By Tim McDonnell & Daniel Wolfe
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But scientists and urban planners often struggle to predict the impacts of these high-tide floods along the Atlantic and Gulf coasts. The mere fact that a town’s local tide gauge registers a flood isn’t particularly helpful for, say, school administrators deciding whether to cancel class, or cops deciding which roads to close, or insurance adjusters looking to raise premiums in vulnerable areas.
So some researchers are looking for clues in a new place: Twitter.
There’s good reason to search for more powerful indicators of flood impacts: Sunny-day floods disrupt traffic, threaten infrastructure, and drain local economies. A study in Science last year found that high-tide flooding cost businesses in downtown Annapolis, MD, more than $100,000 in lost revenue in 2017.
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A new paper in Nature Communications takes a stab at a different approach: Monitoring flooding through peoples’ exasperated tweets. The analysis, which combed through half a million tweets geotagged in more than 200 counties along the East and Gulf coasts from 2014-2016, found that high-tide floods may be even more widespread than a report from NOAA had suggested. In 22 counties—including those of Miami, New York City, and Boston—the study documented a spike in apparently flood-related tweets at tide levels up to half a meter lower than what the gauge recorded as a flood.
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