Risk Assessment Of Glacier Lake Outburst Disaster Based On GIS

The glacier lake outburst debris flow(GLODF)is a unique type of disasters in high-altitude areas.It has the characteristics of sudden,high flood peak,large flow,strong destructive,short duration,and wide range.This is one of the typical disasters in the Tibet Plateau.Glacier lakes are often distributed above the snow line,and it is almost impossible to investigate the risk of glacier lake collapse through traditional geological survey methods.Therefore,based on remote sensing technology,a multisource data combination disaster assessment model was proposed.As an advanced space-to-earth observation technology,remote sensing technology has the advantages of macroscopic,comprehensive and intuitive.Satellite remote sensing images have high spatial resolution,so they can be effectively applied to the identification and dynamic monitoring of disasters,the analysis of environmental characteristics(lithology,slope,aspect and elevation,etc.)and disaster risk mapping.Based on GIS technology,the paper researched on glacier lake outburst disasters risk assessment,in order to provide information and decision support for disaster prevention,disaster reduction,etc.This paper draws the following conclusions:(1)Geographic Information System(GIS)has great application prospects in geological disaster research.GIS has powerful spatial data management,spatial analysis and visualization capabilities,which help to achieve a wide range of disaster risk assessments and geological hazard investigations in remote areas.(2)The risk of glacier lake collapse is determined by the characteristics of the glaciers,the lake itself and the moraine dam.If the number of steep ridges is large,the cracks are developed,the average slope near 8°,or he ratio of the thickness and width of the moraine dam is small,then the risk of collapse of the glacier lake will be high.(3)By analyzing and summarizing the characteristics of the existing glacier lakes in the Tibet Plateau,a glacier lake collapse risk index system based on remote sensing is constructed.Using the analytic hierarchy process and the deterministic coefficient method,the spatial analysis modeling function of GIS is used to complete the disaster hazard zoning and mapping of the concentrated distribution areas of Nyalam,Lozha and Jiali glacier lakes on the Tibet Plateau.(4)The evaluation results show that Jialong fault in Nyalam County still has a high risk of collapse.The remote sensing and field investigation methods are used to estimate the personnel,material basis and property risks of the downstream Nyalam County.A visualized map of the risk zone of Nyalam County.