Study on the response of glaciers and climate change in the eastern Himalayas in recent 30 years

Over the past 30 years, marine-type glaciers in the eastern Himalayas have been significantly affected by climate change, making the region a key area for global climate change research. Based on Landsat series remote sensing imagery, this study employs visual interpretation and the band ratio threshold method to analyze the area and variation characteristics of marine-type glaciers in the eastern Himalayas from 1990 to 2015. It further investigates the influence of debris cover, glacial lakes, and climate change on glacier ablation. The results indicate that (1) From 1990 to 2015, marine-type glaciers in the eastern Himalayas showed an accelerating retreat trend, with an average annual retreat rate of 0.48%/a. (2) A significant increase in temperature was the primary climatic factor driving the accelerated retreat of glaciers during the study period. In the future, changes in precipitation may surpass temperature as the dominant climatic factor influencing glacier variation in the study area. (3) Debris cover mainly played a mitigating role in glacier retreat in the eastern Himalayas. Within the 50°–60° slope range, debris-covered glaciers gradually became dominant, resulting in a lower average annual retreat rate during 2000–2015 compared to 1990–2000. (4) The impact of climate change on glaciers in the study area was greater than that of glacial lakes. This study reveals the mechanisms by which debris cover, glacial lakes, and climate change influence glacier ablation, providing scientific support for glacier disaster early warning and water resource assessment.