Over 1.8 Million Exposed as India's Megacities Sink from Groundwater Overuse

A recent study by Virginia Tech scientists reveals that five major Indian megacities, including New Delhi, Mumbai, Chennai, Kolkata, and Bengaluru, are experiencing significant land subsidence primarily due to excessive groundwater extraction. Satellite radar data from 2015 to 2023 shows that approximately 878 square kilometers of urban land is sinking, exposing nearly 1.9 million residents to subsidence rates exceeding four millimeters annually. This sinking ground threatens structural integrity, with over 2,400 buildings already at high risk of damage and projections indicating more than 23,000 buildings could face severe structural failure within the next 50 years if current trends continue. The subsidence exacerbates risks related to natural disasters such as floods and earthquakes by weakening foundations and damaging infrastructure. Researchers emphasize the urgent need for improved groundwater management and infrastructure adaptation to mitigate these hidden yet escalating urban hazards. The study underscores how advanced satellite mapping techniques can help detect and address these risks before catastrophic failures occur.