Near the Imagire-guchi inlet, which is the target area in this study, the shoreline on the west side of a jetty retreats because of a decrease in sediment supply from the east side upstream. This study attempts to ana...Near the Imagire-guchi inlet, which is the target area in this study, the shoreline on the west side of a jetty retreats because of a decrease in sediment supply from the east side upstream. This study attempts to analyze the shoreline and topographic changes around the inlet through analysis of GPS (global position system) measurements and digitized shoreline from aerial photographs. In addition, the DoC (depth of closure) is determined by examining datasets of cross-shore profiles and by calculations using the Hallermeier equation (1981) based on the offshore wave height and period. The results obtained by GPS indicate coastal erosion caused by waves generated by typhoons. The gradual recovery of the shoreline position after the typhoons struck was also captured by the GPS survey. However, analysis of the aerial photographs reveals that the shoreline on the west side of the jetty fluctuated widely. The cross-shore profile datasets reveal that closure depth far from the inlet was deeper than that near the inlet.展开更多
文摘Near the Imagire-guchi inlet, which is the target area in this study, the shoreline on the west side of a jetty retreats because of a decrease in sediment supply from the east side upstream. This study attempts to analyze the shoreline and topographic changes around the inlet through analysis of GPS (global position system) measurements and digitized shoreline from aerial photographs. In addition, the DoC (depth of closure) is determined by examining datasets of cross-shore profiles and by calculations using the Hallermeier equation (1981) based on the offshore wave height and period. The results obtained by GPS indicate coastal erosion caused by waves generated by typhoons. The gradual recovery of the shoreline position after the typhoons struck was also captured by the GPS survey. However, analysis of the aerial photographs reveals that the shoreline on the west side of the jetty fluctuated widely. The cross-shore profile datasets reveal that closure depth far from the inlet was deeper than that near the inlet.