杭州市台风暴雨洪涝灾害风险区划与评价

Risk Division and Assessment of Typhoon Rainstorm Flooding Disasters in Hangzhou City

根据1960—2009年杭州市7个县市区的台风降水资料,结合杭州市的社会经济与自然地理要素,构建一个集致灾因子、孕灾环境、承灾体及防灾能力为一体的区域台风暴雨洪涝灾害风险评价模型。通过GIS空间分析技术实现各评价指标的栅格化,并利用模糊综合评价方法。编制以100 m×100 m栅格为基本评价单元的杭州市台风暴雨洪涝灾害风险区划图。将杭州市域划分为高、次高、中等、次低和低的5级风险。区划结果表明:杭州市台风暴雨洪涝灾害风险从西南至东北呈递增趋势。萧山区、余杭市及杭州主城区等沿海平原区,风险等级相对较高;而建德市、淳安县等中西部山地丘陵区,风险等级略低。

Based on the typhoon precipitation data from seven stations in Hangzhou City during the period from 1960 to 2009 and combined with the society economic and natural geographic factors,this study builds a set of typhoon rainstorm flooding disaster assessment model including hazard factors,hazard inducing environment,hazard-affected body and disaster prevention ability.And a map of Hangzhou＇s typhoon rainstorm flooding disaster risk division was drawn using 100 m X 100 m raster as basic assessment unit, by means of GIS spatial analysis technique for rasterizing evaluation indices and fuzzy comprehensive assessment methods.Finally,the five risk zones of Hangzhou,i.e.higher risk,sub-high risk,medium risk,inferior risk and lower risk,were mapped.Results show that the typhoon rainstorm flooding disaster risk in Hangzhou has an increasing tendency from southwest to northeast.The coastal plain,involved with Xiaoshan District,Yuhang City,main urban area of Hangzhou,and so on,has relative high risk,while the mid-west mountain and hilly area,involved with Jiande City,Chun＇an County,and so on,has slightly lower risk.