Investigating Controls on Barrier Island Overwash and Evolution during Extreme Storms

Over short periods of time, extreme storms can significantly alter barrier island morphology, increasing the vulnerability coastal habitats and communities relative to future storms. These impacts are complex result interactions between oceanographic conditions geomorphic, geological, ecological characteristics island. A 2D XBeach model was developed compared observations in order study these along an undeveloped near landfall Hurricane Florence 2018. Beachface water levels during storm were obtained from two cross-shore arrays pressure sensors for comparison hydrodynamics. Aerial drone imagery used derive pre-storm post-storm elevation data quantify spatially varying erosion overwash. Sediment grain size measured multiple locations, we estimated friction by using Sentinel-2 satellite imagery. The high spatial temporal resolution provided efficient method incorporating land cover. While previous studies have focused on use friction, found that utilization local median sizes full directional wave spectra critical reproducing observed overwash extent.