Glacial lake outburst flood susceptibility and potential downstream implications across the Kashmir Himalaya

Abstract

Glacial lakes in the Kashmir Himalaya have remained understudied despite their destructive potential for outburst floods. This study presents a comprehensive, manually delineated glacial lake inventory of 155 glacial lakes and a baseline for glacial lake outburst flood (GLOF) hazard across the region. Lakes are characterized by type and assessed for long-term spatio-temporal dynamics using a multi-temporal Landsat series in a GIS environment from 1992 to 2024. The area of ice-contact proglacial lakes increased by 26% during the 32-year observation period. A multi-criteria analysis-based framework validated by historical GLOFs in the Himalayan region is employed to evaluate the lake outburst susceptibility. Key factors such as dam material, slope gradient, upstream cascades, seismic activity and permafrost occurrence, are integrated in the susceptibility framework. Potential outburst events from five lakes categorised as having very high GLOF susceptibility threaten several thousand buildings, 15 major bridges, roads and a hydroelectric power project. The study also highlights the potential for GLOF process chains in the region, where upstream lake outbursts could trigger secondary events downstream. The five most susceptible lakes identified here may require intensive monitoring and risk management initiatives to protect vulnerable downstream communities and infrastructure.