Research reveals that nearly half of Chinese cities are sinking due to the weight of buildings

Image: Reproduction/ArchDaily.

In China, nearly half a billion people live in cities that are slowly sinking due to the weight of buildings and the extraction of groundwater beneath urban centers. The warning comes from a study published this week in the scientific journal Science. Information taken from Um Só Planeta.

The research shows that 45% of the country's urban areas are sinking by more than 3 millimeters per year, with land levels falling by 16% at a rate of more than 10 millimeters per year. China currently suffers annual losses of about US$1 billion (R$5.2 billion) due to the sinking of this species.

According to researchers from South China Normal University, by the end of this century, nearly a quarter of China's coastal land may be below sea level, a risk exacerbated by climate change, which has caused the melting of ice at the Earth's poles and the resulting rise. At low tide.

The population of Chinese cities today is about 900 million people, 45% of whom (405 million people) live in a city that is witnessing decline.

Shanghai, China's largest city, sank by 3 meters in the last century, The Independent has revealed. The capital, Beijing, sinks about 45 mm annually, especially near highways and subway stations.

This is the first time scientists have used satellite data to systematically measure the number of cities in China that are sinking. The study took into account measurements made between 2015 and 2022, according to a report issued by American Public Radio NPR.

Similar studies in Europe and the United States also found significant subsidence (the technical term for urban subsidence) in some cities, but did not show the same widespread subsidence found across China.

“This is a national or even an international problem,” says Robert Nicholls, a subsidence expert at the University of East Anglia in England, who was not involved in the study.

Measurements of this type are important for developing preventive plans and even reversing drownings that have already occurred. In places where groundwater removal is the main problem, cities may ban water pumping. In some cases, it is possible to return water to the ground to support the land.

Nicholls cites the example of Tokyo, which experienced a subsidence of 4.5 meters in the 20th century, but has successfully stabilized low-lying parts of the city with strict rules on groundwater use.