| Title: | Evaluating the effects of watershed size on SWAT calibration |
| Authors: | Wallace, C.W., D.C. Flanagan and B.A. Engel |
| Year: | 2018 |
| Journal: | Water |
| Volume (Issue): | 10(7) |
| Pages: | |
| Article ID: | 898 |
| DOI: | 10.3390/w10070898 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | regionalization of input parameters |
| Secondary Application Category: | calibration, sensitivity, and/or uncertainty analysis |
| Watershed Description: | 679 km^2 Cedar creek, a tributary of the St. Joseph River, and three Cedar Creek subwatersheds: 183 km^2 F34, 42 km^2 AXL and 20 km^2 ALG; all located in northeast Indiana, U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The Soil and Water Assessment Tool (SWAT) has been calibrated in many watersheds of
various sizes and physiographic features. However, it is still unclear whether SWAT calibration
parameters will produce satisfactory results if they are implemented in watersheds of different
sizes. Evaluating the transferability of SWAT calibration parameters between watersheds of different
sizes will provide insight into whether it is acceptable to calibrate SWAT in one watershed and
apply the optimized parameters in different size watersheds by assuming both watersheds have
similar physiographic properties. This study investigated the influence of watershed size on the
SWAT model calibration parameters transferability between four watersheds (CCW = 680 km2,
F34 = 183 km2, AXL = 42 km2, and ALG = 20 km2) located in Northeastern Indiana. The results show
that calibrating SWAT at one size and applying the optimized parameters at different watershed sizes
of similar physiographic features provided satisfactory simulation results. The size watershed at
which SWAT was calibrated had little effect on streamflow predictions. Soluble nitrogen loss estimates
were improved when calibration was performed at the larger CCW watershed while calibrating
SWAT at the smaller AXL and ALG watersheds produced improved statistical indicator values
(NSE, R2, and PBIAS) for soluble P and total P when applied to the larger CCW and F34 watersheds. |
| Language: | English |
| Keywords: | nutrients; optimization; runoff; simulation; Soil and Water Assessment Tool (SWAT);
SWAT-CUP; watershed management |