基于不同数学模型的四川省马边县地质灾害易发性评价研究

Comparison of Different Mathematical Models for Geological Hazards Susceptibility Assessment in Mabian County,Sichuan Province

为合理准确地反映四川省马边县地质灾害易发性评价结果,以马边县301处地质灾害点为例,选取海拔、坡度、坡向、坡型、地形起伏、工程岩组、断层、水系、降雨等9个评价指标,基于ArcGIS平台利用信息量模型(I)、确定性系数模型(CF)和考虑权重的加权信息量模型(AHP-I)和加权确定性系数模型(AHP-CF)等4种模型,分别对研究区进行地质灾害易发性评价。结果表明:坡度、工程岩组、断层和降雨对研究区地质灾害易发的贡献度较高。4种评价模型均将研究区划分为极低易发区、低易发区、中易发区、高易发区,其中中-高易发区主要分布在县域的中北部以及软弱岩组、河流和断层两侧沿线区域,与历史灾害点分布高度一致。通过ROC曲线计算AUC值均大于0.75,表明评价结果准确性较高,4种模型的准确性排序为AHP-CF>CF>AHP-I>I。该研究可为马边县地质灾害易发性评价提供理论方法,为地质灾害防治区划提供参考依据。

This work attempts to reasonably and accurately reflect the geological hazard susceptibility of Mabian County in Sichuan Province.Taken the 301 geological hazards in Mabian County as examples,nine evaluation indices,including elevation,slope gradient,slope direction,slope type,topographic relief,engineering rock group,faults,rainfall,were selected.Based on the ArcGIS platform,four models,i.e.,the information model(I),deterministic coefficient model(CF),the analytic hierarchy process-information model(AHP-I)and the analytic hierarchy process-deterministic coefficient model(AHP-CF),were utilized to evaluate the susceptibility of geological hazards in the study area.The results show that slope gradient,engineered rock group,faults and rainfall have a high contribution to susceptibility of geological hazards in the study area.The four evaluation models classify the study area into low-prone,lower-prone,medium-prone,and high-prone areas.The medium-high prone zones are mainly distributed in the central and northern parts of the county,and in the area along the weak rock groups,rivers and faults,which are in high agreement with the distribution of historical hazard sites.Through ROC curve verification,the correct rates were all greater than 0.75,indicating that the evaluation results are highly accurate,and the accuracy of the four models is ranked as AHP-CF>CF>AHP-I>I.This study can provide a theoretical method for evaluating the susceptibility of geologic hazards in Mabian County and provide a reference basis for the planning of geologic hazards prevention and control areas.