基于GIS的贵州省暴雨灾害风险区划

Risk Zonation of Rainstorm Disaster in Guizhou Province

[目的]研究基于GIS的贵州省暴雨灾害风险区划。[方法]选取贵州作为研究区域,以1km×1km栅格数据为评价单元,利用贵州省1961～2008年气象站点日降雨资料,从致灾因子危险性、承受体易损性、孕灾环境敏感性及防灾减灾能力4个方面构建暴雨灾害风险区划指标体系;在层次分析法确定影响因子权重的基础上,构建基于GIS的风险评价模型对4个子指标和风险性总指标分别评价,并最终得到贵州省暴雨灾害风险区划图。[结果]贵州省暴雨灾害风险自中部向四周呈递减的总趋势,低风险区集中在贵州省东北部,暴雨较少、抗灾能力较强是该区风险低的主要原因;高风险区集中在省中部偏西地区,主要因为暴雨集中、地形变化大、森林覆盖率低,其中安顺市较高以上风险地区占该市98.02%,而2010年发生特大地质灾害的贵州省安顺市关岭县岗乌镇也属于高风险区,这与实际受灾情况相吻合。[结论]该研究为以区域为对象的宏观防灾减灾规划提供理论依据。

[ Objective] This paper aimed to study the risk zoning of rainstorm in Guizhou based on GIS. [ Method] Taking Guizhou as study area, 1 km x 1 km grid data as evaluation unit, and by dint of daily precipitation in meteorological station in Guizbeu from 1961 to 2008, the rainstorm risk zoning system was constructed from the aspects of disaster-stricken dangers, suffering flexibility, disaster environment sensitivity and disaster prevention or mitigation; based on the level analysis method to determine factor weight, the risk aa^sessment model base~ on GIS was set up to evaluate the four sub-indicators and risks and to get the rainstorm disaster in Guizhou in the end. [＇Result] The risk asdeasment and zonation results showed a general trend that the risk level decreased from the central to all around. The low risk area distributed in the northwest of Guizhou province because of less heavy rains and high capacity of rainstorm disaster resistant, while high risk area mainly distribu- ted in the west-central of Guizhou due to concentration rainstorms, large terrain undulation and low coverage rate of forest. Especially, accord- ing to Anshun, the high risk area took up 98.02% of the city, and the Gangwu County, where a super-large geological^disaster concurred in 2010 is located at the high risk area, which showed that the risk assessment coincided with the actual situation. [ Conclusion] The study pro- vided theoretical basis for the macro disaster prevention and disaster mitigation plan.