Temporal and spatial variation characteristics of lakes in Qilian Mountains from 1990 to 2020 and analysis of meteorological factors

Abstract

Abstract Lakes are sensitive indicators of climate change. Based on the lake dataset and Landsat remote sensing data, we analyzed the changes in area and number of lakes(>1km2) in the Qilian Mountains from 1990 to 2020, as well as the boundary changes of lakes(>100km2). In addition, we discussed the impact of climate change on lake area. The results showed that: (1) From 1990 to 2020, the total area and total number of lakes in the Qilian Mountains showed an overall increasing trend, with a total area increase of 492.47km2 and a total number increase of 10. Among them, Qinghai Lake, Hala Lake, Xiao Qaidam Lake, and Nauru Nor Lake showed an overall expansion trend, while Caka Salt Lake and Da Caidam Lake showed an overall shrinking trend. (2)The main reasons for the expansion of Qinghai Lake and Hala Lake was the increase in precipitation, while the main reason for the expansion of Xiao Qaidam Lake and Nauru Nor Lake was the increase in temperature and precipitation. The main reason for the shrinkage of Caka Salt Lake was the enhancement of evapotranspiration. (3) Lakes in the Qilian Mountains were mainly expanding, which has a good promoting effect on improving the ecological environment of this region and even larger area. However, we should also pay attention to problems such as floods and salt-alkali land caused by lake expansion in a timely manner. In addition, governments and all sectors of society should take corresponding measures to alleviate further shrinkage of Caka Salt Lake.