基于GIS的崩滑地质灾害孕灾地质条件分析——以西藏嘉黎县为例  

Analysis of the disaster-pregnancy geological conditions of collapse and landslide based on GIS:A case study of Jiali County in Tibet

作　　者：孙小勇 魏龙 唐华 刘子畅 SUN Xiaoyong;WEI Long;TANG Hua;LIU Zichang(The 10th Geological Brigade of Sichuan,Sichuan Mianyang 621000,China)

机构地区：[1]四川省第十地质大队,四川绵阳621000

出　　处：《中国地质调查》2024年第4期92-100,共9页Geological Survey of China

基　　金：西藏自治区地质灾害防治体系2021年度(第二批)建设项目十二标段“那曲市比如县、索县、巴青县、嘉黎县地质灾害风险调查评价(编号:54000021210200001374)”项目资助。

摘　　要：嘉黎县内构造作用强烈,地势陡峭,地质环境条件较差,加之2018—2022年修建国道G349对原有地形的破坏,使得县域内地质灾害数量剧增,每逢汛期或遇强降雨天气,区内地质灾害频发。通过收集嘉黎县2018—2023年地质灾害资料,结合野外实地调查,基于GIS平台对县域内的地质灾害发育分布情况和孕灾地质条件进行详细分析。孕灾地质条件的分析主要选取地形地貌、地质构造、地层岩性、土地利用类型和人类工程活动等因素,选取的孕灾因子有高程、坡度、剖面曲率、断层密度、水系密度、工程地质岩组、土地利用类型和距公路距离。分析结果表明:县域内最主要的孕灾地质条件为人类工程活动、地形地貌、地质构造、工程地质岩组、土地利用类型等。结合县域内各孕灾地质条件特征分成5个孕灾分区,并详细阐述各个分区内地质灾害分布发育规律和孕灾地质条件特征。通过对嘉黎县的孕灾地质条件分析,有利于认识地质灾害的发育规律,建立健全地质灾害防治和风险管控体系,为地质灾害防治管理和国土空间规划提供基础依据。Jiali County has strong tectonic action,steep terrain,and poor geological environment conditions.The original terrain was destroyed by the construction of national highway G349 from 2018 to 2022,resulting in a sharp increase in the number of geological disasters in the county.The occurrence rate of geological hazard is high during flood period and heavy rain period.This paper fully collected the geological disaster data of Jiali County from 2018 to 2023 to analyze the distribution of geological disasters and disaster-pregnancy geological conditions in detail,based on field investigation and GIS platform.The analysis of disaster-pregnancy geological conditions mainly selects landform,geological structure,stratigraphic lithology,land use type and human engineering activities.And disaster-pregnancy factors include elevation,to pography,profile curvature,fault density,water density,engineering geological rock group,land use type and distance from highway.The results show that the most important disaster-pregnancy geological conditions in the county are human engineering activities,topography,geological structure,engineering geological rock group and land use type.According to the characteristics of the geological conditions in the region,the county was divided into 5 disaster zones,and the distribution and development law of geological disasters and the characteristics of geological conditions in each zone were expounded in detail.The analysis of disaster-pregnancy geological conditions in Jiali County is helpful to understand the development law of geological disasters,and establish the geological disaster prevention and risk management system,which could provide basic references for geological disaster prevention and management and territorial space planning.

关 键 词：嘉黎县 崩滑地质灾害 孕灾条件 孕灾分区 孕灾因子 

分 类 号：P694[天文地球—地质学]