Effects of Woody Plants on Dune Erosion and Overwash

Abstract

A laboratory experiment consisting of five tests was conducted to examine the effects of woody plants on erosion and overwash of high and low dunes. Scarping occurred on the foreslope for three high dune tests and no scarping occurred for two low dune tests. A narrow vegetation zone on a steep backslope of a high dune did not reduce wave overtopping and overwash in comparison with the corresponding bare dune. A wide vegetation covering the high dune reduced foreslope scarping, prevented wave overtopping initially, and reduced sand overwash after the initiation of wave overtopping. A wide vegetation zone covering an entire low dune reduced dune erosion by retarding wave uprush and reducing wave overtopping and overwash.