BEIJING, Oct. 13 (Xinhua) -- Global urban land subsidence varies widely but has generally slowed in recent years, according to a study by a Chinese research team published Oct. 12 in the journal Nature Cities.
Researchers from Peking University, South China Normal University and other institutions systematically assessed land subsidence between 2014 and 2023 in 465 cities worldwide, each with a population of over one million.
Land subsidence is a global issue that poses a major challenge to urban infrastructure safety and sustainable development.
According to the research, subsidence is most severe in Southeast Asia, West-Central Asia and North America, with representative cities including Mexico City and Toluca in Mexico, and Medan and Bandung in Indonesia. Mexico City recorded the most intense localized subsidence, with rates exceeding 0.2 meters per year.
Although land subsidence remains widespread, global urban subsidence has generally slowed in recent years. The research team detected marked deceleration in many cities across Southeast and East Asia.
This indicates that water resource allocation and groundwater management measures in the two regions are effective, said Hu Xie, a researcher of the team at Peking University.
"In China's Beijing-Tianjin-Hebei urban agglomeration in particular, large-scale water diversion projects such as the South-to-North Water Diversion Project and stronger groundwater management have helped replenish groundwater in some areas, significantly easing subsidence," Hu said.
The team also built an open platform for global urban land subsidence, offering the dataset in a searchable and visual format to the public.
As geological and groundwater big data accumulate and artificial intelligence and complex models advance, the analysis of subsidence causes and risk assessment will have a stronger data and methodological foundation, said Tao Shengli, a researcher at Peking University. ■
