Development of a New Framework for Watershed Systems Analysis and Modelling under Climate and Environmental Changes

由于气候（如气候变暖）和环境（如土地和水管理）的变化，加拿大河流流域的水流状况正在发生变化。这些变化体现在洪水和干旱等更为极端的事件上。因此，对未来可用水量的可靠评估需要了解这些持续变化下流域系统的动态并建立模型。然而，即使是最严格的水文模型也提供不了什么帮助，因为它们严重依赖于“平稳性”的假设，这表明自然系统随着时间的推移在一个恒定的变化包络内波动。因此，对加拿大和其他地区未来可用水资源变化的预测充满了不确定性。

Flow regime in Canadian river basins is changing as a result of changes in climate (e.g., climate warming) and the environment (e.g, land and water management). These changes are manifested by more extreme events such as floods and droughts. Reliable assessment of future water availability, therefore, requires understanding and modelling the dynamics of watershed systems under these sustained changes. However, even the most rigorous hydrologic models provide little help, as they heavily rely on the assumption of ‘stationarity’, which indicates that natural systems fluctuate within a constant envelope of variability through time. As a result, prediction of future changes in water availability in Canada and elsewhere is fraught with uncertainty. The long-term goal of my research is to develop a new framework for watershed systems analysis and modelling that accounts for non-stationarity. The focus of my work is on understanding how different natural and man-made components of a system function and interact at different time and space scales. The proposed work is conducted within two inter-related work packages that bring together state-of-the-art hydrologic sciences and system-theoretic approaches to enable substantive progress in understanding, modelling, and prediction of changing watershed systems in Canada. The intended outcomes have a key value to Canadian economy and wellbeing by reducing uncertainty in projections of future water availability, leading to improved management of water resources and adaption to the impact of natural hazards such as floods and droughts.