In the past week I’ve seen two very interesting stories about the increase in coastal flooding in recent years.
NASA News reported that while the threat of rising seas due to warming oceans is very real, the phenomenon of large coastal cities sinking has not been well reported. Extraction of groundwater or fossil fuels, and sometimes simply generations of farming, are causing large metropolitan areas in coastal zones around the world to subside surprisingly quickly—making the relative rise of adjacent seas an even greater potential hazard. Subsidence threatens many coastal cities, particularly those that are built on deltas which depend on replenishment of soil by river floods that have been prevented in recent years by levees and other artificial measures. You can read about it at https://climate.nasa.gov/news/2487/big-coastal-cities-sink-faster-than-seas-rise/.
Meanwhile, the New York Times had a lengthy article describing the increase in “sunny-day flooding” or nuisance flooding caused by increasing encroachment of previously unflooded areas in recent years by rising sea levels. They report that “the only road to Tybee Island, Ga., is disappearing beneath the sea several times a year, cutting the town off from the mainland. And … in Fort Lauderdale, Fla., increased tidal flooding is forcing the city to spend millions fixing battered roads and drains — and, at times, to send out giant vacuum trucks to suck saltwater off the streets.” They also note that while these tidal floods are often just a foot or two deep, they can stop traffic, swamp basements, damage cars, kill lawns and forests, and poison wells with salt. You can read the full article here, including stories by scientists who are identifying the encroachment of salt water into coastal neighborhoods and the issues of homeowners in areas that may be unusable in future decades.
