On the Akashi coast, beach nourishment using gravel with the grain size ranging between 3 and 15 mm was begun in November 2008. The beach changes were monitored using the photographs from several fixed points. It was found that fine sand was deposited over the gravel layer under the calm wave conditions, whereas the nourished gravel was transported onshore and deposited in front of the seawall under the storm wave conditions. Assuming that the equilibrium slope changes in response to the change in thickness of sand layer, a model for predicting the deposition of fine sand over the gravel layer in beach nourishment using gravel and the shoreward movement of gravel during storms was developed on the basis of the contour-line-change model.
