在鱼道入口处吸引鱼类对于确保鱼类通行效率至关重要,这就需要考虑鱼的游泳特性。本案例研究的目的是提出青藏高原大坝下游的优化水流条件,以吸引鱼类进入鱼道。Cyprinidae的六种当地特有物种:Schizothoracinae被认为是保护目标。然而,高原上大多数特有鱼类的游泳能力尚不清楚,在这方面没有以前的项目可以作为参考。因此,首先根据三个指标测试目标物种的游泳性能,感应速度,临界游泳速度和爆裂游泳速度,根据测试结果,通过不同的流速阈值对六个行为区进行了分类。然后采用经过验证的3D水动力模型对四种典型水库运行场景下大坝下游的流场进行了模拟。通过将模拟的流场与不同的行为区域相匹配,评估所有方案的目标鱼类的通过性,结果表明,在每种情况下都会有不同的潜在迁移路线。对于鱼类通道季节最常见的情况,建议对称使用涡轮机T1和T6,以便与当前状态相比,鱼道入口附近的流速较低,湍流强度较低。此外,建议在具有高潜力的迁徙路线上增加新的入口,以增加鱼类进入的机会。除了为这种具体情况提供解决方案之外,这项研究丰富了有关青藏高原特有鱼类游泳特征的知识。此外,这项研究提供了一种可能的技术方法,在确定类似鱼类通道项目中的吸引流量时,将鱼类行为特征和水力指标相结合。
Attracting fish at fishway entrances is vital for ensuring fish passage efficiency, which requires consideration of the swimming characteristics of fish. The objective of this
case study was to propose optimized flow conditions downstream of a dam on the Tibetan Plateau to attract fish into fishways. Six local endemic species of Cyprinidae: Schizothoracinae were considered as protection targets. However, the swimming abilities of most endemic fishes on the plateau remain unclear, and no previous projects in this area could serve as a reference. Thus, the swimming performances of the target species were first tested based on three indexes, induction velocity, critical swimming speed and bursting swimming speed, and six behavior zones were classified by different flow velocity thresholds based on the test results. A verified 3D hydrodynamic model was then adopted to simulate the flow field downstream of the dam under four typical reservoir operation scenarios. By matching the simulated flow fields to the different behavior zones, all scenarios were assessed for the passability of the target fishes, and the results showed that there would be different potential migration routes under each scenario. For the most common scenario during the fish passage season, symmetrical use of turbines T1 and T6 was recommended so that the flow would be lower velocity and the turbulence would be less intense near the fishway entrances than the current regime. Moreover, the addition of a new entrance was suggested on the migration routes with high potential use to increase the chance that fish would enter. Beyond providing a solution for this specific
case, this study enriches knowledge about the swimming features of endemic fishes on the Tibetan Plateau. Furthermore, this research provides a possible technical methodology that combines fish behavioral characteristics and hydraulic indexes when determining attraction flows in similar fish passage projects.