澜沧江流域重大水电工程扰动灾害风险评价

RISK ASSESSMENT OF DISTURBANCE DISATER IN MAJOR HYDROPOWER ENGINEERING OF LANCANG RIVER BASIN

地质灾害风险性评价对当地防灾减灾具有指导意义。本文以澜沧江重大水电工程扰动灾害为例,在遥感解译与野外实际调查的基础上,选取高程、坡度、坡向、植被归一化指数、距库区距离、工程地质岩组、断裂带密度、年均降雨量、地震峰值加速度9个因素,并基于加权信息量模型进行危险性评价,然后以人口密度、水电站、道路、土地覆盖类型和GDP为承灾体进行易损性评价,最后将危险性和易损性进行信息融合,构建地质灾害风险性矩阵,完成地质灾害风险性评价。评价结果表明:极高和高风险区主要分布在乌弄龙及其上游水电站附近,以及下游库区两岸人类活动相对密集区域,中风险区主要分布在乌弄龙上游库区两岸以及乌弄龙—托巴水电站全域,在下游零散分布;低风险区主要分布在中游高山峡谷段。本次研究较为准确地评估了地质灾害风险性,可为澜沧江流域扰动地质灾害风险规划提供科学依据和技术指导。

The geological hazard risk assessment is guiding significance to local disaster prevention and mitigation.Taking the Lancang River major hydropower engineering area as the research area,this study was based on the remote sensing interpretation and field surveys,and 9 impact factors(the elevation,slope,aspect,difference vegetation index(NDVI),distance to reservoir area,engineering geological rock group,fault zone density,average annual rainfall and peak acceleration of earthquake)were selected to evaluate the risk assessment based on weighted information model.Then,population density,hydropower station,road,land cover type and GDP are taken as the disaster bearing bodies to carry out vulnerability evaluation.Finally,the risk matrix of geological disaster is constructed,and the risk and vulnerability information is integrated to complete the risk evaluation of geological disaster.The evaluation results show that:the extremely high and high risk areas are mainly distributed in the vicinity of Wunonglong reservoir and its upstream hydropower station,and the regions with relatively intensive human activities on both sides of the downstream reservoir,while the medium risk areas are mainly distributed in the two sides of Wunonglong reservoir and the whole region of Wunonglong Toba Hydropower Station,scattered in the downstream.The low risk area is mainly distributed in the middle mountain valley.This study accurately evaluates the risk of geological hazards,which can provide scientific basis and technical guidance for the risk planning of geological hazards in Lancang River Basin.