause other problems such as delayed setting. The
sandless concrete exhibited slump values of between 50 and 100 mm, except for
the group with w/c = 0.40, as shown in Figure 2, which had slump values between
25 and 50 mm. According to ACI 211 (2002), the minimum slump requirement
for structural construction is 25 mm; thus the sandless concrete satisfied thisrequirement. It is also noted that the replacement of cement by fly ash did not
substantially improve the workability of concrete.

Figure 2: Slump of sandless concrete
Sustainable concrete for urban infrastructural application

0ctober 2010, Kobe, Japan

2.3 Mechanical Properties
Figure 3 shows the mechanical properties of sandless concrete at 28 days, basedon average of three samples per data point. It is seen from Figure 3(a) thatsandless concrete without fly ash or with fly ash replacement ratio less than 20%
exhibited similar compressive strength as normal concrete with the same w/c ratio.
It was further found that at 90 days, the compressive strength for sandless concretewith w/c ratios of 0.40 and 0.45 was comparable to normal concrete, even with
50% fly ash replacement ratio, due to the late pozzolanic reaction of fly ash.
Figure 3(b) shows that the splitting tensile strength of sandless concrete without
fly ash was comparable to normal concrete, and about the same regardless of the
w/c ratio. The splitting tensile strength in fact increased with cement partiallyreplaced by fly ash by up to about 30%, when w/c was below 0.5. For mixes withhigher w/c ratios or with the fly ash replacement ratio exceeding 30%, the splitting
tensile strength tended to decrease.

(a)

(b)

(c)

(d)

Figure 3: Mechanical properties of sandless concrete
The flexural strength refers to the modulus of rupture, obtained from prism tests.
Similar to splitting tensile strength, Figure 3(c) shows that the flexural strength ofsandless concrete was quite independent of the w/c ratio as long as it was below
0.50. The substitution of cement by fly ash did not lead to adverse effect if thereplacement ratio was less than 30%. Also, at higher w/c ratios or with the fly ash
replacement ratio exceeding 30%, the flexural strength tended to decrease.

New Technologies for Urban Safety of Mega Cities in Asia

The elastic modulus of sandless concrete, measured from cylinder tests and shownin Figure 3(d), was generally smaller than normal concrete due to the smaller
stiffness of cement paste in the former compared to mortar paste in the latter. The
modulus decreased with the w/c ratio, as is in normal concrete. For a given w/c
ratio, the elastic modulus decreased with a higher fly ash replacement ratio,
especially above 20 to 30%.
2.4 Drying Shrinkage
Figure 4 shows the drying shrinkage of sandless concrete. All the concrete mixes
showed shrinkage less than 700 ×10-6 mm/mm after 180 days of drying. Also, theamount of drying shrinkage decreased with lower w/c ratio and increasing fly ash
content. Compared to normal concrete, the drying shrinkage of sandless concrete
without fly ash was higher at w/c = 0.55, slightly lower at w/c = 0.45 and 0.50,
and lower at w/c = 040. With 50% sand replaced by fly ash, the reduction in
drying shrinkage could be 27, 19, 24 and 40% for w/c ratios of 0.40, 0.45, 0.50,
and 0.55, respectively.

Figure 4: Drying shrinkage of sandless concrete
2.5 Chloride Resistance
Figure 5 shows the Rapid Chloride Penetration Test (RCPT) results of sandlessconcrete with w/c ratios between 0.4 and 0.55 inclusive at 180 days, as well as
those of sandless concrete mix with w/c = 0.45 at 28 days. Sandless concrete
showed lesser amount of charge passed, indicating a higher resistance to chloride
ingress than normal concrete. This may be attributed to a reduction in the total

Sustainable concrete for urban infrastructural application

0ctober 2010, Kobe, Japansurface area of aggregate particles and thus a smaller Interface Transition Zone
(ITZ) that would have allowed the ingress of chloride ions (Mindess et al., 2003).

Figure 5: RCPT results for sandless concrete
The total charge passed was higher at 28 days than at 180 days. This was due to ahigher degree of cement hydration which lowered the permeability of concrete.
Also, the charge passed decreased with lower w/c ratios for sandless concrete,similar to normal concrete. It decreased with cement partially replaced by fly ash,and the effect was particularly significant for a fly ash replacement ratio of up to
about 30%. This was because the microstructure of cement paste had beenenhanced by pozzolanic reaction of fly ash, which resulted in reduced porosityand pore connectivity.
3. WASTE GLASS CONCRETE
In this study, recycled brown glass was used as sand replacement, withreplacement ratio varying from 0 to 100%, in steps of 25%. Soda-lime glass
bottles were first collected, washed and crushed into smaller particles, to satisfy
the ASTM C 33 requirement for fine aggregates (see Figure 6). The crushed glass
sand had more irregular shape, sharper edge, smoother surface and higher aspectratio, compared to natural sand.

New Technologies for Urban Safety of Mega Cities in Asia

Figure 6: Grading of glass sandThree concrete grades with target characteristic cube compressive strengths of 30,
45 and 60 MPa and mix proportions listed in Table 2 were considered. The waterand coarse aggregate content were kept constant at 185 and 1048 kg/m3
respectively. To achieve a slump of 100 mm, superplasticizer was added at 1.3,
2.6 and 3.6 litres per cubic metre of concrete, for C30, C45 and C60 mixes,
respectively.
Table 2: Mix proportion for glass concrete
Mix proportions (kg/m3)
Concrete
w/c
Grade
Water Cement 20-mm Coarse Agg. Sand
C30
185
378
1048
741 0.49
C45
185
487
1048
649 0.38
C60
185
617
1048
540 0.32
3.1 Fresh Properties
The density, air content and slump of freshly mixed glass concrete are shown in
Figure 7. Concretes with higher content of glass sand exhibited lower fresh
density, due to the smaller specific gravity of glass compared to natural sand. The
air content of glass concrete decreased initially with 25% glass sand, but thereafter
increased consistently up to 100% glass sand. As regards workability, glass
concrete showed slump values comparable to normal concrete without waste glass.

Sustainable concrete for urban infrastructural application

0ctober 2010, Kobe, Japan(a) Density(b) Air content(c) Slump

Figure 7: Fresh properties of glass concrete
3.2 Mechanical Properties
Figure 8 shows the compressive strength, splitting tensile strength, flexuralstrength and static modulus at 28 days. It is noted that the compressive strength of
concrete was not affected by the replacement of natural sand by glass sand even at
100%, especially for the lower grade concretes. For Grade C60 concrete, the useof glass sand led to slightly lower compressive strength. On the other hand, thetensile strength, especially flexural strength, was found to increase with higher
glass sand content. This was due to the longer aspect ratio of glass sand andhence better interlocking action among aggregates. The static elastic modulus
showed marginal increase with the use of glass sand.

Figure 8: Mechanical properties of glass concrete
New Technologies for Urban Safety of Mega Cities in Asia

3.3 Alkali-Silica Reaction
Alkali-silica reaction (ASR) may be considered as the most deleterious
mechanism for concrete containing glass sand. In this study, ASR expansions
were measured according to ASTM C 1260 using mortar screened from freshly
mixed glass concrete with a 4.75-mm sieve. Figures 9(a) to (c) shows the test
results, up to 28 days for each concrete mix.
In general, glass sand showed less alkali-silica reactivity with cement than naturalsand, regardless of the concrete grade. The ASR expansion continuously
decreased with higher glass sand content. The increase in ASR expansion was also
slower with higher glass sand content.
From Figure 9(d), each concrete mix showed ASR expansion less than 0.1% at 14days, indicative of the innocuous nature of both the natural and glass sand used.
Furthermore, the ASR expansion was found to be highest in the medium concrete
grade C50. This pessimum effect occurred because while a lower w/c ratio in
higher grade concrete led to more alkali ions for alkali-silica reaction, it also led toa higher tensile modulus of cement paste which resulted in lower ASR expansion.
The former factor predominated in lower grade concrete, while the latter factor
governed in higher grade concrete.

Figure 9: ASR expansion of glass concrete
3.4 Chloride Resistance

Sustainable concrete for urban infrastructural application

0ctober 2010, Kobe, JapanThe resistance to chloride ingress was determined using the ASTM C 1202 Rapid
Chloride Penetration Test (RCPT) method, and the NT BUILD 492 method(NORDTEST, 1999) for the determination of migration coefficient of chloride
D nssm . Figure 10 shows the test results at 28 days.
The resistance to chloride penetration was enhanced by the replacement of natural
sand by glass sand. This could be attributed to the larger fraction of fines in glass
sand (see Figure 6) which improved the micro-structure in the Interface Transition
Zone (ITZ) between the paste matrix and glass particles (Mindess et al., 2003).
Also, the lower porosity and irregular shape of glass particles compared to natural
sand helped to reduce the ingress of chloride ions. Another possible reason could
be due to the pozzolanic reaction of fine glass particles.
It was also noted that with higher grade concrete or with a lower w/c ratio, thetotal charge passed was substantially reduced due to reduced porosity of paste andincreased impermeability of concrete, especially when the glass content was lower
than 75%. The above observations were supported by the values of D nssm , which
also decreasd with lower w/c ratio and increasing glass content.

Figure 10: RCPT results of glass concrete at 28 days
4. CONCLUSIONSIn this study, sandless concrete was proportioned using dual coarse aggregatessatisfying the ASTM C33 grading requirement for size 67 aggregates, while waste
glass concrete was made using brown glass particles satisfying the grading
requirement for fine aggregates. Test results indicated that both the sandlessconcrete and waste glass concrete possessed comparable fresh, mechanical anddurability properties as normal concrete when the w/c ratio was lower than 0.5.
The use of flyash as cement replacement further improved the properties when thereplacement ratio was less than 30%. Such concretes were shown to be promisingas alternative materials to conventional concrete, and should be explored further.
REFERENCES

New Technologies for Urban Safety of Mega Cities in Asia

ACI Committee 211, 2002. Standard practice for selecting proportions fornormal, heavyweight, and mass concrete (ACI 211.1-91), American Concrete
Institute, Farmington Hills, Michigan, USA.
ASTM, 1997, Standard test method for bulk density (“unit weight”) and voids inaggregate (C 29), USA.
ASTM, 2003. Standard specification for concrete aggregates (C 33), USA.
ASTM, 2007. Standard test method for determining the potential alkali-silica
reactivity of aggregates (mortar-bar method) (C 1260), USA
ASTM, 2005, Standard test method for electrical indication of concrete’s ability
to resist chloride ion penetration (C 1202), USA.
Mindess, S., Yong, J.F., and Darwin, D., 2003. Concrete. 2nd edition, Prentice
Hall, New Jersey, USA.
NORDTEST, 1999, Concrete, mortar and cement-based repair materials:
chloride migration coefficient from non-steady-state migration experiments, NT
Build 492, Finland.

Sustainable concrete for urban infrastructural application

Potential strategies for promoting
sustainable concrete practices in Thailand
Michael HENRY1, Raktipong SAHAMITMONGKOL2,
Pakawat SANCHAROEN2, Yoshitaka KATO3
1
Project researcher, International Center for Urban Safety Engineering,
Institute of Industrial Science, The University of Tokyo, Japanmwhenry@iis.u-tokyo.ac.jp
2
Construction & Maintenance Technology Research Center,
Sirindhorn International Institute of Technology, Thammasat University, Thailand
3
Assoc. professor, International Center for Urban Safety Engineering,
Institute of Industrial Science, The University of Tokyo, Japan
ABSTRACT
Sustainable development depends on a wide variety of factors but particularly onsocio-economic conditions. Similarly, sustainable concrete practice may also vary,
particularly between developed and developing countries – therefore, therelationship between sustainable concrete and such factors needs to be better
understood. This research was conducted as a first step towards clarifying thisrelationship by interviewing stakeholders in the Thai concrete industry. Thailand
represents a unique case for sustainable practice due to widespread adoption of
fly ash concrete as the normal concrete material. Since the environmental impact
of concrete is already reduced, the results of the interviews were used to not only
explore the afore-mentioned relationship but also to consider potential strategies
for promoting sustainability. It was found that, due to the low cost of labor, priceserves as the most important criteria for concrete. This makes it difficult to test or
adopt new technologies due to high cost competition. Most technology is diffusedthrough the cement companies, which have the highest investment in R&D,
although foreign consultants also provide such support. Finally, the lack ofsustainability education makes it difficult to convince customers of additional
value such as environmental impact reduction – thus education should form thebase of promoting sustainable practice. Since environmental technologies cannot
compete on cost, criteria for additional value are also necessary to concretely
evaluate these characteristics.
Keywords: Sustainability, concrete, Thailand, construction, environmental impact

1. INTRODUCTION
More than 20 years after being initially defined in the Brundtland Report to theUnited Nations, sustainability remains difficult to implement due to the wide
variety of perspectives on what, exactly, constitutes sustainability. This may be
attributed to a critical aspect underlying the concept of sustainability: that it is ahuman vision with human values (Bell & Morse, 2008). What may be sustainableOctober 2010, Kobe, Japanin one region of the world under a given set of social, economic, andenvironmental conditions may not be sustainable in a different region of the world
under different conditions.
In a similar fashion, it is also difficult to establish a global strategy for sustainableconcrete practice. General principles such as limiting CO 2 emissions, recycling
and resource consumption reduction, and enhanced durability have been proposed(Mehta, 1999; Sakai, 2009), but how to practically achieve these goals depends
heavily on available resources, construction industry culture and stakeholders,institutional systems, technology level, and more. These factors are affected by
the regional or local socio-economic conditions, and in turn affect the potential forsustainable concrete practice and materials (Figure 1).
Socio-economic conditions

Institution

Technology
Interactions
Resources

Stakeholders

Sustainable concrete practice & materials

Figure 1: Conceptual framework for relating socio-economic conditions tosustainable concrete practice and materials
The Thai concrete industry was selected for this research because Thailand
represents a unique case for sustainable concrete practice – not only due to its
economic growth but also due to the widespread adoption of fly ash concrete as
the standard material for concrete construction. Since the environmental impact –particularly CO 2 emissions – of concrete itself has already been reduced due to fly
ash usage, other strategies for promoting sustainable concrete practice need to beconsidered. Through interviews with concrete industry members, this research
investigated the relationship between socio-economic conditions and sustainableconcrete practice and, from these results, proposed strategies for promoting
sustainability considering Thailand’s conditions.
2. RESEARCH METHODOLOGY
Conditions in the Thai concrete industry were investigated using semi-structured
interviews, which followed a general outline but allowed for areas of interest to be
explored in further detail (Punch, 2005). The interview contents were broken into
four sections, as summarized in Table 1, with the goals of understanding thestructure and relations among stakeholders, identifying different concepts forsustainability and sustainable concrete practice and materials in Thailand, andclarifying barriers to implementing those practices and materials.

New Technologies for Urban Safety of Mega Cities in Asia

Table 1: Outline of interview contents
Sec. Theme12
3
4

Description
Identify the stakeholders and their relationships,
Thai concrete
concrete evaluation criteria, characteristics uniqueindustry conditions
to Thailand, and environmental impact
Knowledge ofSurvey definitions, evaluation criteria, and level ofsustainability
awareness for sustainability in Thailand
Identify changes needed to achieve sustainability,
Sustainable concrete
evaluation criteria, and opportunities for Thailand
practice and materials
to improve concrete sustainability
Barriers toClarify barriers and characteristics of Thailand
sustainable concrete
which may overcome these barriers
practice and materials

The interviewees were not selected based upon any specific criteria, but were
contacted through social and professional networking. Seven interviews wereconducted in total, as shown in Figure 2.
1
2

Cement company
Ready-mix company
University

2

Real estate/developer
2

Figure 2: Distribution of interviewees
3. INTERVIEW RESULTS & DISCUSSION
3.1 Thai concrete industry conditions
The Thai concrete industry is composed of private owners, consultants, academics,
government (as both public owner and material supplier), contractors, and readymix concrete (RMC), cement, and admixture companies. The two leading cementcompanies are the major stakeholders, and both have a large investment inresearch and development (R&D). Both companies also have their own RMC, anddistribute cement both to their own producers as well as independent RMC plants.
Fly ash, on the other hand, is produced by a public utility company from a power
plant in northern Thailand. The RMC not only purchases chemical admixtures,but may also cooperate with admixture companies to develop customized
admixtures based on specific requirements; the cement companies may also
cooperate with admixture companies in a similar way. Investment in R&D in the
cement/RMC companies focuses on cement technology and the development of
new materials.

Potential strategies for promoting sustainable concrete practices in ThailandOctober 2010, Kobe, JapanThe customer of the RMC is either the contractor (generally for public projects) or
the project owner (more typical of private sector projects). Local contractors havea lower level of technology compared to the cement companies and generally only
work on smaller projects; overseas contractors, on the other hand, have a higher
level of technology and work on major projects, either alone or as a venture withlocal companies. On the owner side, for public works there is limited investment
in R&D in only a few government departments – the owner generally relies on a
consultant who may then cooperate with a university, joint venture, foreign
investment or other entity. Outside of the private sector, leading universities havea large investment in R&D and work to solve industry problems and support
industry stakeholders through associations and collaborative works.
Transfer of new technologies generally occurs through the cement/RMC
companies or from the leading universities. This is done by understanding
customer needs, current technologies, market opportunities, lessons learned frompractice, and so on. However, in Thailand the most critical aspect of any newtechnology is cost. Most concrete-making materials – cement, fly ash, andaggregates – are locally available and thus their cost is very low. But more so thanmaterials, the cost of labor in Thailand is extremely cheap, to the point wheremost technologies simply cost more than the labor they are intended to replace or
supplement and, thus, it’s cheaper to use people rather than machines. One
example is fiber-reinforced concrete (FRC). FRC replaces reinforcing steel bars
with fibers, which reduces labor costs due to reduced steel content; however, thecost of the fibers is much higher than the labor cost so it’s not economical.
Another example is self-compacting concrete, which saves labor costs related to
casting, but again the increased cost of materials is more than the labor costs.
Therefore, the industry operates at a lower level of technology compared todeveloped countries such as Japan, where labor costs are significantly higher.
Due to the low cost of labor and local availability of materials, competition in theconcrete industry is intensely focused on cost, and the majority of government
projects still rely on initial cost only. Therefore, introduction of new materials or
construction processes is difficult if they don’t reduce cost or construction time.
There is little consideration of additional value (such as durability, life cycle cost,etc.), making it hard for “value-added products” to compete in the marketplace.
Some companies have tried to move towards additional value in the form ofservice, such as guarantees and customer support, but these are typically offered“free of charge” to maintain price-competitiveness of the product or service being
sold while trying to gain an additional advantage.
A good example of cost minimization in concrete materials is the wide-spread useof fly ash in concrete in Thailand, which is mostly due to its lower cost relative tocement. Since cement is the most expensive material component in concrete, large
cost savings can be realized if this volume is reduced. The environmental andmaterial benefits of fly ash are therefore secondary to the cost savings, and were
fly ash to cost more than cement it would become a premium product. Even
though fly ash is widely accepted, however, its usage is still restricted byprescriptive design codes which specify a minimum cement content in concrete.

New Technologies for Urban Safety of Mega Cities in Asia

Finally, for environmental impact, waste generation and disposal is an issue whichneeds addressing. It’s cheaper to throw away demolition waste and left-overconcrete from construction sites and RMC plants than it is to recycle it.
Furthermore, the cost of recycling technology is high, and resources are stillabundant, so there is little motivation to consider this problem. Another issue isthe generation of dust, noise, and other social and environmental hazards aroundcement and RMC plants and construction sites. These stakeholders are concerned
that, if they don’t maintain good relations with their surrounding communities, it
may lead to protests or other difficulties which could negatively affect the
stakeholders’ productivity and image.
3.2 Knowledge of sustainability
When asked to define sustainability in their own words, the interviewees gave avariety of responses. These included the minimization of resource and energy
consumption, the “three pillars” (economy, environment, society), and corporate
governance. However, it was acknowledged by some interviewees thatsustainability can have different meanings, making it difficult to clearly define.
The consumption of natural resources, CO 2 emissions, and waste production wereidentified as general means of evaluating sustainability.
For Thailand in particular, it was said that generally few people are aware ofsustainability as an important issue. People just want a nice living space and are
not concerned about green construction. Cost is the primary consideration, and it’s
hard to weigh sustainability against cost because people do not consider social orenvironmental factors. On the business side, however, it’s important forcompanies to consider the social impact of their activities in particular, in order tomaintain good relations with the local communities. Another important aspect ofsustainability for Thailand is the lack of domestic energy production.
Conservation of energy is important because of the difficulty in constructing large
energy facilities in Thailand. Finally, instability and corruption in the government
were also identified by the interviewees as important issues which need to be
overcome for sustainability, because when the government changes it often
discontinues the policies of the previous administration in order to forge a new
identity, thus making it difficult to have confidence in new policies.
3.3 Sustainable concrete practice and materials
To move towards sustainable concrete practice and materials, the interviewees
identified several different areas which need to be considered for Thailand. These
are summarized in Figure 3 and are divided into three groups: concrete andsustainability evaluation criteria and general actions.
On the concrete aspect, the interviewees suggested that durability needs greater
consideration in order to use concrete structures longer. This is best evaluated byutilizing life cycle cost (LCC) as an evaluation criterion, which provides aquantifiable means for understanding and comparing; however, a Thai-specificstandard, rather than international standards adapted for Thailand’s uses, isnecessary to properly capture the conditions experienced in Thailand.

Potential strategies for promoting sustainable concrete practices in ThailandOctober 2010, Kobe, JapanFor the sustainability aspects, CO 2 emissions was mentioned as a usefulevaluation criterion for environmental impact because it can be easily quantified,such as mass of CO 2 per cubic meter of concrete. Although the cement content in
concrete is already reduced due to usage of fly ash, the cement industry needs toreduce its environmental impact further, particularly looking at the CO 2 emissions
and resource and energy consumption in cement production. This is one area
where the Thai industry may be able to implement strong action because thecement companies are the strongest stakeholders; in addition, they can control the
production of concrete within their own companies and thus can directly reduce
environmental impact from the beginning of the material production process.
However, performance-based design and standards need to be implemented toallow greater freedom in utilizing new materials or technologies.
Sustainable concrete practiceGeneralactions

Evaluation
criteria

Concrete aspect
LCC
Durability

Sustainability aspect
CO2 emissions
Resource & energy
Dust, noise, & water pollution

Standardized code
Governmental regulation
Consideration of additional value
Education on concrete & sustainability

Figure 3: Evaluation criteria and actions for moving towards
sustainable concrete practice and materials
Not only should the environmental impact of the materials be reduced, but the
impact of the manufacturing and production plants themselves should also be
reduced. This includes dust, noise, and water pollution, all of which can havedetrimental effects on the surrounding community. Governmental regulation forestablishing air-borne particulate matter standards, noise limits, and so forthwould help the cement and RMC plants and construction sites better manage theirlocal impact and establish benchmarks for improvement.
To move towards these evaluation criteria, the first important action is theestablishment of codes and guidelines to provide the industry with a standardized
method for evaluating and design considering durability, life cycle cost, andenvironmental impact. As mentioned before, such codes and guidelines need to be
developed considering the Thai industry’s conditions. Governmental regulation
was also already mentioned as necessary, for guiding not only the environmental
impact reduction but also durability and long-term maintenance of concrete
structures. These actions will require increased consideration of the additional
value of concrete materials, such as durability and environmental impact, in orderto shift the focus away from pure cost evaluation. However, the most fundamental
action necessary is education at all levels of the industry, as well as education of
non-industry members who interact with the industry, such as owners,
New Technologies for Urban Safety of Mega Cities in Asia

government official and bureaucrats, local communities, and more. First, thiseducation is necessary to reduce the emphasis on cost by providing information
about the additional benefits concrete can have. Second, the education isnecessary to raise the ability of those working in rural areas, whose skill levels
and knowledge of concrete materials and construction are much lower than that ofworkers in Bangkok. Third, the education should change people’s perception of
concrete, from that of a simple construction material to that of a complicated,
multi-component material which can provide a given service level in any numberof ways and combinations of component materials. Finally, people are not awareof sustainability as an issue and thus need to be instructed about the principles ofsustainability and how it applies to construction and concrete.
3.4 Barriers to sustainable concrete practice and materials
The barriers to sustainable concrete practice and materials are given in Table 2.
Fourteen barriers were identified in total, and these are separated into five generalcategories: institutional, socio-political, economic, technological, and knowledge.
Table 2: Barriers to sustainable concrete practice and materials by category
Institutional• Lack of performance-based design for concrete materials and structures• Lack of standardized codes for durability and life cycle assessment• Lack of institutional laws and regulations from the government• Gap between research activities and practical implementation• Focus on initial cost only in construction contract bidding
Socio-political• No motivation to specify or utilize sustainable materials and technologies• Political instability leads to inconsistent public policies
Economic• Investment in research and development doesn’t increase market share• No market for sustainable or environmentally-friendly products• Cost of new technologies is higher than cost of labor or materials
Technological• Low level of technology
Knowledge• Lack of knowledge on sustainability and environmental impact• Lack of education among concrete industry stakeholders• Lack of knowledge on additional value (durability, environmental impact, etc.)
Institutional barriers number the largest and include the need for performancebased design and standardized codes for durability and life cycle assessment, as
well as action on the part of the government such as laws and regulations toprovide incentive and guidelines for the industry to operate within. Difficulty inconverting research results into practical and implementable technologies andmethodologies was also a concern. However, the most emphasis was placed on
the focus on initial cost in construction. This supports previous statements

Potential strategies for promoting sustainable concrete practices in ThailandOctober 2010, Kobe, Japan

regarding the importance of cost over other criteria and the high cost competitionin the Thai concrete industry.
Socio-political barriers include the lack of motivation to specify sustainable
materials and technologies in concrete-related areas and the lack of consistentpublic policies due to political instability. These are directly related to theinstitutional barriers discussed above; laws and regulations would provide a
motivating factor for specifying and utilizing sustainable materials andtechnologies, but it’s difficult to implement such policies due to the changing
political situation. The three economic barriers cover the difficult in investing in
R&D when competing on cost, the lack of a market for sustainable orenvironmentally-friendly products, and the cost of new technologies relative tothe cost of labor and materials. Since competition is primarily based on cost, there
is no guarantee that investment in R&D will provide economic returns.
Furthermore, since the cost of labor and materials is already so low, even if newtechnologies are developed they may still be difficult to implement due to theirhigher cost.
The technological barrier focuses entirely on the low level of technology in theThai industry, which is understandable in the context of the previous discussion
on the costs of higher-level technology. Finally, the knowledge barriers arefocused on the lack of knowledge about sustainability, environmental impact, andthe additional value of concrete materials, as well as a lack of higher education
among some members of the concrete industry, particularly in rural areas.
4. POTENTIAL PROMOTION STRATEGIES
Based upon the interview results, the low cost of concrete-making materials andlabor in concrete construction in Thailand is a large obstacle for moving towards
more sustainable practices and materials, making it difficult to introduce
additional value and experiment with new technologies in practice. This low cost
can be seen as a function of the low cost of labor and the local availability ofconcrete-making materials. Since these factors are fundamental aspects ofThailand’s socio-economic status and location, means for promoting sustainableconcrete practices and materials need to be considered which can complement
these conditions.
The starting point should be education, as people are unaware of both thecomplexity of concrete and the potential for concrete as a sustainable construction
material. Raising awareness is a necessary step towards developing a market forenvironmentally-friendly and sustainable technologies. In addition, by bettereducating people about the possibilities of concrete, such as the variety ofalternative cementitious materials, durability against environmental deterioration,
usage of recycled materials, and so on, it may open possibilities for new uses andnew technologies, which will in turn help raise the level of technology. Educationof the government and owners will help move towards regulation andstandardization based upon Thai needs and conditions. These may be necessary tospur the industry into action and push technology forward.
New Technologies for Urban Safety of Mega Cities in Asia

As discussed with the interviewees, one of Thailand’s strengths lies in its
academic and professional institutions. There is already some push towards
consideration of sustainability in these (for example, the Thai Concrete
Association has a subcommittee on energy and environmental conservation), andthese institutions can help to overcome many of the barriers discussed above, andmay even work in tandem with the education suggested previously. For example,
if there is no demand for a standard such as durability or CO 2 emissions, theinstitutions may develop or provide such a framework based upon theirprofessional knowledge and make the framework available to interested parties.
Then, if interest or demand grows, such a framework could serve as a base for alarger, more-industry wide standard – or could be modified depending on theneeds of the industry. In this way, as found in the interviews, the academic andprofessional institutions in Thailand may serve to provide a foundation for futureindustry growth to build upon.
5. CONCLUSIONS
It is necessary to consider differences in socio-economic conditions as part of the
movement towards sustainability in the concrete industry, as concrete construction
depends on so many conditions – such as resource availability, technology level,
institutional framework, industry culture, and more – which vary widely. In thecase of Thailand, it was found that local availability of resources and low laborcosts have led to an industry which focuses intensely on cost competition, making
it difficult to introduce new technologies which don’t reduce cost or to evaluationmaterials, technologies, or services on criteria other than cost. Education could
help raise awareness of industry stakeholders and thus open new markets forsustainable technologies, but such education needs to take into account the needsof the Thai industry and Thailand. Academic and professional institutions can also
serve a powerful role by preparing the way for future trends and setting a basic
framework in place which could be later taken up by the wider industry, should
demand and interest increase. However, the cement and RMC companies willprobably play the largest part, as they are both the strongest stakeholders, with thelargest investment in R&D, and can also help reduce environmental impact fromthe initial stages of production.
REFERENCES
Bell, S. and Morse, S., 2008. Sustainability indicators: measuring theimmeasurable?. Earthscan, London.
Mehta, P.K., 1999. Concrete technology for sustainable development. ConcreteInternational 21(11), 47-53.
Punch, K.F., 2005. Introduction to Social Research. SAGE Publications, London.
Sakai, K., 2009. Towards environmental revolution in concrete technologies. Proc.
11th Annual International fib Symposium, Concrete: 21st Century Superhero. fib,Lausanne.

Potential strategies for promoting sustainable concrete practices in Thailand

Feasibility study of new repair methods
for underground civil infrastructures
based on crack self-healing technologies
Masaru MORITA1, Tae-Ho AHN2,
Ryota TOBE3, Toshiharu KISHI2
1
Department of Civil Engineering, Graduate School of Engineering,
The University of Tokyo, Japanm-morita@iis.u-tokyo.ac.jp
2
Department of Human & Social Systems, Institute of Industrial Science,
The University of Tokyo, Japan3
Department of Urban Development,
Tokyo Special District Sumida Ward Office, Japan

ABSTRACTIn this study, new repair methods based on crack self-healing technologies weresuggested in order to prevent water leakage in underground civil infrastructuresuch as tunnels. First, shotcrete with self-healing capability was examined incomparison with normal shotcrete without self-healing capability. The results ofwater pass test after cracking show that cracked shotcrete concrete mixtures
incorporating self-healing agents exhibit much higher self-healing behavior thanin cracked normal shotcrete concrete mixtures. For new repair materials with
self-healing capability based on crack injection method, various repair materials
were observed. Cracks with an initial width of 0.2 mm in the case of some mix
proportions were almost healed after water passing tests. Finally, the effects ofvarious hydration phases on the self-healing mechanism were analyzed using TGDTA, Digital Microscopy and SEM(EDS). From these concepts, some particular
mix-proportions for new repair method with self-healing capability weresuggested.
Keywords: crack self-healing, repair materials, shotcrete, crack injection method

1. INTRODUCTION
Crack in concrete is one of the biggest problems in terms of durability of
infrastructures. Maintenance and repair of cracked concrete are also very
important for civil engineering fields. In such a background, there is the muchinterest to the practical use of the crack self-healing concrete that can be greatly
reduced the maintenance cost. Water proofing sheets are usually provided
between concrete lining and surrounding ground for tunnel and large-scale
underground structure as the water leakage prevention method. However, it isextremely difficult to achieve a complete waterproof because water easily
penetrates through defect parts. Therefore, if the function to recover the water0ctober 2010, Kobe, Japan

leakage prevention effect can be provided to concrete, it will be ideal for engineer
and owner. (T.H. Ahn, 2008)(T.H. Ahn et. al, 2009)
Recently, several researchers suggested new repair methods based on crack selfhealing technologies for underground civil infrastructures as tunnels.
This study aims to develop the shotcrete incorporating self-healing agents for theunderground civil infrastructures without water-leakage as shown in Figure 1(a).
Moreover, new repair method was also studied as shown in Figure 1(b) where thehole was prepared for repair work of cracks with suitable intervals under waterleakage, and it was filled with the inorganic repair materials incorporating selfhealing agents. This study was performed to investigate the self-healing capabilityof inorganic repair materials to cracks under water leakage conditions.
Existing Shotcrete(a)New Shotcrete(Inclusion of Self-healing materials）
Self-healing of crack

Lock Bolt

New shotcrete⇒Flow out Self-healing
components⇒Self-healing of crack

Existing
Countermeasure
Waterproof
Sheet

Lining Concrete(b)Repairing materials(Inclusion of
Self-healing materials)

Water

Diffusion Direction

Figure 1:Application concept of self-healing technologies for underground civil
infrastructures as tunnels

2. EXPERIMENTAL PROGRAM
2.1 Raw materials1)
In this research, various mineral admixtures such as expansive agent, geomaterials, and chemical agents were used in order to fabricate the self-healing
admixture based on previous research.
2.2 Estimation of waterproofing effects based on the new shotcrete
incorporating self-healing agents
When the cracks occur in the shotcrete incorporating self-healing agent, it isexpected that the self-healing agent begin to diffuse into underground water which
passes the crack. When this underground water passes the crack of the lining
concrete, the self-healing hydrates form in the crack, and there is a possibility that

New Technologies for Urban Safety of Mega Cities in Asia

the crack becomes blocked. From the above-mentioned scenario, the waterproof
effects of the shotcrete incorporating self-healing agents were investigated.
2.2.1 Specimens and water pass test
12 specimens (φ100×300mm) were prepared, Table 1 and 2 show the mix
proportions of shotcrete and tunnel lining concrete in this research.
Table 1: Mix-proportion of artificial shotcrete
Waterbinderratio
W/C(%)
OPC
SH10%
SH30%
SH50%
SH15%(1)
SH15%(2)

59.2

Water

Cement

W

C
360
324
252
180
306
306

213

Selfhealing
agent
SH
0
36
108
180
54
54

Sand

Gravel

S

G

1074

692

Super
plasticizer
SP
0
5
7
16
0
7

Quick
setting
admixture

18

Table 2: Mix-proportion of tunnel lining concrete
Unit content(kg/m 3 )Water
Cement Sand Gravel
W
C
S
G
175
370
809
920

W/C(%)
47.3

20cm

Ⓐ

Lining Concrete(OPC)

Shotcrete(Including of Self10cm healing material)

Ⓑ

Water

30cm

45cm 5mm
30cm
binding

45cm

Ⓑ Ⓐ

10cm
Setting of specimen

Figure 3: Specimens and water pass test for the shotcreteFirst, artificial shotcrete incorporating self-healing agents was cast with around 10
cm thickness. And then, 20cm thickness of ordinary concrete was cast as thetunnel lining concrete after one day. The accelerating agent with aluminate salts
was also used in the artificial shotcrete. Particularly, SH15%(1) and SH15%(2)have high amounts of expansive agent and swelling materials respectively
compared to other specimens. The specimens were demolded and cured for 28
days. After curing, all specimens were splitted by compression testing machine
and then crack width was controlled around 0.2mm by Teflon sheets. Finally, thespecimens were re-bonded with the hose clamp, and then the circumference sideof the specimen was sealed and also the inside container is closed with epoxy
Feasibility study of new repair methods for underground civil infrastructures based on
crack self-healing technologies

0ctober 2010, Kobe, Japan

resin. The set-up for water pass test was prepared as shown in Figure 3 The waterflow through a crack was measured after filling water in the container. The
elapsed time are recorded when the surface of the water decreased 5mm. Thismeasurement was conducted on the 0, 1, 3, 7 and 14 days.
2.3 Estimation of water leakage proofing effect by plugged inorganic repair
materials incorporating self-healing agentsIn the second stage, waterproof effects of plugged repair materials incorporating
self-healing agents were investigated based on the concept as shown in Figure1(b).
Table 3: Mix-proportions of repairing materials

Specimen
A
C
D

Water
binderratio
W/B(%)
030

Ordinary
poltrandcement
OPC
0
60
140

Unit content(g)SelfRepairing
healing
material
agent
types
SH
0
None
140
Swelling type
60
Complex type

※B: Commercial products
The length of the specimens was fixed around 30cm by referring that of generallining concrete in tunnels. Moreover, two types of specimens (φ100mm and φ
150mm) were prepared in order to estimate the diffusion area of repair materials.
Small hole (φ2cm X 10cm) from crack surface was prepared and then the repair
material is plugged. Table 3 shows the mix proportions of repair materials in thisresearch. And then, waterproof effects of repair materials were estimated underwater leakage condition as shown in Figure 4.

Different specimens sizefor testing of diffusion range
Water pass test
10cm

15cm

120cm
45cm

30cm

(a) Infusion of repairing materials (b) Setting of Specimens

Figure 4: Specimens and water pass test for repair materials

New Technologies for Urban Safety of Mega Cities in Asia

2.4 Observation and analysis of the specimens after water pass test
All specimens after water pass test were observed in order to clarify the selfhealing capability. Microscopy and SEM with EDS-detector were carried out toinvestigate the morphology, shape, and size of re-hydration products and to clarify
the mass transport process for recrystallization. Moreover, the carbonation of rehydration products was measured using TG-DTA.

3. RESULTS AND DISCUSSION
3.1 Waterproof effects of shotcrete incorporating self-healing agents
Figure 5 shows the result of water pass test using the self-healing concrete in the
shotcrete. Figure 5(a) shows water surface decrease time, Figure 5(b) shows waterflow per unit time and Figure 5(c) shows the change of crack width index. In
Figure 5(a) and (b), the negligible differences were seen at the initial values, since
the introduced crack widths and surface shapes are not uniform though the widthof the crack was controlled to about 0.2mm. Therefore, two dimension Poiseuille
Equation (1) that was able to consider the difference of ruggedness in the crack
width and crack shape in each specimen was used and examined. The crack width
index is evaluated by the cube root of flowing quantity q calculated from Equation(2) as shown in Equation (3).

Water surface
decrease time(s)

800

OPC
SH50%

SH10%
SH15%(1)SH30%
SH15(2)

5
10
Test period(day)

15

600
400
200
0
0

Change ofcrack width index

Flow(mm3/s)(a) Water level
6000
5000
4000
3000
2000
1000
0
0

5
10
Test period(day)

15

0
‐1
‐2
‐3
‐4
‐5
‐6
0

5
10
Test period(day)15(b) Water flow(c) Change of crack width index
Figure 5: Waterproof effects of shotcrete incorporating self-healing agents

Feasibility study of new repair methods for underground civil infrastructures based on
crack self-healing technologies

0ctober 2010, Kobe, Japanq =C⋅b ⋅ ∆P 3w(1)
12 ⋅ µ ⋅ L

,

q=

V
t

(2)

Where,
q:flow(mm3/s), C: Coefficient in which ruggedness of crack is considered,b:Length of crack (mm), ⊿P:Water head difference (N/mm2), µ:Viscous modulus
of water , L: Length of waterway (mm), w:Crack width (mm), V:Decrease
volume of 5mm water surface (mm3), t:Decrease time of 5mm water surface (s)b ⋅ ∆P 3
w' = 3 q
q =C⋅
w
(3)
12 ⋅ µ ⋅ L
W = w ' − w0' = 3 q − 3 q0
Assumption
assumed to be constant
Where,
w’:Crack width index , q:flow (mm3/s), W: variation of crack width index (mm)，w’0:Initial crack width index (mm), 3 q 0 :Initial flow (mm3/s)
This study aims to estimate the crack self-healing capability according to thechange of crack width index. Figure 5(c) shows that OPC without the self-healing
agents didn’t change the crack width index. On the other hand, SH10%, 30%
crack width index decrease gradually until the 14th day. As for the final value
case, SH10% is better than SH30%, and SH10% waterproof effect became
significant. A great waterproof effect is demonstrated in ease SH50% on 1st day.
However, it is almost constant after the seventh day. The result of SH15%(2) has
improved most and it is thought that the swelling agents became more runny
because initial flow quantity was large as shown in Figure 5(b). Consequently, it
can be confirmed that the waterproof effect is promoted with increase of the selfhealing agents. However, if the increased amount is too much, the waterproof
effect may be not effective. This fact may indicate that chemical stability of
products decreases if dosage of self-healing agent exceeds a certain value.
3.2 Diffusion effect of self-healing agents incorporated in shotcrete
The specimens were divided after the water pass test in order to investigate effectsof shotcrete with the self-healing capability. And then, the crack section of thespecimens were observed and analyzed.
OPC
OPC(Assumed lining concrete) (Assumed shotcrete)

Water flow
Ca
Si
O
C
Al Ca

(a) Normal shotcrete (OPC)
New Technologies for Urban Safety of Mega Cities in Asia

OPC
Self-healing concrete(Assumed lining concrete) (Assumed shotcrete)

Water flow

Ca
O
CSi
MgCa

(b) Shotcrete incorporating self-healing agents (SH50%)
Figure 6: Re-crystallization between cracks under water leakage
The SH50% specimen showed best waterproof effect at the early stage comparedto OPC and thus, the crack surface of SH50% specimen was observed andanalysed in comparison with OPC one as shown in Figure 6. It was found that rehydration products such as CaCO3, MgCO3, and magnesium silicate phases wereformed between cracks due to accelerated diffusion in SH50% specimen.
Moreover, crystal size of re-hydration products was also bigger than that of OPC.
This indicates that self-healing agents significantly affect the formation of rehydration products and its size may become bigger. It is suggested that selfhealing agents may be worthy to be adopted for the design of new shotcrete.
3.3 Waterproof effects of inorganic repair materials incorporating selfhealing agentsThe results of the φ150mm specimen are shown in Figure 7. Figure 7(a) shows
the result of the water surface decrease time and Figure 7(b) shows the result offlow evaluated. Moreover, the crack width index was evaluated by Equation (3) as
the cube root of water flow q. Further, to relatively evaluate the change in thecrack width by the self-healing agents, the change of the crack width index fromthe initial value is shown in Figure 7(c). In a case of φ100mm specimens it was
found that B showed the best performance for waterproof effect. As shown in
Figure 7, however, C and D appeared to be most effective in waterproof effect incase of φ 150mm specimens. A lot of swelling materials are contained in
specimen C and D.
A NoneC Swelling type

B Commercial type
D Complex type

Water surface
decrease time(s)

30000
25000
20000
15000
10000
5000
0
0

10
20
Test period(day)30(a) Water level
Feasibility study of new repair methods for underground civil infrastructures based on
crack self-healing technologies

0ctober 2010, Kobe, Japan

0

Change ofcrack width index

Flow(mm3/s)

2000
1500
1000
500

‐2
‐4
‐6
‐8

‐10

0
0

10
20
Test period(day)

0

30

10
20
Test period(day)30(b) Water flow(c) Change of crack width index
Figure 7: Waterproof effects of inorganic repair materials incorporating selfhealing agents(φ150mm)
3.4 Diffusion effect of self-healing agents incorporated inorganic repair
materials
Photo 1 shows surface of the specimens after water pass test. The secondary
phases were formed on the upper side of the surface in case of specimen B. It did
not depend on the specimen size. On the other hand, it was also found thatspecimen D had both clean surface and good waterproof effect under waterleakage condition. Therefore, the fracture surface of specimen D was observed indetail after water pass test. First, SEM-EDS and TG-DTA analysis wereconducted for specimen D with φ100mm and the diffusion section which is thearea near plugged repairing material at crack surface of repair materials wasinvestigated as shown in Photo 2 and Figure 8.

A

B

C

D

A

B

C

D

Photo 1: Specimens after water test(Above: φ100mm, Below:φ150mm )It was found that some air void is occupied by crystals as shown in Photo 2(a) left
picture. It was confirmed by SEM-EDS result that alumina-silicate-hydrates
phases were formed there as shown in Photo 2(a) right picture. Moreover, thecrystal formation of Ca(OH)2 seems to be a reaction from the unhydrated part ofcement. In addition, it was found a lot of CaCO3 also formed on the surface of
matrix around air void as shown in Photo 2(b). And then, it is confirmed that peakof CaCO3 exists at about 750℃ in the result of TG-DTA as shown in Figure 8.
Furthermore, It was found by DTA curve at around 100℃ that the ettringite wasalso formed. Therefore, the re-hydration products such as aluminate-silicate
hydrates, CaCO3 and ettringite were formed at crack surface near plugged
repairing material in specimen D. Furthermore, the results of analyses by the

New Technologies for Urban Safety of Mega Cities in Asia

SEM-EDS and TG-DTA for the product formed on the end bottom of the same
specimen are shown in Photo 3 and Figure 9. From these results, it was found that
the CaCO3 is mainly formed in the bottom end surface. It is unique that the crystal
shape of CaCO3 was oval type. In Figure 10 the detailed observation at various
positions on the crack surface of the same specimen along the path of the waterflow is shown. The observed Parts A, B, C, and D are located at 0cm, 10cm, 15cm,
and 20cm from the water inflow point as shown in Figure 10. At Part A, it isfound that a lot of tiny holes are seen and it is supposed that a part of pastes ortiny aggregates were flowed out. A lot of defective parts on the surface were also
seen at Part B, too. On the other hand, the needle shape crystals are generated inPart C and D. Because Part C is far away from the plugged repairing material, thegeneration of the needle crystal is sparse compared to Part D. In part D somebright products are also seen. The tiny particles released near the inflow aresupposed to be carried down by the influence of advection and they might betrapped at the narrow space between crack surfaces. Subsequently they might playroll as formation sites and the crack blockage by clogging might happen.
0

-5

C
O

Ca

Mass change(%)

Si
Mg Al

Ca

(a) Near the air void(SEM-EDS)

TG
DTA

-10

-10
-20

-15

-30

-20

-40

-25

-50

-30

-60

Change ofheat quantity(µV)0Ca(b) Inside the air void(SEM-EDS)
Photo 2:Cross section near the crack(φ100mm)-70
300 500 700 900 1000
Temperature(℃)

20 100Figure 8:TG-DTA(φ100mm,
Specimen D diffusion section)

Ca

C
O

Si
Al

Ca

Photo 3:Specimen D bottom surface(φ100mm)

Mass change(%)

10

TG
DTA

0

-40

-10

-60

-20

-80

-30

-100

-40
-50

20 100

0
-20

-120
300

500

700

900

Temperature(℃)

-140

1000

Figure 9: TG-DTA(φ100mm
Specimen D bottom surface)

Feasibility study of new repair methods for underground civil infrastructures based on
crack self-healing technologies

Change ofheat quantity(µV)

-35

C
O

0ctober 2010, Kobe, JapanF

Water flow

F E

E

D

C

10cm

15cm

B

A

C

A
120cm

D

30cm

B

(a) Infusion of repairing materials
Figure 10: 100mm Cross-section of specimen
From these results it is supposed that there are various phenomena brought byrepairing material including self-healing agents, such as the spreading of repairing
materials, the formation of CaCO3, the swelling effect by alumina-silicate hydrate,
the expansive action by the formation of the ettringite, and the re-hydration by theformation of Ca(OH)2 in the crack area.

4. CONCLUSTIONS
1. The addition of self-healing agents to the shotcrete seems to improvewaterproof effects, which are attributed to the formation CaCO3, MgCO3, andmagnesium silicate phases at crack surface under the water leakage condition.
2. It was supposed that repair material having self-healing capability andwaterproof effect could be manufactured by using inorganic self-healing agents.
3. It is considered that the utilization of self-healing agents with appropriate
dosage has a possibility as new repairing methods for cracked concrete under thewater leaking situation, which is common among underground structures.

REFERENCES
T.H. Ahn“Development of self-healing concrete incorporating geo-materials, A
study on its mechanism and behavior in cracked concrete”, Ph.D. dissertation,
Dept. of Civil Engineering, The University of Tokyo, Japan ,2008.
T.H. Ahn, T. Kishi ”New method as the self-healing design to repair cracks incracked concrete”, Proc. of 4th International Conference on Construction
Materials : Performance, Innovations and Structural Implications, pp. 1339- 1346,
Nagoya, Japan, Aug. 24-26 (2009)

New Technologies for Urban Safety of Mega Cities in Asia

The Driving force of Private Sectors Emergedin 1999 Taiwan Earthquake Condominium
Reconstruction
Cho-Fang TSAI1, Osamu Koide2, Takaaki Kato3
1
PHD candidate, Department of Urban Engineering,
The University of Tokyo, Japan
nancy@city.t.u-tokyo.ac.jp
2
Professor, Department of Urban Engineering,
The University of Tokyo, Japan.
koide@city.t.u-tokyo.ac.jp
3
Associate Professor, Institute of Industrial Science,
The University of Tokyo, Japankato-t@iis.u-tokyo.ac.jp

ABSTRACT
Condominium is the major housing form in the city, but also a latent problem
when it comes to post-disaster reconstruction. The private sector emerged as adriving force in the condominium reconstruction process while the government
with limited power to intervene in private properties, and little market profit
making housing developers retreat from investing. This study discusses following
issues by the experiences of “921 Earthquake Relief Foundation”, a key NGO
assisting in condominium reconstruction, and the interviews of 11 condominium
communities in Taichung City and Taichung County in Taiwan.
The fist issue is the formation of cooperation partnership for reconstruction. It
discusses the allocation of responsibilities and establishment of cooperation
relations among the condominium communities, private foundations andgovernment departments during the reconstruction process.
The second issue is the reconstruction mechanism based on the cooperation
partnership. This issue analyzes the reconstruction results created by theinteraction among developing community collective resources, removing
obstacles, and accessing external assistances.
It is found that, at the community level, rather than economic resource, but
community consensus and leadership were the two essential community collective
resources for condominium reconstruction. Secondly, at state level, “921
Earthquake Relief Foundation” played a big role in substituting the government
to concentrate and transmit society resources, and empowered the communities
simultaneously. Thus, it is suggested that to foster the capacity of private sector toparticipate in public affairs is an important strategy for disaster mitigation andpost-disaster recovery.
Keywords: earthquake, reconstruction, condominium0ctober 2010, Kobe, Japan

1. INTRODUCTION
1.1 Background & Objective
The Chi-Chi Earthquake, Magnitude7.3, hit central Taiwan in September 1999,
which was believed to be the most severe disaster in the past 100 years in Taiwan.
A total of 50,625 housing units were severely damaged, including 153
condominiums (10,974 households), accounting for over 1/5 of all collapsed
housing. In 2006, after the reconstruction period, about 57.84% of the collapsed
condominiums were successfully reconstructed (921EPRC, 2006).
Condominium reconstruction associated with complex problems of property
adjustment and with little market profit, kept the government and housingdevelopers from being involved, and posed the communities to conduct thereconstruction business by themselves. Unexpectedly, through the reconstruction
process, a unique private force appeared in the private sector, the reconstruction
communities and “921 Earthquake Relief Foundation, 921ERF”in particular.
Thus, this study aims to explore the key issues of self led reconstruction in thecondominium community. More specifically, we are interested in the formation ofcooperation partnership between the communities, NGO, and the government
department, and the reconstruction mechanism by which the community
developed their collective resources, removed obstacles, and accessed to external
assistances.

1.2 Method & Data
In this study, Taichung City and Taichung County, as the biggest metropolis incentral Taiwan and one of severe disaster-hit areas, were selected to be the study
areas.
The research materials were mainly constituted by governmental archives andface-to-face interviews. Interviewees included superintendents related toreconstruction department in Taichung City and Taichung County government,
the members of 921ERF in charge of guiding condominium reconstruction, andthe leaders of community renewal committee. 11 intervened communities wereselected according to the community size, and the interviews were held at
September 2008, and February 2009 (Table 1).
This study was conducted in two phases. Firstly, it discussed the interaction
performance between reconstruction resources, obstacles, and external assistances,according to the experiences of all the 25 failure cases in the study area. Secondly,
it explored how the communities developed their collective resources, i.e.
community consensus, public participation, organizational operation, andleadership, applying in reconstruction business, by the experiences of 11
successful condominium communities.

New Technologies for Urban Safety of Mega Cities in Asia

2. Characteristics, resources, and obstacles
As Komori (1997) suggested, compared to single building, the condominium withcharacteristics of both high-rise building type, and community living style,accordingly derives the unique collective resources and obstacles forreconstruction (Figure 1).
Summing up our investigation result, ownership, consensus, financing andcoordination could be considered to be the top four main issues influencing
reconstruction , which showed as follows：(1) Interest conflict due to different positions
The confrontation positions coming from the variant land value in the mixed use
community, or the opposite expectations for reconstruction between residential
owners and developer owner always raised disputes or litigations and thendelayed reconstruction progress.
(2) Joint ownership problem
It was hard to excess the threshold proportion of ownerships committed to rebuild,and the heavy burden of compensation to withdrawer went beyond thoseparticipants’ affordability.
(3) Difficult to receive financeAttributed to the high risk of financing to the community with households ofvariant financial capacity and economy credit, it was not easy for the communities
to receive the funding for rebuilding projects.
(4) Co-structure problem
In Taiwan, the building structure of condominiums usually jointed in the same
basement, it caused technical difficulties and safety concerns when the collapsedbuildings rebuilt.
(5)Lack of operational ability
Sudden change in the role of developer, communities were lack of operational
ability when they took up the responsibility of self led reconstruction in the after
math of earthquake.
Reconstruction obstacles

High-rise building type
˙Large scale development
˙Mixed land use
˙Co-structure

InduceCondominium
housing

˙Technical difficulty & safety concern
˙Hard to reach reconstruction
agreement: ①Interest conflict or dispute,②too many households withdrew fromrebuilding

Cope with
Community living style
˙Joint ownership
˙Variety of households

InduceCollective resources
˙Consensus
˙Organization

˙Participation
˙Leadership

Access toExternal assistances
˙Public sector—economy assistance, procedure
simplification, regular amendment
˙Private sector---guidance, extra finance

Figure1 Relationship between condominiumy characteristics , andreconstruction resources and obstacles
The Driving force of Private Sectors Emerged in 1999 Taiwan Earthquake Condominium
Reconstruction

0ctober 2010, Kobe, Japan

3. External Assistance
3.1 Public sector
In terms of public assistance, according to “Provisional Statute For September 21
Earthquakes Disasters Reconstruction 九二一震災重建暫行條例 ”, the authority
lowered the threshold proportion of the ownerships committed to rebuild, andincreased the floor area ratio to subsidy reconstruction costs. However, thecountermeasures did not work, while there were too many empty houses inTaichung area, most of the collapsed condominiums were located on non-profit
locations, and meet housing market downturn during the rebuilding duration
simultaneously. In economy assistance, the central government provided free /low-interest loans to support rebuilding funding; moreover, it innovated the”
Negotiation loan assumption ” scheme allowing affected households offset theirprevious home loans obligations with collapsed house and land property, which
effectively lift the burden of double loans on affected households.
3.2 Private sector“921 Earthquake Relief Foundation, 921ERF” , a NGO established by 921
Earthquake donations, supervised by social leaders, and directed by Professor Xie,a professor of Taiwan University, play a significant role in guiding and financing
community reconstruction. For ownership’s problem solving, 921ERF made up
for the restraint that the government can not intervene or aid private property,
implementing the " Blessing Program 臨門方案", by which it bought out theownerships which were unwilling or unable to participate reconstruction, andproved interest-free loan to finance communities during the rebuilding period. To
ensure the reconstruction quality, professional consultancies were introduced tosupervise rebuilding process. it also set up a "Family of Blessing Program ", via
symposiums, learning courses, site visit, to improve their operating capacity andencourage their confidence. " Blessing Program " not only provided practicalassistances, but also accompanied the communities to go through the rebuilding
process. Consequently, it helped 5,410households (70 plots) to rebuild, and got
back 228 housing unites, with total spending eight billion NTD, and earned great
praise.
4. Stakeholders, organization, and role allotment
As the reconstruction process is a collaborative process, it needs communities,
NGO, professional bodies, and the government work together to successfully
accomplish reconstruction task. To overcome the problems of informationtransmission, department coordination, and barriers identification and elimination,a three-level interaction network, in which community acted as a center linking
local society, and central government, was developed. Characterized in that eachlevel had a host subject associated with an intermediate unit playing contact,
coordination and guidance functions, and then The 921 Earthquake Post-disaster
Recovery Commission,921EPRC, responsible for leading the reconstruction affairs incentral government, along with 921ERF ran through each level to integrate all themembers. The illustration of stakeholders, contact relations and division of

New Technologies for Urban Safety of Mega Cities in Asia

Initiating phase

921 EPRC

Reconstructing process (community)side)
Establish renewal
committee

Acts & strategies
˙Final collapsed judgment
˙Level down reconstruction

Investigate residents’
willingness

Designate therenewal unites

thresholdContrasted
thplanning
team

Local
government

Help to hold residents’congress

Set up counselingstationHelp to eliminate
disputes

Supervise
progress &accommodate
disputes˙Determination of
Determine the renewal implementer

Knowledge & skill

collapsed situation(Implemented by committee itself or entrust to other

˙Renewal training courses
˙Renewal specific handbook

Summit a brief outline ofrenewal business plan

Conduct a public
hearing

˙Co-constructing structure
˙Doubt about the rights
transformation

˙Integration ofreconstruction consensus

Renewal planning phase

Approve therenewalcommittee

Register the
renewal committee

Subsidy planning fee

Draft the renewalplans
˙Land uses plan
˙Detailed plan andspecifications
˙Financial plan
˙Removing andsettlement plan

Draft the rights
transformation
˙Investigate willingness
˙Coordinate ownershiptransformation

˙Appraise right value
˙Compensating plan

921ERF

Negotiate with
Syndicate of banks
˙Investigate loanbalance˙Calculate rebuilding
expense˙Concert the sum of
take-over˙Apply interest subsidy

˙Draft renewal plan
˙Assist in negotiating

Application of renewal plan
& rights transformation plan permits

Approve
renewal plan

Approve 臨門方案

Promulgate & implement

Reconstructing
Reconstructing
phase
phase

Subsidy facility
expenseApply forbuilding permit

Housing
construction

Economic support
Subsidy banks to afford
˙Negotiation loan
assumption
˙Low-interest loan
˙Credit Guarantee

Amend rights
transformation

Issue
compensation

Apply forusage permit

Assist in contracting& supervise
construction work

˙˙Advance

Pay off the debt owing to 921ERF& rights transformation

Move into rebuilt housing

˙˙Non-interest loan forrebuilding finance˙˙Supervise rebuilding
quality

Assist in rights
allocation &transformation

Figure 2 Stakeholders and roll allotments during condominium reconstructing process

The Driving force of Private Sectors Emerged in 1999 Taiwan Earthquake Condominium Reconstruction

compensation
˙˙Purchase abandonedownership titles

0ctober 2010, Kobe, Japantasks please refer to Figure 2, and Figure 3.
Private sector

Subjects & intermediary
(1)

(2)

(3)

(4)

Community level---community &commissioned Planning and design team(link：community, local government, and921 ERF)
Local level --- local government &commissioned consultant group (link：
local government, and community)Central level---Executive Yuan
&921EPRC(link：Central government,
local government, and 921EF)
921ERF(Link：921EPRC, communities,
professional groups, and banks)

Local level

Syndicate of banks

Community Level

Community

Planning and design teamReal estate management co.

Commissioned consultant group
group
Local government地

921 ERF921 EPRC

Central government
Contact &coordination

Support &supervision

Figure 3

Public sector

Central level

Stakeholders and interaction network

5. Reconstruction result & case study
In Taichung County and Taichung City, there were 72 (size range between 10 to801housing unites) condominium buildings collapsed, of which 47 buildings wererebuilt, spending 4~7 years after 921 Earthquake. 43 rebuilding condominiums
were supported by “Blessing Program”. The remaining 25 condominiums,
because of disputes on collapsed judgment or interest conflict over ownership
adjustment, had not yet begun to rebuild at the end of reconstruction period.
5.1 Resources, obstacles, and external assistances
Though the experiences of 25 abandoned communities, it was found that inaddition to the reasons of community size and missing the timing of launching thereconstruction business, the failure causes mainly focus on insufficient collective
resources：Weak consensus (rank=1, N=18), loose community organizations andresidents with low willingness to participate (rank 3, N = 11), and the leader notinterested in the reconstruction work (rank 2, N = 14) or lack of implementation
The w hole process

EconomyLaunch phase

Obstacles

Planning phase

Rebuilding phase

AssistanceCommunity resources

20
15
10
5
0
Interest

Knowledge

Planning
team

Negotiatio
n loanassumptio

14

1

8

11

4

2

0

0

2

0

8

8

1

6

7

3

1

4

0

2

2

1

Down
payment

Costructure

Collapse
Organizatio
Mixed use Ownership Litigation Consensus repurchase
Attitude
judgmentn

The whole process

2

6

4

7

6

5

18

9

11

Launch phase

0

0

1

2

2

3

3

2

2

Planning phase

2

6

3

4

4

1

13

5

Rebuilding phase

0

0

0

1

0

1

2

2

Figure 4 Analysis of failure causes of condominium reconstruction---community resources, obstacles, and external assistances
Source: Taichung City government, and Taichung County government; adapted by author

New Technologies for Urban Safety of Mega Cities in Asia

capacity (Rank 6, N = 8). Second is the issue of external assistances ：The
contracted consultant lacking of professional competence, or dropping out of the
project (rank 3, N = 11). Unexpectedly, individual household’s economic
problems, i.e. insufficient down payment, were not serious (N = 2). It confirms theopinion of this study that the collective resources are more important than
individual economic resources, and a lack of the capacity to access to external
resources will more likely result in vulnerable reconstruction result (Figure 4).
5.2 Successful experiences of self led reconstruction
In this study, 11 communities were interviewed and their basic information was
illustrated as table 1. According to their experiences, we explore their formationof collective resources, leadership performance, and organization operation, toidentify the relationship between the collective resources and successfulreconstruction. Through interviews, we found that the meaning of successfulreconstruction is not only for the community to overcome extreme difficulty toregain their homes, but also to develop their own potential. More importantly,
they created a new community empowerment experience in Taiwan.
(1) Building reconstruction consensus
Strong community sense and clear analysis of the advantages and disadvantagesof reconstruction immediately after disaster is the key point of building
reconstruction consensus. Yi Shu 藝術 Community, the first rebuilt community
by way of renewal, is a community full of strong community sense; Pre-disaster,
they had held regular monthly party and clean-up activities, and initiated theslogan “creating a safety, peace, and harmony community” to encouraged
themselves. On the third day after the disaster, they gathered in the neighborhood
center and reach initial consensus of rebuilding under candlelight. (Leader Liu)
Simple and clear explanation of the pros and cons is the basis of reconstruction
Table 1 Basic information of interviewed communities
Community

Scale hhPre- Post-

Duration

Community composition

Socio-economic
conditions of the leader
Female, 40s, high school,
employee
Female, 30s, high school, shop
owner
Male, 40s, collage, trader
Male, 50s, collage , retired civil
servant
Male, ,50s, collage, owner ofland administration office

A-1 Wen Xin
文心 community
A-2 Tai Zi
太子 Community
A-3 Long Ge
龍閣 Community
A-4 Yuan Jian
遠見 Community
A-5 Tian Xia
天下 Community

445

270

6Yrs,8Mos

198

197

4Yrs,5Mos

167

40

5Yrs,2Mos

employee, labor, landlord,shop owner
civil servant, labor, landlord,shop ownerlandlord, employee, trader

106

106

5Yrs,4Mos

civil servant, service trade

132

105

7Yrs,3Mos

employee, labor, shop owner

B-1 Xiang Yang
向陽 Community
B-2 Feng Tian豐田 Community
B-3 Yi Shu
藝術 Community

78

75

4Yrs,11Mos

78

73

---

employee, service trade, civil
servant, shop owner
employee, labor, shop owner

56

56

3Yrs,1Mos

civil servant, employee

Male, 60s, high school, designer
Female, 60s, Primary school,
employee
Male, 60s, collage, retired civil
servant

C-1 Zhang Xing
38
38--professor, employee, vendor,
Female, 60s, doctor, professor
中興 Community
shop owner
C-2 Jin Xiang
20
20
7Yrs,6Mos
landlord, employee, labor,
Female,40s, high school, owner
錦祥 Communityof housing agency
C-3 Wei Dau
18
18
5Yrs,3Mos
employee, labor, landlord
Female, 40s, high school,
衛道 Community
accountant
Note: A >100、B 41~100、C <40 households, divided according to the standard of renewal subsidy
Source:921ERF, and interviewed communities; adopted by author.

The Driving force of Private Sectors Emerged in 1999 Taiwan Earthquake Condominium
Reconstruction

0ctober 2010, Kobe, Japan

consensus building, by which residents can judge whether reconstruction is
worthy and reduce the delay time for hesitation(A-1WenWin 文心 Community
director-general Lin).
(2) Reconstruction leaders emerging from grass roots
This time, most of the chairman and the director-general of the community
renewal committee were served by housewives, blue collar workers and farmers.
Not willing to let their home became wasteland they resolutely took up the task of
the rebuilding leaders. With the unswerving determination and enthusiasm, they
visited previous neighbors one by one across all the Taiwan persuading them tocome back to participate reconstruction. In the beginning, they even not knowing
about rebuilding works, nor how to conduct a meeting, by way of trial and error
and the guidance from 921ERF, eventually they overcame all the difficulties andaccomplished reconstruction mission. It really the magic power of grass-rootssociety revealed in the recovery process. They unanimously believed that afterreconstruction they not only regain their home, but also deepen their community
consensus. (Mrs. Peng, leader of B-2 FenTian 豐田 Community; Mrs. Zhang,leader of C-2 Jin Xiang 錦祥 Community; Mrs. Wu, leader of C-3Wei Dau 衛道
Community)(3)Reconstruction community operation
As a variety of residents living in the community, if we can explore their expertiseto serve community works, on the one hand it can heighten residents’ selfawareness and enhance their interest on the reconstruction, and can promoteneighbor relationships via mutual inspiration to maintain reconstruction
confidence on the other, Mr. You , director-general of Tai Zi 太子 Community,
said. The followings were their experiences：

Collapsed condition of
XingYiang 向陽 Community

Children panting class

Reconstructed condition of
XingYiang 向陽 Community

Site visit

Reconstructed condition ofLong Ge 龍閣 Community

Blessing Program Congress

Source：XingYiang 向陽 Community, Tai Zi 太子 Community’s website, and author

New Technologies for Urban Safety of Mega Cities in Asia

A. Construct the website & issue periodical
In order to share community information to boost mutual trust and enhance
residents’ concern about reconstruction affairs, they set up the website and issued
periodical to post community events, administrative information of thecommunity renewal committee, reconstruction progress, financial reports, andseismic test results, etc.; also set the column for opinion exchanges to eliminate
misgivings.
B. Calling residents with specialty together to join in volunteer team
To promote reconstruction works, Tai Zi 太子 Community called the residents
together to form community volunteer teams to serve as administrative staffs or
the teacher for various learning courses.
C. Giving training courses and learning classes
There is also training courses, led by the residents with professional expertise ofenterprise, legal, or public affairs, via education and training activities to enhance
volunteers’ capability applied in community administration tasks. They held
learning activities such as painting, writing classes for children and computerclass for residents as well. Learning along with the progress of reconstruction
made residents feel full of energy.
E. Experiences exchange
Sometimes Tai Zi 太子 Community also associated with 921ERF to hold site
visiting or workshop to pass on their reconstruction experiences to the othercommunities.
6. CONCLUSIONS(1) Collective resources and reconstruction opportunities
Compared to individual reconstruction, collective reconstruction heavily rely on
community resources, that reveals a opportunity to get rid of the retrain ofindividual households’ social-economic situation, and to enhance reconstruction
capacities by way of community empowerment in the aftermath of severe disaster.
(2) Networks and intermediaries are essential for community empowerment
Condominium reconstruction is not only community’s own affairs, but also thecooperation result of community, government, and intermediary. The experienceof 921ERF enlightened us that the intermediary is essential in assistance in theaffairs of information transmission, guidance, and coordination, when theauthority implementing reconstruction supporting policies. With their assistances,
communities can enhance their ability for self led construction immediately after
disaster.
(3) Private force is an indispensable prop for disaster mitigation and postdisaster recovery
The principle of Taiwan government’s reconstruction policy, not directlyintervening in the reconstruction affairs as much as possible, unexpectedly
boosted the vigorous private force and got a great achievement. The wave of self
development in civil society, not only occurred in the upper classes of society
The Driving force of Private Sectors Emerged in 1999 Taiwan Earthquake Condominium
Reconstruction

0ctober 2010, Kobe, Japan(921ERF), more generally occurred at the grassroots level (renewal communities).
Therefore, how to develop a social environment which can stimulate the potentials
of private forces, and effectively induce them involved in the disaster mitigationand post-disaster recovery affairs, is a critical issue for us to consider.

REFERENCES
921 Earthquake Relief Foundation, 2006. Report on “Blessing Program 臨門方案”, Website:http://www.taiwan921.lib.ntu.edu.tw/
Chang Fang Engineering Consultants, Ltd., 2005. Report on the Advisory Service
for Housing and Community Renewal in Taichung County, Taichung Taiwan.
David W. McMillan, Nashville, and Tennessee, 1996. Sense of community: A
definition and theory. Journal of Community Psychology, 24(4), 315-325.
Honda Assets Valuation Co. Ltd., 2004. Final Report on Follow-up Consultant
service for 921 Earthquake Reconstruction in Taichung City, Taichung Taiwan.
Hobfoll, S. E. (1998). Stress-, Culture, and Community ： The Psychology andPhilosophy of Stress. New York：Plenum.
Lyouzi, M.T., 1999. Condominium Reconstruction--- Struggle against Hannsinn
Earthquake, Tokyo：NIKEI Architure.
Talen, E. (1999). Sense of Community and Neighborhood Form: An Assessmentof the Social Doctrine of New Urbanism Emily. Urban Studies, 36(8), 1361-1379.
The 921 Earthquake Post-disaster Recovery Commission, EY, 2006. Review of
Housing reconstruction after 921 Earthquake, Taichung Taiwan.
Yap, K.S. (1999). Community Participation in Low-income Housing Projects:
problems and prospects. Community Development Journal, 25(1), 56-65.

New Technologies for Urban Safety of Mega Cities in Asia

Influence of resin properties on the shear
capacity of RC beams repaired by TST-FiSH
Yoshitaka KATO1, Masamitsu SUZUKI2, Masanori ITO2 and Takeshi MAKI3
1
Associate Professor, ICUS, IIS, The University of Tokyo, Japankatoyosh@iis.u-tokyo.ac.jp
2
Researcher, Tokyu Construction, Japan
3
Associate Professor, School of Engineering, Saitama University, Japan
ABSTRACT
After disasters such as earthquakes it is necessary to quickly repair damage inorder to ensure safety and speed recovery efforts. However, conventional methods
require large-scale operations and the repair effect may be delayed. Therefore,
the authors proposed an emergency rapid retrofitting method utilizing fiber sheetscontaining hydraulic resin (TST-FiSH) for the repair of reinforced concrete
structures. The goals of this new method are to provide higher safety, speed, andease of application compared to conventional methods. The basic properties of
TST-FiSH and the repair effect have been investigated, and in this paper the
influence of resin material properties on the shear capacity of RC beams repairedby fiber sheet is reported. It was experimentally understood that the joint strength
between fiber sheets is an important factor for improving the shear capacity of RC
beams even if the bond and adhesion strengths between fiber sheet and concretesurface are not so strong.
Keywords: hydraulic resin, continuous fiber sheet, shear capacity, joint strength

1. INTRODUCTION
In Japan, the importance of a seismic reinforcement in concrete structures was
realized after the Hanshin/Awaji great earthquake disaster of 1995. Seismic
reinforcement improves ductility primarily by avoiding the brittle “shear fracture”
which occurs in column members. Main transportation and emergency
transportation roads in the Tokyo metropolitan area are mostly reinforced by thismethod; however, there are still many structures which may suffer damage due tothe magnitude of the earthquake. In addition, new structures cannot avoid damage,as they are designed to permit some damage during a large-scale earthquake.
When structures are damaged by natural disasters, they require emergency
retrofitting to ensure safety and functionality. Conventional methods, however,cannot adequately cope with subsequent aftershocks, and large-scale repair works
are time consuming. From a concept inspired by medical plaster casts, a new
repair method utilizing fiber sheets containing hydraulic resin (TST-FiSH) was
developed to address this problem. This method can repair reinforced-concrete
structures through the hardening effect of hydraulic resin when sprayed withwater, and can provide higher safety, speed, and ease of application compared toconventional methods (Figure 1).

0ctober 2010, Kobe, Japan

Figure 1: Conceptual figure of proposed method
The fiber sheet is lightweight and can be wrapped around structures of various
forms and this method utilizes the fiber sheet containing hydraulic resin as afinished product. By utilizing a manufactured product, construction time is
reduced compared to conventional methods since it is not necessary to apply anadhesive to the structure or to perform extensive preparations. The repair effect of
TST-FiSH using different types of fiber sheets such as carbon, aramid or vinylon
was examined experimentally in a previous investigation, and it was confirmedthat the shear capacity could recover to the same level or higher than before
damage occurred (Suzuki et al., 2009). The handling of the aramid fiber sheet waseasiest from the construction performance viewpoint, and its construction time
was less than 1/3 that of a conventional method. This is the most significant
advantage of this method because we can reduce the repair cost. However, thereliability of the hydraulic resin is less than that of the epoxy resin in construction
field repair works. In order to improve the reliability for practical use, the detailed
mechanism, especially the influence of hydraulic resin properties on the shear
capacity of RC beams, should be examined. In this study, two types of hydraulicresin and an epoxy resin were prepared to understand this influence.
2. EXPERIMENTAL PROCEDURE
2.1 Material properties
The hydraulic polyurethane resin (viscosity：35,000～45,000 mPa･s at 25℃)
used in this study is a single liquid-hardening resin which reacts and begins
hardening after contact with water and in the presence of carbon dioxide. The
hydraulic polyurethane resin was diluted with glycol ether solvent (HPR-A) orreactiveness monomer (HPR-B) because the pure resin was difficult to handle due
to high viscosity. The amount of resin spreading on an aramid fiber sheet is 0.45
kg/m2 and 0.85 kg/m2, respectively. For the repair procedure, the fiber sheet
impregnated with the resin is applied on the test specimen.
The epoxy resin (viscosity：20,000 mPa･s at 20℃) used in this study, which is
widely used as a resin for continuous fiber sheets in the construction field, is adouble liquid-hardening resin. The amount of resin spread on an aramid fiber
sheet is 0.8 kg/m2, and the repair procedure is as follows. The primer is spread on

New Technologies for Urban Safety of Mega Cities in Asia

the test specimen and the undercoat resin is spread, then the fiber sheet is applied
to the specimen, followed by the topcoat.
The physical properties of the aramid fiber sheet used in the experiments areshown in Table 1.
Sheet typeAramidTable 1: Physical properties of aramid fiber sheet
Weight Tensile strength Young’s modulus
Fracture strain(g/m2)(N/mm2)(N/mm2)
(%)
5
280
2,060
1.18 x 10
1.8

2.2 Mechanical tests of fiber sheet impregnated with resin
2.2.1 Tensile test
Tensile test of the fiber sheet and the fiber sheet impregnated with the resins was
conducted following JSCE-E 541-2007 (Japan Society of Civil Engineers). The
fiber sheet impregnated with the resins was cured in the air (20℃，RH60%) for 7
days. Tensile strength (f fu ) and Young’s modulus (E f ) were calculated by
Equations (1) and (2), respectively.
FuA
F60 − F20
Ef =(ε 60 − ε 20 ・) A
f fu =(1)(2)
where, F u : maximum load (N), A: cross sectional area (mm ), F 20 , F 60 : load at
20% or 60% of maximum load (N), ε 20 , ε 60 : strain at F 20 or F 60
2

2.2.2 Joint test
Joint test was conducted following JSCE-E 542-2007. The curing condition was
the same as the tensile test. The joint length was changed (150mm, 200mm, and250mm), and joint strength (f fus ) was calculated by Equation (3).
f fus =

Fu
A

(3)

2.2.3 Bond test
Bond test was conducted following JSCE-E 543-2007. The curing condition was
the same as the tensile test. Bond strength (τ u ) and de-bonding energy between
fiber sheet and concrete interface (G f ) were calculated by Equations (4) and (5),respectively.
τu =
Gf =

Pmax
2b・l
2

Pmax
8b ・E ・
t
f
2

(4)

(5)
where, P max : maximum load (N), b: width of fiber sheet (mm), l: effective lengthof fiber sheet, t: thickness of fiber sheet (mm)Influence of resin properties on the shear capacity of RC beams repaired by TST-FiSH

0ctober 2010, Kobe, Japan

2.2.4 Adhesion test
Adhesion test was conducted following JSCE-E 545-2007. The curing condition
was the same as the tensile test. Adhesion strength (f au ) was calculated by
Equation (6).
f au =

Fau
As

(6)

2

where, F au : maximum load (N), A s : area of steel jig (40mm× 40mm: mm )2.3 Loading test of RC beam repaired by fiber sheet

The repair effect of TST-FiSH was evaluated using beam specimens under twopoint loading. Specimen dimensions are shown in Figure 1 and specimen
specifications and material properties are given in Table 2. The beam was repairedby wrapping TST-FiSH in a single-layer in the shear span (Figure 2) with a
200mm overlap on top of the beam. Loading test was conducted after 7 days
curing. Loading was applied one-directionally with gradual but steady increase.
Cracks were observed visually and load, vertical displacement, axial
reinforcement strain and shear reinforcement strain were measured.
6@50=300

6@150=900

300

6@150=900

6@50=300

250
50

50

350
100 100

180

75

75

280

2100

300

mm)
（(unit:
単位：mm）

300

2700

Figure 1: Beam specimen dimension
Table 2: Specimen specifications and material properties
No.
1
2
3
4

d
(mm)
300

a
(mm)
900

a/d

Main rebar
Steel ratio
Material(%)

Shear reinforcement
Steel ratio
Material
(%)

3

SD490
D29

SD295A
D6

Concrete

Compressive(N/mm2)

No.1
No.2
No.3
No.4

32.5
30.6
33.5
32.5

Young’smodulus(N/mm2)
2.43×104
2.35×104
2.45×104
2.43×104

3.06

Reinforcement
SD490
D29
SD295A
D6

0.15

Fiber
sheet
AramidYield
Tensile(N/mm2) (N/mm2)

Resin
Epoxy
HPR-A
HPR-B
Young’smodulus(N/mm2)523

677

1.87×105

349

506

1.82×105

New Technologies for Urban Safety of Mega Cities in Asia

Wrapping direction

Fiber sheet

Figure 2: Repaired specimen
3. EXPERIMENTAL RESULT AND DISCUSSION
3.1 Physical properties of resins
3.1.1 Tensile test result
Tensile test results are shown in Figure 3. The tensile strength of the fiber sheetwith resin was mostly same although the young’s modulus of epoxy type wassmaller than that of HPR series.
4000
3500

Fiber sheet
Epoxy
HPR-A
HPR-B

Stress (N/mm2)

3000
2500

Tensile Strength2130 (N/mm 2)2610 (N/mm 2)2460 (N/mm 2)2660 (N/mm 2)

2000
1500

Fiber sheet

1000

Epoxy
HPR-A

500

HPR-B

0
0

5000

10000
15000
Strain (µ)

20000

25000

Figure 3: Tensile test result
3.1.2 Joint test result
Joint test results are shown in Figure 4. In the case of epoxy, fracture within the
joint part was not observed so that the joint strength was same as the tensile
strength of the fiber sheet with epoxy resin. In the case of HPR-A, the joint
strength was smaller than the tensile strength of the fiber sheet with HPR-A,
although fracture mostly happened in the non-joint area. In the case of HPR-B, thejoint strength was very weak compared with other cases and fracture happened in
the joint area. The joint strength was mostly the same although the joint lengthchanged depending on the case.

Influence of resin properties on the shear capacity of RC beams repaired by TST-FiSH

0ctober 2010, Kobe, Japan

3000
HPR-A

Joint strength (N/mm2)

2500

HPR-B

2000
1500
1000
500
0
100

150

200
Joint length (mm)

250

300

Figure 4: Joint test result
3.1.3 Bond test result
The de-bonding energy between fiber sheet and concrete interface (G f ) and thebond strength are shown in Figure 5. The de-bonding energy and the bondstrength of epoxy were higher than those of other resins. In the case of HPR-B,
the de-bonding energy was quite low though the bond strength was almost thesame as the epoxy. In the case of HPR-A, the de-bonding energy was not so low
though the bond strength was not so high.
1.2

4.0

Gf

Gf (N/mm)

3.0

0.6

2.0

0.3

1.0

0

0
Epoxy

HPR-A

Bond strength (N/mm 2)

Bond strength

0.9

HPR-B

Figure 5: G f and bond strength
3.1.4 Adhesion test result
The adhesion strength of epoxy, HPR-A and HPR-B was 5.1 N/mm2, 2.1 N/mm2
and 3.2 N/mm2, respectively.
3.1.5 Summary of material test results
A summary of the above material test results is shown in Figure 6 using a radar
chart and normalizing by the test results of epoxy (100%). It could be understoodthat the epoxy resin showed higher performance and the material properties of
HPR series showed different properties. Therefore, the influence of resin
properties on the shear capacity of RC beam repaired by fiber sheet may beclarified by using these different types of material.

New Technologies for Urban Safety of Mega Cities in Asia

Tensile－Epoxy－HPR-A－HPR-B

100%
80%
60%

Adhesion

40%

Joint

20%
0%

De-bonding
energyBond

Figure 6: Summary of material test
3.2 Loading test result
The load displacement curve is shown in Figure 7. The fracture mode was shear
fracture after yielding of the shear reinforcement in all cases. It could be clearly
understood that the HPR-A (No.3) showed mostly same repair effect as the epoxy
one (No.2) though the adhesion strength and the bond strength were very small. In
the case of HPR-B (No.4), the repair effect was smaller than epoxy and HPR-A;
however, the maximum load was almost twice that of the non-repaired RC beam
(No.1). When comparing with the material test results (Figure 6), it wasconsidered that the joint strength and the de-bonding energy were importantfactors to increase the shear capacity of RC beam. On the other hand, the bondstrength between the fiber sheet with resin and the concrete was not important. In
order to verify this consideration, two additional test cases were conducted.
900
800

No.1

No.2

10

20

No.3

No.4

700

Load (kN)

600
500
400
300
200
100
0
0

30

40

50

Displacement (mm)Figure 7: Load displacement curve (No.1 – No.4)
3.3 Additional loading test and result
In order to clarify the influence of the bond strength on the shear capacity of RC
beam, an RC beam without bonding between the fiber sheet using HPR-A and theconcrete surface was made. In this specimen, only the joint strength between fiber
sheets is effective to improve the shear capacity of RC beam.

Influence of resin properties on the shear capacity of RC beams repaired by TST-FiSH

0ctober 2010, Kobe, Japan

Figure 8 shows the test result of the non-bonded case with the bonded case (HPRA (No.3)). In the non-bonded case, the displacement was larger than that ofbonded case because the bonding effect of fiber sheet contributed to reduce thetotal displacement of RC beam. However, the maximum load and displacement
were almost same as the bonded case. From this experimental result, it wasverified that the bond strength between the fiber sheet with resin and the concrete
was not important. Furthermore, the shear capacity of HPR-B (No.4) might be
improved if the joint strength would be improved by reinforcing.
The joint of HPR-B was only reinforced by epoxy resin and the joint strength of
was around 730 N/mm2, which is roughly 1.6 times the original HPR-B but onlyaround 0.4 times HPR-A. Figure 9 shows the loading test result. The maximum
load and displacement were improved and the maximum load was similar to thatof HPR-A (No.3) although the maximum displacement was smaller than that of
HPR-A (No.3). This was due to the weaker joint strength of the reinforced HPR-B.
Through these additional loading tests, it could be concluded that joint strength is
an important factor for improving the shear capacity of RC beam.
800
700
600

Load (kN)

500
400
300

No.3

200

un-bonding

100
0
0

10

20

30

40

50

Displacement (mm)Figure 8: Load displacement curve (un-bonding case)
900

No.3

800

No.4

reinforce

700

Load (kN)

600
500
400
300
200
100
0
0

10

20

30

40

50

Displacement (mm)Figure 9: Load displacement curve (reinforced HPR-B)

New Technologies for Urban Safety of Mega Cities in Asia

4. CONCLUSION
In this paper, the influence of resin material properties on the shear capacity of
RC beams repaired by fiber sheet was experimentally investigated. It was
concluded that the joint strength between fiber sheets is the most important factor
for improving the shear capacity of RC beams even if the bond and adhesion
strengths between the fiber sheet and the concrete surface are not so strong.
ACKNOWLEDGEMENT
This research was supported by a financial grant from the Japanese Ministry ofLand, Infrastructure, Transport, and Tourism (MILT) for the research anddevelopment of construction technology. The authors would also like to thank MC
Industries, Co., Ltd., Tokyu Construction Co., Ltd., and Dr. Michael W. Henry for
their support.
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Influence of resin properties on the shear capacity of RC beams repaired by TST-FiSH