SYLLABUS
GS-1: Geographical features and their location- changes in critical geographical features (including waterbodies and ice-caps).
Context: The Hindu Kush Himalaya (HKH) Snow Update 2026 by the International Centre for Integrated Mountain Development reports a record decline in snow persistence, raising concerns over a regional water crisis.
About the Report
• The HKH Snow Update 2026 is an annual assessment of seasonal snow anomalies across the Hindu Kush Himalaya region during the winter months (November–March).
• It defines snow persistence as the fraction of time snow remains on the ground after snowfall, a key indicator of mountain water reserves.
• The report analyses snow conditions across 12 major river basins, which collectively support nearly two billion people through water supply, agriculture, and hydropower.
• Snowmelt contributes about 23–25% of annual river runoff, making seasonal snow crucial for early summer water availability, especially in western basins.
Key Findings of the Report
• Record Decline in Snow Persistence:
- Snow persistence in the 2025–26 winter was 27.8% below the long-term average, the lowest in over two decades.
- This surpasses the previous record deficit of 23.6% (2024–25).
- It marks the fourth consecutive year of below-normal snow persistence and reflects a recurring long-term trend (14 such winters since 2003).
• Basin-wise Variations: Snow persistence was below normal in 10 out of 12 river basins.
- Above-average snow persistence was recorded only in the Ganga Basin (+16.3%) and the Irrawaddy Basin (+21%).
- The sharpest declines were observed in the Mekong Basin (–59.5%), the Tibetan Plateau (–47.4%), and the Salween Basin (–41.8%).
• High Dependence on Snowmelt:
- Snowmelt contributes significantly to river flow, particularly in western basins such as the Amu Darya (~74.4%), Helmand (~77.5%), Indus (~39.7%), and Tarim (~23.9%).
- The declining snow levels therefore pose a serious threat to water availability in these regions.
• Implications for Water Security:
- Reduced snow persistence leads to lower early summer river runoff, increased groundwater extraction, and a higher risk of droughts.
- These impacts extend downstream, affecting agriculture, hydropower generation, and livelihoods.
• Climate Change Link and Cryosphere Stress:
- HKH glaciers are melting twice as fast since 2000, indicating accelerating cryospheric loss.
- The region, known as the “Water Tower of Asia”, holds over 60,000 glaciers and ~6,000 cubic km of ice.
• Urgent Need for Policy Action: With snow persistence declining in 10 of 12 HKH river basins, there is a pressing need for immediate, basin-level targeted interventions.
- Countries should develop national preparedness and response plans to address negative snow anomalies and emerging drought conditions.
- Snow anomaly data must be effectively disseminated to enable evidence-based decision-making and improve cross-sectoral coordination.
- Governments need to integrate snow-related data into national water strategies, especially for hydropower, agriculture, and allied sectors.
- There is a need to invest in adaptive infrastructure, such as seasonal water storage systems, to buffer variability in water availability.
- Efficient and sustainable use of meltwater resources should be prioritised to reduce stress on water systems.
- Policymaking must shift towards a science-based, forward-looking approach to address long-term cryospheric changes.
- Strengthening regional cooperation is essential to tackle the shared snow crisis and ensure long-term food, water, and energy security across the HKH region.
Sources:
Down to Earth
ICIMOD