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，除了公开水域洪水，有必要考虑冰塞洪水(IJF)，因为几乎所有的河流系统在一年中有几个月都受到冰的影响。IJF每年给加拿大人造成数亿美元的损失。最近在阿肯色州麦克默里堡的阿萨巴斯卡河(2020年春季)和博斯地区的乔迪耶尔河(2017年春季和2019年春季)举行的国际嘉年华证明，尽管近年来技术取得了所有进步，但我们成功预测和准备这些活动的能力仍然有限。在这方面，开发可操作的IJF预警系统(IJF-EWS)是加拿大政府和市政当局的当务之急，以便能够制定可持续的洪灾缓解措施。冰塞是非常复杂的，因此，如果开发一个基于物理的水文-河流冰耦合模型，就可以成功地开发出能够预测冰塞的时间、位置和大小的IJF-EWS。近年来，这类模型的研究取得了一定的进展，但由于解体过程中现场数据的不精确性和稀疏性，阻碍了这类模型的改进和进一步发展。为了满足这一需求，我提出了一个雄心勃勃的研究计划，作为一个长期目标，建立一个可操作的、可转移的和可适应的IJF-EWS。拟议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)，并使这些方法适用于冰盖和解冻期间的连续测量(时间方面)。(2)开发新的方法(或调整现有方法)，以连续测量较长范围内的河冰特征(空间方面)。(3)开发和验证水文-河流冰耦合模型，以准确模拟解体过程(建模方面)。三名博士生和三名硕士研究生将致力于上述目标。这些学生将接受关于使用各种复杂的现场仪器、先进的数据处理方法和数值建模的培训。将在多个冬季对两条河流进行实地测量。将在Delft-FEWS平台上使用HOPHLA(用于水文学)和River1D(用于河冰过程)开发水文-河冰耦合模型。耦合模型将使用多年的现场数据进行验证。开发的IJF-EWS将产生重大影响，提供预报信息，指导制定可持续的洪灾缓解措施。

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.