Evaluation and Verification of the Effect of An Examination of Beach Nourishment Focused on the Grain Size

Abstract

The effect of the beach nourishment on the Yamamoto coast which has been suffering from serious beach erosion was evaluated. From the fluorescent sand survey, even medium sand with diameter of about 0.3mm passed over the headland in coming of significant waves higher than 2m. About 80% of sand particles moved out from the injection point within 1 year. According to the Bruun equation, the profile of this beach was identified as the concave and eroded type. Sediment survey showed that sand particles larger than 0.25mm stayed in shallow area with depth less than 2m and remained there for more than 1 year. In addition, Numerical model built to estimate the effectiveness of different grain size on beach nourishment demonstrated availability of gravels for effective nourishment.