基于GIS的模糊数学模型在泥石流敏感性评价中的应用

Application of GIS-based fuzzy mathematics model to sensitivity evaluation of debris flow

以四川省汶川县为典型研究区,采用GIS技术与层次分析法、模糊数学等数学模型相结合的方法,进行了泥石流敏感性评价研究。选取流域高差、沟壑密度、沟道坡度、主沟纵比降、崩滑体核密度强度、年最大日降雨量等6个指标作为评价因子,构建了泥石流敏感性评价指标体系。采用模糊综合评判法对汶川县160条泥石流的敏感性进行了评价,利用ARCGIS空间分析功能求出了每个因子对上一级的隶属度图层。最后,根据最大隶属度原则,选取每个流域上泥石流的敏感性隶属度的最大值作为该流域单元泥石流的敏感性等级。检验分析表明,评价的泥石流敏感性空间分布与实际调查结果较为吻合。

In order to establish a model to evaluate the sensitivity of the debris flow, we took Wenchuan County of Sichuan Province as a typical study area, then derived a mathematical model that combines concepts of GIS technology, analytic hierarchy process and fuzzy mathematics. Basin relief, ravine density, channel slope, longitudinal specifc drop of major gully, crumble-sliding body＇ s kernel density and the maximum daily rainfall amount in a year were chosen as evaluation indices to build debris flow susceptibility evaluation index system. Fuzzy comprehensive evaluation method was used to evaluate the sensitivity of 160 debris flow in Wenchuan County, we took advantage of ARCGIS＇ s space analysis function to calculate the membership degree of each layer for factors. Finally, according to the maximum membership principle, we chose the maximum membership degrees of debris flow in each water- shed as the watershed unit＇ s debris flow susceptibility level. Check analyses show that the evaluated spatial distribution of the susceptibility coincides with the investigated results in filed.