Imperative Needs to Develop
Water‐related Disaster Risk Information
June 23 2014
Hisaya SAWANO
Chief Researcher, International Center for Water Hazard and Risk management
under the auspices of UNESCO (ICHARM), Japan (e‐mail: hs‐sawano@pwri.go.jp)(Former Director of IWRM Strategy Office,Water and Disaster Management Bureau, MLIT, Japan)

What Information Is Missingin the Water‐Related Disaster Risk Management?
UNESCO International Hydrological Programme (2012): Eighth Phase (2014‐2021)
Strategic Plan – Focal Area 1.1: Risk management as adaptation to global changes

There remains a big gap between the relatively accurate estimates by latest hydrological models
and the information required to support decision making based on an evaluation of risk. The
relationship between flow volume or rain intensity and expected damages, such as number ofcasualties, economic losses, and affected area/population, are critical but poorly studied. There is aneed to establish methodologies to assess risk, considering the hydro‐climatological and social
conditions of the area of concern.
Compile, share, and analyze data on socio‐
economic damages due to water‐related
hazards, taking into consideration themagnitude of the hydrological hazard andthe social vulnerabilities.

Water‐Related Disaster Risk Management
Practices at All Phases of Flood Disasters

IMPORTANT DATA &INFORMATION

Hydro‐meteorologicalobservations & simulation
Condition of shelters& critical facilities
Performances ofInfrastructure

Hydro‐meteorologicalobservations & simulation
Locations of shelters& critical facilities

Rapid need assessment
Past flood records

Situation information

Past flood records
Flood hazard map
Flood risk mapetc.

Normal Times• Monitoring• River maintenance &improvement• Preventive investment• Preparedness

Situation information
Rapid need assessment
etc.

Flood damage assessment
etc.

During Flooding

After Flood• Forecasting & warning• Operation of flood management
infrastructure• Evacuation & shelter operations• Flood fighting operations• Humanitarian aid• Emergency recovery• Reconstruction• Supports for losses &damages

Evaluation of flood risk management practicesAll practices and actions require data and information.

Crucial Roles of Government Officers
in Developing Risk Information (1)1)

Develop water‐related disaster risk management strategy fordecision‐making using available data.
Identify the gaps of data andinformation2)

Improve the quantity and quality of data and information.

 Water‐Related Disaster Risk Management Strategy
Emergency actions
Preventive investment

Crucial Roles of Government Officers
in Developing Risk Information (2) Data/Information Requirement for Emergency Actions
Advanced Stage

First Stage‐‐‐

X‐band data
High‐resolution image data (camera, etc.)
Geographic data integration on GIS‐‐‐‐

Development of network of telemetry systems
River cross section
increased number of stations
Advanced hydrologic simulation with localmeasurements (RRI, etc.)‐‐Simple method observation systems for weather and river condition
Simplified model for hydrologic simulation with satellite rainfall data
(BTOP, FID, IFAS, etc.)

 Grasp the situation precisely and in a timely manner.

Example of the simple methodobservation system (gauging rainfall)

Crucial Roles of Government Officers
in Developing Risk Information (3) Data/Information Requirement for Preventive Investment‐ Risk evaluation

 Hazard: data/information about hydrological characteristics
 Exposure: data/information about population, assets & socio‐
economic activities
 Vulnerability: data/information about socio‐economic conditions
and coping capacity

 Number of casualties, socio‐economic damages and affectedarea/population
 Show the current level of risk and the effectiveness of preventive
investment to policy‐makers, practitioners, and the public

Crucial Roles of Government Officers
in Developing Risk Information (4) Hold the view that preventive investment isinevitable to protect people and economic
growth from disasters.

Int. Research Organizations

 Compile, share and analyze technical data
about hazard, exposure, vulnerability, anddamage at all levels.

 Theoretical knowledge Conduct risk assessments at all levels in orderto understand how water‐related disasters
cause casualties and economic damages.
 Evaluate the effect of preventive investment interms of “information required to support
decision making”

and Academia Hydrological models(especially, less data‐dependent
simulation models) Risk assessment tools Know‐how and experiences Global datasets

A Pilot Practice Collaboration between ICHARM and Government of Philippines
 Investigation of flood disaster risks in the Pampanga River Basin

6/26/20148

Pampanga River Basin: General Features
 Catchment Area: 10,434 km2
 River Length: 260 km
 Population: 5.8 million
 Average annual rainfall:
1,155mm/year At least one flooding in a year The frequency of tropical
cyclone passage over the basin
is about 5 in 3 years
 Flood prone area: low‐lying areas(approximately 2,600 km2) of the lower
river basin
 2 major dams: Pantabangan and Angat
 2 Swamps: Candaba and San Antonio

Meetings for Collaboration among ICHARM and Government Offices

Meetings

17 June 2013 at DPWH

 Dates: 16 – 22 June 2013
 Government of Philippines: PAGASA,
Department of Public Works and Highways,
Office of Civil Defense, Bureau of
Agricultural statistics, many dam offices, etc.
Collaboration
 Launch pilot activities using available government offices’ data and ICHARM’s technologies‐ Example of data available to develop flood risk information

Identification of locations at higher risk due to floodfrom the viewpoint of human lossesUsing ICHARM’s hydrologic simulation models (BTOP, FID,etc.) and collected data to develop the formula
correlating human losses and flood conditions
Simulate the disaster for 50‐yr return period condition

Simulation results
 The total number of affected people: 993,000 persons
 The value of risk indicator: 301 (as an estimate
correlated with the equivalent number of deaths)
 Areas at high risk: Southern areas (municipalities in
Pampanga and Bulacan provinces)(1) Pulian: 22 (76,000 affected)(2) Calumpit: 17 (60,000 affected)(3) Macabebe: 16 (54,000 affected)
River basinboundary
Municipality
expected to havedeaths more than 1

Number of affectedpeople (persons)

20,0001Indicator for flood
fatalities for the(value)municipality

Procedures: [data collection]  [risk calculation formula building]  [simulation]

Analyzing the effectiveness of the Pantabangan dam in reducing
the number of affected people under 50‐yr return period condition
Number of affectedpeople (persons)

14,0001

Cabanatuan
Cabanatuan
Santa Rosa

By 40% reduction(mainly, in the Cabanatuan city)

The number of affected people
within the management zone:
100,977 persons

Santa Rosa

The number of affected people
within the management zone:

60,729 persons

Identification of locations at higher risk due to floodfrom the viewpoint of agricultural damages
 Using ICHARM’s methods (RRI, questionnaire survey, etc.)
and collected data to develop the formula correlating
agricultural damages and flood conditions ‐ for the period
September 26th to October 4th, 2011

Calculated agriculture(rice-crops) damages(500m x 500m grid) Simulation results
Rice crops damages (million Peso)
Descriptions

Reportedvalues

Calculated using
proposed damage
functionsPampanga River Basin(Affected area 45,900 ha)-1,461

Pampanga Province(Affected area 15,900 ha)

1,376652

Calumpit Municipality(Affected area 1,250 ha)

37

42

Procedures: [data collection]  [risk calculation formula building]  [simulation]

THANK YOU FOR YOUR ATTENTIONOBJECTIVE OF ICHARM

25 April, 2014 at Tokyo(1st Governing Board Meeting)

To be the global Center of
Excellence to provide and assist
implementation of the bestpracticable strategies to localities,
nations, regions and the world
to manage the risk of water
related hazards including floods,
droughts, land slides, debris
flows and water contamination.
At the first stage, the priority is
flood‐related disasters.