State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resource & Hydropower, Sichuan University, Chengdu, 610065, Sichuan, China; Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, China; Cooperative Institute for Great Lakes Research, School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, 48109, United States.
Sichuan Province Zipingpu Development Co., Ltd., Chengdu, 610091, China.
J Environ Manage. 2023 Jan 1;325(Pt A):116470. doi: 10.1016/j.jenvman.2022.116470. Epub 2022 Oct 13.
Reservoir operation strategies with low cost and high efficiency have been proposed to control algal blooms. However, the key hydrodynamic principle for performing reservoir operation strategies is still unknown, posing an obstacle to practical applications. To address this challenge, we proposed short-term emergency reservoir operation strategies (EROSs), established a three-dimensional (3D) eutrophication model of the Zipingpu Reservoir, and designed six 14-day reservoir operation cases to explore the mechanism of EROSs in controlling algal blooms. Large outflows with rapid water exchange should be adopted early in EROSs to control algal blooms in the reservoir. Small variations in the surface water temperature or the mixed layer depth/euphotic layer depth (Z/Z) ratio were found for different EROSs, indicating that these variations might not have been responsible for the differences in the algal blooms in the reservoir. The EROSs induced high surface flow velocity (V) and depth-averaged velocity (V) values in the reservoir, thereby controlling algal blooms by inhibiting algal growth and disrupting algal accumulation in the upper water layers. The flow of V against the direction of the water intake was detected during the execution of the EROSs, suggesting that increasing V might enhance water retention in the reservoir. Increasing V not only promoted water exchange to disrupt algal accumulation but also enhanced V to inhibit algal growth. Moreover, V demonstrated a strong linear relationship with the inhibition ratio of algal blooms. These results demonstrate that V is the key hydrodynamic indicator for performing EROSs and that accelerating V to exceed 0.039 m s in the near-dam region can control algal blooms. Overall, in this study, we develop a novel EROS and elucidate corresponding principles for the use of EROSs to control algal blooms in reservoirs.
已提出具有低成本和高效率的水库运行策略来控制藻类水华。然而，执行水库运行策略的关键水动力原理仍然未知，这对实际应用构成了障碍。为了解决这一挑战，我们提出了短期应急水库运行策略（EROSs），建立了紫坪铺水库的三维（3D）富营养化模型，并设计了六个 14 天的水库运行案例，以探讨 EROSs 控制藻类水华的机制。在 EROSs 中，应尽早采用大流量放水来控制水库中的藻类水华。对于不同的 EROSs，发现表层水温或混合层深度/透光层深度（Z/Z）比的变化很小，这表明这些变化可能不是水库中藻类水华差异的原因。EROSs 导致水库中表面流速（V）和水深平均流速（V）值较高，从而通过抑制藻类生长和破坏上层水层中的藻类积累来控制藻类水华。在执行 EROSs 期间，检测到 V 沿与进水方向相反的方向流动，这表明增加 V 可能会增强水库的蓄水能力。增加 V 不仅促进了水交换以破坏藻类积累，而且增强了 V 以抑制藻类生长。此外，V 与藻类水华抑制率之间呈很强的线性关系。这些结果表明，V 是执行 EROSs 的关键水动力指标，并且在近坝区将 V 加速到超过 0.039 m s 可以控制藻类水华。总的来说，在本研究中，我们开发了一种新的 EROS，并阐明了使用 EROSs 控制水库中藻类水华的相应原理。
