Refined identification and expansion mechanisms of glacier-fed lakes in high mountain Asia

Glacier-fed lakes are expanding, but research on the driving factors of their expansion is insufficient. The primary reason for this gap lies in the current definition of glacial lakes, which includes all lakes within 10 km of glaciers, regardless of whether they are glacier-fed or non-glacier-fed lakes, and does not consider glacier-fed lakes located more than 10 km from glaciers. To address this, this study presents a novel classification and analysis framework for glacier-fed lakes in High Mountain Asia using Landsat images and the CBAM-UNet model. We identify 17,382 glacier-fed lakes covering an area of 2,309.5 ± 223.4 km² as of 2020s. A key finding is that 21% of these lakes, accounting for 42% of the total area, are located more than 10 km from glaciers. Additionally, we highlight that the expansion of glacier-fed lakes is influenced by both glacier meltwater and precipitation. When the glacial contribution exceeds 10%, lake dynamics are predominantly driven by glacier changes. However, for lakes with a glacial contribution below 10%, precipitation plays a more significant role in shaping lake expansion. These findings offer new insights into glacier-lake interactions and provide a more accurate basis for future GLOF risk assessments in the region.