基于信息量与灾害熵的泥石流危险性评价对比研究——以成兰铁路松潘段为例

A Comparative Study on Debris Flow Hazard Assessment Based on Information Volume and Disaster Entropy:a Case Study of Songpan Section of Chengdu⁃Lanzhou Railway

以成兰铁路松潘段为研究区域,根据野外调查分析、研究区基本环境地质条件,选取9项影响因子:高程、坡度、降雨量、岩性、地震烈度、NDVI(归一化植被指数)、距离断裂距离、HI(物源参照值)以及流域形状系数,分析泥石流的分布特征。基于GIS技术,通过信息量和灾害熵两种不同的模型,对各评价指标图层进行分类计算,并进行泥石流危险性评价。结果:在信息量模型中,研究区内危险中度及以上占总面积的87%;泥石流沟内危险中度及以上占沟总面积的65%,共31条。灾害熵模型中,研究区内中危及以上危险区占总面积的81%;泥石流沟内中危区及以上危险区占沟总面积的80%,共38条。与灾害的实际分布相比,灾害熵模型给出了更接近实际的结果。

Focusing on the Songpan section of the Chengdu-Lanzhou Railway as the study area,the study analyzed the distribution characteristics of debris flow based on field investigation and the re-gion′s basic environmental geological conditions.Nine influencing factors were considered,including elevation,slope,rainfall,lithology,seismic intensity,normalized difference vegetation index(ND-VI),distance from faults,source material reference value(HI),and watershed shape coefficient.Us-ing GIS technology,two different models-information volume and disaster entropy-were applied to classify and calculate each assessment index layer,and the debris flow hazards were assessed.Results showed that,according to the information volume model,87%of the total area in the study area was classified as moderate hazard or above,with 65%of the total area within the debris flow ditches classi-fied as moderate or higher hazard,covering 31 ditches.In the disaster entropy model,areas with mod-erate or higher hazard levels accounted for 81%of the total study area,and 80%of the total area with-in the debris flow ditches were classified as moderate or higher hazard,covering a total of 38 ditches.Compared to the actual distribution of hazards,the disaster entropy model provided results that were closer to reality.