Replenishment of groundwater storage at regional scale

Amid concern over dwindling groundwater resources in India, a research team from IIT Kharagpur in collaboration with NASA scientists have reported regional-scale groundwater storage (GWS) replenishment through long-term observations.
The long-term (1996-2014) observations by the researchers used more than 19,000 groundwater observation locations, ground-based measurements and decadal-scale (2003-2014) satellite-based groundwater storage measurements all over the country.
IIT Kharagpur has issued this information quoting the research as reported by Nature Scientific Report this month.
The dwindling groundwater resource of India has been of great concern in recent years with almost 60 per cent of the country being regarded as water stressed.

Both the Centre and state governments over the years has undertaken several projects to replenish ground water through efficient ground water management and utilisation policies.
However, the effects were not known until now. For the first time, researchers from India and abroad have given positive confirmation on the replenishment of groundwater storage at regional scale.

Lead author Dr Soumendra Bhanja noted that in recent times, large parts of the country reels through severe water crisis during every summer.
It has been said that India, has been the largest consumer of global groundwater, is going through a 'groundwater drought', with every possibility that the drought may continue and aggravate in impending future.

This pervasive, unregulated abstraction for enhanced irrigation of water-intensive cultivation is resulting to one of the most rapid and drastic groundwater depletion in human history.
"Our study shows that recent paradigm shift in the Indian groundwater withdrawal and management policies for sustainable water utilisation, probably have started replenishing the aquifers by increasing storage in western and southern parts of India," said research lead Prof. Abhijit Mukherjee from IIT Kharagpur.
The team used numerical analysis and simulation results of groundwater management policy change effect on groundwater storage changes in western and southern India for this study.
Dr Matthew Rodell, NASA Chief of Hydrological Sciences Laboratory helped in interpreting the NASA satellite (GRACE) data (2003-2014) of groundwater storage changes in India for this study.

Prof Mukherjee pointed out at the recent changes in Indian policies (both by the Centre and state governments) on groundwater withdrawal and stress on management strategies, such as restriction of subsidised electricity for irrigation, separate electricity distribution for agricultural purpose etc.
"We have been able to demonstrate the initial scenarios of rejuvenating groundwater in parts of the India that optimistically has the potential to eventually become the largest groundwater replenishment occurrence in the human history," added Prof Mukherjee.