SWAT Literature Database for Peer-Reviewed Journal Articles

Simulating landscape sediment transport capacity by using a modified SWAT model 
Bonumá, N.B., C.G. Rossi, J.G. Arnold, J.M. Reichert, J.P. Minella, P.M. Allen and M. Volk 
Journal:Journal of Environmental Quality 
Article ID: 
URL (non-DOI journals): 
Model:SWAT-landscape & SWAT 
Broad Application Category:hydrologic & pollutant 
Primary Application Category:sediment loss and transport 
Secondary Application Category:model comparison 
Watershed Description:
4.8 km^2 Arroio Lino located in the state of Rio Grande de Sul in southern Brazil 
Calibration Summary:
Validation Summary: 
General Comments:This paper is part of a JEQ special SWAT section. 
Abstract:Sediment delivery from hillslopes to rivers is spatially variable and may lead to long-term delays between initial erosion and related sediment yield at the watershed outlet. Consideration of spatial variability is important for developing sound strategies for water quality improvement and soil protection at the watershed scale. Hence, the Soil and Water Assessment Tool (SWAT) was modified and tested in this study to simulate the landscape transport capacity of sediment. The study area was the steeply sloped Arroio Lino watershed in southern Brazil. Observed sediment yield data at the watershed outlet were used to calibrate and validate a modified SWAT model. For the calibration period, the modified model performed better than the unaltered SWAT2009 version; the models achieved Nash–Sutcliffe efficiency (NSE) values of 0.7 and −0.1, respectively. Nash–Sutcliff efficiencies were less for the validation period, but the modified model’s NSE was higher than the unaltered model (−1.4 and −12.1, respectively). Despite the relatively low NSE values, the results of this first test are promising because the model modifi cations lowered the percent bias in sediment yield from 73 to 18%. Simulation results for the modified model indicated that approximately 60% of the mobilized soil is deposited along the landscape before it reaches the river channels. This research demonstrates the modified model’s ability to simulate sediment yield in watersheds with steep slopes. The results suggest that integration of the sediment deposition routine in SWAT increases accuracy in steeper areas while significantly improving its ability to predict the spatial distribution of sediment deposition areas. Further work is needed regarding (i) improved strategies for spatially distributed sediment transport measurements (for improving process knowledge and model evaluation) and (ii) extensive model tests in other well instrumented experimental watersheds with differing topographic configurations and land uses. 
Keywords:SWAT landscape, sediment transport capacity, sediment loss, Brazil