Overview
The snow persistence in the HKH region hit a historic low in 2024. The International Centre for Integrated Mountain Development (ICIMOD) reported that the Ganga, Brahmaputra and Indus basins in India recorded the lowest values in more than two decades, threatening water supply for millions downstream.
Key Developments
- 2024 saw the Ganga basin’s snow persistence fall 17% below the long‑term normal, the worst in 22 years.
- The Brahmaputra basin was 14.6% below normal, while the Indus basin dropped 23.3% below normal.
- Weak western disturbances were identified as the primary cause.
- Higher sea‑surface temperatures in the storm‑source region disrupted the timing and intensity of these disturbances.
- In contrast, China’s Yellow River basin recorded a 20.2% above‑normal snow persistence due to the East Asian winter monsoon.
Important Facts
Snow melt contributes 10.3% of the Ganga’s flow, compared with 3.1% from glacier melt. In the Brahmaputra, snow provides 13.2% of water, while the Indus relies on snow for about 40% of its discharge. The 2024 decline therefore risks reduced river flow, especially during the early monsoon season.
Experts link the weakening of western disturbances to changing La Niña–El Niño cycles, which are becoming more intense under global warming.
Exam Relevance
Understanding snow dynamics is crucial for several GS papers. GS3 (Environment & Climate Change) requires knowledge of how Himalayan snow feeds major river basins and the impact of climate variability on water security. GS3 (Water Resources) examines trans‑boundary rivers like the Ganga, Brahmaputra and Indus, where reduced snow melt can heighten interstate disputes. GS3 (International Institutions) covers bodies such as ICIMOD, which provide data for policy‑making.
Way Forward
Short‑term measures include improving weather forecasting and early‑warning systems to help farmers and municipal authorities plan for water stress. Long‑term strategies focus on:
- Reforestation with native species in catchment areas.
- Upgrading water‑storage infrastructure, such as reservoirs and rain‑water harvesting, to capture meltwater.
- Formulating policies that protect snowfall zones and promote community participation in water‑management decisions.
- Accelerating emission‑reduction commitments to curb global warming, which drives higher sea‑surface temperatures and weakens western disturbances.
Collective action by national governments, regional bodies and local communities is essential to safeguard the “water towers of Asia” for future generations.