基于GIS和信息量法的四川峨眉山市地质灾害易发性定量评价  

Quantitative Evalution of geohazards susceptibility based on GIS and information value model for Emeishan City, Sichuan

作　　者：陈绪钰[1] 李明辉[1] 王德伟[1] 田凯[1] 高延超[1] CHEN Xuyu;LI Minghui;WANG Dewei;TIAN Kai;GAO Yanchao(Chengdu Center,China Geological Survey,Chengdu 610081,Sichuan,China)

机构地区：[1]中国地质调查局成都地质调查中心

出　　处：《沉积与特提斯地质》2019年第4期100-112,共13页Sedimentary Geology and Tethyan Geology

基　　金：国家重点研发计划(2018YFC1505406);中国地质调查局项目(DD20190524;DD20160249)

摘　　要：以四川峨眉山市为研究区,选取坡度、坡高、坡向、岩土体类型、构造、河流侵蚀、地表覆被、降雨、工程切坡以及矿产开发10个影响因素作为评价因子,采用改进信息量法,在评价因子分级分析的基础上,利用GIS技术,对研究区地质灾害易发性进行了定量评价。结果表明:方法科学可靠,评价结果与实际基本相符;地质灾害在高陡斜坡区域、坚硬薄层-厚层状砂岩、粉砂岩夹白云岩、灰岩岩组、构造密集区最为发育,地形地貌、地质构造是地质灾害发育最主要的控制因素;地质灾害易发性划分为高易发、中易发、低易发、极低易发4个等级,分布面积分别为169.37km^2、429.07km^2、363.43km^2和221.12km^2。易发性评价精度74.80%。评价方法可为县域地质灾害易发性评价提供理论指导,评价结果可为该区域地质灾害防治工作提供科学依据。Exemplified by Emeishan City,Sichuan,10 factors are selected as the evaluation factors including slope gradient,slope height,slope direction,rock and soil type,geological structure,river erosion,surface cover,rainfall,engineering slope cutting and mineral exploration.On the basis of the grading analysis of the evaluation factors and GIS techniques,the geohazards susceptibility is evaluated for Emeishan City,Sichuan with the aid of the improved information value model.The results of research show that the information value model is scientific and reliable,and the evaluation results are in general agreement with the actual conditions.The geological hazards are best developed in high and steep slopes,hard thin-to thick-bedded sandstones,siltstone intercalated with dolostones,limestone formation and closely spaced structures.Topography,geomorphology and geological structures are believed to be the main factors controlling the geological hazards in this region.The susceptibility of the geological hazards may be classified into four grades:highly,moderately,low and extremely low susceptibility,with the covering areas of 169.37,429.07,363.43 and 221.12 km^2,respectively.The precision of the susceptibility evaluation accounts for 74.80%.It can be seen that the evaluation method presented in this study may serve as a theorectical guide for the susceptibility evaluation of county-scale geological hazards,and the evaluation results may provide scientific data for the prevention and control of the geological hazards in the study area.

关 键 词：地质灾害 易发性评价 信息量法 GIS 峨眉山市 

分 类 号：P642.2[天文地球—工程地质学] P627[天文地球—地质矿产勘探]