Recent research conducted by researchers from the U.S. Geological Survey and the Graduate School of Oceanography at the University of Rhode Island – in a paper titled The Weight of New York City: Possible Contributions to Subsidence From Anthropogenic Sources – calculated the mass of all the buildings in New York City, and its contribution on the metropolis’ environment. Depending on soil types, in fact, it was analyzed how buildings have the potential to sink up to 600 millimeters. According to the researchers, this subsidence adds to the risk of flooding, which has already increased in New York due to rising sea levels and increased storm intensity.

The collected results testify that the city’s total of 1,084,954 buildings have a total mass of 760 billion kilograms distributed over an area of 778.2 kilometers with an average mass of 704,000 kilograms. This implies that the areas of soft, clay-rich soils and artificial fills have the highest potential subsidence, ranging from 75 to 600 millimeters, with a median of 294 millimeters. The least impact is in areas where all foundations are anchored to rock, bringing subsidence close to zero.

“With the global growth of coastal cities, the combination of building densification and sea level rise implies an increased risk of flooding,” the researchers write. “The purpose of the paper is to raise awareness that any high-rise buildings constructed in coastal, river or lake areas could contribute to future flood risk and that mitigation strategies may be needed.”

Openingi image: New York City. Photo Joe Taylor, via Unsplash