Explorations of morphological change at Cape Henlopen, DE using remote sensing, rapid-response GPS-equipped vehicles and numerical modeling

Puleo, Jack A.Delaware beaches are influenced by north-directed sediment transport for the majority of their length, starting at a fluctuating sediment transport nodal point, near Bethany Beach. Northerly transport terminates at the Cape Henlopen Spit, a morphological feature located at the northern tip of the coastline. Over the past 250 years, this littoral sink has matured from a cuspate headland growing 2 km into a simple spit, fed by the eroding Delaware coastline. Despite rapid development, few studies have been completed on the nature and causes of this remarkable expansion. This exploration provides methods to produce comprehensive datasets for quantifying the short term morphological development at the Cape, along with the hydrodynamic conditions governing the region. A video-imaging system was installed at the Cape to supply shoreline position, planform information and insight into the alongshore variability in breaker intensity. Several rapid response GPS-equipped vehicles were developed to acquire robust survey data covering the Cape's offshore bathymetry, intertidal zone, beach face and dune fields. Current meters and pressure sensors were deployed for several tidal cycles, on a small intertidal bathymetric feature on the bayside and a stretch of the oceanside of the Cape to study the currents in the region. Finally, a numerical model was tested to examine its ability to simulate morphological change due to large weather events, in order to determine its appropriateness for use along the Delaware coastline.University of Delaware, Department of Civil and Environmental EngineeringM.C.E