Drought driven shrinkage of surface water bodies in India

Surface water bodies (SWBs) are vital in sustaining regional water storage, ecosystems, and water demands. However, the impact of climate extremes, particularly droughts, on these SWBs in India remains poorly understood. Here, we examine the changes and variability of the 10,476 SWB during 1990–2017 based on the Landsat satellite-derived SWB area, using Trend-Free Pre-Whitening Mann-Kendall (FPW-MK) and Sen's slope tests. We also evaluated the impacts of drought severity (defined using Standardized Precipitation-Evapotranspiration Index) on SWB. We found that 79% of SWB across India exhibit a significant ( p < 0.05) trend, with 44.5% decreasing and 29.4% increasing. Seasonal area anomalies reveal that a dry summer-monsoon causes the highest decline (5%) in SWB, compared to dry winter (2.7%) and dry pre-monsoon seasons (0.65%). Moreover, successive droughts during the summer-monsoon and winter seasons result in 3-fold more shrinkage (∼10%) than a single-season drought. Our findings highlight the critical need for strategies to sustainably manage SWB across India.