INSTALLATION OF T-SHAPE AND L-SHAPE GROINS IN RIVERS WITH BARS TO SUPPRESS THE SEDIMENT DEPOSITION AND SPATIOTEMPORAL CHANGE OF PHYSICAL ENVIRONMENT IN RIVERS

Abstract

The method to install T-shape and L-shape groins in rivers with bars to suppress the sediment deposition and spatiotemporal change of physical environment in rivers are discussed. Subsequently, dynamic management of the shape of groins to improve bed material environment is discussed. The results show that the spatial distributions of velocity and water depth become, respectively, wide and narrow by installation of groins. This result indicates the possibility that the diversity of the physical environment is decreased by installation of groins in rivers with bars, because the bars can produce diversified physical environment originally. Furthermore, the results show that the bed material conditions can be improved by the change of the shape of groins temporally.