Prediction of Dynamic Ice Processes in Complex River Systems

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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.