MODELING DUNE RESPONSE BY OVERWASH TRANSPORT

Abstract

A numerical model is presented that simulates sediment transport and profile response produced by overwash of dunes by wave runup. Transport formulas are derived for the different regions of the subaerial portion of the beach covering the swash zone, beach and dune crest, and region landward of the crest. After calculating the distribution of the cross-shore sediment transport rate, profile response is determined through the sediment volume conservation equation. The model is validated with two high-quality data sets from the United States east coast involving overwash of (1) high dunes at Ocean City, and (2) a low and wide barrier island at Assateague Island.