摘要
作为在山地地区易发的自然灾种,地质灾害每年都给中国造成严重的经济损失。为揭示阐明典型高山峡谷区地质灾害易发性影响因素,文章以昌都市为研究区例,基于区内孕灾环境的差异,对其进行流域划分,同时选取海拔、坡度、地形起伏度等10个指标构建地质灾害易发性评价指标体系,基于随机森林模型对各流域地质灾害易发性空间分布进行研究。结果表明:(1)昌都市地质灾害类型主要以小型灾害为主,大型灾害分布相对较少但危害巨大,险情等级较高,同时,区域内地质灾害的空间分布具有沿河流与道路呈条带状分布的特征;(2)总体来看,各流域地质灾害的影响因素大致相同,但仍具有一定的差异性,金沙江流域受海拔与道路影响较为突出,澜沧江流域受居民点密度影响较为突出,而怒江流域受道路因素影响较为突出;(3)各流域地质灾害易发性空间分布存在差异,金沙江流域低易发面积占比最大,澜沧江与怒江流域均为中易发面积占比最大;三大流域均以高易发所占比最小,但在全流域内均有分布,且主要分布于人类活动较为强烈、岩性较软等区域。
As a natural disaster prone to occur in mountainous areas,geological hazards cause serious economic losses to China every year.In order to reveal the factors influencing of geological hazards susceptibility in typical mountain valley,this paper takes Changdu City as the study area.Firstly,we analyze the spatial distribution of geological hazards,and then divides it into three major watersheds based on the differences of disaster-inducing environments in the study area,selects 10 indicators such as elevation,slope and terrain relief to build a evaluation index system of geological hazard susceptibility,and the weights of index determined based on the Random Forest.The spatial distribution of geological hazards in each watershed of Changdu City is obtained by overlaying with GIS,and it is found that:(1)The types of geological hazards in Changdu City are mainly small disasters,while the distribution of large disasters is relatively small but the hazards are huge and the danger level is high.(2)In general,the factors influencing geological hazards are more or less the same in each basin,but there are still some differences,with the factor of medium altitude and road being more prominent in the Jinsha River basin,the factor of density of settlements being more prominent in the Lancang River basin,and the factor of road being more prominent in the Nujiang River basin.(3)The Jinsha River basin has the largest area of low susceptibility,and the Lancang and Nujiang River basins have the largest area of medium susceptibility;all three basins have the smallest area of high susceptibility,but they are distributed in the whole basin,and mainly in areas with strong human activities and soft lithology.
作者
支泽民
刘峰贵
周强
夏兴生
陈琼
ZHI Zemin;LIU Fenggui;ZHOU Qiang;XIA Xingsheng;CHEN Qiong(College of Geography,Qinghai Normal University,Xining,Qinghai 810008,China;Academy of Plateau Science and Sustainability,Xining,Qinghai 810008,China)
出处
《中国地质灾害与防治学报》
CSCD
2023年第1期139-150,共12页
The Chinese Journal of Geological Hazard and Control
基金
第二次青藏高原综合科学考察研究项目(2019QZKK0906)。
关键词
昌都市
随机森林
地质灾害
易发性
流域单元
Changdu City
random forest
geological hazards
susceptibility
watershed unit