区域洪灾风险评价方法初探——以浙江省为例

Preliminary study on regional flood disaster risk assessment method——a case of Zhejiang Province

本文选取我国浙江省作为研究区,以其县域作为基础的计算单元,从洪水灾害系统理论出发,构建洪灾风险评估模型和风险因子指标体系对宏观区域上的洪灾风险评价方法进行了探讨。根据洪水灾害风险的原理,结合致灾因子危险性、承灾体暴露性和易损性、区域防灾力等要素选取了15个风险评价指标,并为各风险因子及其基础指标分配了权重。根据所建立的计算模型和风险分级方法,对研究区的洪灾风险等级及风险类型做了定量化分析。经计算,浙江省高等级的洪灾风险集中分布于浙北的冲积平原区和浙东的沿海丘陵平原区,在浙西的金华衢州盆地也有高等级洪灾风险呈点状分布。评价结果可用于指导浙江省的洪水风险管理和防灾减灾措施建设。

Taking Zhejiang Province in China as a study case,the flood disaster risk assessment model and the index system of risk factors are established from the aspect of the systems theory of flood disaster by taking the county regions therein as the basic calculation elements,and then the flood disaster assessment method on the macro-regional scale is discussed herein.In accordance with the principle of flood disaster risk,15 risk evaluation indexes are selected under the consideration of the key elements such as the dangers of hazard factors,exposure and vulnerability of disaster-bearing bodies,regional disaster prevention capacity,etc.,and then the weights of all the risk factors and their basic indexes are determined.Furthermore,the quantitative analysis is made on both the risk factors and types of risk within the study area with the established calculation model and risk classification method.Through the relevant calculation,it is indicated that the flood disasters with high risk levels in Zhejiang Province are mainly distributed in the alluvial plains of the North Zhejiang and the coastal hilly-plains of the East Zhejiang,however,some scattered distributions of the flood disaster risk with high level are also there in Jinhua—Quzhou Basin of the West Zhejiang.The result of the assessment can be used to guide the flood risk management and the construction of the measures of disaster prevention and mitigation concerned in Zhejiang Province.