| Title: | Using SWAT-LUD to estimate the influence of water exchange and shallow aquifer denitrification on water and nitrate flux |
| Authors: | Sun, X., L. Bernard-Jannin, Y. Grusson, S. Sauvage, J. Arnold, R. Srinivasan and J.M.S. Perez |
| Year: | 2018 |
| Journal: | Water |
| Volume (Issue): | 10(4) |
| Pages: | |
| Article ID: | 528 |
| DOI: | 10.3390/w10040528 |
| URL (non-DOI journals): | |
| Model: | SWAT-LUD |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | groundwater and/or soil water impacts |
| Secondary Application Category: | nitrogen cycling/loss and transport |
| Watershed Description: | 51,500 km^2 Garonne River, located in southwest France |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Numerous studies have pointed out the importance of groundwater and surface water
interaction (SW–GW) in a river system. However; those functions have rarely been considered
in large scale hydrological models. The SWAT-LUD model has been developed based on the Soil
and Water Assessment Tool (SWAT) model; and it integrates a new type of subbasin; which is
called subbasin-LU (SL); to represent the floodplain area. New modules representing SW–GW
exchanges and shallow aquifer denitrification are developed in the SWAT-LUD model. In this study;
the SWAT-LUD model was applied to the middle floodplain area of the Garonne catchment in France.
The results showed that the SWAT-LUD model could represent the SW–GW exchange and shallow
aquifer denitrification appropriately. An annual 44.1 x 107 m3 of water flowed into the river from the
study area; but the annual exchanged water volume was 6.4 x 107 m3; which represented just 1% of
the river discharge. A total of 384 tons of N-NO3-
(0.023 t ha-1) was consumed by denitrification in
the floodplain shallow aquifer annually. The nitrate concentration (N-NO3-) decrease in the channel
was 0.12 mg L-1; but in the shallow aquifer it reached 11.40 mg L-1; 8.05 mg L-1; and 5.41 mg L-1
in LU1; LU2; and LU3; respectively. Our study reveals that; in the Garonne floodplain; denitrification
plays a significant role in the attenuation of nitrate associated with groundwater; but the impacts of
denitrification on nitrate associated with river water is much less significant. |
| Language: | English |
| Keywords: | SWAT-LUD model; water exchange; denitrification; floodplain aquifer; Garonne River |