The vital Gangotri Glacier, the primary source of the Ganga River, has seen a significant 10% melt over the past 40 years, primarily due to climate change. A groundbreaking study conducted by the Indian Institute of Technology (IIT) Indore, along with international collaborators, sheds light on this alarming shift. This study reveals a reduced contribution from snowmelt while there is a surge in flow from rainfall and groundwater, potentially creating severe challenges for water resources in Northern India.
Key Findings of the Study
Under the leadership of doctoral scholar Parul Vinje from IIT Indore's Glacio-Hydro-Climate Lab, this research, published in the Journal of the Indian Society of Remote Sensing, highlights a significant trend with contributions from American universities and Nepal’s International Center for Integrated Mountain Development (ICIMOD). These analyses utilized satellite and real data (1980-2020) to model the Gangotri Glacier System (GGS).
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Changing Dynamics of Gangotri's Flow
Contribution from snowmelt has decreased: Over the last 40 years, snowmelt accounted for 64% of Gangotri's total flow, followed by glacier melt (21%), rain runoff (11%), and groundwater (4%). However, the percentage of snowmelt contribution plummeted from 73% in 1980-90 to 63% in 2010-20.
Source: aajtak
Improvements in 2010-20:
During 2000-10, snowmelt contribution dropped to 52%, but rebounded to 63% in 2010-20. Researchers noted that winter temperatures dropped by 2°C, and rainfall increased by 262 mm, boosting snow volume and causing significant summer melt, augmenting Ganga's flow.
Temperature Rise:
During 2001-2020, the average temperature in the Gangotri region increased by 0.5°C compared to 1980-2000, causing earlier melting with peak discharge shifting from August to July.
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Effects of Climate Change
The study identified reduced snowfall due to climate change in the Gangotri region, resulting in decreased snow formation. Consequently...
Diminished snowmelt: A decrease in snow cover and glacial flow was noted, alongside increased rainfall and groundwater flow.
Peak discharge shift: Since the 1990s, peak discharge now occurs in July instead of August, posing challenges for hydropower, irrigation, and water security in high-altitude areas.
Statistics: Between 2001-2010, with the highest decadal temperature (3.4°C), the maximum decadal discharge (28.9 cubic meters/second) was recorded, with a 7.8% increase in average discharge over the previous decade.
Source: aajtak
Consensus Among Studies
Other studies corroborate these findings. Kalyan Rudra, chairman of the West Bengal Pollution Control Board and river expert, noted that Himalayan glaciers are losing 46 cm thickness annually. His three-decade study of Gangotri shows continuous snout recession.
An additional study published in May 2025 in The Cryosphere Journal, involving scientists from various IITs and the Indian Institute of Science Bhopal, also underscores climate change's impact on the Gangotri Glacier. It outlines a reduction in glacier water volume between 2017-2023. Similar melting patterns are observed in regions like Ladakh, according to IIT Kharagpur’s groundwater scientist Abhijit Mukherjee.
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Impact on Ganga and Water Resources
The Gangotri Glacier is vital for Northern India's water supply, feeding the Ganges. A decline in snowmelt and increased reliance on rainfall could severely impact water resources. Changes in Ganga's flow could lead to...
Source: aajtak
Agricultural impact: Ganga basin farming, a lifeline for millions, could be affected.
Threat to hydropower: Shifts in peak discharge times could disrupt production.
Water security: Availability in high-altitude areas may decline.
This study is crucial for understanding climate change's impact on the Gangotri Glacier. Researcher Mohammad Farooq Aja stated that snowmelt is a primary component of Gangotri’s flow, but its contribution is dwindling, indicating climate change's pervasive influence. The study aids policymakers in strategizing for water resource management, glacier conservation, and climate adaptation.
The loss of 10% glacier flow due to snow melting emphasizes climate change's urgency. With rising temperatures and diminished snowfall altering the Ganga's flow dynamics, challenges for Northern India loom large. Immediate action in water resource management and glacier preservation is vital to safeguard the future of the Ganga and its dependent communities.
