Groundwater, not glaciers, is the Ganga’s lifeline, says study

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, 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...

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