A novel framework for predicting glacial lake outburst debris flows in the Himalayas amidst climate change.

ABSTRACT

The retreat of Himalayan glaciers and the expansion of glacial lakes due to global warming have increased the occurrence of glacial lake outburst debris flow (GLODF), posing a serious threat to downstream communities. However, there are gaps in understanding the changes in GLODF occurrence driven by climate change, which challenges disaster management and cross-border cooperation in the Himalayas. To consider this issue, our study presents a novel framework integrating environmental evolution, a process-driven indicator system, and a hybrid machine learning model to predict Himalayan GLODF occurrence in the 21st century. Our findings indicate ongoing temperature (0.27-0.60 °C/10a) and precipitation (1.30-5.00 %/10a) increases under both SSP245 and SSP585 scenarios. Meanwhile, Himalayan glaciers are projected to lose between 70 % and 86 % of their mass by 2100 compared to 2020. Additionally, 2722 ± 207 new glacial lakes are expected to emerge by 2100. GLODF occurrence probability index is anticipated to rise to 1.27-1.30 times the current levels, with the Western Himalayas and Indus basin as high-incidence areas. Currently and in the future, the China-Nepal border remains a hotspot for cross-border GLODF. Our framework offers valuable long-term insights into Himalayan GLODF occurrence trends in response to climate change.