28 densely populated cities predicted to be flooded

American megacities are sinking underground: the safety of 34 million people is at risk

According to a sensational study by Columbia University, dozens of major US cities are gradually sinking underground. Scientists identify excessive groundwater extraction as the main culprit for this alarming phenomenon. Surprisingly, not only coastal cities are at risk, but also megacities located far from oceans.

Houston turned out to be the real "champion" in terms of sinking speed – almost 50% of the city's territory is descending at a rate of more than 5 mm per year, and some areas are subsiding at a shocking 5 cm annually. Dallas and Fort Worth rank second and third in this alarming rating with indicators of 4-5 mm per year. A critical situation is also observed in the area of LaGuardia Airport in New York, certain parts of Las Vegas, Washington, and San Francisco.

"As cities grow, more territories will expand into subsiding regions," warns the lead author of the study, Leonard Ohenhen. "Over time, this can create a load on infrastructure that exceeds its safety limits."

Scientists used satellite data to compile detailed subsidence maps for all US cities with populations over 600,000. Although only about 1% of the territory in the 28 studied cities experiences critical subsidence, these zones are usually located in the most densely populated areas where thousands of buildings are concentrated.

Buildings in San Antonio (every 45th building), Austin, Fort Worth, and Memphis are at the greatest risk.

In addition to groundwater pumping, other factors affect subsidence: consequences of ancient glacier melting, the weight of urban structures themselves, and new construction. Researchers urge city authorities to use the obtained data to develop strategies for reducing the risks of flooding and infrastructure destruction.