Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA) MNHN, CNRS, IRD, SU, UCN, UA, Station Marine de Dinard - CRESCO, 38 rue du Port Blanc 35800 Dinard, France.
EDF R&D LNHE - Laboratoire National d'Hydraulique et Environnement, 6 Quai Watier, 78401, Chatou, Cedex, France.
J Environ Manage. 2020 May 1;261:110212. doi: 10.1016/j.jenvman.2020.110212. Epub 2020 Jan 31.
Hydropower plants are commonly reported as a major cause of the worldwide decline of freshwater eels (Anguillidae), so that management solutions are urgently needed to mitigate their impacts. Where downstream passage solutions are complex to develop, turbine shutdown appears as an effective management solution to protect silver eels during their river migration toward spawning areas. However, the definition of operational decision rules for turbine shutdown is challenging due to the duality between the benefit for eel conservation and the concomitant cost in term of hydropower production. Here, we proposed a decision framework for turbine shutdown based on simple hydrological criteria to guide negotiations between stakeholders toward a trade-off between silver eel escapement and hydropower generation. Eel migration was assumed to be triggered by a minimum river flow associated with a minimum discharge pulse, so that threshold values can be directly implemented as decision rules for turbine shutdown. To estimate relevant thresholds, a generic methodological framework was developed to generate alternative decision rules from data collected at hydropower plants, which can include telemetry surveys and estimates of eel abundance. A multiple-criteria decision analysis was then conducted to rank alternatives and to determine the best compromise between promoting silver eel escapement and limiting turbine shutdown duration. Graphic outputs can help stakeholders to understand the competitive interests between eel conservation and hydropower production, while visually identifying a range of consensual alternatives to support negotiations in the choice of operational thresholds. The method was illustrated for three river systems in Europe featured by distinct hydrological conditions and can be applied in other areas, providing that eel monitoring surveys and flow data are available.
水力发电厂通常被报道为导致全球淡水鳗（鳗鲡科）数量减少的主要原因之一，因此迫切需要管理解决方案来减轻其影响。在开发下游通道解决方案较为复杂的情况下，关闭涡轮机似乎是一种有效的管理解决方案，可以在银鳗向产卵区洄游的过程中保护它们。然而，由于鳗鱼保护的好处与水力发电生产的相应成本之间的双重性，定义涡轮机关闭的操作决策规则具有挑战性。在这里，我们提出了一种基于简单水文学标准的涡轮机关闭决策框架，以指导利益相关者之间就银鳗逃逸和水力发电之间的权衡进行谈判。假设鳗鱼的洄游是由与最小排放脉冲相关的最小河流流量触发的，因此阈值可以直接作为涡轮机关闭的决策规则实施。为了估计相关阈值，开发了一个通用的方法框架，从水力发电厂收集的数据中生成替代决策规则，其中可以包括遥测调查和鳗鱼丰度估计。然后进行了多标准决策分析，以对替代方案进行排名，并确定促进银鳗逃逸和限制涡轮机关闭持续时间之间的最佳折衷方案。图形输出可以帮助利益相关者了解鳗鱼保护和水力发电生产之间的竞争利益，同时直观地识别一系列共识替代方案，以支持在操作阈值选择方面的谈判。该方法在具有不同水文条件的欧洲三个河流系统中进行了说明，并且可以在其他地区应用，只要有鳗鱼监测调查和流量数据。
