| Title: | Testing the SWAT model with gridded weather data of different spatial resolutions |
| Authors: | Grusson, Y., F. Anctil, S. Sauvage and J.M Sánchez Pérez |
| Year: | 2017 |
| Journal: | Water |
| Volume (Issue): | 9(1) |
| Pages: | |
| Article ID: | 59 |
| DOI: | 10.3390/w9010054 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | climate data effects |
| Secondary Application Category: | hydrologic assessment |
| Watershed Description: | 55,000 km^2 Garonne River,located in southwest France. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | This study explored the influence of the spatial resolution of a gridded weather dataset
when inputted in the soil and water assessment tool (SWAT) over the Garonne River watershed.
Several datasets are compared: ground-based weather stations, the 8-km SAFRAN product
(Système d’Analyse Fournissant des Renseignements Adaptés à la Nivologie), the 0.5 CFSR product
(Climate Forecasting System Reanalysis) and several derived SAFRAN grids upscaled to 16, 32, 64 and
128 km. The SWAT model, calibrated on weather stations, was successively run with each gridded
weather dataset. Performances with SAFRAN up to 64 or 128 km were poor, due to a contraction of
the spatial variance of daily precipitation. Performances with 8-km SAFRAN are similar to that of the
aggregated 16- and 32-km SAFRAN grids. The ~30-km CFSR product was found to perform well at
some sites, while in others, its performance was considerably inferior because of grid points where
precipitation was overestimated. The same problem was found in the calibration, where data at some
weather stations did not appear to be representative of the subwatershed in which they are used to
compute hydrology. These results suggest that the difference in the representation of the climate was
more influential than its spatial resolution, an analysis that was confirmed by similar performances
obtained with the SWAT model calibrated on the 16- and 32-km SAFRAN grids. However, the better
performances obtained from these two weather datasets than from the ground-based stations’ dataset
confirmed the advantage of using the SAFRAN product in SWAT modelling. |
| Language: | English |
| Keywords: | SWAT; SAFRAN; weather data input; spatial resolution |