Water, sediment and nutrient connectivity in engineered Prairie landscapes

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Canadians believe that water is their most important natural resource and worry that current management systems are not adequate for environmental protection. This is especially true in Prairie regions where floods, droughts and diffuse agricultural pollution are the greatest environmental issues in terms of social and economic costs. Our ability to deal with excesses and shortages of quality water rests on our understanding of when and where runoff, sediments and nutrients are likely to leave our lands and reach streams, rivers and lakes. The concept of connectivity is meant to help quantify this likelikood but it has not been fully explored in highly impacted, agricultural Prairie landscapes. The proposed research program will contribute to filling that gap by addressing four questions: 1) Is connectivity controlled by one dominant flow process or many?, 2) What are the temporal and spatial thresholds of connectivity initiation and cessation?, 3) How to manage the enhancing or disruptive effect of stormwater-control structures on natural connectivity?, and 4) Which essential elements should be included in connectivity prediction frameworks? The research will be done at multiple study sites in Manitoba to ensure that a good variety of Prairie landscapes is considered. State-of-the-art hydrometric instruments and high-end water quality monitoring devices will be used to monitor water, sediment and nutrient movement. The field data will be synthesized across sites to examine the effects of physiography, spatial scale or stormwater-control structures such as tile and ditch networks, wetland drainage systems or farm dams, on connectivity. Field data will also be used to inform hydrological model development and parameterization. This research will improve our understanding of watershed dynamics in heavily modified landscapes and provide a unique opportunity to train new scientists in Prairie hydrology. Its outcomes will ultimately benefit Western Canadian communities by guiding the development of water management systems toward reduced flood risk and sediment and nutrient contamination.