基于不同空间尺度资料的自然灾害风险评估对比分析——以暴雨洪涝灾害为例

Comparative Analysis of Natural Disaster Risk Assessment Based on Different Spatial Resolution Data——Taking Rainstorm and Flood Disaster as an Example

以致灾危险性、承灾体暴露性和脆弱性评估为理论基础,采用GIS空间分析技术,对黑龙江省位于平原的富裕县和位于山区的呼玛县进行了暴雨洪涝风险评估研究。致灾危险性评估指标包括暴雨洪涝指数和孕灾环境影响指数;承灾体暴露性评估指标包括人口密度、单位面积GDP和农作物耕种密度;脆弱性评估指标包括老幼人口占比、直接经济损失占比和受灾耕地面积占比。评估过程中针对各因子量纲不同,采用均一化方法进行了处理。权重采用层次分析法和专家打分法确定。重点研究基于不同空间尺度降水资料所得出的致灾危险性评估和风险评估结果的异同。研究发现,与基于空间分辨率较低降水资料所得到的暴雨洪涝指数和风险分区结果相比,采用较高空间分辨率降水资料的暴雨洪涝指数分布更加平滑,突出了暴雨高值和低值区,对暴雨洪涝指数的空间差异刻画更加细致;平原区暴雨洪涝风险分区连续性增强,山区风险分区不但连续性增强,且与地形分布趋势高度一致的状况得到了显著改善,结果更加科学合理。

Based on the assessment of hazard,exposure and vulnerability of disaster bearing body,the risk assessments of rainstorm and flood in Fuyu in plain and Huma in mountainous area by using GIS spatial analysis technology are studied.Hazard assessment indicators include rainstorm flood Index and disaster pregnant environmental impact index.Exposure assessment indicators of disaster bearing bodies include population density,GDP per unit area and crop cultivation density and vulnerability assessment indicators include the proportion of old and young population,the proportion of direct economic losses and the proportion of affected cultivated land.The homogenization method is used to deal with the different units of each factor.The weight coefficients are determined by analytic hierarchy process and expert scoring method.This paper focuses on the similarities and differences of hazard assessment and risk assessment results based on precipitation data at different spatial resolutions.It is found that compared with the results of rainstorm flood index and risk zoning based on precipitation data with sparse spatial resolution,the rainstorm flood index distribution using precipitation data with finer spatial resolution is smoother,highlighting the high and low value areas of rainstorm,and describing the spatial difference of rainstorm flood index more carefully.The continuity of rainstorm and flood risk zoning in plain area is enhanced,and the risk zoning in mountainous area is not only enhanced,but also highly consistent with the topographic distribution trend has been significantly improved.In general,the hazard assessment and the risk assessment of rainstorm and flood using precipitation data with finer spatial resolution are more scientific and reasonable.