MODEL FOR PREDICTING TOPOGRAPHIC CHANGES ON BEACHES COMPOSED OF SAND OF MIXED GRAIN SIZE DUE TO WAVES AND WINDBLOWN SAND

Abstract

 On a coast, which is composed of sediments with mixed grain sizes and is affected by strong winds, fine sand and medium-size sand are selectively transported to the back of the coast as windblown sand, leaving coarse sand and gravel on the foreshore. In this study, we proposed a model for predicting beach changes on coasts composed of sand of mixed grain size while taking not only effects due to waves but also windblown sand into account. To verify the validity of the model, a model calculation was carried out on a coast with a wave-shelter zone produced by the construction of an offshore breakwater as well as the application to the Inage coast. The calculation results were in good agreement with the field condition, and the effectiveness of the model was confirmed.