BEACH CHANGES ON SAGARA-SUZUKI COAST AND BEACH NOURISHMENT TO RECOVER SANDY BEACH

Abstract

 The recovery method of sandy beach in front of the seawall against tsunami on the Sagara-suzuki coast was investigated using the contour-line change model considering change in grain size of sand. The beach changes between 1977 and 2014 were reproduced first to confirm the effect of the model, and then future beach changes were predicted. As a result, the best way to recover sandy beach with a 30 m width, which is required for the protection against waves, was such that nine groins with a crown height of 2 m above MSL are installed at intervals of 350-400 m north of Jitogata fishing port together with the beach nourishment of 8.0×10⁵ m³ using fine sand of grain size 0.2 mm.