OFFSHORE SAND DISCHARGE CAUSED BY CONSTRUCTING COASTAL STRUCTURES ON A STEEP COAST WITH A LARGE SHORELINE CURVATURE

Shiho Miyahara, Takaaki Uda, Masumi Serizawa, Shusuke Watanabe

Abstract


A groin or a detached breakwater was installed at a cuspate foreland formed on a coast with an abrupt change in coastline orientation and the effect of obstructing longshore sand transport was investigated. The results of the experiment were reproduced using the BG model (a 3-D model for predicting beach changes based on Bagnold’s concept). The beach changes around the structures installed at the cuspate foreland were successfully predicted and the experimental and numerical results were in good agreement. The differences between the effects of the groin and detached breakwater in controlling longshore sand transport and the offshore sand discharge caused by constructing such coastal structures on a steep coast were successfully explained.

Keywords


beach changes; large shoreline curvature; submarine canyon; BG model; groin; detached breakwater

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