Key Highlights
- Record low snow persistence in the Hindu Kush Himalaya, the lowest in 23 years.
- Snow cover fell 23.6% below the 20‑year average, threatening river flows.
- Major rivers such as Ganga, Brahmaputra, Indus, Mekong and Salween face significant reductions in discharge.
- Over 2 billion people in South Asia depend on these melt‑water streams.
- The region, covering 4.2 million km² across nine countries, hosts 54,000 glaciers and supplies water to 1.9 billion people.
Detailed Insights
The International Centre for Integrated Mountain Development (ICIMOD) released its 2025 assessment on April 21, 2025, documenting the lowest snow persistence recorded in the Hindu Kush Himalaya (HKH) in more than two decades. Snow persistence, the duration that snow remains on the ground, dipped 23.6% below the 20‑year mean, a decline that directly translates into reduced melt‑water availability for downstream users.
Consequences ripple across the region’s hydrological network. The Ganga, Brahmaputra and Indus rivers saw flow reductions of 24.1%, 27.9% and 16.0% respectively, while the Mekong and Salween basins suffered the most severe drops at 51.9% and 48.3%. These rivers supply drinking water, irrigation, and hydropower to nearly 2 billion people, making the decline a critical threat to food security, energy generation and regional stability.
With snowmelt contributing roughly 23% of annual river discharge, the diminished snow cover forces communities to rely more heavily on groundwater extraction, heightening the risk of over‑exploitation and long‑term scarcity. The situation underscores the urgent need for improved water‑management practices and cross‑border cooperation among the nine countries that share the HKH basin.
Key Concepts
- Snow Persistence – The length of time snow remains on the surface, a key indicator of future water availability.
- Third Pole – A nickname for the Himalayan region, reflecting its status as the world’s largest reservoir of fresh‑water glaciers.
- ICIMOD – The International Centre for Integrated Mountain Development, a research and policy hub focused on sustainable mountain ecosystems.
- Hydropower – Electricity generated from the kinetic energy of flowing water, heavily dependent on melt‑water streams.
- Groundwater Extraction – The removal of water from aquifers, often intensified when surface water supplies decline.