Action Plan toward Effective Flood Hazard Mapping in ChinaA) The role of flood hazard maps to mitigate flood damages in China
A-1) the flood status in China
China is endowed with about 50,000 rivers, including 1,600 rivers with water basin larger
than 1,000 km2 each. The topography of China is characterized by high west part and low
east part, gradually descending in elevation from the west towards the east to form threesteps. The main river systems consist of seven major rivers, the Yangtze, Yellow, Pearl,Haihe, Huaihe, Liaohe and Songhua rivers. Most rivers, including seven major rivers,
flow from west to east, directly or indirectly emptying into the Pacific Ocean. And thetotal annual average runoff is about 2,800 billion m3.
China is subject to strong monsoon climate and most of the areas are under the impacts ofthe southeastern and southwestern monsoons. The average annual precipitation in China
is 648 mm. About 70% of annual rainfall is concentrated in the flood season lasting fromJune to September in most area. The floods have the characteristic of high peak dischargeand great amount of flood volume. The water volume of one large flood may account for
the annual runoff of the river. The extremely uneven temporal and spatial distribution ofprecipitation and river runoff constitute the fundamental cause of frequent floods andwaterlogging in flood season.
Floods occurred frequently in China. According to statistics, in the past two thousandyears, nearly one thousand comparable large floods have occurred altogether, and one
flood disaster occurred in two years in average. During the 1990s, six out of 10 years
witnessed major floods taking place in the major river basins. In some areas, floods occur
every year. On average, there are seven typhoons that land on the mainland of China
every year. Torrential rains also cause mudflow and landslide problems. The total floodprone areas are about 1.06 million km2, nearly 11 percent of Chinese territory. In theseareas there is a population of 840 million people, and GDP is about 6562.8 billion RMB.
These areas are the major regions of Chinese social and economic activities.
In 1990s, annual economic losses caused by floods accounted for 1.7% of GDP. But indeveloped countries the flood damage rate to GDP is less than 0.5%. In 2005, up toOctober, 16.26 million hectares of farmlands were affected by flood and waterlogging,
212 million people affected, 1404 people killed in flood and sediment disasters, and thedirect economic losses 160.7 billion RMB. Zhejiang, Fujian, Hainan, Guangxi, Sichuan,Anhui, Jiangxi, Liaoning provicnes heavily suffered from flood disasters. Generally
speaking, the loss from flood and waterlogging disasters in 2005 was serious as comparedwith those in recent years.

The injury, death and property losses caused by floods, landslide and mudflow, rank thefirst among all natural disasters in China. Floods seriously threaten the social andeconomic development. As a significant strategic issue, flood control and flood security
attract high attention all over the country.
A-2) the outline of the present countermeasures for mitigating flood damages in China
In China, the flood control systems are composed of structural and non-structural
measures.
In the late 20th century, the floods in the Yangtze, Nenjiang and Songhuajiang rivers in1998 were the most serious natural disasters. China made great efforts to implement theproject to prevent floods. In China the flood control systems are composed of structuraland non-structural measures. Combined these measures, the main goal of flood
management is prevention of casualties and reduction of economic losses to the least.
Structural measures are aimed at releasing, detaining, confining, diverting and storing
floodwater, to reduce the frequency and magnitude of flooding. Flood control facilities
construction in the river basin is the basic way to mitigate flood risk and damage. Thesefacilities include reservoirs, embankments, food detention areas, pumping stations, etc.
Reservoirs were constructed in upstream areas to store floodwaters and decrease flood
peak, to reduce flood magnitude. Levees and embankments along the rivers wereconstructed to confine extents of inundation. Flood detention areas, for temporary storageof floodwaters to control discharge to downstream, were built up in the lower rivers.
With the effort of fifty years, the comparable integrated flood and waterlogging
mitigation system, which can control normal flood disasters, had been accomplished. It
can be summarized as follows: about 246-thousand kilometers levees and embankments
constructed; more than 860-thousand reservoirs with a total storage capacity more than
475.1-billion cubic meters; 98 national specified flood detention areas with total capacity
near 100-billion cubic meters. According to incompletion statistics, the flood prevention
system that has been built has reduced losses of 1,500 billion RMB from floods.
Up to now, the key flood control projects were constructed up in seven major rivers inChina. The Xiaolangdi reservoir located at the lower Yellow River commenced its
operation in 2000, to control floods and reduce aggradation rate in the lower Yellow
River. Three Gorges Project is under construction, it will be completed in 2009. InHuaihe River, Linhuaigang hydraulic complex project will be completed soon, which will
improve the flood control standard in the middle reach of Huaihe River to 100-year flood.
Non-structural measures play a very important role in China. These methods include
legal and institutional system, recovery of floodplain storage, flood forecasting andtelecommunication system, flood emergency planning and response, and post-flood

recovery, etc. These activities directly modify the vulnerability of communities exposed
to flood risk.
Till now, China has set up a series of flood control legal and institutional system. FloodControl Law was adopted on August. 29 1997, and came into force on January.1 1998.
According to the law, all units and individuals shall have the obligations to protect flood
control works and to take part in flood control and flood fighting. The administrative
heads of people's governments at all levels have the obligation to assume overall
responsibility for the work of flood control, this is the basic rule in Chinese floodmanagement. So the local government, such as province, city and county, should be incharge of flood facilities construction and flood fighting. And central government andMinistry of Water Resources provide capital and technical support separately to the localgovernment. Defense planning for the Seven Large Rivers are compiled by State FloodControl and Drought Relief Headquarters, which comprise the operation principle offlood facilities and the flood fighting obligation of local government concerned.
Recovery of floodplain storage in river systems is also used to increase flood storage
capacity. After 1998 flood of Yangtze River, farmlands around the Poyang Lake andDongting Lake, the two largest lakes in middle stream of Yangtze river, are returned torecover lakes and rivers, 2.42 million affected populations were resettled to nearby places,
water area of 2900 km2 was recovered and flood storage capacity of 13 billion cubic
kilometers was increased.
Flood forecasting is another non-structure measure widely used in China. Hydrologicalinformation system can collect and disseminate hydrological information promptly, andmake hydrological forecasting. The real-time rainfall and flood information of thenational hydrological stations can be collected within 30 minutes, and forecasting results
can be obtained within 1 hour. The hydrological information is the most important data
for flood-decision. Research is ongoing to maintain and improve technical capabilities.
In addition, China has formulated a compensation policy for the local people living insideflood detention areas since 2000. Central and local governments share the expenses on
personal property and crop loss compensation due to flood detention in the national flooddetention areas. In the past five years, ten flood detention areas were utilized to storage
floods, nearly 200 million RMB capitals were compensated for the affected residents.
In 1998, extraordinary severe floods occurred in the Yangtze River basin. Flood-control
system construction for rivers is oriented towards harmonious coexistence between manand nature. In other words, floods should be provided a way out, and thoughts should be
gradually transformed from endless disorderly struggle for land between man and waterto orderly and sustainable harmony between man and flood. A new flood thoughts,
transfer from the flood control to flood management, has been brought forward since2003. So In the process of flood management, flood, drought and water shortage issues
are considered concurrently, firstly to ensure the flood safety, and utilize the flood source
to mitigate water shortage.
A-3) do you think flood hazard maps will be useful in China? Why?
Flood hazard maps could be widely used for several aspects of flood management. For
example, flood hazard map information facilitates flood hazard zoning, which is aprerequisite for land use planning and management to ensure that appropriate
development occurs in flood risk areas. Delineations of inundation areas and estimates ofwater depths and velocities of flow in standard planning floods are an aid to land use
planning and development controls, emergency planning, evacuations and response,raising public awareness of flood risk, and for establishment of flood insurance premiums.
Flood hazard mapping could be used to develop public education programs for schools,communities and companies, and could play an important role in raising people’s
awareness of flood risk. More effort is required in raising awareness of flood risk, so thatpeople are better prepared and the losses incurred by those in flood risk areas in China aremitigated.
B) The allocation of roles in making flood hazard maps in China
B-1) which organization should hold the main responsibility for making a fundamental
map such as an anticipated inundation area map?
Department of Water Hazard Research (DWHR) should hold the main responsibility formaking a fundamental map. DWHR is both a non-profit research department of China
Institute of Water Resources and Hydropower Research (IWHR) and technical entity ofthe Research Center on Flood and Drought Disaster Reduction (CDR) of the Ministry ofWater Resources (MWR). With flood simulation technology they have developed floodinundation maps in some detention areas such as Jingjiang Detention Areas on the middle
reach of the Yangtze River and some cities such as Guangzhou City and Shanghai Cityand so on. They also have developed real-time rainfall forecasting model for Tianjin CityB-2) which organization should hold the main responsibility for making anddisseminating flood hazard maps?
Office of State Flood Control and Drought Relief Headquarters (OSFCDRH)C) The ‘Action Plan’ of making flood hazard maps in China
C-1) which area do you choose for the target river basin area? Why?
As we know, there are some distinct characteristics of flood disaster of particular concern
in China in recent years. These are: 1) Flash flooding and debris flows, which cause mostcasualties. 2) Urban flooding. 3) Detention areas, where conflicts between floodmanagement and socio-economic development remain a major problem. To help resolve
the problems cited above that are particularly acute in recent years, flood hazard maps
can first be developed for mountain cities, most large cities and some important detention
areas.
Guidelines for flood hazard mapping were issued by the Office of State Flood Controland Drought Relief Headquarters in May, 2005. And order about carrying on the flood
hazard mapping work in pilots was promulgated by OSFCDRH in November, 2005. 36
pilot studies in seven major river basins have been arranged, including some detention
areas, cities, dike protected areas and dam failure events. Criterion for flood hazard
mapping is going to prepare.
Up to now, task in most pilots has been finished and that in some pilots gets oncomparatively slowly due to the lack of basic data. 20 pilot studies have finished theflood risk analysis or sketch maps. Studies in 11 pilots are on going. And studies of 5pilots just startup. We have got much experience from the pilot studies of flood hazard
mapping, and there are also some problems which should be solved in the next step.
For myself, I want to choose Mengwa flood detention area, which is located on the northbank of middle Huaihe River in Anhui Province, as my target area to make flood hazardmap.
C-2) what do you think is necessary to make flood hazard maps in the chosen area? Do
you have data, maps, or budgets necessary for making flood hazard maps?
In July 2003, Mengwa flood detention area was utilized to storage floodwater twice. Near
200,000 people have been evacuated to the earth platforms and embankment village
polders. During the past 53 years from being established in 1953, this detention area has
been used 14 times in 11 years. Mengwa flood detention area is an extremely importantpart of Huai River flood control system which taking on the duty of cutting flood peakand storing floodwater.
In April 2005, I went to Anhui province to investigate the utilization and compensation ofMengwa detention area. There were some problems emerged. Then I just focused myresearch on the compensation policy and finished my thesis about compensation policy inflood detention areas with the case study of Mengwa detention area. I developed theinundation map of Mengwa detention area for identifying the inherent risk and additionalrisk. These maps are as follows:Anticipated inundation map caused by rainfall

Anticipated inundation map caused by both rainfall and division water
It is very important for the residents living in the detention areas to evacuate fast when
the detention area is utilized. Flood hazard mapping is an effective measure to solve thisproblem. And now national flood hazard mapping is planning to be carried on in China. It
is a good chance to budget for making flood hazard map.
After the completing of flood hazard map, it will be disseminated to every household.
When the government determines to use the flood detention area during flood seasons thelocal government issues order to organize residents to evacuate to designed shelters
which have been shown in flood hazard maps. It can greatly shorten the evacuation time.

Residents are aroused to adjust plant category to reduce crop losses according toanticipated inundation duration and depth, such as appropriate places to plant grain,
vegetables or fruit.
C-3) Propose your own ‘Action Plan’ within the next five years
National flood hazard mapping in China is proposed to make right now. And mydepartment will offer the technical support to this big project. So my action plan iscorresponding with this project. The following is a draft of my action plan:Dec. 2006
Report to my office.
Introduction of history, procedure, method, effectiveness, practice, etc ofJapanese flood hazard maps.
 Jan. ~ Jun. 2007 Produce record flood maps
Cooperate with related provinces office of flood control headquarters.
Choose research institutions.
Collect past floods information, topography data, flood damage, etc.
Compile history inundation maps
 July. ~ Dec. 2007 Produce flood risk maps
Through hydraulic calculation and simulation, estimate the anticipatedinundation areas (such as extent of inundation, water depth, flow rate, arrival
timing etc.)
Compile flood risk area
 Jan. ~ April. 2008
Produce flood hazard maps
Calculation population required to evacuate, accommodation provided byshelters.
Formulation of an evacuation plan
Inquire the public suggestion
Compile flood hazard maps
 May. ~ Jun. 2008
Publication and dissemination of flood hazard maps
Approval by the local government
Dissemination
Flood prevention education in schools
 July. 2008~ 2010
Verification and actual application
Survey report and verification the effectiveness of flood hazard maps in theemergency of flooding
Modify and improve the flood hazard mapsC-4) what seems a problem in making flood hazard maps in China?
In China, because of the number, scale and complexity of structural flood management
systems, flood hazard mapping will be an enormous undertaking. The resources requiredin the PRC in terms of funding, basic data, technical personnel and training skills areconsiderable. These challenges require reliable funding sources for future recurrent
expenditure, and regular updates of flood hazard maps to reflect hydrological andcatchment changes, future development, and improvements in flood control and floodmanagement systems.

If there is insufficient funding to complete all flood hazard maps at present, it is possible
to progress it step by step. As we know, there are some distinct characteristics of flood
disaster of particular concern in China in recent years. These are: 1) Flash flooding anddebris flows, which cause most casualties. 2) Urban flooding. 3) Detention areas, whereconflicts between flood management and socio-economic development remain a majorproblem.
To help resolve the problems cited above that are particularly acute in recent years, flood
hazard maps can first be developed for mountain cities, most large cities and some
important detention areas.
Key elements of flood hazard mapping are: 1) Data acquisition. 2) Methodology. 3)
Information display. 4) Updating. 5) Public release and education. Each of these key
elements deserves special attention in developing maps for flood management systems inChina.
At present, data acquisition is difficult in China. Many types of data are required whengenerating flood hazard maps, including hydrological, topographic and land surface
classifications, river cross sections and flood control works information. In China, thisdata is stored and managed by different administrative departments. Unsatisfactory data
sharing mechanisms and management attitudes are serious constraints for flood hazard
mapping. Development of Digital Terrain Models (DTMs) is another major constraint,since much more remains to be done in the PRC, and DTMs are extremely valuable inachieving good accuracy in hydraulic simulation of flood behavior.

D) My own Flood hazard map in Ise cityD-1) what is the improvement from the FHM on Ise city currently available?
The improvement from the FHM on Ise city currently available is I have added
evacuation routes to the new FHM and it is more convenient for the residents to evacuate.
It can greatly decrease the evacuation time.