PREDICTION OF BEACH CHANGES ON KOZU AND MAEKAWA COASTS IN ODAWARA CITY

Abstract

 A large submarine canyon is located offshore of the Morito River mouth 2.5 km east of the Sakawa River, and an embayment surrounded by a steep slope approaches the shoreline. Severe beach erosion occurred on the Kozu and Maekawa coasts behind this submarine canyon. The shoreline changes of these coasts between 2009 and 2020 were investigated using aerial photographs as well as the investigation on change in longitudinal profiles. Furthermore, beach changes were reproduced using the BG model and the effect of beach nourishment was investigated. It was found that beach nourishment of 2×10⁴ and 0.8×10⁴ m³/yr are required on the Kozu and Maekawa coasts, respectively, to maintain these coasts.