Sea levels are rising faster than expected in U.S. coastal cities, primarily due to land subsidence from groundwater and fossil fuel extraction. This means up to 518,000 additional people living in these areas could be at risk of major flooding by 2050 if adequate protection is not in place.
Coastal cities often experience subsidence, where the land gradually sinks over time. One of the biggest factors causing this is the compaction of the earth by extracting resources such as water and fossil fuels from the ground.
To investigate how land subsidence and sea level rise will impact coastal communities. leonard owenhen The Virginia Tech researchers created a model based on land elevation changes in 32 major coastal cities, including Boston and San Francisco, and sea level rise projections through 2050.
Researchers found that cities on the Atlantic and Gulf coasts, such as New Orleans, have lower elevations and are sinking faster. It is sinking at least two millimeters more per year than other cities in the region, increasing the risk of future flooding. . Urban areas along the Pacific coast are better protected from rising sea levels because of their higher elevations.
“We were surprised to see that Biloxi, Mississippi, experienced the most rapid subsidence,” Owenhen says.
They also found that existing flood risk assessments in the United States do not take into account the combined effects of land subsidence, underestimating its threat. Researchers have found that nearly 1,400 square kilometers more land will be at risk of flooding by 2050 than current estimates. That means, in total, 1 in 50 people and 1 in 35 homes in 32 cities are at risk. .
This would put an additional 518,000 people and more than 288,000 homes at risk of flooding.
These findings highlight the urgent need to strengthen U.S. flood protection now, team members say Manuchel Shirzai, also at Virginia Tech. “Individual cities will need to adapt differently. New Orleans will need to strengthen city-wide flood protection, while San Francisco will probably only need to protect its critical infrastructure.”
Other things could be done to reduce the threat. “If land subsidence is being caused by groundwater extraction, oil and gas development, or other human-induced stresses, we need to do everything we can to reverse these trends before it’s too late.” he says. Simon Anisfeld At Yale University.
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Source: www.newscientist.com