Abstract
Topographic changes in the river-mouth bar in the Yuragawa River are continuously activated by river and ocean currents and sea wave. The bar recently shows the imbalance situation of its geometry, it may cause sedimentation problems. In order to avoid the problems, it is important to understand the characteristics of the topographic change in the river-mouth bar, and to propose a control method of the bar geometry. In this study, variations in geometrical properties of the river-mouth bar are analyzed on the basis of the hydrological data (river water discharge and sea wave height). As for the bar control, the effectiveness of spur dikes, which can change the flow direction, for erosion of the bar was evaluated by means of flume experiments. The two-dimensional numerical model (iRIC Project) is also applied to further investigate the effect of spur dike on the bar control.
