The rapid urbanization of Chinese cities has led to a concerning phenomenon – nearly half of the major cities in China are sinking due to water extraction and the weight of their expansion. This subsidence poses a serious threat to millions of people living in these urban areas, especially in coastal regions where sea levels are rising. Researchers have found that 45% of urban areas in China are subsiding by more than 3mm per year, with 16% experiencing rapid descent of over 10mm per year. This means that 67 million people are at risk of flooding in sinking areas.
The main reason behind this subsidence is the extraction of groundwater to meet the demands of the growing population. This significant loss of groundwater has led to the sinking of land, especially in regions like Pingdingshan where coal mining is prevalent. In addition to groundwater extraction, factors such as urban transportation systems and mining activities also contribute to the subsidence issue.
The threat of flooding due to subsidence and sea level rise caused by climate change is a major concern for China. While the land is sinking faster than the seas are rising, the combined effect could put hundreds of millions of people at risk. However, there are strategies that can help mitigate the impact of subsidence, as seen in the case of Tokyo where effective measures were implemented to stop the sinking.
As China grapples with the challenges of rapid urbanization and subsidence, policymakers and urban planners need to prioritize sustainable water management practices and regulations to prevent further land sinking and protect the urban population from flooding. The findings of the study published in the journal Science serve as a wakeup call to address the pressing issue of subsidence in Chinese cities before it escalates further and endangers more lives.
