Understanding the hydrologic function of catchments and identifying catchment streamflow sensitivity to climate change

点击翻译按钮获取中文摘要

Climate change is expected to affect most aspects of streamflow. This will impact all sectors of water resource management such as water allocation and security, and flood/drought risk reduction. Without time-and cost-intensive data collection and modelling, it is difficult to predict how sensitive a catchment's streamflow is to changes in climatic attributes, such as rainfall. This uncertainty stems from limited capacity to assess what water storage compartments exist in a given catchment (especially underground), and how they contribute to streamflow, in times of rain or snowmelt abundance and shortage. Changes to the use of land within a catchment (e.g., agriculture) may also alter how a catchment stores water and generates streamflow-otherwise known as a Catchment's Hydrologic Function (CHF). To efficiently anticipate changes to a catchment's streamflow as a result of climate change, the field of hydrology requires a framework considering easily attainable information to characterize CHF, and how likely it is to alter with various degrees of land use change. Such a framework could lead to scientific strategies to manage water resources, inform land use decisions, and identify priority catchments for protection, under a changing climate. I have advanced the scientific knowledge on CHF and have developed new techniques and metrics to characterize it in different catchments around the world, with important scientific and management implications. However, previous research by myself and others in this context have been conducted only in certain types of environmental settings, leading to inability to develop a widely applicable framework on CHF. Over the next five years, my goal is to assess hydrologic function at a large number of catchments that cover a large spectrum of environmental settings across Canada. In so doing, I will: 1) identify the factors that most strongly determine CHF; 2) develop new scientific equations able to characterize CHF; 3) determine the impact of land-use change on CHF; and ultimately 4) develop the first process-based generalizable framework allowing for the characterization of hydrologic function in poorly-studied catchments across Canada. To achieve these goals, we will leverage our recent scientific and methodological advancements, including new function-based hydrologic model and Canada-wide environmental data linkage, supplemented with data-mining algorithms and laboratory experiments. Plans are in place to train 8 HQP (2 PhD, 3 MSc, 3 UG), using equitable and inclusive recruitment and mentoring practices. The resultant framework will be used to create maps on streamflow sensitivity to climate change and drought/flood vulnerable regions across Canada, and to develop environmentally low-impact strategies for land-use planning. Given the strong gradient of environmental setting considered in this research program, I expect that the findings can be extrapolated to other landscapes around the world.