LARGE-SCALE BEACH CHANGES ASSOCIATED WITH MERGENCE OF ISOLATED SAND BAR ON TIDAL FLAT TO LAND

Abstract

 On the tidal flat offshore of Kanda City facing the Suo-nada Sea, an isolated sand bar develops. This sand bar forms a sand body on the tidal flat under waves, and it deforms while maintaining a semicircular shape. On October 17, 2014, the north end of this isolated sand bar approached the land, and a flood/ebb tidal delta was formed owing to the flood/ebb tidal current at the opening between the tip of the sand bar and the land. Then, due to the second field observation on September 17, 2016, severe beach erosion occurred immediately before the attachment of the tip of the sand bar to the land, and finally the mergence of the sand bar to the land occurred, causing large-scale beach changes.