The researchers studied groundwater in India, particularly in the Palar Basin of Tamil Nadu. They wanted to figure out how to manage groundwater sustainably. To do this, they looked at 30 years of data from 80 wells in the area. Using a special method, they calculated how severe droughts affected groundwater levels. They found which areas were at risk of groundwater shortages. By mapping these risky spots, they can make better decisions to protect and manage groundwater for the future.