Reference number : GC-2017-Q1-02900, amendment number : , agreement type : G, recipient legal name : Wellen, Christopher (University of Windsor), recipient country : CA, recipient province : nan, recipient city : Ontario, recipient postal code : nan, program name english : Discovery Grants Program - Individual, program name french : Programme de subventions à la découverte - individuelles, program purpose english : Agricultural intensification is necessary to meet the food demands of the growing world population and economy. However, food production can cause water quality impairments through loss of nutrients, including phosphorus. Indeed, excessive algal growth caused by excessive phosphorus inputs are the primary water quality impairment in freshwater ecosystems around the world and around Canada. Watershed models are often used to understand the factors that control the loss of phosphorus in agroecosystems and to predict how long it will take for reduced nutrient inputs to translate into reduced nutrient outputs and water quality benefits. However, watershed models have been criticized for their simplistic representation of hydrology, which may strongly affect the lag time required to realize nutrient outputs. The ability of catchment water quality models to represent processes in cold regions has also been questioned. The focus of the proposed work is to understand how agricultural headwaters function to transport water and phosphorus in cold regions. Using watershed models designed specifically for cold regions as well as environmental tracers, I will quantify the lag times to realize improvements in stream water quality at the headwaters after changes to phosphorus inputs are made. These estimates are essential to crafting policy that can protect the environment while allowing the agricultural sector of the economy to grow, while integrating environmental tracers will ensure that the model estimates of lag times are robust., program purpose french : Agricultural intensification is necessary to meet the food demands of the growing world population and economy. However, food production can cause water quality impairments through loss of nutrients, including phosphorus. Indeed, excessive algal growth caused by excessive phosphorus inputs are the primary water quality impairment in freshwater ecosystems around the world and around Canada. Watershed models are often used to understand the factors that control the loss of phosphorus in agroecosystems and to predict how long it will take for reduced nutrient inputs to translate into reduced nutrient outputs and water quality benefits. However, watershed models have been criticized for their simplistic representation of hydrology, which may strongly affect the lag time required to realize nutrient outputs. The ability of catchment water quality models to represent processes in cold regions has also been questioned. The focus of the proposed work is to understand how agricultural headwaters function to transport water and phosphorus in cold regions. Using watershed models designed specifically for cold regions as well as environmental tracers, I will quantify the lag times to realize improvements in stream water quality at the headwaters after changes to phosphorus inputs are made. These estimates are essential to crafting policy that can protect the environment while allowing the agricultural sector of the economy to grow, while integrating environmental tracers will ensure that the model estimates of lag times are robust., agreement title english : Towards an integrated hydro-chemical understanding of phosphorus transport from headwater agro-ecosystems, agreement title french : Towards an integrated hydro-chemical understanding of phosphorus transport from headwater agro-ecosystems, agreement number : RGPIN, agreement value : 135000.0, agreement start date : 2017-05-10, agreement end date : nan, description english : nan, description french : nan, expected results english : nan, expected results french : nan, additional information english : Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023), additional information french : Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023), owner organization : nserc-crsng, owner organization title : Natural Sciences and Engineering Research Council of Canada | Conseil de recherches en sciences naturelles et en génie du Canada