SIMULTANEOUS PREDICTION OF BEACH CHANGES AND GRAIN SIZE DISTRIBUTION ON COAST WITH ARTIFICIAL HEADLANDS

摘要

A model for predicting not only the beach changes but also grain size distribution is applied to the Kashimanada coast, and the changes in grain size and beach topography associated with the construction of artificial headlands and beach nourishment are predicted. On this coast, longshore sand transport toward the wave-shelter zone of the breakwater of Kashima Port had been triggered by the construction of a long breakwater since 1960, resulting in sand accumulation inside the port and erosion on the surrounding coast. In particular, fine sand selectively accumulated in the port, whereas coarse materials were left behind along the eroded coast. These characteristics were reproduced well by the numerical model, as well as the evaluation of the effect of the artificial headlands built as a measure against beach erosion.