NUMERICAL SIMULATIONS OF RIDGE ACCRETION AND ONSHORE MIGRATION BASED ON FIELD DATA FROM A STEEP MESO-TIDAL ENGINEERED BEACH
AbstractPreviously, the accretion of a slip-faced ridge and runnel (RR) system was observed during a 3-week field experiment on a steep meso-tidal engineered beach at South Bethany Beach, Delaware. Detailed measurements of wading depth beach profiles and nearbed flow velocities were obtained in the inner surf and swash zones along with offshore wave and current records. In the beginning of this 3-week field campaign on February 13, 2014 a Nor'easter eroded significant portions of the inner beach during this 1-day long storm event. Immediately after the storm during the less energetic conditions, the rapid formation of a pronounced RR system was observed which then continuously evolved over the duration of 2-week poststorm recovery periods. In the last day of the field campaign, 85% of the sediment volume eroded during the storm was recovered in the swash zone. However, no more evolution of the RR system toward the runnel infilling or landward migration was observed.
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