Drying Ganga could stall food security, claims study
COPENHAGEN, DENMARK: Millions of people residing in the lower reaches of the Ganga basin in India may face food shortage in the next three decades if the river continues to lose water due to factors that include unsustainable groundwater extraction, a study has claimed.
Researchers associated with the study added that low river flows could also have implications for achieving the United Nations’ Sustainable Development Goals.
But experts, not associated with the study, also pointed to the combined blow of surface and groundwater misuse that has beleaguered the Ganga river basin, sheltering around 10% of the global population. Agricultural inefficiency is a chink in the chain, they say, when it comes to sustainable water use.
T he analysis was conducted by Abhijit Mukherjee at the Iit-kharagpur, Soumendra Nath Bhanja (formerly at IIT Kharagpur) and Yoshihide Wada from Austria’s International Institute for Applied Systems Analysis on the stretch of the river from Varanasi to the Bay of Bengal.
“The impacts of groundwater depletion on Ganga river flows are very com- plex. However, our study found that there is significant concern that ongoing groundwater pumping over the basin is unsustainable, leading to not only lowering groundwater levels but also reduction in river flows during summer time,” Wada told Mongabay-india.
This problem is more serious downstream of the Ganga river, Wada said.
Mukherjee said: “So far, in the last three decades we have seen the groundwater input to the river decline by 50% during summer. This decline could go up to 75% compared to the scenario in the 1970s in the summer months.”
The Ganga’s 2,525 km watercourse is sustained by rainfall in the hinterlands of the Ganga basin, Himalayan glacial melt as also groundwater discharge. In summer, this groundwater contribution to the river can be 30% in some sections and can even swell up to 60 to 70%, said Mukherjee.