面向鱼卵苗漂流通道维持的水库生态调度方法研究

现有面向鱼类保护的水库生态调度方法侧重于栖息、洄游和产卵过程，而对卵苗（鱼卵和仔鱼）产生后的孵化发育过程考虑很少。“四大家鱼”等卵苗需近/数百公里的漂流过程才能孵化发育，但在漂流到库区时，因水流速度降低会沉降、死亡。本项目以解决卵苗漂流通道中断问题，提高卵苗穿过库区和大坝的效率为目标，以仔鱼期为重点，以泄水孔洞为关键节点，以“漂下去”、“活下来”、“相协调”为导向，针对水流和仔鱼垂向自主运动对仔鱼漂流轨迹的影响规律以及漂流过程中环境要素变化对卵苗孵化发育的影响机制，将仔鱼的垂向自主运动能力纳入仔鱼漂流轨迹模拟模型，以提高轨迹模拟精度（漂下去）；将泄水孔洞前的环境条件与泄水孔洞内的水压条件相结合，以确定卵苗所需的环境阈值（活下来）；将兴利需求与漂流通道大小相协调，以优化漂流通道开启时间、路径和通量（相协调）。本项目有利于实现鱼类全生命周期保护，提高建库河流的鱼类保护效果。

The present eco-friendly reservoir operating methods for fish protection focus on the stages of inhabiting, foraging, migrating and spawning, while seldom consider the egg hatching and larval development stage. The pelagic fish eggs and their larvae, such as the four major Chinese carps, require near one or even several hundred kilometers of drift process to hatch and develop. Due to the low flow velocity in reservoirs, the pelagic fish eggs and larvae will sink and consequently die in reservoirs. It is essential to modify the methods of reservoir operation aiming at addressing the disconnect problem of drift passages for pelagic eggs and larvae and improving fish protection effect during the drift stage. In this research, two key mechanisms will be revealed, i.e., larval movement mechanism under the influence of both the flows and their inherent intermittent vertical movement ability, and the egg and larval growth mechanism under the changes of environmental factors during their drift process. In addition, we will establish the trajectory simulation model for egg and larval drift combining the intermittent vertical movement of larvae and the hydrodynamic processes, will identify the thresholds of DO, temperature and pressure combining the impacts of these environmental factors within and before the drainage holes, and will establish reservoir operating rules with the parameters of opening timing, location and magnitude for drift passages by balancing the requirements of human and fish. This research will be useful for life-cycle protection of fishes, and thus improve the effect of fish protection for dammed rivers.