Remote Sensing Monitoring Evaluation And Simulation Analysis Of Glacier Lake Outburst Flood In Southwest Tibet

Southwest Tibet of China is located in the middle of Himalayas.It is one of the most serious areas of glacier lake outburst flood in China and even in the world.At the same time,the region is one of the important channels for the country's “The Belt and Road”strategy to face South Asia,and various development plans are being gradually implemented.Therefore,in the face of the increasingly serious threat of glacier lake outburst flood,it is imperative to carry out the application research of moraine lake outburst disaster prevention and mitigation in southwest Tibet.At present,under the background of global warming,the research on glacier lake outburst flood mainly focuses on the mechanism,cause,evaluation method,regional moraine lake identification and change monitoring,glacier lake outburst flood chain,simulation of cement flow in glacier lake outburst flood and so on.Although these research directions have made great progress in the exploration of certain theories and methods,due to the uniqueness of different research directions in theories and methods,these research directions have different research situations to some extent.However,due to the uniqueness of different research directions,the moraine lake outbreak disaster lacks an effective and systematic application system for disaster prevention and mitigation.Therefore,in this paper,the moraine lake in southwest Tibet is selected as the research object.From the three independent research directions of moraine lake dynamic change remote sensing monitoring,glacier lake outburst flood flood prone evaluation and glacier lake outburst flood debris flow disaster simulation,the author proposes to build a combination of "monitoring-evaluation-simulation" moraine lake outburst disaster prevention and mitigation system to realize the unity of systematicness and independence of the application system of disaster prevention and reduction in theory and method.Based on literature and related data,remote sensing interpretation and literature data calculation were used to obtain the area information,relevant evaluation factors and simulation parameters of moraine lake and mother glacier,respectively.Using spatial information technology,mathematical and hydrodynamic model,the monitoring and analysis of the dynamic changes of typical moraine lakes in the study area,the optimization of the evaluation factors of the moraine lake outburst and the establishment of the susceptibility evaluation model and numerical simulation study on the debris flow disaster of moraine lake are conducted,respectively.In order to provide a reasonable application theory and method system for the prevention and control of glacier lake outburst flood.The main research results of this paper are as follows:(1)Based on the long-term remote sensing monitoring in the past 40 years,the overall expansion trend of the typical moraine lake is obvious,its area growth rate and expansion rate are relatively high,and the risk of collapse of the typical moraine lake is increasing,which is highlighted by Longbasaba,Rongxiazangbu,Qiangzongkeco,Gangxico and Jilipuco.Due to the small area and reserves of the mother glacier,there is little recharge,and even there is no replenishment of the mother glacier.The area of scared measures Xiaquco and Zongkeco changes slightly.Through the analysis of the influencing factors of the mother glaciers,the scale and retreat of the mother glaciers is one of the important factors affecting the dynamic change of the typical moraine lake.(2)Based on the combination of the grey correlation model and the logistic regression model,the selection of the evaluation parameters and the establishment of the evaluation model of the Bingyu Lake are carried out.Five evaluation parameters are obtained: the degree of avalanche development on both banks and the back of the lake,the average slope of the mother glacier snow region,the slope of the mother glacier tongue,the degree of crack development of the mother glacier,and the area of the lake.Evaluation model,and the evaluation model is verified by application accuracy.It is shown that the evaluation model can better meet the needs of the assessment of the vulnerability of glacier lake outburst flood.(3)The FLO-2D model is used to simulate the demolition debris flow disaster in the historically typical typical Moraine Lake(Cirenmaco Moraine Lake).After comparing the simulation results of the disaster in the simulation area with the actual measured data in the field,it is concluded that the simulation error is small,and it is in good agreement with the actual defeat situation.The results show that the FLO-2D model is better suitable for the simulation of typical glacier lake outburst flood.(4)This article establishes the "monitoring-evaluation-simulation" application process system of the moraine lake disaster prevention and mitigation,and realizes the organic combination of remote monitoring,vulnerability assessment and numerical simulation of the moraine lake disaster.It provides a new application idea for risk prevention and response in southwestern Tibet.