Center for Ecohydraulics Research, University of Idaho, USA.
Department of Fish and Wildlife Sciences University of Idaho, USA.
J Environ Manage. 2020 Apr 15;260:110107. doi: 10.1016/j.jenvman.2020.110107. Epub 2020 Jan 28.
Sustainable reservoir-river management requires balancing complex trade-offs and decision-making to support both human water demands and ecological function. Current numerical simulation and optimization algorithms can guide reservoir-river operations for optimal hydropower production, irrigation, nutrient management, and municipal consumption, yet much less is known about optimization of associated ecosystems. This ten-year study demonstrates an ecosystem assessment approach that links the environmental processes to an ecosystem response in order to evaluate the impact of climatic forcing and reservoir operations on the aquatic ecosystems of a coupled headwater reservoir-river system. The approach uses a series of numerical, statistical, and empirical models to explore reservoir operational flexibility aimed at improving the environmental processes that support aquatic ecosystem function. The results illustrate that understanding the seasonal biogeochemical changes in reservoirs is critical for determining environmental flow releases and the ecological trajectory of both the reservoir and river systems. The coupled models show that reservoir management can improve the ecological function of complex aquatic ecosystems under certain climatic conditions. During dry hydrologic years, the high post-irrigation release can increase the downstream primary and macroinvertebrate production by 99% and 45% respectively. However, this flow release would reduce total fish biomass in the reservoir by 16%, providing management tradeoffs to the different ecosystems. Additionally, low post-irrigation flows during the winter season supports water temperature that can maintain ice cover in the downstream river for improved ecosystem function. The ecosystem assessment approach provides operational flexibility for large infrastructure, supports transparent decision-making by management agencies, and facilitates framing of environmental legislation.
可持续的水库-河流管理需要平衡复杂的权衡和决策，以支持人类的水需求和生态功能。当前的数值模拟和优化算法可以指导水库-河流运行，以实现最佳的水力发电、灌溉、养分管理和城市消费，但对于相关生态系统的优化知之甚少。这项为期十年的研究展示了一种生态系统评估方法，该方法将环境过程与生态系统响应联系起来，以评估气候强迫和水库运行对耦合的上游水库-河流系统中水生生态系统的影响。该方法使用一系列数值、统计和经验模型来探索旨在改善支持水生生态系统功能的环境过程的水库运行灵活性。研究结果表明，了解水库中的季节性生物地球化学变化对于确定环境流量释放以及水库和河流系统的生态轨迹至关重要。耦合模型表明，在某些气候条件下，水库管理可以改善复杂水生生态系统的生态功能。在干旱水文年份，高灌溉后放水可以分别将下游初级和大型无脊椎动物的产量提高 99%和 45%。然而，这种流量释放会使水库中的总鱼类生物量减少 16%，为不同的生态系统提供了管理权衡。此外，冬季灌溉后放水较低，有助于维持下游河流的水温，以提高生态系统功能。生态系统评估方法为大型基础设施提供了运行灵活性，支持管理机构的透明决策，并有助于制定环境法规。
