Towards Developing a Physically Based Ice Jam Flood Early Warning System

河流洪水是最常见的自然灾害。在加拿大，除了开放水域的洪水，还必须考虑冰塞洪水（IJF），因为几乎所有的河流系统一年中都有几个月受到冰的影响。IJFs每年花费加拿大人数亿美元。最近在AB麦克默里堡的阿萨巴斯卡河（2020年春季）和QC Beauce地区的chaudi<e:1>河（2017年春季和2019年春季）上进行的ijf证明，尽管近年来技术进步，但我们成功预测和准备这些事件的能力仍然有限。在这方面，开发一个可操作的洪水预警系统（IJF- ews）是加拿大政府和市政当局的紧急优先事项，以便能够制定可持续的洪水缓解措施。冰阻塞是非常复杂的，因此，如果开发出基于物理的水文-河流冰耦合模型，就可以成功地开发出能够预测冰阻塞时间、位置和大小的IJF-EWS。近年来，这类模型的开发取得了一些进展，但压裂过程中现场数据的不准确性和稀疏性阻碍了这些模型的改进和进一步发展。为了满足这一需求，我提出了一项雄心勃勃的研究计划，其长期目标是建立一个可操作、可转移和适应性强的IJF-EWS。本研究计划的短期目标是：(1)评估冰影响流量测量方法对不同河流大小和类型的适用性（区域方面），并使这些方法适应冰盖和破碎期的连续测量（时间方面）。(2)开发新方法（或改进现有方法），以实现更长河段（空间方面）河冰特征的连续测量。(3)开发并验证了一个水文-河流冰耦合模型，以准确模拟破碎过程（建模方面）。三名博士和三名硕士学生将致力于上述目标。学生将接受有关使用各种复杂现场仪器、先进数据处理方法和数值模拟的培训。实地测量将在两条河流上进行多个冬季。将在Delft-FEWS平台上使用HOOPLA（用于水文）和River1D（用于河流冰过程）开发一个耦合的水文-河流冰模型。该耦合模型将使用多年的现场数据进行验证。发展的IJF-EWS将通过提供预报信息来指导可持续防洪措施的制定而产生重大影响。

River floods are the most common natural disaster. In Canada, besides open water floods, it is necessary to consider ice jam floods (IJF) since almost all river systems are ice-affected for several months of the year. IJFs are costing Canadians hundreds of millions of dollars each year. Recent IJFs on the Athabasca River at Fort McMurray, AB (spring 2020), and on the Chaudière River in the Beauce region, QC (spring 2017 and 2019) are evidences that despite all the technological advancements in recent years, still our abilities to successfully predict and prepare for these events are limited. In this context, developing an operational IJF Early Warning Systems (IJF-EWS), is an urgent priority for Canadian governments and municipalities so that sustainable flood mitigation measures can be developed. Ice jams are very complex, and therefore, the development of an IJF-EWS that can predict the timing, location and magnitude of ice jams can be successfully achieved if a physically based coupled hydrological-river ice model is developed. Progress has been made in recent years developing this type of models, but the inaccuracy and sparsity of field data during break-up are preventing the improvement and further developments of these models. To address this need, I am proposing an ambitious research program having as a long-term goal to build an operational, transferable and adaptable IJF-EWS. The short-term objectives of the proposed research program are to:   (1) Assess the applicability of ice-affected discharge measurements methods to different river sizes and types (regional aspect) and to adapt these methods for continuous measurements during the ice cover and break-up periods (temporal aspect).   (2) Develop new methods (or adapt existing ones) for continuous measurements of river ice characteristics over longer reaches (spatial aspect).   (3) Develop and validate a coupled hydrological-river ice model to accurately simulate break-up processes (modeling aspect). Three PhD and three MSc students will work on the above objectives. The students will receive training on the use of a wide variety of sophisticated field instrumentation, advanced data processing methods and numerical modelling. Field measurements will be conducted on two rivers over multiple winters. A coupled hydrological-river ice model will be developed in the Delft-FEWS platform using HOOPLA (for hydrology) and River1D (for river ice processes). The coupled model will be validated using multi-year field data. The developed IJF-EWS will have a great impact by providing forecasting information to guide the development of sustainable flood mitigation measures.