中国洪灾风险区划研究

考虑气候、地貌和流域水系作为洪水发生的影响因素,分别选取特定频率下的三日降水量、中国气候分区图、坡度图、高程图和河湖缓冲区作为洪水发生的影响因子,并兼顾历史洪水频次数据,采用成因分析法和层次分析法确定各影响因子的权重,在ArcGIS环境下制作了特定频率下的中国洪水风险区划图。分别以人口和GDP作为社会经济指标,分析并制作了中国发生特定频率洪水时的受灾人口分布图和GDP损失分布图。区划图符合历史洪水资料的统计情况,客观反映了中国洪水风险区域的空间分布情况。

Flood risk zoning in China

The occurrence of flood disaster is usually affected by climate, topography and river net system. Therefore, six factors including maximum 3-day precipitation, climate zoning, the magnitude of slope, Digital Elevation Model (DEM), buffer zones of river nets and lakes, and statistic data were selected to represent this kind of effect in this study. The weight for each factor was determined by the combination of cause analysis of flood formation and the analytic hierarchy process. The flood zoning map of China was obtained through overlay analysis by using Geographical Information System (GIS). Potential economic and social impacts of flooding were assessed using the distribution of population and Gross Domestic Product (GDP). The zoning map obtained is consistent with historically statistical flood zoning and it indicates that the technique used in this paper was suitable to analyze the spatial characteristics of flood risk in China.