杭州市暴雨洪涝灾害风险区划

RISK DIVISION OF RAINSTORM FLOODING DISASTERS IN HANGZHOU CITY

暴雨洪涝灾害是一个多因素耦合的复杂系统,在自然灾害系统理论基础上,根据杭州市1959～2009年的降水资料、自然环境以及社会经济要素,综合致灾因子、孕灾环境、承灾体以及防灾减灾能力,构建区域暴雨洪涝灾害风险评价模型。考虑到降水、地形、水系以及GDP和耕地等因子,通过ArcGIS空间分析技术结合模糊综合评价法,编制以100m×100m栅格为基本评价单元的杭州市暴雨洪涝灾害风险区划图。区划结果表明杭州暴雨洪涝风险东北部高于西南部。杭州暴雨洪涝风险高值区主要在杭州市区、余杭区、临安市、富阳市和桐庐县的富春江流域、淳安千岛湖西南部地区。暴雨洪涝风险高值区主要集中在山谷、河边、江边、人口密集地区等区域。

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.