Detail

The study’s authors examined 82 Chinese cities with populations of more than 2 million. They used radar pulses from satellites to detect changes in the distance between the satellite and the earth. They then measured how the height of the cities changed between 2015 and 2022.

They found that Shanghai, China’s largest city, continues to sink, even though it has sunk nearly 3 meters in the last 100 years. Cities such as Beijing and Tianjin were also affected more than others. What are the reasons for this phenomenon?

There are a number of factors that lead to land subsidence, but Robert Nicholls, a professor of climate adaptation at the University of East Anglia who was not involved in the research, told the BBC he believed water extraction was “probably the dominant cause”.

Many people in China live in areas that were deposited relatively recently in geological terms. So when you extract groundwater or drain the soil, they tend to collapse.
– said.

The article also suggests eliminating the problem “It could consist of long-term, sustainable control of groundwater extraction.”.

Nicholls warns of ‘land collapse’ It compromises the structural integrity of buildings and critical infrastructure” and “intensifies the impacts of climate change in terms of flooding.”“especially in coastal cities, which is exacerbating sea level rise.”

Land subsidence currently costs China more than 7.5 billion yuan, or about $1.05 billion a year.

Not just China

However, the problem is not limited to China. Another paper published in February said about 6.3 million square kilometers of the planet’s surface was at risk of collapse, with Indonesia among the worst-hit countries.

The problem has also affected parts of the United States, with more than 17,000 square miles of land in 45 states directly affected, according to the U.S. Geological Survey. More than 80 percent of detected subsidence cases in the United States are due to groundwater use.