基于GIS的河南省洪灾风险评价

Risk Evaluation of Flood Disasters in Henan Province Based on GIS

区域洪灾风险评价是洪水灾害管理的基础。以洪灾频发的河南省为研究区,在综合分析洪水致灾主要影响因素的基础上,从洪灾的危险性和承灾体的易损性两个角度出发,选取绝对高程、坡度、年均降水量、河网分布、人口密度和GDP密度6个指标构建了河南省洪灾风险评价体系。借助ArcGIS平台空间分析和叠加功能,获得了河南省洪灾风险评价图。结果表明:(1)河南省洪灾风险呈现明显地带性,总体来说从南到北逐渐降低;(2)从行政区划上来看,信阳市大部分地区和驻马店中南部处于洪灾高风险区,三门峡、焦作、新乡、鹤壁和濮阳处于低风险区,其他地区皆处于中度风险区。

Risk assessment of regional floods is the basis of flood disaster management. This paper takes Henan Province as the study area, where has suffered from frequent flood disasters. The main factors of flood disasters were first analyzed, and six indexes were chosen to build the assessment system of flood disaster risk from the aspects of dangerousness and vulnerability of flood disasters. The six indexes were absolute elevation, slope, average annual precipitation, river distribution, population density and the GDP density. The risk distribution map of flood disasters was obtained by using the functions of spatial analysis and over- lay of ArcGIS software. Results showed that： （1） The risk of flood disaster decreased gradually from the south to north. （2） From administrative divisions, most areas of Xinyang City and some of the southern are- as of Zhumadian City were in the high risk zone, Sanmenxia, Jiaozuo, Xinxiang, Hebi and Puyang Cities were in the low risk zone, and other areas were in the middle, risk zone