Quantitative Prediction of Sand Discharge into Submarine Canyons - Application to Kozu Coast

Abstract

On the Seisho coast, submarine canyons have developed very close to the coastline and the discharge of fluvial sand of the Sakawa River into the submarine canyons has been reported, resulting in the net loss of sand into the offshore zone. The beach topography under the dynamically equilibrium conditions owing to the sediment supply from the river and the sand loss into the submarine canyons during several thousand years was reproduced using the contourline-change model considering the grain size composition. Long-term beach changes around the submarine canyons were accurately predicted and the effect of beach nourishment using a mixture of fine and coarse materials was investigated.