Grant: Discovery Grants Program - Individual

Urban areas account for 0.25 % of the land area in Canada, they are home to over 74 % of the Canadian population, and these numbers are projected to increase with immigration and the movement of people from rural regions to cities. Urban areas have characteristics that fundamentally alter the water cycle, including the removal of vegetation, extensive impervious surface cover, stormwater and sanitary drainage infrastructure, and high population density. Precipitation is more likely to generate overland flow instead of infiltrating into the subsurface and sewer systems are designed to rapidly drain stormflow to streams or wastewater treatment plants. These changes result in a variety of impacts to natural drainage systems, including flashy storm hydrographs, the transport of non-point source pollutants to surface waters, and more frequent flooding. Over the past 50 years, research on the water cycle in urban areas has mainly focused on impacts of impervious surfaces on streamflow through the lens of infrastructure management and flood mitigation. However, questions remain regarding the role of unpaved areas on watershed hydrologic functioning, the importance of infrastructure-mediated flow pathways for streamflow generation, and whether dominant hydrological processes are consistent across cities. In Canada, the extent of interactions between built-up land and surface waters is not broadly documented. The long-term objective of my research program is to contribute new knowledge on the impacts of urbanization on the water cycle and water quality in a changing climate. The short-term objectives I will address over the next five years are to: (1) advance our understanding of the water sources and flow pathways that contribute to urban streamflow, (2) characterize the time scales of urban water transport, (3) compare the hydrological signatures of urban watersheds across Canada and the United States, and (4) map the spatial interaction between urban land use and rivers in Canada. The proposed research program will apply concepts and tools from the field of watershed hydrology, including local field studies, inter-city watershed comparisons, and national scale geospatial analyses to address these objectives. The proposed research will contribute to fundamental scientific advancements in the field of urban hydrology that support predictive hydrologic and water quality modelling. Applied outcomes of the research will include a framework for assessing the hydrologic functioning of unpaved urban areas that can be used as a tool for prioritizing green infrastructure, and the development of national urban water threat and data scarcity indices that can inform monitoring, management, and policy responses to urban impacts on freshwaters. The latter is particularly timely given the federal governments renewal and expansion of the Freshwater Action Plan and establishment of a new Canada Water Agency to address the changing reality of freshwater in Canada.