Glacier and glacial lake evolution in response to local climate forcing: A quantitative assessment in Ulugh Muztagh, Eastern Kunlun Mountains

Abstract

As an important part of the glaciated region on the Qinghai-Tibet Plateau, the western part of the Kunlun Mountains has mainly been studied, while little research has been conducted in the eastern part of the Kunlun Mountains due to its harsh environment and poor accessibility. In this study, the Ulugh Muztagh region of the largest glaciated region in the eastern Kunlun Mountains was selected as the study area to estimate the changes in the glaciers, glacial lakes, and local climate. The outlines of the glaciers and glacial lakes were manually extracted to obtain an accurate glacier inventory, and the characteristics of these glaciers and glacial lakes during 1990–2020 were analyzed. The results revealed that there were 245 glaciers and 16 glacial lakes in 1990 and 2020. During this period, the glacier area decreased by 7.95 ± 1.26 km² and the glacial lake area decreased by 0.24 km². The area of these glaciers exhibited a slight retreat, and the area of the glacial lakes shrank by 7.2 km². The number of glacial lakes exhibited a fluctuating increasing trend. Two glacial lake outbursts occurred in an ice-dammed lake in the northwestern part of Ulugh Muztagh during 1998–2002, exhibiting a periodic outburst pattern. In addition, the recession of the glaciers in contact with glacial lakes was more significant than that of the glaciers not in contact with glacial lakes. The significant increase in summer precipitation was a main driving factor in the evolution of the glacial lakes. The slight retreat of the glaciers in this region did not exhibit a significant correlation with the summer air temperature, but it did exhibit a correlation with the precipitation.