Reproduction of Change in Direction of Longshore Sand Transport Caused by Extension of Taito Fishing Port Breakwater and its Measure

Abstract

On the Ichinomiya coast located in the southern part of Kujukuri Beach, beach erosion has occurred due to the decrease in sand supply from sea cliffs of Point Taito. As a measure against beach erosion, ten artificial headlands have been constructed since 1990. During their construction period, a Taito fishing port breakwater was extended, resulting in change in wave field. Then, the direction of longshore sand transport was entirely changed from north to south because of wave sheltering effect. These beach changes were reproduced numerically using the BG model proposed by Serizawa et al. It was concluded that the artificial headland can be effectively used as a measure for preventing reverse sand transport to the fishing port.