Spaciotemporal distribution characteristics of glacial lakes and the factors influencing the Southeast Tibetan Plateau from 1993 to 2023

The southeastern region of Tibet, which serves as the primary concentration area for marine-type glaciers, has fostered a multitude of glacial lakes that are highly sensitive to global climate change. Glacial lakes play a crucial role in regulating the freshwater ecosystems of the region, but they also pose a significant threat to local infrastructure and populations due to flooding caused by glacial lake outbursts. Currently, a limited amount of research has focused on the monitoring and analysis of glacial lakes in southeastern Tibet. Using Google Earth Engine (GEE) data in conjunction with meteorological data, this study examined the variation characteristics of glacial lakes in southeastern Tibet from 1993 to 2023. The region is subjected to segmentation and extraction of glacial lake boundaries via the FCN model. According to research findings, by 2023, southeastern Tibet is projected to contain 3,877 glacial lakes, encompassing an area of approximately 395.74 +/- 22.72 km(2). The distribution of glacial lakes in this region follows a pattern characterized by a relatively high concentration in the southern region and a relatively low concentration in the northern region. The glacial lakes with areas less than 0.1 km(2) accounted for 94.24%, whereas those exceeding 3.0 km(2) experienced the least amount of change. The analysis of regional elevation using the natural segmentation method reveals that glacial lakes are predominantly distributed within the altitude range of 4442 similar to 4909 m. The fluctuations in the annual mean precipitation and average annual temperature in the study area have decreased since 2008, while the growth trajectories of both the area and number of glacial lakes have gradually stabilized. However, given the backdrop of a slight increase in precipitation and a gradual increase in temperature, the proliferation of glacial lakes is projected to accelerate predominantly in Nyingchi City's eastern and western regions.