1 The present situation of flood risk map in China
1.1 Present phase
The flood threatening area of the seven great river basins in China is about one
million km2. In these areas, the level of flood risk mapping in different regions is far
different because of the difference of social economic development level and theconsciousness of flood management. There are all kinds of flood risk maps fromphase C to G. For some regions where the historical flood inundation maps have been
investigated and mapped, they are in the phase of C or D; for regions where typicalhistorical floods and design floods have been simulated using hydrological andhydraulic methods, the phase is E or F; only in several regions, the flood forecast andwarning has been implemented using real-time rainfall and water regime information.
However, most of forecast is concentrated on the flood stage and discharge in rivercourse instead of inundation of flood flowing out of river course.
Map A: map without elevation data
Map B: map with elevation data
Map C: inundation map of single historical flood event
Map D: inundation map of several historical flood eventsMap E: inundation map of historical flood events simulated
Map F: inundation map of design flood
Map G: forecast map by real-time analysis

1.2 Present condition
Since 1980s, some institutions, provinces, cities and insurance companies have been
carried out the study on flood risk maps and mapped various flood risk maps fordifferent uses.
The study areas of those flood risk maps include the flood detention area such as
floodplain of Yongding River and flood diversion area of Xiaoqing River, etc., riverbasins such as Taizi River Basin and Liao River Basin etc., cities such as Shenyang,Guangzhou, Tianjin, etc. as well as the whole province area such as Zhejiang andFujian province.
1) The first phase
In early 1997, the Office of State Flood Control and Drought Relief Headquarters(SFDH) released the document No.1 which required the whole country to carry out
the flood risk mapping. Whereafter, the SFDH used the form of supplementary
document to put forward that the drawing of flood risk maps in China would be
divided into three steps. The first step is to draw the flood influence area according tohistorical flood data and existing study achievements, and give the distribution ofpopulation and assets in flood influence area in the form of table. The second step isto analyze and calculate the distribution characteristics of flood risk in a region
according to the features of study area and provide reference information for making
flood planning and flood control preparedness. The third steps is to combine with themonitoring and forecast system of real-time rain, water and flood control projects
information to provide service for flood-prevention and dispatch command anddisaster evaluation, etc.
2) The second phase (2003.7-2008.1)
In July 2003, the SFDH started to formulate the Guideline for Flood Risk Mapping toguide and standardize the flood risk mapping in the whole country. In February 2005,
the main contents of the Guideline for Flood Risk Mapping were finished, and themapping of flood risk maps in pilots began all over the country. The number of pilots
is 36 which cover all kinds of flood risk maps (including river basin, city, flood
detention area and reservoir). The pilot project was finished in January 2008.
The formulation of Letter of assignment for Flood Risk Mapping Program in theWhole Country was started in the middle July, 2005. The draft of the Letter ofassignment for Flood Risk Mapping Program, the Preliminary Work Outline for FloodRisk Mapping in the Whole Country and the Letter of Assignment for Preliminary
Work were finished in the end of July, 2006.
3) The third phase (2007.11-2010.12)
In November 2007, the Letter of assignment for Flood Risk Mapping Program in theWhole Country (Phase ) was approved. The main tasks in this phase including:z Investigate and summarize the study at home and abroadz Formulate the technical standard and measures for the administration of floodrisk mappingz Develop the models and software for flood risk mappingz The collection and processing of basic data for flood risk mappingz Develop the flood risk map management platform softwarez Map the templates of flood risk maps
z The pilot projects of flood risk mapping in each river basin.

1.3 Two casesz

Flood risk map in the middle and lower reaches of Beijiang

Where：in the middle and lower reaches of Beijing River Basin which includes flood
protection area of Beijiang levee, Feilaixia reservoir, Pajiang flood detention area,Guangzhou and Foshan city.
Why: This project is the pilots of flood risk mapping for both SFDH and Guangdong
province. The five pilots represents flood protection area, reservoir, flood detention

area and city respectively. Beijiang is one of the key flood control areas in Guangdong
province. In the flood protection area of Beijiang levee, there area high value of assets
and dense population.
When: 2007.5-2008.1
By Whom: IWHR
To Whom: Office of Flood Control, Drought Relief and Typhoon Protection
Headquarters of Guangdong Province
How: Phase E，hydraulic methodzThe demonstration project of flood risk maps in Hubei province

Where: Hubei province, including Dujiatai flood detention area, Honghu flooddiversion area and Zhanghe reservoir
Why: This project is the pilots of flood risk mapping for Hubei province, the threepilots represent flood detention area, flood protection area of levee and reservoir
respectively and the study area is the key flood control area with high value of asset
and dense population.
When: 2008.1-2008.12
By Whom: IWHR
To Whom: Office of Flood Control, Drought Relief and Typhoon ProtectionHeadquarters of Hubei Province
How: Phase E，hydraulic method

1.4 Stage objectives
In my opinion, the map G should be the objective the flood control departments hopeto carry out. The reasons include two aspects as follows:
One is the requirement of flood control commander. The map G can help decision
makers give reasonable warning and decision in order to reduce casualty and property
losses furthest by simulating possible inundation area and affected population andassets according to real-time rain, water information.
The other is that the basic data in China has been satisfied the demand of flood risk
mapping. Currently, the Flood Control Command System of China (Phase Ⅰ) covers
the main flood threatening area of the country on the whole. The automatic
monitoring and data acquisition of rain and water information have been carried out
basically. However, because of the secrecy system, the terrain data are hard to obtainand use. This difficulty is being solved now.

2 Flood risk mapping
1. System for flood risk map
In China, there is still no relevant law for flood risk map. The work of flood risk
mapping is leaded by the Office of State Flood Control and Drought Relief
Headquarters.
2. Data condition
Hydrological and terrain data, etc.
Currently, the Flood Control Command System of China (Phase Ⅰ) covers the main
flood threatening area of the country on the whole. The automatic monitoring and dataacquisition of rain and water information have been carried out basically.
Terrain data are kept by State Bureau of Surveying and Mapping. Because of thesecrecy system and benefit relation between different departments, the terrain data are
hard to obtain and use. This difficulty is being solved now. In addition, the terrain datawith scale of 1:250,000 have been shared in public. The DEM data are hard to beobtained.
3. Problems during the mapping of flood risk maps
In my opinion:
1) System and administration measures
Up to now, there is no clear system for flood risk map in China. It indicates that theproblems on status and use of flood risk maps, the qualification of departments whodraw the flood risk maps, the source of outlay, organization who publishes the maps
and, the update and maintenance, etc. exist in current situation.
2) Technology
The technical manual is still being formulated. The practicality of technical method
for flood analysis needs to be improved. The technical training still needs to bereinforced. There is no relevant certification department.
3) Basic data
The share of data is difficult. The density of data is not enough, for example, the waterlevel station and Stream Gauging Station are lacing in mountain area.

3 The publishing and use of flood risk map
1. The system of publishing and use
The systems of flood risk map publishing and use are being formulated. They include

Measures for the Administration of Flood Risk Map, Quota of Flood Risk Mapping
and relevant laws such as the suggestion on flood risk map in the Flood Control Law.
2. Problems during publishing and use
As the lack of correlative laws, the legal status of flood risk map in flood control anddisaster reduction or land use planning, etc. is not clear. The problems also exist in themapping, publishing, use and update of flood risk map. At present, flood risk maps are
only taken as reference by water sectors in the formulation of flood control planningor flood control decision making.
3. How to use flood risk map?
Flood risk maps can be used in following fields:z Land use planningz Flood control and land drainage planningz The establishment of flood contingency planz Flood control and warning
z Evacuationz Emergency flood fighting

4 Suggestion for the flood risk map project of ICHARM
B- (1) – (1) Efficiency of disaster prevention
In 2006, the total number of households of television audiences in the whole country
reached to 306 million. The total number of television audiences reached to 1.07
billion. The average popularization rate of television was 85.88%.
B- (1) – (2) Process of flood evacuation information
The weather sectors of state, river basin, province and city release the rainfall forecast
data; the offices of flood control and drought relief headquarters of state, river basin,
province and city (generally consists of weather, water conservancy, armed policy andcivil administration sectors.) release flood forecast, warning and evacuation
information.
B- (1) – (3)In China, the disaster prevention consciousness of people is less, the general disasterprevention knowledge is lacking. The flood control drill is generally implemented inthe flood control sectors.
B- (2) Suggestion on the Guideline for Flood Risk Mapping
China published “The Guidelines for flood hazard mapping” in 2005. It is revising
now. I think “Guidelines for flood hazard mapping in developing countries” can beused for reference in the revising work.