When it comes to identifying localized sea level rise flooding, tidal gauges aren’t necessarily giving the full picture.
Climate researchers published a study this week in the journal Nature Communications that concluded Twitter may provide a more accurate read on what’s actually going on on the ground. Why? For one thing, there are only 132 tidal gauge stations covering over 3,700 miles of the U.S. Gulf of Mexico and Atlantic coastlines. That leaves enormous gaps between the measuring locations.
As a result, the same high tide that causes little or no flooding in a location with a gauge could cause damaging flooding in another location with a different elevation or concentration of people and structures. The study says, “The same degree of inundation could have substantially different social impacts, depending on the distribution of people, infrastructure and economic activity along the coast.”
To get a clearer picture of how the flooding is impacting coastal locations, the researchers studied nearly half a million tweets sent by 5 million Twitter users in about 235 counties. What they found was that nuisance flooding was occurring in many locations that was not detected by tide gauges.
Most of the undetected nuisance flooding occurred in 22 counties, including those that encompass Miami, New York and Boston, with over 13 million people.
Having a clear picture of what’s happening everywhere is critical to drawing up plans to address the sea level rise flooding as the ocean level rises. “Understanding where coastal floods happen, identifying which meteorological and tide conditions produce floods, and grasping the consequences for flood-affected communities and infrastructure is critical for coastal flood preparation and response,” the study said.
Study co-authors, Frances C. Moore, of the Department of Environmental Science and Policy at the University of California, Davis, and Nick Obradovich, of the Max Plank Institute of Human Development in Berlin, Germany, caution that one major limit of their study is that once people get used to the nuisance flooding they become less likely to report it on social media.
The fact that even tidal gauges can’t always be relied on to give the complete picture of sea level rise flooding in a given area is all the more reason that buyers, sellers, owners and real estate agents need to rely on more than one source when considering the flood risk for a given piece of property.