A study published in ‘Nature Sustainability’ reports that land across India’s major metropolitan areas”Delhi, Mumbai, Chennai, Kolkata, and Bengaluru”is steadily sinking, with nearly 878 sq. km affected.
Using radar data from the European Sentinel-1 satellite collected between 2015 and 2023, researchers found that several zones in these cities are subsiding at rates that already threaten buildings, roads, and water pipelines, or will soon do so.
Scientists identify excessive groundwater extraction as the main cause. When water is pumped out rapidly, soil layers lose moisture, compact over time, and begin to sink. This problem is intensified by rapid urban expansion, poor water management, erratic rainfall, and the spread of concrete surfaces that prevent natural recharge.
Among the five cities, Delhi records the fastest sinking”up to 51 mm per year”followed by Chennai (31.7 mm), Mumbai (26.1 mm), Kolkata (16.4 mm), and Bengaluru (6.7 mm). The findings highlight the urgent need for long-term environmental planning and corrective action.
Experts warn that without stricter regulation and robust groundwater recharge initiatives, infrastructure damage and heightened flood risks could rapidly escalate.
