Flood risk assessment based on hydrodynamic model and fuzzy comprehensive evaluation with GIS technique

Flood is a commonly-seen disaster, which has the potential to cause severe impact on the daily operations of cities and endanger the safety of people. In this study, a multi-index fuzzy comprehensive evaluation model (MFCE model) for flood disaster risk is developed. The MFCE model contains three input indicators: the hazard factor, the exposure factor and the vulnerability factor. In addition, these three indicators contain eight subindicators. Hazard factors are obtained using the DigitalWater Simulation hydrodynamic model (DS Model) developed by Chinese scholars. Then, hazard factors, exposure factors and vulnerability factors are all put into the geographic information system (GIS) to accomplish overlay analysis and fuzzy matrix calculation. The method has been successfully applied to the flood disaster risk assessment in the urban area of Yifeng, Jiangxi Province, China. The assessment results show that compared with the risk assessment of the MFCE model, the risk distribution map of the hazard factor changes greatly when the study area encounters the storm of 50a. The very high risk zones may occur somewhere with serious flooding, high impermeability and high building density.