Weber M, Rinke K, Hipsey M R, Boehrer B
Department of Lake Research, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany.
Department of Lake Research, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany.
J Environ Manage. 2017 Jul 15;197:96-105. doi: 10.1016/j.jenvman.2017.03.020. Epub 2017 Mar 21.
Sustainable management of drinking water reservoirs requires balancing the demands of water supply whilst minimizing environmental impact. This study numerically simulates the effect of an improved withdrawal scheme designed to alleviate the temperature pollution downstream of a reservoir. The aim was to identify an optimal withdrawal strategy such that water of a desirable discharge temperature can be supplied downstream without leading to unacceptably low oxygen concentrations within the reservoir. First, we calibrated a one-dimensional numerical model for hydrodynamics and oxygen dynamics (GLM-AED2), verifying that the model reproduced water temperatures and hypolimnetic dissolved oxygen concentrations accurately over a 5 year period. Second, the model was extended to include an adaptive withdrawal functionality, allowing for a prescribed withdrawal temperature to be found, with the potential constraint of hypolimnetic oxygen concentration. Scenario simulations on epi-/metalimnetic withdrawal demonstrate that the model is able to autonomously determine the best withdrawal height depending on the thermal structure and the hypolimnetic oxygen concentration thereby optimizing the ability to supply a desirable discharge temperature to the downstream river during summer. This new withdrawal strategy also increased the hypolimnetic raw water volume to be used for drinking water supply, but reduced the dissolved oxygen concentrations in the deep and cold water layers (hypolimnion). Implications of the results for reservoir management are discussed and the numerical model is provided for operators as a simple and efficient tool for optimizing the withdrawal strategy within different reservoir contexts.
饮用水水库的可持续管理需要在满足供水需求的同时，将环境影响降至最低。本研究通过数值模拟改进后的取水方案对水库下游温度污染的缓解效果。目的是确定一种最优取水策略，以便能向下游供应具有理想排放温度的水，同时不会导致水库内的氧浓度低至不可接受的水平。首先，我们校准了一个用于水动力和氧动力学的一维数值模型（GLM - AED2），验证该模型在5年时间内能够准确再现水温及温跃层下溶解氧浓度。其次，该模型进行了扩展，纳入了自适应取水功能，可在考虑温跃层氧浓度潜在限制的情况下，找到规定的取水温度。对上/温跃层取水的情景模拟表明，该模型能够根据热结构和温跃层氧浓度自主确定最佳取水高度，从而优化夏季向下游河流供应理想排放温度水的能力。这种新的取水策略还增加了用于饮用水供应的温跃层原水量，但降低了深层冷水层（温跃层）中的溶解氧浓度。文中讨论了研究结果对水库管理的影响，并为运营者提供了该数值模型，作为在不同水库环境下优化取水策略的简单有效工具。
