| Title: | Slope effects on SWAT modeling in a mountainous basin |
| Authors: | Yacoub, C. and A.P. Foguet |
| Year: | 2013 |
| Journal: | Journal of Hydrologic Engineering |
| Volume (Issue): | 18(12) |
| Pages: | 1663–1673 |
| Article ID: | |
| DOI: | 10.1061/(ASCE)HE.1943-5584.0000756 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | DEM data resolution effects |
| Secondary Application Category: | calibration, sensitivity, and/or uncertainty analysis |
| Watershed Description: | 4,372.5 km^2 Jequotopeque River in northern Peru |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The soil and water assessment tool (SWAT) is a distributed basin model that includes
the option of defining spatial discretization in terms of terrain slope. Influence of terrain
slope in runoff results from mountain basins is a determining factor in its simulation
results; however, its use as a criterion for basin discretization and for the parameter
calibration has not been analyzed yet. In this study, this influence is analyzed for
calibrations using two different cases. Ten discretization cases were carried out to
evaluate the relative importance of slope discretization as compared to other
discretization criteria. Data from 1999 to 2005 were used for model calibration, and
those from 2006 to 2009, for model validation. Parameter identification and
specification were performed with the the combined latin hypercube and one-factor-ata-
time (LH-OAT) and the shuffled complex evolution-uncertainty analysis methods
(SCE-UA), respectively, both of which are included in ArcSWAT2005. All cases
resulted in very good statistical values, with the Nash-Sutcliffe efficiency coefficient of
0.82-0.85, a percent bias of 2-10%, and the observations standard deviation ratio of
0.4-0.3. More realistic calibrated parameters were found when terrain slope variation
was not included in the spatial discretization criteria. The inclusion of slope did not
significantly improve simulations results when a good set of parameters was used but it
did enhance the calibration when a reduced number of sub-basins was used. |
| Language: | English |
| Keywords: | Spatial discretization, hydrological parameters, sensitivity analysis, autocalibration, uncertainty |