NUMERICAL SIMULATION OF SAND DEPOSITION INSIDE ORDINARY-TYPE FLOODWAY USING BG MODEL

Abstract

 The mechanism of sand deposition inside the Numakawa-Daini Floodway on the Fuji coast was investigated using the BG model (a model for predicting three-dimensional beach changes based on Bagnold's concept). The shape of the floodway was selected to be the one with two or three openings, the point depth of the floodway to be 3 or 5 m, and the floor depth to be 3 or 5 m below MSL. Moreover, the redeposition mechanism of sand was also investigated after the removal of all deposited sand. Sand deposition was induced by landward sand transport due to ongoing waves, and sand deposition on down-coast opening was the largest, resulting in the deposition length of 30 m inside the floodway. Even if sand is removed, quick redeposition occurred.