Author(s): Takashi Sumi; Hiroshi Takebayashi; Masami Sakuma
Linked Author(s): Hiroshi Takebayashi
Keywords: Groin; Bed Material Conditions; Adaptive Management; Diversity; Bed Deformation
Abstract: This study concerns a method to install 2 types of groins (T-shaped and L-shaped) in rivers, using sandbars to suppress sediment deposition and diversify the bed material environment around the groins. Based on numerical analysis of the spatiotemporal change of the bed material conditions, the effects on the bed material conditions around the installed groins, are evaluated. Based on the field survey results following the installation of groins, the effect of suppressing sediment deposition is also discussed. Furthermore, adaptive management to improve the bed material conditions is discussed. The results show that, by installing the groins with a focus on hydraulic conditions when forming sandbars in the channel, sediment deposition should be suppressed in the channel between the groin edge and the opposite bank. The field survey results also demonstrate that sediment deposition in the channel is also suppressed, and by installing the groins, the bed material conditions can be diversified. Furthermore, by installing the groins using large movable sandbags and changing the height of the groins after several years, it is possible to maintain a diverse bed material conditions for a long time.
Year: 2014