State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Department of Water Resources (DWR), China Institute of Water Resources and Hydropower Research, Beijing 100038, PR China.
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Department of Water Resources (DWR), China Institute of Water Resources and Hydropower Research, Beijing 100038, PR China.
Sci Total Environ. 2019 Nov 1;689:865-874. doi: 10.1016/j.scitotenv.2019.06.411. Epub 2019 Jun 26.
Hydropower projects have changed the physical habitat of rivers, which has a serious impact on the survival of local fish. The reproduction of fish producing semi-buoyant eggs requires a specific hydrodynamic condition. To predict the influence of cascade hydropower development on the reproductive process of fish with semi-buoyant eggs, a MIKE 21 Flow Model was applied. Lagrangian particle tracking was used to simulate the movement of semi-buoyant eggs and larvae using the Agent-based Modeling (ABM) lab module. The calibrated model showed good agreement between the simulated and observed data for the hydrodynamic process in the reservoir. Twelve scenarios were defined to fully understand whether fish with semi-buoyant eggs can reproduce naturally. The results showed the following: (1) It is difficult to form a fish migration passage in the reservoir in all potential scenarios. (2) Semi-buoyant eggs and larvae sank to the bottom and perished before they hatched and were old enough to survive, since the hydrodynamic conditions could not meet the minimum flow velocity required to keep them in the drift. (3) Even if the hydrodynamic conditions can keep them in the drift in impossible high-discharge conditions, there was not enough drifting time and distance in the reservoir. The results implied that fishes with semi-buoyant eggs cannot reproduce naturally in the main stream, but it is possible that they can reproduce successfully after the protection of the tributary. The method is transferrable to other locations via establishment of models with relevant data to a particular area.
水力发电项目改变了河流的自然生境，对当地鱼类的生存造成了严重影响。产半浮性卵鱼类的繁殖需要特定的水动力条件。为了预测梯级水力开发对产半浮性卵鱼类繁殖过程的影响，应用了 MIKE 21 水流模型。使用基于代理的建模（ABM）实验室模块的拉格朗日粒子追踪法来模拟半浮性卵和仔鱼的运动。校准后的模型显示，在水库水动力过程的模拟和观测数据之间具有良好的一致性。定义了 12 种情景来全面了解产半浮性卵的鱼类是否能够自然繁殖。结果表明：（1）在所有潜在情景中，水库内都难以形成鱼类洄游通道。（2）半浮性卵和仔鱼在孵化前就沉到底部并死亡，因为水动力条件无法满足使它们保持漂流的最小流速要求。（3）即使在不可能的高流量条件下水动力条件可以使它们保持漂流，但水库内的漂流时间和距离都不够。结果表明，产半浮性卵的鱼类不能在主流中自然繁殖，但在支流得到保护的情况下，它们有可能成功繁殖。该方法可通过在特定区域建立具有相关数据的模型，推广到其他地点。
