Monitoring glacial lake formation and GLOF hazard in Kanchenjunga conservation area of Nepal (2010–2023): a high-resolution approach

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Glacial lakes in the Himalaya are expanding rapidly due to climate-induced glacier retreat, significantly increasing the risk of Glacial Lake Outburst Floods (GLOFs) for downstream communities and infrastructure. This study evaluates the distribution, characteristics, evolution, and associated GLOF hazards of glacial lakes in Nepal's Kanchenjunga Conservation Area (KCA) from 2010 to 2023. The region is highly sensitive to glacier retreat and has a documented history of GLOF events. Using high-resolution RapidEye and PlanetScope imagery, an updated inventory identified 140 glacier-proximal lakes (3.37 ± 0.074 km 2 ) in 2023, including 76 supraglacial lakes and 27 proglacial lakes. Most were small (<0.05 km 2 ) and located between 4500 and 5500 m above sea level (masl). From 2010 to 2023, the number of lakes increased from 113 to 140 (+23.9 %), while total area expanded by 16.6 %. Supraglacial lakes dominated the numerical increase, reflecting rapid turnover, whereas proglacial lakes contributed most to areal expansion, highlighting their greater hazard potential. Modeled storage estimates increased from 69.97 to 76.55 × 10 6 m 3 . A multi-criteria GLOF hazard assessment using the Analytic Hierarchy Process (AHP)—incorporating lake area and expansion, dam characteristics and slope, glacier proximity and slope difference, and potential triggers—was conducted on ten large lakes. Results classified one lake as Very High, two as High, four as Low, and three as Very Low. These findings underscore accelerating lake expansion, increasing water storage, and evolving hazards, emphasizing the urgent need for continuous high-resolution monitoring, integration of field validation, and targeted disaster preparedness in the KCA and the wider Himalaya. • Mapped 140 glacial lakes in KCA in 2023 using NDWI and PlanetScope imagery. • Total glacial lake area increased by 17.3 % from 2010 to 2023. • 66 new supraglacial lakes formed over 13 years. • GLOF hazard assessment conducted for 10 lakes ≥0.05 km 2 using AHP. • Newly classified Tilpile Lake as highly hazardous, emphasizing monitoring need.