Shanghai Sinking at an Alarming Rate, Amplifying Flood Risks, New study Finds
Shanghai, China – A new study published in the journal Nature reveals Shanghai is sinking faster than previously understood, exacerbating the threat of rising sea levels and increasing the risk of catastrophic flooding. While rising seas pose a meaningful threat on their own, the city’s location on soft delta soil at the mouth of the Yangtze River, combined with extensive groundwater extraction, is accelerating its descent.
The research indicates that approximately 94% of Shanghai’s sinking is attributable to human activity,primarily the pumping of groundwater for industrial,construction,and residential purposes. In the 1960s,at the peak of water extraction,the city was sinking at a rate of 3.93 inches (10 cm) per year.Over the past century, some areas have subsided by more than a full meter. This rate of sinking outpaces sea-level rise, dramatically increasing vulnerability to flood and storm surge events.
The consequences extend beyond Shanghai. Other major Chinese cities situated in delta regions, including Shenzhen and Hong Kong, face similar risks. These areas are critical economic and manufacturing hubs,meaning disruptions from flooding or land loss could significantly impact global supply chains.
The same dynamic threatens other megacities built on deltas worldwide, such as Jakarta, Manila, and New York. Shanghai has begun to address the issue by tightening groundwater regulations and artificially recharging aquifers, which has slowed the rate of subsidence. However, the combined effects of rising seas and sinking land mean long-term risks persist.
Between 2001 and 2020, Shanghai alone incurred over $3 billion (USD) in damages due to subsidence. china’s total losses from this phenomenon currently average $1.5 billion per year. Researchers emphasize that even small increases in sea level can have substantial consequences, making robust flood control, water management, and coastal engineering essential for both China’s economy and global trade stability.
“Deltas are great places…but they are really flat yet prone to human-caused subsidence, so sustained sea-level rise could submerge them really fast,” the research team stated.
