基于空间信息格网的南京市洪水风险评估

Flood disaster risk assessment in Nanjing City based on spatial information grids

分别采用MIKE模型和ArcGIS平台搭建洪水风险自然属性和社会属性空间信息格网并进行格网叠加,构建洪水风险评价指标体系,利用层次分析法和熵权法确定主客观权重,进而计算得出洪水风险综合指数并对南京市秦淮区3个相邻街道进行洪水风险评估。结果表明:不同降雨强度下,洪水风险综合指数西北部较高、东南部较低、易受损敏感区相对较高;随着降雨强度增大,洪水风险综合指数较高的区域范围不断扩大;研究区主要积淹点均处于洪水风险综合指数较高区域;基于空间信息格网的洪水风险评估可为精细化、动态化的洪水灾害风险评估与洪水管理提供参考。

Using the MIKE model and the ArcGIS platform,spatial information grids for the natural and social attributes of flood risks were respectively constructed and superimposed.The subjective and objective weights were calculated using the analytic hierarchy process and the entropy weight method,and the comprehensive flood risk index was computed to conduct a risk assessment for three adjacent streets in Qinhuai District of Nanjing City.The results show that,under different rainfall intensities,the spatial distribution of the comprehensive flood risk index is mainly characterized by higher values in the northwest and lower values in the southeast,with relatively higher values in vulnerable and sensitive areas.As the rainfall intensity increases,the area with higher values of the comprehensive flood risk index continuously expands.The main waterlogging treatment points in the study area are all located in regions with higher comprehensive flood risk indices.The flood risk assessment based on spatial information grids can provide references for more refined and dynamic flood disaster risk assessment and flood management.