Graduate student Sheppard Medlin recently defended his thesis on Simulating the Effects of Barrier Island Scale on Storm Surge Attenuation. Medlin grew up in coastal North Carolina, where he developed a deep appreciation for the ocean and all the coastal communities that depend on it.
Nature Based Infrastructure (NBI) is an increasingly popular flood reduction solution that provides other benefits such as habitat generation, recreation opportunities, and increased aesthetic value over conventional flood control infrastructure. However, information is lacking on the scales at which barrier islands become useful tools for flood reduction. This study attempts to fill this gap by finding scaling relationships between barrier island characteristics and their flood response for a variety of synthetic storms. Data was collected from multiple sources for 16 morphological variables over more than a dozen different islands along both the Gulf and Atlantic coasts of the United States and compiled into a single database. This database was used to generate idealized models of coastal landscapes containing barrier islands. These idealized landscapes were combined with synthetic storm surge forcings as inputs to the ADvanced CIRCulation model (ADCIRC). In a series of experiments, barrier island dune height and length, inlet cross sectional area, and distance from the barrier island to mainland were all individually adjusted to determine their effects on storm surge inundation. It was found that barrier islands could reduce maximum water elevations by up to 38%. These results will help encourage barrier islands as a form of flood control infrastructure moving forward.