Roadmap toward Effective Flood Hazard Mapping in China
Wang Jinxing
Organization: Bureau of Hydrology, Ministry of Water Resources, China
Address: No.2 Lane 2 Baiguang Road, Xuanwu District, Beijing 100053
Email address: wjxmwr@mwr.gov.cn

1. The role of flood hazard maps to mitigate flood damages in China
1.1 The flood status in China

China has a large territory with great difference in climate, landform andgeology, and with the natural conditions and socioeconomic historical conditions
to create various kinds of floods and the concerned disasters. China ischaracteristic of the uneven distribution of annual rainfall due to its uniquelocation in the Asia monsoon area. Nearly 60 to 80 percents of annual
precipitation is concentrated in summer flood season, and China is hit frequently
by rainstorm and typhoon. In China, there are about 40% of the population, 35%of the agricultural lands and 70% of the gross product in the alluvial plains
vulnerable to water inundation. With economic growth, urbanization and thesubsequent concentration of population and property, the direct economic loss
per unit area has increased to 166 thousand dollars per km2 in the 1990s, about 6times than in the 1950s. Therefore, the flood damage relief is an important andurgent task in China.
In 2005, China has experienced severe floods in the flood season.
Devastating deluges plagued on whole Pearl River Basin in the last ten days ofJune, one of 7 main basins in China. The special great flood had occurred in themidstream & downstream of Xijiang River, the maximal peak levels of somemain stream and sub-stream had exceeded the highest in history. In the first tendays of July, the fujiang river and qujiang river of Yangtze River had occurred
over warning level or big floods. In the middle ten days of July, the upstream ofHuai River Basin and Minjiang River of Fujian province had occurred big flood.
In the middle ten days of August, the sub-river of Liao River Basin, Qing River,
Cai River, Hun River and Taizi River had occurred big floods.

1.2 The outline of the present countermeasures for mitigating flood damages

In order to prevent potential great flood disasters, Chinese Government has
taken many measures to construct the structure measures and non-structure
measures flood preventing systems over the main rivers. 246,000 km longembankments were constructed, more than 860,000 reservoirs had been builtwith a total storage capacity more than 475 billion cubic meters, 98 national
flood detention areas were opened up along the main rivers, with total capacity
near 100-billion cubic meters. All these have initially controlled the normal
flood disasters. However, these are not economic and impossible to raise thestandard without limit. When the over standard flood can not be controlled withthe structure measures, the non-structure measures will be taken as the mostimportant tool for flood disaster preventing. Our country has developed someno-structure measures, such as legal and institutional system, hydrologicaltelemetering system, flood forecasting and warning system andtelecommunication system etc. All these will be taken as the most important tool
for flood disaster preventing. As one of the non-structure measures, I think flood
hazard mapping also will play an effective mitigation role in China in the future.
Because the flood hazard map shows some inundation and evacuation
information in an easy-to-understand format, the local residents can easy know
the route to a safe place. Compare with the Japan, I think Chinese flood hazard
map has some different with Japanese flood hazard map, because our basin andcity are also very large. And China is a developing country, we still need timeand fund to build and perfect our structure measures.
2. The allocation of roles in making flood hazard maps in china
The work of flood defense belongs to the issues of flood control and water
management in China. The Organizations have been separately set up at state,province, region and county levels. They are responsible for water management
and construction management of engineering works. The water administrative
organization at the state level is the Ministry of Water Resources (MWR). Under
the Ministry of Water Resources, seven water resources commissions wereseparately established in the Seven Large River basins. Each of them is incharge of one river basin’s water planning and water management. The2

provincial, regional and county level water management organizations performtheir respective responsibilities under the leadership of their one-step-high water
management organization as well as the government at the same administrative
level. Management organizations are also responsible for every day managementof the engineering projects (See figure 1). The state, provinces, municipalities,
and related regions and counties have also established flood control
organizations respectively, so as to perform centralized arrangement of foodfighting activities.
Office of the State Flood Control & Drought
Relief Headquarters

Office of the Flood Control &Drought Relief Headquarters under
Each River Authority

Provincial (Municipality or AutonomousRegions) Office of the Flood Control & Drought
Relief Headquarters

Management Offices in Major
River Reaches and Reservoirs

Prefectural Office of the Flood Control &Drought Relief Headquarters

Office of the Flood Control & Drought
Relief in Counties reservoirs

Fig 1.

The organization structure of flood defense

The State Flood Control and Drought Relief Headquarters (SFCDRH) isthe highest flood control organization in China. The routine job office of theSFCDRH is called the Office of State Flood Control and Drought Relief
Headquarters (OSFCDRH), which is put inside the Ministry of Water Resources.
Those administrative regions above the county level also established floodcontrol organizations at their respective levels, if they have flood control
problems. And the composition of any level flood control organizations is justlike the SFCDRH. Each member of the river flood control organization is eithera governor of the related provinces or a general director from the water
resources commission of the river. The commander of the river flood control
organization is the chief governor of one province designated by the central3

government. And the deputy commander is the highest executive of the water
resources management organization in the river. The routine job office of a riverflood control organization is inside the water resources management
organization in the same river.
Because the flood defense in China is undertaken in both central and local
levels, so I think that the central flood defense organization (OSFCDRH andother correlative organizations which sustain the technology of draw flood
hazard map) should take the responsibility for make anticipated inundation area
maps of seven major rivers. In the other hand, the local government should takethe Responsibility for making and disseminating flood hazard maps, the Bureauof water resources and Office of Flood Control Headquarters of the localgovernment should bear the concrete works.
In China, the first flood risk map had drawn in 1976, it is very simple.
From 1997, China was practices of drawing flood risk mapping. Such as
zhejiang province, the risk map is concerned the probability in 5, 10, 20, 50 and
100 years. By use of color, the risk map shows that as the scale of probability
grows, the inundation areas expand. In 2005, the guideline for draw Flood risk
mapping was issued by the OSFCH. I think we should spend a long time andfund in basal work of flood risk map. After this, we may draw the flood hazard
map in some detention areas, major cities, dike protected areas. And I think in
the flood hazard map, we should consider the dam failure events.
All the arrangements and all the concrete actions for flood defense musttake ensuring the people’s life into consideration. It is one important principlethat we have to stick to in flood fighting activities in China.

3. Acquirement of the training course
All parts of the curriculum are very interesting and impressive to me and I
have acquired much from this training course. It includes:
1) Meaning, significance, effectiveness, contents and development of flood
hazard map.
2) Procedure of producing flood hazard and fundamental analyzing method4necessary such as hydrologic and hydraulic analysis, runoff simulation andinundation simulation.
3) Preliminary production, dissemination and utilization of flood hazard
map.
4) Great enhancement of my awareness about the above by field study andtrip on flood hazard map and river management.

4. My actions about flood hazard mapping
In view of the significance of flood hazard Mapping, I think it is verynecessary to impel the relevant works in China. According to the practicalsituation, it seems that two steps should be taken. First, flood hazard maps offlood retardation areas should be produced to meet the need of the changing idea
about flood fighting in China. Then we can do the same work for the alluvial
plains that are possible to be flooded.
After i return to China, i plan to make a report about this training and flood
hazard mapping for my organization first. Secondly, I want to apply for theapplied research on How to lengthen the effective flood forecast period. Finally,
i will suggest my organization cooperating with the Office of Flood Control andDrought Relief Headquarter to produce the flood hazard map of a typicalretardation area.

5. Thoughts for more effective flood management in JapanThe flood management in Japan is very effective and efficient because of
its perfect organization, proper river law amended continuously to reflectchanging socio-economic conditions, high-standard flood control facilities,
comprehensive mitigation measures, etc. So i can not put forth any valuablesuggestions and only some private immature thoughts regarding flood
management for reference are listed below.
1) More effective anti-disaster education for understanding is expected sothat it will facilitate the evacuation of residents.
2) The capacity of some shelters should be enhanced.
53) The land planning of the areas vulnerable to water inundation should bemade more precise or the plan should be implemented more completely.

6. Suggestions for a more meaningful training course
As mentioned above, the training course is very successful and I appreciate
the chance provided by JICA and the up-most efforts made by the staff of JICA
and PWRI. Some suggestions are put forth only to meet the will of theorganizers for better training effect.
1) Longer training period is expected, such as three months or half a year.
2) A whole exercise of produce flood hazard map is also expected.
3) More detailed contents such as inundation simulation may be more
useful to produce flood hazard map.
4) More field studies and visits may be more effective.

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