Modeling sediment storage and transfer for simulating regional coastal evolution

he regional coastal evolution model Cascade was enhanced to better describe the transfer and storage of sediment. Focus was on the cross-shore exchange of material from the subaerial to the sub-aqueous portion of the beach and on shoal evolution at coastal inlets. Cross-shore material exchange now includes erosion due to wave impact and overwash, and barrier and dune build-up by wind. Cascade was validated with a data set from Ocean City, Maryland, for the long-term response of a barrier island to these types of cross-shore exchange. The sub-model of the inlet shoals now includes the flood shoal, which previously has not been described by Cascade, and all coupling coefficients specifying the transfer of material between the inlet morphological elements were obtained through analytical expressions. The capability of Cascade to simulate inlet shoal evolution was evaluated with data from the south shore of Long Island, New York. Predictions have yielded robust and reliable results, although further testing is required to determine empirical coefficient values needed in the model.