SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Development and testing of an in-stream phosphorus cycling model for the Soil and Water Assessment Tool 
Authors:White, M.J., D.E. Storm, A. Mittelstet, P.R. Busteed, B.E. Haggard and C. Rossi 
Journal:Journal of Environmental Quality 
Volume (Issue):43(1) 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic and pollutant 
Primary Application Category:in-stream and/or channel processes 
Secondary Application Category:phosphorus cycling/loss and transport 
Watershed Description:4,600 km^2 Illinois River, which drains parts of northwest Arkansas and northeast Oklahoma, U.S. 
Calibration Summary: 
Validation Summary: 
General Comments:This article is part of a JEQ special SWAT section. 
Abstract:The Soil and Water Assessment Tool (SWAT) is widely used to predict the fate and transport of phosphorus (P) from the landscape through streams and rivers. The current in-stream P submodel may not be suitable for many stream systems, particularly those dominated by attached algae and impacted by point sources. In this research, we developed an alternative submodel based on the Equilibrium P Concentration (EPC) concept coupled with a particulate scour and deposition model. This submodel was integrated with the SWAT model and applied to the Illinois River Watershed in Oklahoma, a basin influenced by waste water treatment plant (WWTP) discharges and extensive poultry litter application. The model was calibrated and validated using measured data. Highly variable in-stream P concentrations and EPC values were predicted both spatially and temporally. The model also predicted the gradual storage of P in streambed sediments and the resuspension of this P during periodic high flow flushing events. WWTPs were predicted to have a profound effect on P dynamics in the Illinois River due to their constant discharge even under base flow conditions. A better understanding of P dynamics in stream systems using the revised submodel may lead to the development of more effective mitigation strategies to control the impact of P from both point and nonpoint sources.