Due to the complex structure and the multiformity of boulder arrangements, there is currently no perfect design criterion for nature-like fishways. This paper proposes four types of nature-like fishways arranged with an impermeable partition wall (IPW), a semi-permeable partition wall (SPPW) or a fully permeable partition wall (FPPW). The hydraulic characteristics of these fishways were investigated experimentally. The results show that the discharge of the fishway arranged with a FPPW was almost twice that of an IPW fishway, and the discharge of a SPPW fishway was between the two extremes. The mean flow velocity of the FPPW fishway was larger than that of the other schemes. For the fishway arranged with an IPW, the flow information was basically consistent with that of the engineered technical fishway. In the FPPW or SPPW fishway, there was more abundant flow information and no obvious recirculation zones in the fishway pool, and these conditions are suitable for migratory fish moving up- and downstream. Notably, for the fishway arranged with two fish passages, two mainstreams were formed in the pool, which divided the flow pattern of the pool into three flow regions. A weak recirculation area was formed in the low-velocity region, which facilitates swimming for migratory fish. According to this comprehensive comparative study, the SPPW fishway with two fish passages had low discharge, abundant flow information and favorable fish migration characteristics; thus, it is the optimal fishway scheme among those studied in this paper.

中文翻译：

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仿自然鱼道水力特性比较研究

由于结构复杂，巨石排列形式多样，目前还没有完美的自然鱼道设计标准。本文提出了四种具有不透水隔墙（IPW）、半透水隔墙（SPPW）或全透水隔墙（FPPW）的类自然鱼道。通过实验研究了这些鱼道的水力特性。结果表明，布置有FPPW的鱼道的排放量几乎是IPW鱼道的两倍，而SPPW鱼道的排放量介于两个极端之间。FPPW 鱼道的平均流速大于其他方案。布置有IPW的鱼道，其流量信息与工程技术鱼道的流量信息基本一致。在 FPPW 或 SPPW 鱼道中，鱼道池水流信息较丰富，无明显回流区，适宜洄游鱼类上下游移动。值得一提的是，布置两条鱼道的鱼道，在池内形成了两条干流，将池内的流态划分为三个流域。低速区形成弱回流区，有利于洄游鱼类的游动。综合对比研究，两条鱼道的SPPW鱼道流量低，水流信息丰富，鱼类洄游特性良好；因此，这是本文研究的最佳鱼道方案。这些条件适合上下游移动的洄游鱼类。值得一提的是，布置两条鱼道的鱼道，在池内形成了两条干流，将池内的流态划分为三个流域。低速区形成弱回流区，有利于洄游鱼类的游动。综合对比研究，两条鱼道的SPPW鱼道流量低，水流信息丰富，鱼类洄游特性良好；因此，这是本文研究的最佳鱼道方案。这些条件适合上下游移动的洄游鱼类。值得一提的是，布置两条鱼道的鱼道，在池内形成了两条干流，将池内的流态划分为三个流域。低速区形成弱回流区，有利于洄游鱼类的游动。综合对比研究，两条鱼道的SPPW鱼道流量低，水流信息丰富，鱼类洄游特性良好；因此，这是本文研究的最佳鱼道方案。这有利于洄游鱼类游泳。综合对比研究，两条鱼道的SPPW鱼道流量低，水流信息丰富，鱼类洄游特性良好；因此，它是本文研究的最佳鱼道方案。这有利于洄游鱼类游泳。综合对比研究，两条鱼道的SPPW鱼道流量低，水流信息丰富，鱼类洄游特性良好；因此，这是本文研究的最佳鱼道方案。