Beijing: A new study using satellite imagery has revealed that parts of Beijing, especially its central business district, are sinking by up as much as 11 centimetres, or more than four inches each year.
According to a report in The Guardian, the most developed parts of China are sinking at a rate of about four inches every year as a result of excessive pumping of groundwater.
The study has asserted that excessive exploitation of underground water is the reason behind this environmental threat, which is expected to affect at least 50 cities of the country.
The study has further revealed that Beijing sits on extensive natural reservoirs of water that are drying out through human use and the continued subsidence is posing threat to Beijing’s infrastructure, particularly to its high-speed railway network.
The study has been published in the peer-reviewed journal Remote Sensing and is based on InSAR, a type of radar that monitors land elevation changes.
“We are currently carrying out a detailed analysis of the impacts of subsidence on critical infrastructure (eg high-speed railways) in the Beijing plain. Hopefully a paper summarising our findings will come out later this year,” the researchers involved in the study told The Guardian.
The study finds that the entire Beijing city is sinking but the effect is most pronounced in Chaoyang district, which has boomed since 1990 and is replete with hotels and offices.
Tens of thousands of wells are known to exist in and around Beijing, which are used for farming and landscaping purposes. Though the state has regulatory powers over the installation of wells but the enforcement is inconsistent.
Like Beijing, there are many other cities around the world that are sinking due to excessive pumping of underground water by humans. Mexico City is subsiding at an alarming rate of 28 centimetres a year, whereas Bangkok is sinking annually by about 12 centimetres.
