Environmental restoration and flow analysis technique in a steep river including boulder and bridge pier

大坝建成后，下游水沙条件发生变化。例如，由于大坝截留的沉积物，装甲层不断发展。因此，我提出了通过改善河床形态来促进砾石沉积的技术。所提出的技术的效果进行了研究，使用二维数值模型。结果表明，所提出的技术是有用的，以减少在陡峭的河流牵引力。它们可以为具有各种砾石尺寸的河流生态系统创造理想的河床状态。

After dam construction, the flow and sediment regime change downstream from the dam. For example, the armor coat progresses because of sediment trapping by the dam. Therefore, I have proposed techniques that promote gravel sedimentation by improving riverbed forms. The effects of proposed techniques were investigated using a two-dimensional numerical model. Results showed that the proposed techniques are useful to reduce tractive force in steep rivers. They can create a desirable bed state for river ecosystems with various gravel sizes.