Nearly half of China's major cities are skinking because of water extraction and due to the increasing weight of urban buildings and infrastructure, a new study has found. The research, published in the journal Science, discovered that Chinese cities, including Beijing and Tianjin, are facing a "moderate to severe" risk of subsidence. 45% of China's urban land was sinking faster than 3 millimetres per year, with 16% at a rate of over 10 millimetres per year, the study revealed.
For the research, scientists measured land subsidence in every Chinese city with a population of more than 2 million people over the period from 2015 to 2022. Of the 82 cities they examined, the team found that some cities are subsiding rapidly, with one in six exceeding 10mm per year. They also found that while China's biggest city Shanghai continues to subside after sinking up to 3 meters over the past century, Beijing is sinking 45 millimetres annually near its subways and highways.
"The subsidence appears to be associated with a range of factors such as groundwater withdrawal and the weight of buildings," the researchers wrote in the study, as per Live Science. "High-rise buildings are sprouting up, road systems are expanding, and groundwater is being used, all at a rapid pace," they explained.
"In addition to the national pattern of city subsidence, we identified several natural and human factors that were associated with city subsidence," the team wrote in the study. The natural factors include the geological setting of each city and the depth of the bedrock, which influenced the amount of weight the ground could hold up without sinking. The scientists also found a strong link between sinking cities and groundwater loss, which leaves empty pore space in the crust that becomes compacted as weight piles on above.
Also read | Alien Life Might Be Purple In Colour And Not Green, Reveals Study
Other factors, according to research, include urban transportation networks, as well as hydrocarbon extraction and mining. But "the key to addressing China's city subsidence could lie in the long-term, sustained control of groundwater extraction," the researchers emphasised.
"Subsidence jeopardizes the structural integrity of buildings and critical infrastructure and exacerbates the impacts of climate change in terms of flooding, particularly in coastal cities where it reinforces sea-level rise," Robert Nicholls, a professor of climate adaptation at the University of East Anglia in the UK said in a statement.
Researchers cautioned that the new findings reinforce the need for a national response even in other susceptible cities outside China.
Featured Video Of The Day
Book Explores Bharat Ratna Awardee Karpoori Thakur's Legacy
Indian Vlogger Forces Scooter Lift, Travels Ticketless In Bus In China, Internet Outraged China's Third Plenum Addresses Economic Challenges, Sets Long Term Reforms Chinese Influencer Teaches Women How To Marry Rich, Earns Rs 163 Crore Per Year Homeless Man, Carrying Knives, Shot Dead By Cops Outside Republican Event 4 Top Leaders Quit Ajit Pawar's Party In Major Setback After Poll Drubbing Karnataka's 100% Quota Bill For Kannadigas In Private Firms For These Posts Watch: Sun Unleashes Powerful Solar Flare, Australia And Japan Hit Mumbai University Invites Applications For MCA And MMS Courses Homeless Man, Carrying Knives, Shot Dead By Cops Outside Republican Event Track Latest News Live on NDTV.com and get news updates from India and around the world.