Prediction of Dynamic Ice Processes in Complex River Systems

复杂河流系统动态冰过程的预测

• 批准号: RGPIN-2021-02887
• 负责人: She, Yuntong
• 金额: $ 3.13万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742263
• 关键词: Prediction; Dynamic; Ice; Processes; Complex

Ice processes during river freeze-up and breakup can be very dynamic, greatly affecting the hydrological, morphological, and ecological processes in river systems. One such process is the evolution of anchor ice, which forms on the riverbeds when turbulent water cools to just below 0°C. It is often ephemeral and can adversely impact fish habitat and water resources infrastructure (e.g. hydropower facilities). Another dynamic process is the formation of ice jams. Ice jams are thick accumulations of broken ice that constrict river flow and thus are often associated with high flood risks. Multi-channel systems such as river deltas and confluences are particularly prone to ice jams. For example, the recent Fort McMurray flood was due to an ice jam formed at the Athabasca-Clearwater River confluence. The complex ways that ice interacts with the flow and river morphology, makes observing and forecasting these dynamic ice events very difficult. There are still many unanswered questions regarding the processes of anchor ice evolution and ice jam forming in multi-channel systems. There is a great need for improving our predictive ability of these dynamic ice events. Climate change makes this even more urgent as the timing, frequency and severity of these ice events are all expected to change. Physics-based numerical models provide powerful forecasting tools, and when used with good laboratory and field data, can also provide great insights into these complex processes. Therefore, I am proposing a research program to address the knowledge gaps related to ice jam and anchor ice processes by developing physics-based modelling methods, conducting laboratory experiments, and/or utilizing field data. The long-term goal is to significantly improve our understanding of, and ability to predict, dynamic ice processes in complex river environments. The short-term objectives are to:     (1)Investigate the dynamic processes occurring in river deltas during ice jamming.     (2)Develop an operational model for predicting flood risk of ice jam prone multi-channel systems.     (3)Determine the meteo-hydrological factors controlling anchor ice formation and release mechanisms.     (4)Assess and improve anchor ice algorithms of existing river ice models. The proposed research program will lead to improved understanding and predictive ability of ice jam and anchor ice events. It will greatly benefit the development and operation of water resources infrastructure and have significant economic value by reducing the adverse impacts of these ice events. It will immediately benefit public safety by providing reliable flood forecasting tool and reducing flood damage. The research will produce an enhanced, physics-based river ice numerical model, which will provide an essential tool to assess the impacts of human activities or climate change on ice regime of northern rivers. This program will also provide high-quality training to a team of graduate and undergraduate students.

河流封冻和断裂过程中的冰过程是非常动态的，对河流系统的水文、形态和生态过程有很大的影响。其中一个过程是锚冰的演变，当湍流的水冷却到略低于0°C时，在河床上形成。它往往是短暂的，可能对鱼类生境和水资源基础设施（如水电设施）产生不利影响。另一个动态过程是冰塞的形成。冰塞是碎冰的厚堆积物，它限制了河流的流量，因此通常与高洪水风险有关。多通道系统，如河流三角洲和汇合处，特别容易发生冰塞。例如，最近的麦克默里堡洪水是由于阿萨巴斯卡-清水河汇合处形成的冰塞。冰与水流和河流形态相互作用的复杂方式使得观测和预测这些动态冰事件非常困难。关于多渠道系统中锚冰演变和冰塞形成的过程，目前仍有许多问题没有得到解答。有一个很大的需要，以提高我们的预测能力，这些动态冰事件。气候变化使这一问题变得更加紧迫，因为预计这些冰事件的时间、频率和严重程度都将发生变化。基于物理的数值模型提供了强大的预测工具，当与良好的实验室和现场数据一起使用时，还可以为这些复杂的过程提供很好的见解。因此，我提出了一个研究计划，以解决相关的知识差距冰塞和锚冰过程开发基于物理的建模方法，进行实验室实验，和/或利用现场数据。长期目标是显著提高我们对复杂河流环境中动态冰过程的理解和预测能力。短期目标是： （1）研究冰堵期间三角洲的动力过程。 （2）开发了一个预测易冰塞多渠道系统洪水风险的业务模型。 （3）确定控制锚冰形成和释放机制的气象水文因素。 （4）对现有河冰模型的锚冰算法进行了评价和改进。建议的研究计划将导致提高理解和预测能力的冰塞和锚冰事件。这将大大有利于水资源基础设施的开发和运营，并通过减少这些冰事件的不利影响具有显着的经济价值。它将通过提供可靠的洪水预报工具和减少洪水损失，立即有利于公共安全。该研究将产生一个增强的，基于物理学的河冰数值模型，这将提供一个重要的工具，以评估人类活动或气候变化对北方河流冰情的影响。该计划还将为研究生和本科生团队提供高质量的培训。