地质灾害的易损性主要是指受灾体发生损坏的难易程度与遭受地质灾害破坏的机率.贡献率模型是评价作用程度的一种指标模型,它通过贡献率均值化、归一化处理,利用权重转换模型建立贡献率转化的权重关系.以汶川县为例,综合考虑汶川县自身自然和社会经济特点,结合四川统计年鉴(2010年),以及利用GIS技术获取区域地质灾害易损性评价因子时功能约束等条件,选取人口密度、林地密度、耕地密度、滑坡灾害密度、居民点密度、道路密度等6个因子作为汶川县地质灾害易损性评价因子.将汶川县14个乡镇作为基本评价单元,利用贡献率模型进行汶川县滑坡灾害易损性等级区划,划分为5个等级:极高易损区、高易损区、中易损区、低易损区、极低易损区.分析结果显示易损性分布基本上与人口密度、道路密度、林地密度分布相一致,体现了评价结果的合理性.%Geological disaster vulnerability is mainly refers to the damage difficulty level and the geological disasters failure probability of the affected objects.Contributing weight model,which uses weight conversion model to build the contributing rate weight conversion relation through the process of mean treatment and normalization,is one of the index models for evaluating effect degree.Taking the landslide disaster vulnerability assessment in Wenchuan County for example,six factors of population density,forest density,cultivated density,landslide disaster density,residential density and road network density are selected to assess the geological disaster vulnerability of Wenchuan County based on the overall consideration of the natural and social features of Wenchuan County,the 2010 yearbook of Sichuan Province and the limitation of GIS technology in obtaining the assessment factors,choosing the 14 villages and towns in Wenchuan County as the basic evaluation unit,the vulnerability zoning of Wenchuan landslides finally can be divided into five grades by using the contributing rate weight model:very high vulnerability zone,high vulnerability zone,moderate vulnerability zone,low vulnerability zone,very low vulnerability zone.It is revealed that the vulnerability distribution is basically consistent with the distributions of population density,road network density,forest density,so as to reflect the rationality of the evaluation results.
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