Spatio-Temporal Distribution Characteristics of Glacial lakes and the Factors Influencing in Southeast Tibetan Plateau from 1993 to 2023

Abstract The southeastern region of Tibet, serving as the primary concentration area for marine-type glaciers, has fostered a multitude of glacial lakes that exhibit high sensitivity to global climate change. The 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 outburst. Currently, there is a limited amount of research focused on the monitoring and analysis of glacial lakes in southeastern Tibet. Utilizing Google Earth Engine (GEE) 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 utilizing 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 km2. The distribution of glacial lakes in this region follows a pattern characterized by a higher concentration in the south and a lower concentration in the north.The glacial lakes with an area less than 0.1km2 accounted for 94.24%, while those exceeding 3.0km2 experienced the least amount of change. The analysis of regional elevation using the natural segmentation method reveals that the glacial lakes are predominantly distributed within the altitude range of 4442 ~ 4909m. The fluctuation of annual mean precipitation and average annual temperature in the study area has exhibited a deceleration trend since 2008, while the growth trajectory of both the area and number of glacial lakes has gradually stabilized. However, given the backdrop of a slight increase in precipitation and a gradual temperature rise, the proliferation of glacial lakes is projected to accelerate predominantly in Nyingchi City's eastern and western regions.