Characteristics of sand transport around the submerged breakwaters installed in Songdo Beach, Busan, South Korean

Abstract

Songdo Beach, a pocket beach, is directly affected by wave activities. During the First Coast Repair Project (20002009), two submerged breakwaters were installed to reduce incoming wave energy and trap the sand eroded from the beach. After that the submerged breakwaters have played an important roll to determine the hydrodynamics behind the submerged breakwaters and the sand transport along the Songdo beach. For these reasons, five-year monitoring (20042008) was carried out for the prediction of shoreline change and for the maintenance of shoreline of Songdo beach. On the basis of the accumulated monitoring data, we analyzed the sand movement in Songdo beach to predict beach erosion. The results reveals that beach erosion occurs by the typhoons during the summer season but beach is recovered in its equilibrium during calm wave period. We also analyzed the flow pattern behind the submerged breakwaters to provide the preliminary data for a long-term stability of the shoreline.