Monitoring and modelling water quality under ice affected conditions in rivers

在加拿大和其他寒冷地区，河冰可以持续半年或更长时间。河冰的存在极大地影响了河流中化学物质的水动力学、运输和命运，对河流生态系统和河流功能产生了重大影响。在受冰影响的阶段，了解和预测很少被探索的水质与开放水域阶段同样重要。然而，目前的知识有限，现有的模型对稳定的冰盖阶段的能力有限，无法处理更复杂的动态阶段（冻结和破裂）。气候变化和人为活动的增加使这一问题进一步复杂化，需要对已经敏感的冬季河流水质进行影响评估。本研究将采用野外监测、室内实验和数值模拟等方法，在以下几个方面获得新的认识：1)提高对冬季不同河冰阶段和形态对河流水质影响的认识；2)一个新颖、全面的模型/工具，能够同时模拟水质、河冰和水动力，使它们之间的反馈得到考虑；3)为气候变化和人类活动背景下的寒区河流水质保护和改善提供科学、实用的政策指导。这项研究将在加拿大和国外产生重要的社会影响。从科学上讲，它将把目前对河流水质的了解从开放水域扩展到冰期。实际上，它将为监管者、决策者、研究人员、咨询公司和工业用户提供一个重要的工具/模型和指南，以改善水质、冰和流量（洪水）方面的河流管理。这项研究还将培养下一代高素质人才（HQP）。

In Canada and other cold regions, river ice could last for half a year or more. The presence of river ice substantially impacts hydrodynamics and transport and fate of chemicals in rivers, resulting in great implications to river ecosystems and river functions. Understanding and predicting the much less explored water quality during ice-affected stages is equally important as the open-water stage. However, current knowledge is limited, and current models have limited capability for stable ice-cover stage and cannot handle the more complex, dynamic stages (freeze-up and break-up). Climate change and increased anthropogenic activities further complicate this issue, and their impacts need to be assessed for the already sensitive winter river water quality. This research will use field monitoring, lab experiments and numerical simulation to generate new knowledge in the following areas: 1) an improved understanding on the impacts of various river ice stages and forms to river water quality in winter; 2) a novel, comprehensive model/tool that is capable of simultaneously modelling water quality, river ice and hydrodynamics, allowing the feedbacks amongst them to be accounted for; and 3) a science-based, practical guideline for policy makers in protecting and improving water quality in cold region rivers in the context of climate change and anthropogenic activities. This research will have important societal impacts within Canada and abroad. Scientifically, it will expand the current knowledge of river water quality from open-water to the ice seasons. Practically, it will provide an important tool/model and guideline for regulators, policy makers, researchers, consulting firms and industrial users to improve river management in terms of water quality, ice and flow (flooding). This research will also train highly qualified personnel (HQP) of the next generation.