2024 Volume 80 Issue 16 Article ID: 23-16059
In the middle reach of Tama River, the low channel bed height has been controlled by continuous river improvements, and the river channel has been transformed into the ship-bottom-shaped channel as the low channel width has been increased in response to flood flow. In this study, we evaluated the hydraulic and environmental characteristics of the ship-bottom-shaped channel by flood flow and river bed variation analysis. In the ship-bottom-shaped channel, sandbar bed is moderately disturbed by floods according to the height of sandbar, which dynamically maintains the habitat for herbaceous vegetation and facilitates tree management. In addition, the water surface width widens as the flow rate increases and the increase in bottom velocity becomes slow, resulting in creating continuous low velocity area that can provide refuge for fish during flooding. Thus, the ship-bottom-shaped channel contributes to the conservation of diverse habitats. And the results of this highly accurate analysis provide important information for design and management of the channel in harmony with flood control and river environment.
