Laboratoire de Constructions Hydrauliques (LCH), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
Water Science and Engineering Department, IHE Delft Institute for Water Education, 2611 AX, Delft, The Netherlands.
Sci Rep. 2019 Mar 26;9(1):5176. doi: 10.1038/s41598-019-41575-6.
River reaches downstream dams where a constant residual flow discharge is imposed, often lack sediment supply and periodic inundation due to the absence of natural flood events. In this study, a two-year return flood was released from an upstream reservoir and combined with sediment replenishment to enhance instream habitat conditions downstream of Rossens hydropower dam on the Sarine River in western Switzerland. Sediment replenishment consisted of four sediment deposits distributed as alternate bars along the river banks, a solution which was previously tested in laboratory. The morphological evolution of the replenishment and of the downstream riverbed were surveyed including pre- and post-flood topography. A hydro-morphological index to evaluate the quality of riverine habitats, based on the variability of flow depth and flow velocity in the analyzed reach, was investigated. The combination of the artificial flood with sediment replenishment proved to be a robust measure to supply a river with sediment and to enhance hydraulic habitat suitability.
河流到达下游水坝，那里强制施加恒定的剩余流量排放，由于缺乏自然洪水事件，经常缺乏泥沙供应和周期性淹没。在这项研究中，从上游水库释放了两年一遇的洪水，并结合泥沙补给，以增强瑞士西部萨林河罗森斯水电站下游的河流栖息地条件。泥沙补给由四个沉积物组成，沿着河岸分布为交替的沙洲，这是以前在实验室中测试过的解决方案。调查了补给和下游河床的形态演变，包括洪水前和洪水后的地形。还研究了一种基于所分析河段水流深度和流速变化的水-形态指数，以评估河流栖息地的质量。事实证明，将人工洪水与泥沙补给相结合是为河流提供泥沙和提高水力栖息地适宜性的有效措施。
