COMPARISON OF BEACH TOPOGRAPHY AROUND ORDINARY- AND SETBACK-TYPE FLOODWAYS LOCATED ON FUJI COAST

Abstract

 A new floodway is planned to be extended in the vicinity of the junction of the Numakawa and Takahashi Rivers on Ukishimagahara Lowland behind the Fuji coast because of the high possibility of flooding. In this plan, setback-type floodway was planned to prevent sand from depositing inside the floodway, by which the location of the gate is positioned in further landward compared with the ordinary-type floodway. On the other hand, a culvert-type floodway has been successfully constructed near Numazu, and it resembles to the setback-type floodway. Therefore, the beach changes around these structures were compared, and the difference in beach changes around two-type floodways was studied.