SWAT Literature Database for Peer-Reviewed Journal Articles

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 
Article ID:528 
URL (non-DOI journals): 
Broad Application Category:hydrologic & 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 
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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. 
Keywords:SWAT-LUD model; water exchange; denitrification; floodplain aquifer; Garonne River