Groundwater more crucial for Ganga’s summer flow, than glaciersA new study shows that groundwater, not glaciers, is the lifeline of the Ganga ...

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Groundwater more crucial for Ganga’s summer flow, than glaciersA new study shows that groundwater, not glaciers, is the lifeline of the Ganga ...
Groundwater more crucial for Ganga’s summer flow, than glaciers
A new study shows that groundwater, not glaciers, is the lifeline of the Ganga river.
Groundwater discharge increases the Ganga river’s volume by about 120% in the Gangetic Plains compared to its initial volume at its origin.
Researchers and experts note that rejuvenation and preservation programmes for the Ganga should prioritise groundwater recharge and the health of its tributaries.
Himalayan glaciers, including the one feeding the Ganga river, are shrinking at unprecedented rates, stirring concerns about its water flow. However, a new study shows that groundwater, not glaciers, is the lifeline of the river.

The study published in Hydrological Processes, is the first comprehensive isotope study to show that groundwater aquifers are the main source of the Ganga river’s summer flow, study author Abhayanand Singh Maurya notes.

“Although in the upstream region, glacier and snow melts contribute significantly to the river flow, this is not the case in the regions beyond the Himalayan foothills,” Maurya, a professor at the Department of Earth Sciences at Indian Institute of Technology (IIT), Roorkee, tells Mongabay India.

The idea for the study goes back to 2011, when Maurya, during his research work on the Ganga river in Rishikesh, found that the contribution of glacier melts to the river was only about 32% of the total flow. This got him wondering about the source of the remaining water in the plains, where discharge is several times higher than the discharge at Rishikesh.

Groundwater as the primary source
The Ganga river, which originates from the Gangotri glacier in the western Himalayas and flows through the Indo-Gangetic Plain of India and Bangladesh, is crucial for ecosystems such as wetlands, and fish populations.

Another recent study by IIT Indore and international collaborators revealed that the Gangotri glacier has lost 10% of its snowmelt flow over four decades because of climate change. With the increasing impact of climate change on glaciers across the world, one of the key concerns has been the impact on rivers that depend on them.

Attached link

https://india.mongabay.com/2025/10/groundwater-more-crucial-for-gangas-summer-flow-than-glaciers

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