基于组合赋权法的中巴公路奥依塔克至布伦口段泥石流危险性评价

目的]研究泥石流危险性,为泥石流多发地区危险性评价指标权重的确定提供一种有效的方法。方法]针对单一赋权法确定权重的缺陷,分别采用层次分析法和熵值法确定中巴公路泥石流危险性评价指标的主观和客观权重,再用组合赋权法确定指标的综合权重。以中巴公路沿线重点单沟泥石流为例,选取爆发规模、爆发频率、主沟长度、流域切割密度、流域面积、流域相对高差、主沟纵坡、24h最大降雨量、松散堆积物厚度、泥沙补给段长度比10个指标作为评价因子。获取泥石流现场调查数据后,依据上述方法对该区域泥石流的危险性进行评价,并将计算结果与集对分析方法和现场调查结果进行了对比分析。结果]属于中度危险的沟谷只有5条,占25%,说明该地区大部分泥石流危险性偏高。结论]评价结果与现场调查结果吻合,证明了该方法的可行性。

Hazard Assessment of Debris Flow at Aoyitake-Bulunkou Section of China-Pakistan Highway Based on Combined Weight Method

Objective] The hazard assessment of debris flow was studied in order to provide an effective method for determining the weights of hazard assessment indexes in debris flow prone area.Methods] In view of the weakness of single assigning weight method, analytic hierarchy process (AHP) and entropy method were adopted respectively to determine the subjective and objective weights of the debris flow hazard assessment indexes for the China-Pakistan highway, then the comprehensive weights were estimated based on combined weight method. Taking the debris flow along the China-Pakistan highway as a case study, this paper selected ten assessment indexes including magnitude, frequency, length of main groove, basin incision density, basin area, relative difference of elevation, longitudinal slope of main groove, maximum rainfall during 24 hours, thickness of loose deposit, length of mud and sand supply. The method mentioned above was used to assess the hazard of debris flow in this area after the acquisition of field data of debris flow. Besides, the results coincided with the set pair analysis method and field investigation results.Results] Only five debris flow gullies, accounting for 25% of the total, were moderate dangerous, which meant that most debris flow gullies in this area were high dangerous.Conclusion] The evaluation results were consistent with the field investigation, which confirmed the reliability of the method.