Evolution of present and potential future glacial lakes and implications for GLOF hazard in the Chenab Basin, Western Himalaya

Accelerated glacier retreat in the Western Himalaya has led to rapid expansion of glacial lakes and increasing concern over Glacial Lake Outburst Flood (GLOF) hazards. This study presents a basin-scale assessment of glacial lake evolution, potential future lake formation, and GLOF susceptibility in the Chenab Basin, integrating multi-temporal remote sensing, terrain analysis, and probabilistic exposure modelling. A decadal inventory of glacial lakes was developed for five time periods (1990, 2000, 2010, 2020 and 2025) using Landsat and Sentinel-2 imagery, combined with semi-automated extraction and geomorphological classification. Results reveal a consistent increase in both lake number and total area over the last three decades. Potential future glacial lakes were identified using various ice-thickness modeling approach applied to current glacier extents. This analysis presents an inventory of the future glacial lake in the entire basin giving special emphasis to determining the characteristics of the future lake including maximum extent of the future lakes and volume of the future glacial lakes. GLOF susceptibility of existing lakes was evaluated using a multi-criteria framework to identify critical lakes requiring priority monitoring. Downstream exposure was further assessed using the Monte Carlo Least Cost path approach, explicitly accounting for uncertainty in breach location and flood routing parameters to delineate probable impact corridors. The framework provides new insights into evolving cryospheric hazards in the Chenab Basin and demonstrates the utility of combining lake dynamics, future lake potential, susceptibility assessment, and probabilistic exposure analysis for improved GLOF risk prioritization in the Western Himalayas.