Many frameworks have been used to identify environmental flows for sustaining river ecosystems or specific taxa in the face of widespread flow alteration. However, these frameworks largely focus on identifying suitable flows and often ignore the important links between management actions, resulting flows, and valued ecosystem or social responses. Structured decision making (SDM) could assist the comparison of environmental flows by providing a mature framework to link management actions to objectives via environmental flow science. We describe SDM and illustrate its application using a case study focused on comparing environmental flow scenarios for the mainstem Willamette River, Oregon. In a short timeframe, SDM was applied to identify objectives, develop empirical and expert opinion‐based models, and compare flow scenarios while accounting for interannual flow variability and partial controllability. No scenario was clearly preferred based on available knowledge, largely because river flows could only be partially controlled through dam operations. Participants agreed that SDM was useful for comparing alternative dam operations, but that refined predictive models and additional objectives were needed to better inform basinwide flow decisions. In our view, SDM can provide more realistic comparisons of environmental flows by accounting for partial controllability and uncertainty, which may result in greater implementation of available flow management actions.

中文翻译：

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比较环境流量实施方案和结构化决策：来自俄勒冈州威拉米特河的案例研究

面对广泛的流量变化，已经使用了许多框架来确定维持河流生态系统或特定分类群的环境流量。但是，这些框架主要侧重于确定合适的流程，而常常忽略了管理行为，产生的流程以及有价值的生态系统或社会响应之间的重要联系。结构化决策（SDM）可以通过提供一个成熟的框架，通过环境流科学将管理行为与目标联系起来，从而帮助比较环境流。我们通过案例研究来描述SDM并说明其应用，该案例研究的重点是比较俄勒冈州威拉米特河干流的环境流量方案。在短时间内，SDM被用于确定目标，开发基于经验和专家意见的模型，并在考虑年际流量变化和部分可控性的同时比较流量方案。根据现有知识，显然没有任何方案是可取的，主要是因为只能通过大坝运营来部分控制河流的流量。与会者一致认为，SDM可用于比较替代性大坝运行，但需要完善的预测模型和其他目标，才能更好地为流域范围内的流量决策提供依据。我们认为，SDM可以通过考虑部分可控性和不确定性来提供对环境流量的更现实的比较，这可能会导致更多实施可用的流量管理措施。主要是因为只能通过大坝运营来部分控制河流流量。与会者一致认为，SDM可用于比较替代性大坝运行，但是需要完善的预测模型和其他目标，才能更好地为流域范围内的流量决策提供依据。我们认为，SDM可以通过考虑部分可控性和不确定性来提供对环境流量的更现实的比较，这可能会导致更多实施可用的流量管理措施。很大程度上是因为只能通过大坝运营来部分控制河流流量。与会者一致认为，SDM可用于比较替代性大坝运行，但是需要完善的预测模型和其他目标，才能更好地为流域范围内的流量决策提供依据。我们认为，SDM可以通过考虑部分可控性和不确定性来提供对环境流量的更现实的比较，这可能会导致更多实施可用的流量管理措施。