Interannual Variability of Waves and Influence of Submerged Breakwater on Wave Characteristics at Shirarahama Beach

本研究は，白良浜海岸における地形と波浪特性の関係の経年変化を調べること，および岩礁背後に建設された潜堤が湾内の波浪に及ぼす影響を調べることを目的としている。白良浜の海底地形は，浜中央付近で深くなってきている。波高の経年変化については，浜の北側において経年で1.5縲・倍に大きく増大した。潜堤が波高へ及ぼす影響については，波向がWSWのうねりの条件のときに，潜堤設置前に比べて浜の北側と南側で波高が10縲・0%増大することがわかった。

The purpose of this study is to investigate an interannual variability of waves and influence of submerged breakwater on wave characteristics at the Shirarahama Beach. The wave transformation model with the theory of energy balance equation including wave diffractions effect is used for the evaluation. We used three different topography conditions, with or without submerged breakwater and two different wave conditions which are a swell and a wind wave. It was found that the wave characteristics are varied year by year according to changing of topographic conditions. The influence of submerged breakwater on the wave characteristic is also investigated in case of swell and WSW wave direction.