Abstract
Field investuigation was carried out on the Hokota coast in Ibaraki Prefecture to investigate seasonal beach changes around the artificial headlands. As a result, the beach materials of the Hokota coast was composed of fine and medium-sized sand with the content of 90 % by two grain sizes, and medium-sized sand was mainly deposited in the zone shallower than 3 m depth. On the immediately north side of artificial headland No. 23 located on the south side, the amount of medium-sized sand increases in summer compared with that in winter, wheras vice versa near the south side of headland No. 29. This phenomenon was explained by the fact that fine sand is transported by northward long-shore sand transport in summer and vice versa in winter. This was also confirmed by the field observation of shoreline changes using UAV.
