SWAT Literature Database for Peer-Reviewed Journal Articles

Title:SWAT modeling of non-point source pollution in depression-dominated basins under varying hydroclimatic conditions 
Authors:Nasab, M.T., K. Grimm, M.H. Bazrkar, L. Zeng, A. Shabani, X. Zhang and X. Chu 
Journal:International Journal of Environmental Research and Public Health 
Volume (Issue):15(11) 
Article ID:2492 
URL (non-DOI journals): 
Broad Application Category:hydrologic and pollutant 
Primary Application Category:depressional (pothole, wetland or pond) effects and/or processes 
Secondary Application Category:nitrogen cycling/loss and transport 
Watershed Description:103,600 km^2 portion of the Red River of the North, that drains parts of northeast North Dakota, northwest Minnesota and northeast South Dakota in the north central U.S. 
Calibration Summary: 
Validation Summary: 
General Comments:Pothole depressional areas were represented with wetlands in this study. 
Abstract:Non-point source (NPS) pollution from agricultural lands is the leading cause of various water quality problems across the United States. Particularly, surface depressions often alter the releasing patterns of NPS pollutants into the environment. However, most commonly-used hydrologic models may not be applicable to such depression-dominated regions. The objective of this study is to improve water quantity/quality modeling and its calibration for depression-dominated basins under wet and dry hydroclimatic conditions. Specifically, the Soil and Water Assessment Tool (SWAT) was applied for hydrologic and water quality modeling in the Red River of the North Basin (RRB). Surface depressions across the RRB were incorporated into the model by employing a surface delineation method and the impacts of depressions were evaluated for two modeling scenarios, MS1 (basic scenario) and MS2 (depression-oriented scenario). Moreover, a traditional calibration scheme (CS1) was compared to a wet-dry calibration scheme (CS2) that accounted for the effects of hydroclimatic variations on hydrologic and water quality modeling. Results indicated that the surface runoff simulation and the associated water quality modeling were improved when topographic characteristics of depressions were incorporated into the model (MS2). The Nash–Sutcliffe efficiency (NSE) coefficient indicated an average increase of 30.4% and 19.6% from CS1 to CS2 for the calibration and validation periods, respectively. Additionally, the CS2 provided acceptable simulations of water quality, with the NSE values of 0.50 and 0.74 for calibration and validation periods, respectively. These results highlight the enhanced capability of the proposed approach for simulating water quantity and quality for depression-dominated basins under the influence of varying hydroclimatic conditions. 
Keywords:SWAT; hydrologic modeling; water quality modeling; depressions; watershed