SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Simulated impacts of climate change and agricultural land use change on surface water quality with and without adaptation management strategies 
Authors:Mehdi, B., B. Lehner, C. Gombault, A. Michaud, I. Beaudin, M.-F. Sottile and A. Blondlot 
Journal:Agriculture Ecosystems and Environment 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic & pollutant 
Primary Application Category:land use change and climate change 
Secondary Application Category:BMP assessment 
Watershed Description:629 km^2 Pike River located at the northern tip of Lake Champlain, straddles the Province of Québec (530 km^2) and the State of Vermont (99 km^2); see Fig. 1 in paper. Pike River is a subwatershed of the Missisquoi Bay, and was identified in 2002 by the Québec government as a priority watershed in need of integrated water resources management. The river is plagued with inputs of excessive nutrients from non-point source pollution stemming from agricultural and forest activities. In particular, the total = phosphorus (TP) in the Bay exceeds the Québec guidelines on surface water quality of 0.02 mg/L (MDDEFP, 2002), as well as the TP limit set for the Missisquoi Bay of 0.025 mg/L (LCBP, 2013). Excess P contributes to regular cyanobacteria algae blooms (Blais, 2002; Simoneau, 2007) that have appeared almost annually in the Bay since 2000. 
Calibration Summary:Overall, the calibration and validation of SWAT were deemed “satisfactory” according to the objective criteria listed in Moriasi et al. (2007) and fell within the ranges of other SWAT studies listed in Gassman et al. (2007) and Douglas-Mankin et al. (2010). We confirm the common tendency of SWAT to perform less well at the daily time step as compared to monthly or yearly steps (Gassman et al., 2007). Therefore, we used monthly results of SWAT in this study, so we focus on the performance evaluation at this time step. The modelled transport of nutrient loads is highly dependent on properly simulated streamflow and snowmelt processes; our SWAT simulations for streamflow had Nash-Sutcliffe Efficiency (NSE) values of 0.75–0.83 (Table S4a). The simulation of nutrients was satisfactory during the calibration stage; except the sediment values were under- estimated compared to observed values. The validation of nutrients, however, had a rather poor model performance; although this is not unusual (Gupta et al., 2009). The discrep- ancies in our case were attributed to the short time periods of available data as well as the weaker simulation of streamflow at the outlets where the nutrients were calibrated (outlets 4 and 6). The performance criteria for sediments and for TP were somewhat better for the independent evaluation (1979–2007) at outlet 18. 
Validation Summary: 
General Comments: 
Keywords:SWAT Nitrate Phosphorus Streamflow Scenarios Management practices