基于函数赋值模型与模糊综合评判法的单沟泥石流危险性评价

Single gully debris flow hazard assessment based on function assignment model and fuzzy comprehensive evaluation method

基于彭阳县丁家渠泥石流前期调查测绘,查明了泥石流的发育特征,分析了泥石流的形成条件,并对其易发程度进行打分综合评判,得出:该泥石流为沟谷降雨诱发型泥石流,易发程度为中等易发,目前正处于衰退期。构建了包括泥石流规模、发生频率、沟谷流域面积、主沟长度、流域相对高差、流域切割密度及不稳定沟床比例等7个指标的单沟泥石流危险度评价指标体系,采用关联度分析与层次分析法相结合的最优组合赋权法对函数赋值模型中的权重进行修正,并运用该模型对丁家渠泥石流进行危险度计算,为了验证该模型在研究区泥石流危险度评价的准确性,同时采用模糊综合评判法进行危险度计算,两种方法得出的危险度等级均为低度危险,与实地调查结果相符。

Based on investigation and mapping of Dingjiaqu debris flow in Pengyang County,this paper discussed its development characteristics and formation conditions,judged the probable occurrence level.We reached the conclusion that this debris flow is a precipitation-induced gully debris flow,the probable occurrence level is moderate and currently in a recession stage.We constructed a single gully debris flow hazard assessment index system,including scale of debris flow,occurrence frequency,gully basin area,the length of main gully,relative height difference,cutting density,and unstable gully bed ratio.The weight of the function assignment model was modified by the optimal combination weight method combined with the correlation analysis and the analytic hierarchy process,and was used to calculate the risk degree of Dingjiaqu debris flow.In order to verify the accuracy of the modified function assignment model,this paper used fuzzy comprehensive evaluation method to calculate the risk degree too,and the results are the same.The risk level is low degree,which is consistent with the field survey results.