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

预计气候变化将影响河流的大多数方面。这将影响水资源管理的所有部门，如水资源分配和安全，以及减少洪水/干旱风险。如果没有时间和成本密集的数据收集和建模，就很难预测集水区的水流对气候属性（如降雨）的变化有多敏感。这种不确定性源于有限的能力来评估在给定的集水区（特别是地下）存在哪些储水隔间，以及它们如何在雨水或融雪丰沛和短缺的时候对水流做出贡献。集水区土地用途的改变（例如农业）也可能改变集水区储水和产生水流的方式，即集水区的水文功能（CHF）。为了有效地预测气候变化对集水区流量的影响，水文学领域需要一个框架，考虑到容易获得的信息来表征CHF，以及它随着不同程度的土地利用变化而变化的可能性。这样一个框架可能导致在气候变化下管理水资源的科学战略，为土地使用决策提供信息，并确定优先保护的集水区。我提高了关于CHF的科学知识，并开发了新的技术和指标来表征世界各地不同流域的CHF，具有重要的科学和管理意义。然而，我和其他人之前在这方面的研究仅在某些类型的环境设置中进行，导致无法开发出广泛适用的CHF框架。在接下来的五年里，我的目标是评估覆盖加拿大大量环境设置的大量集水区的水文功能。在此过程中，我将：1)确定最强烈地决定CHF的因素；2)建立表征CHF的新的科学方程；3)确定土地利用变化对CHF的影响；并最终开发出第一个基于过程的可推广框架，允许在加拿大研究较少的流域中表征水文功能。为了实现这些目标，我们将利用我们最近的科学和方法上的进步，包括新的基于功能的水文模型和加拿大范围的环境数据链接，辅以数据挖掘算法和实验室实验。通过公平和包容的招聘和指导实践，计划培训8名HQP（2名博士，3名硕士，3名本科）。由此产生的框架将用于绘制加拿大各地对气候变化和干旱/洪水脆弱地区的流量敏感性地图，并为土地使用规划制定对环境影响较小的战略。考虑到本研究项目中考虑的环境设置的强梯度，我希望这些发现可以外推到世界各地的其他景观。

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.