Shillong, September 2: Indian farmers have been adapting to rising temperatures by intensifying their use of groundwater for irrigation, warns a recent study led by an Indian-origin researcher. If this trend continues, the rate of groundwater depletion could triple by 2080, posing a significant threat to India’s food and water security.
As per IANS, the study, conducted by the University of Michigan in the US, highlights that reduced water availability in India due to groundwater depletion and climate change could jeopardize the livelihoods of more than one-third of the country’s 1.4 billion residents, with global implications.
India, the second-largest global producer of staple crops like rice and wheat, is heavily dependent on groundwater for agriculture.
The study’s senior author, Meha Jain, an assistant professor at the university’s school for environment and sustainability, emphasized that farmers are already responding to warming temperatures by increasing irrigation, a crucial adaptation strategy that previous projections of groundwater depletion in India had not considered.
“This is of concern, given that India is the world’s largest consumer of groundwater and is a critical resource for the regional and global food supply,” Jain stated.
The research analyzed historical data on groundwater levels, climate, and crop water stress to identify changes in withdrawal rates due to warming. It also used climate models to estimate future rates of groundwater loss across India.
Unlike previous studies, which focused on the individual impacts of climate change and groundwater depletion on crop production in India, this study accounted for farmer decision-making, recognizing how farmers may adapt to climate change by altering irrigation practices.
The study’s lead author, Nishan Bhattarai, formerly a postdoctoral researcher in Jain’s lab and now affiliated with the University of Oklahoma, explained, “Using our model estimates, we project that under a business-as-usual scenario, warming temperatures may triple groundwater depletion rates in the future and expand groundwater depletion hotspots to include south and central India.”
He added, “Without policies and interventions to conserve groundwater, we find that warming temperatures will likely amplify India’s already existing groundwater depletion problem, further challenging India’s food and water security in the face of climate change.”
Previous research had indicated that climate change could reduce the yield of staple Indian crops by up to 20 percent by mid-century, while groundwater depletion continues to escalate, primarily due to irrigation demands.
To conduct the study, researchers compiled a comprehensive dataset containing groundwater depths from thousands of wells across India, high-resolution satellite observations of crop water stress, and temperature and precipitation records. The results suggest that warming temperatures, combined with declining winter precipitation, offset increased groundwater recharge from the monsoon season, leading to accelerated groundwater declines.
In various climate-change scenarios, the study’s estimates anticipate groundwater-level declines between 2041 and 2080 that are more than three times the current depletion rates on average.