New Delhi: Unusually low snowfall this year in the Hindu Kush Himalayas (HKH) could have serious implications for downstream communities, including over 600 million people living in the Gangetic river basin in India, according to new research by the International Centre for Integrated Mountain Development (ICIMOD) released on Sunday.
“Snow melt contributes to 10.3% in the Ganga river basin, while glacier melt contributes 3.1%, so comparatively, the contribution from snow is quite significant,” said Sher Muhammad, lead author of HKH snow update 2024. “This lower snow this year may affect water availability if there is less rainfall in the early season, as the snowmelt contribution primarily contributes early in the summer season.”
For the Ganga, it is a year with lowest snow persistence, or the time snow remains on the ground, since 2003 at 17% below normal, the fresh research found. There were significant fluctuations in snow persistence between 2003 and 2024 during the snow accumulation season between November and April, the ICIMOD report said.
The exceedingly low snow cover this year will have massive implications for communities downstream in entire the HKH region, researchers warned. Snowmelt is the source of approximately 23% of the total water flow of 12 major river basins that originate in the high HKH ranges. But its contribution to water supply varies from river to river, representing 74% of the river flow to the Amu Darya, 77% of the Helmand’s flow, and 40% of the Indus’ flow.
The HKH region depends heavily on the cryosphere, including snow, permafrost, and ice from glaciers, lakes and rivers. This frozen water is a critical source of freshwater for approximately 240 million people living in the HKH region and has far-reaching benefits for around 1.65 billion individuals downstream, ICIMOD said.
In the Gangetic basin, there has been significant fluctuations in snow persistence in the past 22 years according to the update. Prior to 2024, 2018 had the lowest snow persistence at 15.2% below normal, while the highest snow persistence of 25.6% above normal was recorded in 2015. The current year has shown the lowest snow persistence, with a value of 17% below normal. The river basin is home to more than 600 million Indians.
Experts in the ICIMOD have warned water management officials to initiate drought management strategies and pre-emptive emergency water supply. The HKH region experienced a significant anomaly in 2024. The below normal snow persistence may have affected water availability in early summer this year, requiring the implementation for drought management strategies.
“Furthermore, there is an observable trend of decreasing below-average snow persistence from east to west in the region,” the report said. “The below-average snow persistence in the HKH region this winter raises the possibility of decreased water supply downstream in the early summer. It is imperative for relevant agencies to take proactive measures to address the upcoming issue.”
In order to notify populations about drought and water shortages, it is important to effectively communicate the situation and update water management plans to accommodate water stress, as well as to promote collaboration amongst responsible national agencies, ICIMOD said, adding that establishment of local water committees could play a major role in resource allocation.
“These solutions may help to lessen the immediate effects of below normal snowfall on the water supply in the HKH region, but to ensure long-term resilience to climate change, there should be collaboration among countries sharing transboundary rivers to update their water management laws,” the researchers recommended. “These actions could cope with the water shortage in south Asia depending on snowmelt and mitigate their effects on relevant sectors.”
The other rivers originating in the HKH are also facing an unprecedented crisis in recent years. The Amu Darya river basin this year recorded the lowest snow persistence at 28.2% below normal. In the Brahmaputra river basin, 2021 saw the lowest seasonal snow persistence, dropping well below average at 15.5%. The highest recorded snow persistence occurred in 2019, reaching 27.1% above normal. This year, the current snow persistence is notably below normal at 14.6%.
In the Indus river basin, there was a significant decrease in snow persistence, falling 23.3% below normal with some positive patterns on the southern sides, mostly in the lower altitudes.
“Snow persistence essentially means how long snow can remain on the ground. These measurements are taken mainly in winter and spring. We are seeing significant anomalies, which will have impact on river water and availability,” said Anil Kulkarni, glaciologist and distinguished scientist at the Divecha Center for Climate Change.
“It will also impact water flow in mountain streams and lead to major forest fires. All of these we are already seeing. Low snow persistence means less soil moisture,” Kulkarni added. “The monsoon’s arrival may help modulate some of these impacts, but may also make these areas more vulnerable to landslides. We know that absolutely dry soil is more prone to erosion. Snow cover would have helped generate some grass and vegetation,”
Low snow persistence is a classic impact of climate change, he said. “From the temperature data, we know that winters are becoming warmer, especially in the higher altitudes,” Kulkarni said. “Most of the snow is melting in winter itself. We need to be better prepared.”
Dry, snowless peaks have cast a shadow on tourism in Kashmir and Himachal Pradesh, but the impact of the underlying causes on the next few months is far more worrying, for they could portend a warmer spring, HT reported on January 13. In December, the rain deficiency was 79% over Jammu and Kashmir, 85% over Himachal Pradesh, 75% over Uttarakhand and 70% over Punjab. For half of January, there was hardly any snowfall.
While spring temperatures remained moderate, a very severe heat spell started over the country from April onwards. In one of the longest and most severe summers, 14 of 36 subdivisions in the country have recorded over 15 heatwave days between March 1 to June 9, India Meteorological Department data show.
Only the northeastern states, coastal Karnataka and parts of Marathwada have been spared from the heatwaves during this period. The highest heatwave days have been recorded over Odisha (27), followed by Rajasthan (23), Gangetic West Bengal (21), Haryana (20), Chandigarh (20), Delhi (20) and western Uttar Pradesh (20).
