Second-lowest snow persistence on record in 2024

Kathmandu, June 18: The Hindu Kush Himalaya reported lower-than-normal snow persistence in 2024, marking the second lowest level recorded since 2003. The lowest level was recorded in 2018. 

In 2024, snow persistence was 18 per cent below normal, while 2018 set the benchmark with 19 per cent below-normal snow, according to an annual Snow Update Report published by the International Centre for Integrated Mountain Development (ICIMOD) on Monday.

Snow persistence, the fraction of time snow remains on the ground, is significantly lower than normal in the HKH this year, with serious implications for downstream communities’ water security, experts said.

Leading experts from the ICIMOD, those involved in the study, warn water management officials to initiate drought management strategies and pre-emptive emergency water supply.

Monitoring shows snow levels almost a fifth below normal across the region this year, with figures falling dramatically in the west, where its contribution to water supply is highest.

Sher Muhammad, ICIMOD Cryosphere Specialist and author of the Snow Update Report 2024, said, “We have seen a pattern of decreasing amounts and persistence of snow across the Hindu Kush Himalaya, with 13 of the past 22 years registering lower than normal seasonal snow persistence.”

This is a wake-up call for researchers, policymakers and downstream communities -- lower accumulation of snow and fluctuating snow levels pose a severely increased risk of water shortages, particularly this year.

Talking to The Rising Nepal Muhammad said, “Snowmelt contributes to about 10.3 per cent in the Ganges River basin while glacier melts 3.1 per cent, so comparatively, the contribution from snow is quite significant. The Ganges River is closely connected to the country through its tributaries and several major tributaries of the Ganges originate in the Himalayas of Nepal.

Miriam Jackson, ICIMOD’s Senior Cryosphere Specialist stressed the need for proactive measures. She said, “We encourage relevant agencies to take proactive measures to address possible drought situations, especially in the early summer, update plans to accommodate water stress and notify communities of the risks.”

Beyond that, it is clear that governments and people in this region need urgent support to help them adapt to changes in snow patterns that carbon emissions have already locked in, she said.

“And that G20 countries need to cut emissions faster than ever before to prevent even more changes that will prove disastrous to major population centres and industries that rely on snow melt in the mountains,” Jackson said.

Helmand River basin shows the most dramatic fall in persistence at 31.8 per cent below normal. Its previous lowest level was in 2018 when it saw a 42 per cent reduction. In addition, the Indus Basin has fallen to 23.3 per cent below normal, marking the lowest level in the past 22 years. The previous lowest year for this Basin was 2018, with a 9.4 per cent shortfall. The lowest variation from normal snow persistence this year was in the Mekong basin where snow persistence was around 1 per cent below normal.

In the Ganges River Basin, there have been significant fluctuations in the past twenty-two years. Before 2024, the year 2018 had the lowest snow persistence at 15.2 per cent, while the highest snow persistence of 25.6 per cent was recorded in 2015. The current year has shown the lowest snow persistence, with a value of 17 percent, which sharply contrasts between the southern and northern sides, according to the report.

The snow persistence has been studied in 12 major rivers of HKH including the Amu Darya River basin, the Brahmaputra River basin, the Helmand River basin, the Indus River basin, the Irrawaddy River basin, the Mekong River basin, the Salween River basin, the Tarim River Basin, Tibetan Plateau, Yangtze River basin and Yellow River basin.

In the Brahmaputra River basin, the year 2021 experienced the lowest seasonal snow persistence, dropping well below average at 15.5 per cent. The highest recorded snow persistence occurred in 2019, reaching 27.1 per cent. This year, the current snow persistence is also notably below normal at 14.6 per cent, the report said.

In the Indus River basin, there was a notable decrease in seasonal snow persistence in 2018, with a deviation of 9.4 per cent from the average. In contrast, the highest snow persistence above normal was recorded in 2020 with a value of 15.5 per cent. 

However, this year, there has been a remarkable decrease in snow persistence, falling 23.3 per cent below normal levels with some positive patterns on the southern sides mostly in the lower altitudes.