SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Assessment of optional sediment transport functions via the complex watershed simulation model SWAT 
Authors:Yen, H., S. Lu, Q. Feng, R. Wang, J. Gao, D.M. Brady, A. Sharifi, J. Ahn, S.T. Chen, J. Jeong, M. J. White and J.G. Arnold 
Article ID:76 
URL (non-DOI journals): 
Broad Application Category:pollutant only 
Primary Application Category:sediment loss and transport 
Secondary Application Category:in-stream processes 
Watershed Description:1,692 km^2 Arroyo Colorado River, a tributary of the Rio Grande River located in far southern Texas, U.S. 
Calibration Summary: 
Validation Summary: 
General Comments: 
Abstract:The Soil and Water Assessment Tool 2012 (SWAT2012) offers four sediment routing methods as optional alternatives to the default simplified Bagnold method. Previous studies compared only one of these alternative sediment routing methods with the default method. The proposed study evaluated the impacts of all four alternative sediment transport methods on sediment predictions: the modified Bagnold equation, the Kodoatie equation, the Molinas and Wu equation, and the Yang equation. The Arroyo Colorado Watershed, Texas, USA, was first calibrated for daily flow. The sediment parameters were then calibrated to monthly sediment loads, using each of the four sediment routing equations. An automatic calibration tool—Integrated Parameter Estimation and Uncertainty Analysis Tool (IPEAT)—was used to fit model parameters. The four sediment routing equations yielded substantially different sediment sources and sinks. The Yang equation performed best, followed by Kodoatie, Bagnold, and Molinas and Wu equations, according to greater model goodness-of-fit (represented by higher Nash–Sutcliffe Efficiency coefficient and percent bias closer to 0) as well as lower model uncertainty (represented by inclusion of observed data within 95% confidence interval). Since the default method (Bagnold) does not guarantee the best results, modelers should carefully evaluate the selection of alternative methods before conducting relevant studies or engineering projects. 
Keywords:sediment transport; model calibration; SWAT; uncertainty analysis; IPEAT