Changes of glaciers and glacier lakes in alpine and extremely alpine regions using remote sensing technology：A case study in the Shisha Pangma area of southern Tibet

Under the background of global warming, glaciers in southern Tibet continue to retreat and glacier lakes continue to expand, resulting in a series of geological disasters. In this paper, based on the object-oriented classification method, the area of glaciers and glacier lakes in Shisha Pangma peak region of South Tibet from 1994 to 2018 were extracted by using band ratio method and NDWI index. The results show that the net glaciers in Shisha Pangma peak region continue to retreat, with an overall rate of (1.28 ± 0.32)%per year, and the expansion rate of the glacier lakes are about (1.88 ±1. 07) %per year. At the same time, glaciers with an area of less than 1 km² retreat seriously, up to 33.25%. Secondly, the meteorological reanalysis data show that the increase of summer temperature and precipitation may be important reasons for the accelerated retreat of net glaciers in the region, and jointly promote the expansion of glacier lakes, greatly increasing the risk of glacier lakes outburst in the region.