Groundwater 37 times the capacity of the Indira Sagar dam was lost across Northern India between 2001 and 2021. In future the depletion would be worse, according to a recent report
A recent study has revealed a concerning trend in northern India. Approximately 450 cubic kilometres of groundwater have been lost between 2002 and 2021. Worse, this rate of depletion is projected to increase under the impact of climate change.
This amount is about 37 times larger than the total capacity of the Indira Sagar dam, which is India's largest reservoir, according to lead author Vimal Mishra, who serves as the Vikram Sarabhai Chair Professor of Civil Engineering and Earth Sciences at IIT Gandhinagar.
Researchers utilised on-site observations, satellite data, and models to determine that monsoon rainfall in north India decreased by 8.5 percent from 1951 to 2021. Additionally, they found that winters in the region have become 0.3 degrees Celsius warmer during the same period.
The research team, which includes members from the National Geophysical Research Institute (NGRI) in Hyderabad, highlighted that reduced monsoon rainfall and warmer winters would lead to higher irrigation water demand and diminished groundwater recharge, further straining the depleting groundwater resources in north India.
A drier monsoon necessitates increased reliance on groundwater for sustaining crops during periods of low rainfall, while warmer winters lead to relatively drier soils, requiring additional irrigation. This was evident during the unusually warm winter of 2022, which was the fifth warmest since the India Meteorological Department began keeping records in 1901.
The study anticipates that the increasing trend of groundwater depletion will persist as the planet warms. Even though climate change might result in more rainfall, the majority of this rainfall is projected to occur in the form of extreme events, which are not conducive to replenishing groundwater.