COASTAL CHALLANGESChallenges to Tidal Flats Pose Risks to 41M Americans Living in Coastal Counties

About 29 percent of the United States’ population live in coastline counties – more than 41 million are in Atlantic counties. This high population density poses a critical challenge to sustainable developments in coastal areas.

Tidal flats, which make up coastal wetlands, are facing unprecedented challenges because of increased human activities. They are widely recognized as sentinels of coastal environment change. Importantly, they are the guardians for beachfront communities as they can largely mitigate destructive forces from the ocean. Without them, coastal communities are more vulnerable. 

Currently, there isn’t an effective way to identify and quantify the interactions between urban areas and tidal flats, which is essential to preserve the nation’s coastal communities. Moreover, existing research is limited to individual cities, which doesn’t provide the big picture. 

To address this environmental crisis, researchers from Florida Atlantic University have developed a novel approach that quantifies change patterns of tidal flats from a spatiotemporal perspective using data collected across time. Their study is one of the first to investigate correlations between tidal flats and urban areas using this technique.

For the study, researchers selected and analyzed the annual dynamics of three highly urbanized coastal counties in the southeastern U.S., which represent unique environmental settings: a tidal flat system of more than 3,168 square kilometers characterized by numerous sounds, estuaries, as well as the twice-daily ebb and flow of the tides.

They separately assessed the spatiotemporal dynamics of tidal flats and urban areas in the counties of Charleston, South Carolina; Chatham, Georgia; and Duval, Florida between 1985 and 2015. They then identified and quantified the tidal flat losses in these three counties, which are directly or indirectly associated with urban expansion, from a geographic lens that focused on place and space.

Results of the study, published in the international journal, Earth , verifies and highlights the conflicts between intensified human activities and coastal environments. Importantly, this new approach can be revised and applied to the entire U.S.