Hazard Assessment Of Glacier Lake Outbursts In The Parlung Zangbo Basin Based On Catastrophe Progression Method

There is a crustal uplift in the Parlung Zangbo basin of China,where developed thousands of various glacier lakes and occurred the glacier lake outbursts frequently.The frequent occurrence of glacier lake outbursts have caused seriously damage of the environment.And that was seriously threatened to the life and property safety of the local residents.This paper takes the Parlung Zangbo basin as the study area,based on the analysis of the environmental background,with the help of modern remote sensing methods to collect image data of the study area,to analysis the cause and mechanism of glacier lake outbursts and to filter out dangerous glacier lakes.Based on the experience of previous generations,select some proper assessment indexes to access the glacier lakes hazard,establish a more reasonable evaluation model of glacier lakes hazard and improve a more objective hazard assessment system of glacier lakes hazard,The research of this paper finally draws the following conclusions:1.Based on the GIS platform,combined with the images of Landsat and Google Earth of Parlung Zangbo basin to visually interpret the ice lakes in the study area,a total of 72 dangerous ice lakes in the study area were interpreted,and the distribution map of the dangerous ice lakes was obtained.2.The causes of ice glacier lakes hazard include ice / avalanche,strong ice / snow ablation,strong / continuous precipitation,buried ice ablation,pipe surge,and earthquake.there are more than one inducement to cause the glacier lakes hazard,Generally,one inducement causes other factors to change,or many factors together cause the glacier lakes hazard.The mechanism of glacier lake outbursts can be divided into overflow outburst,piping outburst,instantaneous outburst and many combinations of outburst and the mechanism of moraine dam can be divided into two types: the outburst caused by the gradual erosion of moraine dam and the outburst caused by the clearing of some areas of moraine dam.3.Glacier lake elevation,glacier lake area,distance between the glacier lake frontand the moraine lake,the width of the moraine embankment,the slope of the backwater slope,the area of the mother glacier and glacier crack development level were selected as the assessment indexes with the principle of the indexes are easy to access.To explore the relationship between the assessment indexes of glacier lake outbursts.Obtain the corresponding parameters of these seven assessment indexes by remote sensing.Adopted Catastrophe progression method to access the glacier lakes hazard and we can find that there are 6 glacier lakes are high hazardous,13 glacier lakes are relatively high hazardous,53 glacier lakes are medium-low hazardous.4.verified the results by AHP,it can be found that the assessment results of the two methods are basically the same,which shows that the Catastrophe progression method has good accuracy in the assessment of glacier lake outbursts.By interpolating the assessment to get the assessment classification map of glacier lake outbursts in Parlung Zangbo basin,we can find that the high hazardous glacier lakes are mostly distributed in Bagai town,Xumu town and Reza Sa town.It is suggested to adopt the means of monitoring and protection in combination for the high risk glacial lake,and to make the corresponding disaster emergency plan for the dangerous glacial lake,so as to minimizing the harm caused by the glacial lake outburst...