ICIMOD 2025 Report Highlights Decline in Snow Persistence Across Ganga, Indus & Brahmaputra River Basins.
International
In April 2025, the Kathmandu (Nepal)-based International Centre for Integrated Mountain Development (ICIMOD) released the HKH Snow Update Report 2025, highlighting a significant decline in snow persistence across the Ganga, Indus, and Brahmaputra river basins in the Indian subcontinent.
- The report is based on a 23-year time series (2003–2025) analysis of basin-scale snow persistence during the November to March snow seasons. The Hindu Kush Himalaya (HKH) region, which sustains these major rivers, recorded its third consecutive below-normal snow year in 2025.
- According to the report, snow persistence was 23.6% below normal, marking the lowest level in the past 23 years. This decline poses serious concerns for water availability in the region.
- Snow Persistence refers to the number of days snow remains on the ground after snowfall. It plays a critical role in maintaining the water supply, river flow, and ecological balance in snow-fed regions like the HKH.
Main Point :- (i) The HKH Snow Update Report 2025 reveals alarming trends in snow persistence across major South Asian river basins. In the Ganga Basin, snow persistence peaked at +30.2% in 2015 but sharply declined to a 23-year low of just 24.1% in 2025, posing threats to early-summer river flows. Similarly, the Indus Basin, which saw a peak of +19.5% in 2020, experienced a drastic drop to -24.5% in 2024 and further plummeted to -27.9% in 2025, marking its lowest in two decades.
(ii) In the Brahmaputra Basin, snow persistence that peaked at +27.7% in 2019 steadily declined to 27.9% in 2025. This trend raises concerns over the region’s water-dependent sectors like hydropower generation and agriculture. Meanwhile, the Tibetan Plateau, known as the source of many North Indian rivers, saw snow levels plunge from a significant +92.4% in 2022 to a worrying -29.1% in 2025, highlighting its growing climate vulnerability.
(iii) Other regional basins have also shown sharp reductions. The Mekong Basin recorded the most severe drop at -51.9%, closely followed by the Salween Basin at -48.3%. The Yangtze River Basin (Vangtze) also showed a notable decline at -26.3%. These findings underscore the regional scale of snow loss and its potential implications for water security, agriculture, and ecosystems across Asia.
About International Centre for Integrated Mountain Development
Director General (DG) : Pema Gyamtsho (Bhutan)
Headquarters : Kathmandu, Nepal
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