Prospective real estate buyers may well take heed of a new national map, created by environmental scientists at Stanford University, which describes the best places in the United States that provide natural protection from the ravages of Mother Nature, such as coral reefs and wetlands. Though effective, manmade coastal structures such as seawalls and levies act as substitutes for natural structures – but they are also an expensive and environmentally undesirable manipulation of the natural environment.
According to Katie Arkema and her colleagues at Stanford University, conserving and restoring the natural coastal environment provides additional protection from tropical storms, hurricanes, and the potentially devastating storm surges that often accompany these meteorological phenomena. The map, which emerged as an attempt by Arkema and her colleagues to create a “Hazard Index” for national coastlines, also identifies coastal areas that require additional attention to maximize their protective potential.
According to the map data, approximately two-thirds of the nation’s coastlines are protected by such habitats as seagrass beds, marshes, dunes, mangrove forests, kelp beds, oyster beds, and coral reefs. In the case of the latter structure, coral reefs can sap as much as 85 percent of the energy of waves that crash onto shore. By incorporating the human element, the scientists identified where people and property were at risk, using demographic data gathered by the U.S. Census Bureau and incorporating property values developed, in part, from a relationship with the online real-estate service Zillow.
To evaluate the supposed level of protection offered by natural coastal structures, Arkema and her team created a model of national coastlines with these structures removed. The results were catastrophic, as the loss of these natural structures would double the length of highly exposed coastlines. According to the model, this would expose an additional 1.4 million Americans to the environmental threats from which natural coastal structures protected them.
According to Arkema, “That really surprised me. It does make sense. We know for example that there are a lot of people in Florida, and that Florida gets hit with a lot of hurricanes, but when I saw that the totals actually doubled I was really surprised.”
The map, published in Nature Climate Change on July 14, clearly shows that the East and Gulf Coasts are more vulnerable than the West Coast to natural disasters. According to Arkema, “The East Coast and Gulf Coast, in general, are lower-lying and sea level rise will impact those coasts more. Many of the shorelines aren’t as hard, there are more muddy or sandy areas. Of course California has many sandy beaches but much of the West Coast tends to be higher elevation, harder shoreline—think of places like Big Sur for example.”