Abstract：
Understanding how hydraulic cues in the barrier environment affect fish navigation is critical to fish migration in dammed rivers. However, most of the current research on the effects of hydraulic cues on fish navigation focuses on the effects of a single hydraulic parameter on fish migration and usually ignores fish sensory perception and swimming ability. This study presents an effective approach that combines a computational fluid dynamics model of a river with a model of fish behaviour to elucidate the effects of hydraulic cues in the barrier environment on fish migration paths and strategies by simulating the fish\'s perception of flow direction and their regulation of multiple hydraulic parameters. Four release scenarios for the dam were reviewed and it was determined that the modelled fish movements realistically reflected actual observations. In various scenarios, the target fish (Schizothorax chongi) managed to move upstream to the tailrace downstream of the dam, despite the hydraulic barrier created by the mainstem area of the river; they overcame this obstacle by exploiting low-velocity zones on both sides of the mainstem and in the river\'s boundary layer. During upstream movement, the target fish preferred areas with flow velocities between 0.7 and 1.0 m/s and a turbulent kinetic energy of less than 0.3 m2/s2 to maintain aerobic activity. Additionally, the effects of alternative turbine release strategies on the fine-motor movement of target fish were reviewed and an optimised strategy was provided that could increase the proportion of target fish entering the fish passage facility from 0% to 53.8% in the original scenario to 82.6%. This study provides a feasible method for the simulation of fish fine motion in complex flow environments as well as a scientific basis for the management of fish resources in dammed rivers.
摘要：
了解屏障环境中的水力线索如何影响鱼类航行对于大坝河流中的鱼类迁徙至关重要。然而,目前关于水力线索对鱼类航行影响的研究大多集中在单一水力参数对鱼类迁徙的影响上,往往忽略了鱼类的感官知觉和游泳能力。本研究提出了一种有效的方法，将河流的计算流体动力学模型与鱼类行为模型相结合，通过模拟鱼类对流动方向的感知及其对多个水力参数的调节，阐明屏障环境中水力线索对鱼类迁徙路径和策略的影响。对大坝的四种释放方案进行了审查，并确定建模的鱼类运动真实地反映了实际观察结果。在各种情况下，目标鱼（Schizothoraxchongi）设法向上游移动到大坝下游的尾水，尽管河流主干区形成了水力障碍；他们通过利用主干区两侧和河流边界层的低速带克服了这一障碍。在上游移动期间，目标鱼首选流速在0.7至1.0m/s之间，湍流动能小于0.3m2/s2的区域，以维持有氧活动。此外,审查了替代涡轮释放策略对目标鱼精细运动的影响，并提供了一种优化策略，该策略可以将进入鱼类通道设施的目标鱼的比例从原来的0%提高到53.8%，提高到82.6%。该研究为复杂水流环境下鱼类精细运动的模拟提供了一种可行的方法，也为堰塞河鱼类资源管理提供了科学依据。
