To enable prioritization among measures for ecological restoration, knowing the expected benefits and consequences of implementation is imperative but rarely explicitly quantified. We developed a novel method to prioritize among environmental flow measures to rehabilitate ecosystems in the Ume River catchment in northern Sweden, a river system heavily regulated for hydropower production. Our strategy was to identify measures with minimal impact on hydropower production while providing substantial environmental benefits. Based on field surveys of remaining natural values and potential for ecological rehabilitation, we quantified the projected gain in habitat area of implementing environmental flows for target organism groups, for example, lotic fish species and riparian vegetation, along the whole river length. We quantified the consequences for hydropower production by identifying a set of hydropower operational rules reflecting the constraints added by environmental flows. We then used production optimization software to calculate changes in hydropower production and revenues. Implementing restrictions on zero-flow events by mandating minimum discharge at all run-of-river hydropower stations and allocating 1%–12% of mean annual discharge to bypassed reaches in the entire catchment would result in a 2.1% loss of annual electricity production. Adding flow to fishways would increase the loss to 3.1% per year. With implementation of more natural water-level fluctuations in run-of-river impoundments, the loss increases to 3.8%. These actions would increase the habitat for lotic species like the grayling Thymallus more than threefold and increase the area of riparian vegetation by about 66%. Our method forms a basis for ongoing implementation of nationwide environmental rehabilitation schemes.

中文翻译：

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受监管河流系统的环境流量情景：预测全流域生态系统对水力发电的益处和后果

为了对生态恢复措施进行优先排序，了解实施的预期收益和后果是必要的，但很少明确量化。我们开发了一种新方法，优先考虑环境流量措施，以恢复瑞典北部 Ume 河流域的生态系统，该河流系统因水力发电而受到严格监管。我们的策略是确定对水电生产影响最小的措施，同时提供可观的环境效益。基于对剩余自然价值和生态恢复潜力的实地调查，我们量化了在整个河流长度上为目标生物群实施环境流动的栖息地面积的预计收益，例如，活鱼物种和河岸植被。我们通过确定一组反映环境流量增加的限制的水电运行规则来量化水电生产的后果。然后，我们使用生产优化软件来计算水电生产和收入的变化。通过强制所有径流式水电站的最低排放量以及将 1%–12% 的平均年排放量分配给整个流域的旁路河段来实施对零流量事件的限制，将导致年发电量损失 2.1%。增加鱼道的流量将使损失增加至每年 3.1%。随着径流蓄水池实施更多自然水位波动，损失增加至 3.8%。这些行动将增加像小龙虾这样的吸毒物种的栖息地 然后，我们使用生产优化软件来计算水电生产和收入的变化。通过强制所有径流式水电站的最低排放量以及将 1%–12% 的平均年排放量分配给整个流域的旁路河段来实施对零流量事件的限制，将导致年发电量损失 2.1%。增加鱼道的流量将使损失增加至每年 3.1%。随着径流蓄水池实施更多自然水位波动，损失增加至 3.8%。这些行动将增加像小龙虾这样的吸毒物种的栖息地 然后，我们使用生产优化软件来计算水电生产和收入的变化。通过强制所有径流式水电站的最低排放量以及将 1%–12% 的平均年排放量分配给整个流域的旁路河段来实施对零流量事件的限制，将导致年发电量损失 2.1%。增加鱼道的流量将使损失增加至每年 3.1%。随着径流蓄水池实施更多自然水位波动，损失增加至 3.8%。这些行动将增加像小龙虾这样的吸毒物种的栖息地 通过强制所有径流式水电站的最低排放量以及将 1%–12% 的平均年排放量分配给整个流域的旁路河段来实施对零流量事件的限制，将导致年发电量损失 2.1%。增加鱼道的流量将使损失增加至每年 3.1%。随着径流蓄水池实施更多自然水位波动，损失增加至 3.8%。这些行动将增加像小龙虾这样的吸毒物种的栖息地 通过强制所有径流式水电站的最低排放量以及将 1%–12% 的平均年排放量分配给整个流域的旁路河段来实施对零流量事件的限制，将导致年发电量损失 2.1%。增加鱼道的流量将使损失增加至每年 3.1%。随着径流蓄水池实施更多自然水位波动，损失增加至 3.8%。这些行动将增加像小龙虾这样的吸毒物种的栖息地 8%。这些行动将增加像小龙虾这样的吸毒物种的栖息地 8%。这些行动将增加像小龙虾这样的吸毒物种的栖息地Thymallus增加了三倍以上，增加了约 66% 的河岸植被面积。我们的方法为持续实施全国环境恢复计划奠定了基础。