基于信息量模型的综合地质灾害易发性建模方法对比研究

Comparative Study on Modeling Methods of Comprehensive Geological Hazard Susceptibility Based on Information Model

为了更好地实现综合地质灾害易发性评价,以川西地区为例,从考虑不同类型地质灾害的区域地质灾害易发性出发进行综合评价。基于ArcGIS选取地形地貌、工程地质岩组、NDVI等9个地质灾害关键影响因素,采用信息量模型对滑坡、崩塌、泥石流进行易发性评价,进而分别采用栅格最大值法、栅格平均值法以及基于灾害链综合评价的图形叠置法实现综合地质灾害易发性,利用ROC曲线验证单类型地质灾害和综合地质灾害易发性模型精度。按照自然断裂法将川西地区划分为低、中、高和极高易发区,高和极高易发区主要集中在水系附近。研究结果表明信息量模型能较好的对单类别地质灾害评价,栅格最大值法、栅格平均值法以及基于灾害链综合评价的图形叠置法都是获取综合易发性的有效方法,且预测精度从高到低为AVM-IVM>MM-IVM>GOM-IVM。

In order to better realize the comprehensive assessment of geological hazard susceptibility,the western Sichuan area is taken as an example to conduct a comprehensive assessment from the perspective of regional geological hazard susceptibility of different types of geological hazards.Based on ArcGIS,nine key influencing factors of geological disasters,such as topography,engineering geological rock formation and NDVI,are selected,and information model is used to evaluate the vulnerability of landslide,collapse and debris flow,and then grid maximum method,grid average method and graphic overlay method based on comprehensive evaluation of disaster chain are respectively used to achieve comprehensive geological disaster vulnerability,The ROC curve is used to verify the accuracy of single type geological hazard and comprehensive geological hazard susceptibility models.Western Sichuan is divided into low,medium,high and extremely high prone areas according to the natural fracture method,and high and extremely high prone areas are mainly concentrated near the water system.The research results show that the information model can better evaluate the single type of geological disasters.The grid maximum method,grid average method and the graphic overlay method based on the comprehensive evaluation of disaster chain are all effective methods to obtain the comprehensive vulnerability,and the prediction accuracy from high to low is AVM-IVM>MM-IVM>GOM-IVM.