Cities Worldwide Are Sinking Rapidly

Land in major urban centers across the globe is experiencing significant sinking, as revealed by a recent comprehensive satellite survey. Cities like Mexico City, Mexico, and Medan in Indonesia are among those identified with alarming subsidence rates, which can damage buildings, infrastructure, and increase flood risks.

The study, published in Nature Cities, utilized high-resolution satellite data from 2014 to 2023 to track land movement in 465 cities with over a million inhabitants. Researchers found that while some areas of Mexico City are sinking at approximately 217mm annually, and Medan by 33mm per year, the phenomenon is driven by human activities, especially groundwater extraction.

This extraction depletes underground water pressure, leading to the compression of sediments beneath urban areas. The research indicates that subsidence is particularly severe in Southeast Asia, West-Central Asia, and North America. Notably, cities in developing countries tend to exhibit faster sinking rates than those in developed nations, suggesting a need for targeted intervention and policy adjustments.