Abstract:

Rainstorm flooding is a multifactor coupling complex system.Based on the precipitation data from Hangzhou City during the period from 1959 to 2009 and combined with the natural geographic and the society economic factors,according to the natural disaster system theory,this study built a rainstorm flooding disaster assessment model of hazard factors,including environment,hazardaffected body and disaster prevention ability.And the map of rainstorm flooding disaster risk division in Hangzhou was drawn using 100 m×100 m raster as basic assessment unit,by means of ArcGIS and fuzzy comprehensive assessment methods,with lots of factors such as precipitation,topography,water,GDP and cultivated land taken into accounting.Results showed that the rainstorm flooding disaster risk in northeast was higher than that in southwest.The results also indicated that the possibility of flood risk was the biggest in the three urban districts of Hangzhou,Yuhang,Linan as well as the Fuchunjiang River and southwest of the Qiandaohu Lake.In the densely populated areas,valley areas,river and other areas,the rainstorm flooding disaster risk was relatively high.〖