Rapid Subsidence Threatens China's Urban Coastal Land

A recent study published in the journal Science has revealed alarming findings about the sinking of China’s major cities. The research indicates that approximately 16 percent of the country’s main urban areas are experiencing a decrease in elevation of more than 10 millimeters annually. Furthermore, nearly half of these cities are facing a reduction of more than 3 millimeters per year.

Although these measurements may appear insignificant on an annual basis, over time they can have a profound impact. The study forecasts that within a century, approximately 25 percent of China’s urban coastal regions could be situated below sea level due to a combination of subsidence and rising sea levels.

Expert Insight

Climate scientist and civil engineer, Dr. Robert Nicholls from the University of East Anglia, emphasized the gravity of the situation by labeling it a national problem. In his assessment of the study, Dr. Nicholls highlighted that this research marks the pioneering attempt to comprehensively gauge subsidence across multiple urban areas simultaneously, employing cutting-edge radar data from satellites.

The study pinpointed several factors contributing to the subsidence in these cities. The sheer weight of buildings and infrastructure is identified as a significant cause. Additionally, the extraction of water from aquifers beneath the cities, as well as activities such as oil drilling and coal mining, result in the creation of empty space underground, leading to the compaction or collapse of soil and rocks.