2011 Volume 17 Pages 203-208
The Rokkaku river basin faces to the Ariake bay where the maximum tidal range is about 5m at the river mouth. This estuary is characterized by well mixed tidal area and suspended matters are usually transported by tidal dynamics. Sediment transport induces shoaling of river channel, thus it is important to maintain the cross-section of river for reducing the damage of flooding. In addition, mud sedimentation might be some possibility of accelerating the growth of Phragmites communis and vice versa.
In this study, the behaviors of cohesive sediment and the growth of Phragmites communis on the banks of river were investigated in the Ushizu river. As a result, it was shown that mud sedimentation was accelerated over the average water level, and the growth rate of Phragmites communis and the network structures of the underground stem were measured. The interaction between siltation and vegetation close to the edge of water in the river bank is highlighted, and an idea of vegetation control is suggested.
