| 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 |
| Year: | 2017 |
| Journal: | Water |
| Volume (Issue): | 9(2) |
| Pages: | |
| Article ID: | 76 |
| DOI: | 10.3390/w9020076 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | pollutant only |
| Primary Application Category: | sediment loss and transport |
| Secondary Application Category: | in-stream and/or channel 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. |
| Language: | English |
| Keywords: | sediment transport; model calibration; SWAT; uncertainty analysis; IPEAT |