Method Of Flood Risk Estimation And Its Application In Flood Detention Basin

Flood hazard should be interpreted in two aspects, one is flood generation, and the other is hazard formation. The reasons for flood include climatology, runoff, and topography and so on. Flood hazard is based on the loss of lives and properties. Flood risk components such as natural risk, social and economic risk and technical risk should be considered for flood risk estimation.Flood formation depends on climatology and topography, so precipitation, topography, channel network and flood disaster frequency should be taken into account. Population and GDP is the representative indices used to estimate the economic vulnerability, since flood hazard is of social property. In addition, technology must be included for flood hazard estimation. The major tasks are as follows:Firstly,the factors and principles for comprehensive estimation index system are discussed, and the theories and methods for determination of indices'function and weight are introduced in detail. And then the flood hazard estimation index system was presented for the Dahuangpu Depression.Secondly, according to the characteristics of the comprehensive evaluation index system, indices'function was established and fuzzy comprehensive evaluation model for flood risk was put forward. The model is based on the software ARCVIEW GIS, and the area, elevation can be obtained in the software MAPINFO.Finally, the model was applied to 83 villages in this region. Five situations (20y return period before reservoir construction, 50y return period before and after reservoir construction, 100y return period before and after reservoir construction) were compared with one another to assess the significance of Dahuangwa Reservoir.So we can draw the conclusion that the flood risk estimation model is objective and prevailing, and can be expanded to other regions.