Identification, development law and risk assessment of the hidden dangers of glacial lake outburst disasters on the Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau is one of the most frequent glacial lake outburst floods(GLOFs)areas in the world.The GLOF poses a serious threat to the safety of human beings and engineering construction.Based on the remote sensing images and data of Landsat 8 OLI_TIRS from 2015 to 2018, this paper interprets the GLOFs where located within 10 km range of more than 40000 glaciers and its area is greater than 900 m².This paper analyzes the distribution and development characteristics of glacial lakes, establishes the identification index system of GLOFs, and evaluates the hidden danger points by the catastrophe progression method(CPM).The following results the shown.①There are 16481 glacial lakes in Qinghai-Tibet Plateau, which are mainly distributed at 5000~5500 m above sea level, accounting for 43.69% of the total.The area is concentrated between 0.01~0.05 km², accounting for 47.40% of the total.In terms of administrative distribution, the Tibet Autonomous Region has the largest number of glacial lakes, 12664, accounting for 76.84% of the total.In terms of basin distribution, the Yarlung Zangbo River Basin has the largest number of glacial lakes, with 8321, accounting for 50.49% of the total.②369 potential GLOFs were identified, including 126 low-risk points, 177 medium risk points and 66 high-risk points.③The area of hidden danger of GLOFs is mostly 0.1~0.2 km².The altitude is mainly distributed between 5000 ~5500 m above sea level.The distance between the hidden danger point and the mother glacier is less than 100 m, and the width of the moraine dam is mostly less than 300 m.The backwater slope is mostly less than 50°, the slope of the ice tongue of the mother glacier is between 10° and 20°, and most of the GLOFs burst to the north direction.