Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
School of Civil and Environmental Engineering, Ningbo University, Zhejiang, 315211, China.
Water Res. 2022 Sep 1;223:119012. doi: 10.1016/j.watres.2022.119012. Epub 2022 Aug 22.
Total dissolved gas supersaturation (TDG) is a common issue in hydropower facilities as a result of water conveyance structures that increase the amount of air entrainment from the atmosphere and dissolved into the water. Water with TDG supersaturation can negatively impact fish, aquatic invertebrates and their habitats. This study comprehensively reviewed the physical mechanisms of TDG generation and predictive TDG generation models at various facility types. To establish TDG mitigation strategies, it is essential to develop predictive tools for TDG generation that consider both facility geometry as well as the hydrology of the downstream environment. Applications of TDG prediction at different discharge modes included plunging flows, trajectory jets, plunging jets, free-falling jets, and submerged jets were discussed. TDG transport models in downstream rivers involving mixing and dissipation were introduced, which can be integrated with TDG generation models into a platform to describe TDG distribution in river systems. Subsequently, risk ranking procedures for assessing the degree of TDG risk on fish were provided. Potential measures for mitigating TDG supersaturation were reviewed and included engineering, operational, and technical solutions. Outcomes from this review considered a diverse suite of studies on TDG issues in regulated rivers and allowed for recommendations to reduce uncertainties and improve environmental performance at facilities where TDG risks occur.
总溶解气体过饱和（TDG）是水力发电设施中的一个常见问题，这是由于输水结构增加了从大气中夹带并溶解在水中的空气量。过饱和的 TDG 水会对鱼类、水生无脊椎动物及其栖息地产生负面影响。本研究全面回顾了各种设施类型中 TDG 生成的物理机制和预测 TDG 生成模型。为了制定 TDG 缓解策略，开发考虑设施几何形状和下游环境水文学的 TDG 生成预测工具至关重要。讨论了不同排放模式下 TDG 预测的应用，包括跌落流、轨迹射流、跌落射流、自由下落射流和淹没射流。介绍了下游河流中涉及混合和耗散的 TDG 输运模型，可将其与 TDG 生成模型集成到一个平台中，以描述河流系统中的 TDG 分布。随后，提供了评估鱼类 TDG 风险程度的风险排名程序。审查了减轻 TDG 过饱和的潜在措施，包括工程、运营和技术解决方案。本综述的结果考虑了一系列关于受管制河流中 TDG 问题的研究，为减少不确定性和提高发生 TDG 风险的设施的环境性能提供了建议。
