EVALUATION OF EFFECT OF GRAVEL NOURISHMENT USING CONTOUR-LINE-CHANGE MODEL IN KATAYAMAZU AREA ON ISHIKAWA COAST

Abstract

 Beach nourishment using 2.0×10⁵ m³ of gravel has been planned at Katayamazu area of the Ishikawa coast to recover a sandy beach of 20 m width. In this beach nourishment, gravel, which is stably deposited near the shoreline was employed, and 4.7×10⁴ m³ of gravel has been supplied to the coast by 2017. To accomplish the beach nourishment, it is required to evaluate the effect of beach nourishment using coarse material. In this study, measured beach changes after the beach nourishment were reproduced using a contour-line-change model considering the change in grain size of bed material. Beach changes were also predicted when waves are obliquely incident to the shoreline at a large angle to investigate a possibility of sand discharge turning around the tip of the river mouth jetty.