China's major cities face land subsidence threat: Study
What's the story
A significant number of China's major urban regions are grappling with substantial land subsidence, a situation that could potentially endanger millions of lives in the coming years, a study by Chinese scientists revealed.
Land subsidence refers to the gradual sinking of land compared to its surroundings, a global issue that intensifies local sea level rise due to climate change.
Findings
Half of China's major cities experiencing subsidence
The research, a collaborative effort involving over 50 scientists from various Chinese research institutes, reveals that nearly half of 82 major Chinese cities are experiencing measurable subsidence.
These affected areas house approximately one-third of China's urban population.
The researchers predict that around a quarter of China's coastal land will be submerged under sea level within the next century, primarily due to subsidence.
Expert opinion
Subsidence: An international problem
Robert Nicholls, a renowned expert on subsidence from the University of East Anglia in England who was not part of the study, commented on the findings.
"This is a big problem. The scale is large. Without doubt, it brings home that this is not a local problem. This is a national, or even international, problem," said Nicholls.
To recall, in recent years, Joshimath, Uttarakhand, has faced challenges due to subsidence, particularly in areas susceptible to landslides.
Risks
Millions at risk due to rising subsidence and population
The study suggests that millions are already at risk.
This figure is likely to go up if China's urban population continues to expand and subside at their current pace and sea levels continue to rice due to green house gases.
Nicholls said many Asian cities are established on river deltas that are susceptible to sinking when heavy structures are built on top and groundwater is extracted from below.