Inventory and GLOFs susceptibility of pro-glacial lakes in Chenab basin, western Himalaya

Global warming has resulted in an increase in glacial mass loss, leading to the formation and expansion of numerous glacial lakes across high mountain areas worldwide. The expansion of glacial lakes and subsequent Glacial Lake Outburst Floods (GLOFs) pose a significant threat and cause catastrophic damage to livelihoods and infrastructure up to hundreds of kilometers downstream. Previous studies have reported the rapid expansion of glacial lakes and several notable destructive past GLOF events in the Himalayan region, suggesting a necessity for timely and updated inventory and GLOF susceptibility at basin scale. Here, an updated inventory of pro-glacial lakes across the Chenab basin, western Himalayas is generated based on 10-m Sentinel-2 datasets for 2022. Additionally, temporal changes and GLOF susceptibility of glacial lakes (>0.05 km²) were evaluated using multi criteria-based Analytical Hierarchical Process (AHP) where nine factors are considered. Glacial lakes are classified into low, medium, high, and very high GLOF susceptibility classes depending on their susceptibility index. The result shows the presence of 419 lakes (>0.001 km²) with a total area of 9.97 ± 0.67 km² across the basin in 2022. The total area of the glacial lakes in 1990 was 3.92 ± 0.58 km², which expanded by ∼75%, reaching 6.86 ± 0.25 km² in 2022. Furthermore, out of 42 lakes (>0.05 km²) assessed, six were identified with very high GLOF susceptibility. We underline that the role of local geomorphology (i.e., avalanche, rockfall) and pronounced glacier-lake interaction under warming climate scenarios likely increase the GLOF susceptibility in the region. Regular monitoring and more detailed fieldwork-based investigation for these highly susceptible glacial lakes are necessary. This study will benefit early warning and disaster risk reduction of downstream communities.