Abstract

Large multi-purpose reservoirs serve not only to generate hydropower but to supply water for agricultural irrigation, animal and human consumption and to provide flood control. One of the key factors affecting physical functioning and deteriorating aquatic ecosystems in reservoirs is climate change. For instance, increases in water temperature accelerate chemical reaction rates, decomposition rates and oxygen demand at the water-sediment interface. Earlier thermal stratification onset, and longer and more intense reservoir thermal stratification are all consequences of global warming. Such disruptions in thermal stratification have been associated with reductions in hypolimnion dissolved oxygen, increasing anoxia events and enhancing reservoir eutrophication. In this research paper, we implement the 2 D hydrodynamics and water quality model, CE-QUAL-W2, to investigate the effects of climate change and streamflow scenarios on the thermal structure of Lake Diefenbaker, a large, multipurpose reservoir, located in Saskatchewan, Canada. Model results indicate that meteorological variability will dictate a nonlinear increase in reservoir water temperature in the coming decades, where larger increases in water temperature will occur during summer and fall in the upper layers. Also, decreases in reservoir streamflows will reduce water temperature at intermediate layers during summer and fall. Our model can be used as a tool to mitigate and manage the effects of climate change on the reservoir water quality.

摘要

大型多功能水库不仅用于发电，还可以为农业灌溉，动物和人类消费提供水，并提供防洪服务。影响水库物理功能和恶化水生生态系统的关键因素之一是气候变化。例如，水温的升高加速了水-沉积物界面的化学反应速率，分解速率和氧气需求。较早的热分层开始以及更长，更强烈的储层热分层都是全球变暖的结果。热分层的这种破坏与降低次limlimion溶解氧，增加缺氧事件和增强储层富营养化有关。在本文中，我们实现了二维流体动力学和水质模型，CE-QUAL-W2，研究气候变化和水流情景对加拿大萨斯喀彻温省大型多功能水库迪芬贝克湖热结构的影响。模型结果表明，气象变化将决定未来几十年水库水温的非线性升高，夏季和秋季上层水温将出现较大的升高。同样，在夏季和秋季，水库水流的减少将降低中间层的水温。我们的模型可以用作减轻和管理气候变化对水库水质影响的工具。模型结果表明，气象变化将决定未来几十年水库水温的非线性升高，夏季和秋季上层水温将出现较大的升高。同样，在夏季和秋季，水库水流的减少将降低中间层的水温。我们的模型可以用作减轻和管理气候变化对水库水质影响的工具。模型结果表明，气象变化将决定未来几十年水库水温的非线性升高，夏季和秋季上层水温将出现较大的升高。同样，在夏季和秋季，水库水流的减少将降低中间层的水温。我们的模型可以用作减轻和管理气候变化对水库水质影响的工具。