Barrier island dynamics: Overwash processes and eolian transport.

Abstract

The northern 5 miles of shoreline at Assateague Island, Maryland are presently being eroded. During storms, swash surges are able to overtop the most landward (storm) berm as overwash with deposition occurring on the barren flats. Where primary barrier dunes still exist, sediment-charged surges are funnelled through breaches in the dune field for deposition of the entrained material on the washover fan. Sediment budget computations show that there has been a small net loss ef material at each washover area, in spite of 7 discrete overwash events during a 26 month time interval. The predominant northwest winds effectively eroded the overwash material, transporting the majority of the sand back to the beach. This analysis indicates that there exists a balance between mverwash and eolian processes with wind transport being slightly dominant. (A)