Abstract
Shoreline changes of the Akiya coast located in Sagami Bay were investigated on the basis of the comparison of aerial photographs. A breakwater of Kuruwa fishing port was extended forming a wave shelter zone. This induced longshore sand transport from outside to inside the wave shelter zone. Sand accumulated inside the wave shelter zone, whereas beach erosion occurred on the nearby coast. Tracer test using sand with various grain sizes was carried out. The contour-line-change model considering change in grain size given by Kumada et al.(2005) was applied to the coast to investigate the effect of beach nourishment using materials with different grain sizes. It is concluded that beach nourishment using sand composed of coarse materials is effective to recover the stable beach without damages to offshore sea grass field.
