基于ROC曲线与确定性系数法集成模型的三峡库区奉节县滑坡易发性评价

Evaluation of Landslide Susceptibility Based on ROC and Certainty Factor Method in Fengjie County,Three Gorges Reservoir

滑坡易发性评价是区域滑坡灾害风险评估和防控的基础。以滑坡灾害高易发区三峡库区奉节县为研究区,首先初步选取坡度、坡向、高程、剖面曲率、断裂带距离、岩土体类型、水系距离、降雨量、道路距离和植被覆盖度10项基本指标,构建滑坡易发性初始评价指标体系,并采用频率比法对各评价指标进行分级;然后,采用ROC曲线(Receiver Operating Characteristic curve受试者工作特征曲线)法定量分析各评价指标对滑坡易发性建模精度的影响程度,确定对研究区滑坡易发性建模影响的关键评价指标体系;最后,分别应用确定性系数法和逻辑回归模型对研究区滑坡易发性进行建模与分区,并对比分析两种模型评价结果的精度。结果表明:确定性系数法的成功率和预测率为82.1%和82.0%,其值高于逻辑回归模型的80.5%和79.5%;确定性系数法中92.24%的滑坡分布在高易发区和较高易发区,其值高于逻辑回归模型的80.65%,表明集成ROC曲线法与确定性系数法的区域滑坡易发性评价方法具有可靠性和精确性,可为完善滑坡灾害易发性评价理论和技术方法提供新的思路。

Landslide susceptibility evaluation is the basis of regional landslide risk assessment and prevention and control.Taking Fengjie County of Three Gorges Reservoir which is highly prone to landslide disaster as the study area,this paper firstly selects 10 basic factors such as slope,aspect,elevation,profile curvature,distance to faults,rock soil mass types,distance to river,rainfall,distance to road and vegetation coverage to construct an initial evaluation index system for landslide susceptibility,and grades the factors by the frequency ratio method.Then the paper uses the Receiver Operating Characteristic(ROC)curve to quantitatively analyze the influence of various indexes on the modeling accuracy of susceptibility,and determines the key index system affecting the modeling of landslide vulnerability in the study area.Finally,the paper adopts the certainty factor method and the logistic regression model to develop the model and partition the landslide susceptibility of the study area,and compares the accuracy of the two models.The results indicate that the success rate and prediction rate of the certainty factor method are 82.1%and 82.0%,higher than those of the logistic regression model of 80.5%and 79.5%.By the certainty factor method,92.24%of the landslides are distributed in the areas with very high and high susceptibility,higher than that of the logistic regression model of 80.65%.It is showed that the regional landslide susceptibility evaluation method which integrates the ROC curve method with the certainty factor method is reliable and accurate,which can provide new ideas for improving the theory and method of landslide susceptibility evaluation.