SHORELINE CHANGE AND SEDIMENT DYNAMICS AFTER RENOURISHMENT OF FOLLY BEACH, SOUTH CAROLINA
Loading...
Date
Authors
Banner, Robin Lydia
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Folly Beach County Park, located on the southeastern end of Folly Beach, South Carolina has experienced a long history of chronic erosion. In summer 2013, the park was renourished and a terminal groin was built to prevent littoral transport of sediment downdrift. Bimonthly elevation surveys were conducted and beach photography was collected to determine sediment dynamics for eight months following renourishment. The results revealed that during the months immediately following the renourishment, relaxation of the beach fill caused the overall topography to become more even and the beach slope to decrease. After this initial deflation of the profile, longshore transport to the southwest caused sand to accumulate updrift of the terminal groin. The groin appears to be most successful at retaining sediment up to 325 meters updrift. Sand also readily migrated around the groin and was deposited on the upper beachface on the island’s southern end. However, as available updrift sand decreased, erosion south of the terminal groin increased, with the overall effect of the groin on downdrift beaches yet to be determined. Dune growth is also important with regard to maintaining a healthy recreational beach, but the seaward extent of the dune field decreased dramatically and dune elevation remained essentially constant throughout the project period. While continued human intervention will be necessary to preserve this park, the addition of a terminal groin has dramatically slowed beach erosion and likely increased the amount of time between future renourishments in this specific area.
Description
Keywords
Folly Beach, Sediment, Renourishment, Shoreline