COASTAL EROSION CAUSED BY CONSTRUCTION OF AN ARTIFICIAL ISLAND AND PERFORMANCE OF BEACH NOURISHMENT

Abstract

It is well known that the littoral drift carries much sand into a sheltered area caused by the presence of coastal structures such as detached breakwaters. As a result, the shoreline in the sheltered area advances, whereas the shoreline of the neighboring coast recedes to balance a sand budget of the coast. An artificial island for storage of crude oil was constructed off the Kashiwabara coast, Shibushi, Kagoshima Prefecture, Japan since 1985. The island has a rectangular shape roughly 1.5 km long and 1.5 km wide. This paper describes coastal processes related to the construction of the artificial island, and proposes a new dredging and beach fill scheme including a groin to decrease the coastal erosion due to the sheltering effect by the artificial island.