摘要
遵义市地处贵州省地质灾害重点防范区,地质灾害类型多样,灾害隐患点多面广,开展地质灾害易发性评价,对区域地质灾害减灾防灾具有重要现实意义.依托研究区内1659个地质灾害隐患点,以孕灾地质条件为基础,选取地形地貌、高程、坡度、坡向、植被覆盖指数、工程地质岩组、距断层距离、多年年均降雨量、距河流距离、距道路距离和土地利用类型等作为评价指标,基于ArcGIS软件数据分析平台,在信息量模型基础上,采用加权法对研究区滑坡、崩塌、泥石流及其综合地质灾害易发性进行评价,将研究区地质灾害易发性划分为极低、低、中、高、极高易发区5个等级,并进行评价精度检验.研究区地质灾害极低、低、中、高、极高易发性区面积(占比)分别为:2015.6956 km2(6.55％)、7326.9726 km2(23.82％)、10342.2870 km2(33.62％)、7744.6170 km2(25.17％)、3335.4944 km2(10.84％).研究区内灾点密度随着易发性的增加而增大,面积占研究区36.01％的高、极高易发区内,控制着区内72.75％的地质灾害点分布.ROC特征曲线与横坐标轴所围成的面积AUC值为0.767,表明评价结果可靠,分区合理,可为区域地质灾害预警预测和灾害防治工作提供决策参考.
Abstract
Zunyi City is located in the key prevention area of geological disasters in Guizhou Province,in which there are various types of geological disasters and a wide range of disaster hazard sites.Therefore,it is of great practical significance to carry out the geological disaster susceptibility assessment for regional geological disaster reduction and prevention. Based on the 1659 geological hazard sites in the study area and the environment of developing geological hazards,topography and geomorphology,altitude,slope,aspect,vegetation cover index,engineering geology groups of rock,distance from faults,average annual rainfall,distance from rivers,distance from roads and land use types were selected as evaluation indexes. Based on the data analysis platform of ArcGIS software and the information model,the entropy weight method was adopted to evaluate the susceptibility of landslides,avalanches,mudslides and their integrated geological hazards in the study area,which was divided into five grades,namely,very low,low,medium,high and extremely high susceptibility zones. Finally,the accuracy of evaluation was tested.The area (percentage)of zones with very low,low,medium,high and extremely high susceptibility of geological hazards in the study area were 2015.6956 km2 (6.55％),7326.9726 km2 (23.82％),10342.2870 km2 (33.62％),7744.6170 km2 (25.17％),3335.4944 km2 (10.84％),respectively.The density of disaster sites in the study area increases with the increase of susceptibility of evaluated zones,and 72.75％ of the geological disaster sites are distributed in the high and very high susceptibility zones,which account for 36.01％ of the study area.The AUC value,which is area enclosed by the characteristic curve of ROC and the horizontal axis,is 0.767,indicating that the evaluation results are reliable and the zoning is reasonable,so it can provide decision-making reference for regional geological disaster early warning,prediction and disaster prevention.
维普
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