Abstract
Shichiri-Mihama Ida beach is suffering from severe beach erosion. To clarify the mechanism of such beach erosion, short-term beach topographic change including shoreline changes and berm developments obtained by UAV-SfM and network camera was investigated in the relation with wave characteristics. Results showed that UAV-SfM measurement provides the three-dimensional image, sectional view, and calculation of volume amounts of the gravel beach very well and it is useful to understand the beach deformation. Furthermore, it is showed that the beach tends to be erosive under the oblique wave of a significant wave height of 4 m or higher, waves of a significant wave height of the order between 2 m and 4 m from the normal direction of coastline tends to cause deposit, and the beach tends to be stable under waves of a significant wave height of about 1 m or less with regardless of the period and the wave direction, at Shichiri-Mihama Ida beach.
