基于不同耦合模型的县域滑坡易发性评价对比分析——以四川普格县为例

Comparison of landslide susceptibility assessment based on multiple hybrid models at county level:A case study for Puge County,Sichuan Province

为有效预测县域滑坡发生的空间概率,探索不同统计学耦合模型滑坡易发性定量评价结果的合理性和精度,以四川省普格县为研究对象。选取坡度、坡向、高程、工程地质岩组、断层和斜坡结构等6项孕灾因子作为评价指标体系,基于信息量模型(I)、确定性系数模型(CF)、证据权模型(WF)、频率比模型(FR)分别与逻辑回归模型(LR)耦合开展滑坡易发性评价。结果表明:各耦合模型评价结果和易发程度区划均是合理的,极高易发区主要分布于则木河、黑水河河谷两侧斜坡带,面积介于129.04~183.43 km^(2)(占比6.77%~9.62%),各模型评价精度依次为WF-LR模型(AUC=0.869)>I-LR模型(AUC=0.868)>CF-LR模型(AUC=0.866)>NFR-LR模型(AUC=0.858)。研究成果可为川西南山区县域滑坡易发性定量评估提供重要参考。

In order to effectively predict the spatial probability of landslide occurrence at county scale,the quantitative evaluation and comparative study of landslide susceptibility were carried out based on different statistical coupling models in Puge County,Southwest Sichuan.Six evaluation factors including slope,slope direction,elevation,engineering geological rock group,distance from fault and slope structure are selected to construct the evaluation index system.Information model(I),certainty factor model(CF),weight of evidence model(WF)and frequency ratio model(FR)are coupled with logistic regression model(LR)respectively to conduct landslide susceptibility evaluation.The results show that the evaluation results of each coupled model and the zoning of susceptibility are reasonable.The extremely high susceptibility areas with 129.04−183.43 km^(2)(accounting for 6.77%−9.62%)are mainly distributed in the slope zones on both sides of Zemu River and Heishui River Valley.The evaluation accuracy decreases from WF-LR model(AUC=0.869),I-LR model(AUC=0.868),CF-LR model(AUC=0.866),to NFR-LR model(AUC=0.858).The research results can provide an important reference for the quantitative evaluation of county landslide susceptibility in mountainous areas of Southwest Sichuan.