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Temporal variability of nitrate transport through hydrological response during flood events within a large agricultural catchment in south-west France

Oeurng, Chantha and Sauvage, Sabine and Sanchez-Pérez, José-Miguel Temporal variability of nitrate transport through hydrological response during flood events within a large agricultural catchment in south-west France. (2010) Science of the Total Environment, 409 (1). 140-149. ISSN 0048-9697

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Official URL: http://dx.doi.org/10.1016/j.scitotenv.2010.09.006


The temporal variability of nitrate transport was monitored continuously in a large agricultural catchment, the 1110 km2 Save catchment in south-west France, from January 2007 to June 2009. The overall aim was to analyse the temporal transport of nitrate through hydrological response during flood events in the catchment. Nitrate loads and hysteresis were also analysed and the relationships between nitrate and hydro-climatological variables within flood events were determined. During the study period, 19 flood events were analysed using extensive datasets obtained by manual and automatic sampling. ThemaximumNO3 − concentration during flood varied from 8.2 mg l−1 to 41.1 mg l−1 with flood discharge from 6.75 m3 s−1 to 112.60 m3 s−1. The annual NO3 − loads in 2007 and 2008 amounted to 2514 t and 3047 t, respectively, with average specific yield of 2.5 tkm−12 yr−1. The temporal transport of nitrate loads during different seasonal flood events varied from 12 t to 909 t. Nitrate transport during flood events amounted to 1600 t (64% of annual load; 16% of annual duration) in 2007 and 1872 t (62% of annual load; 20% of annual duration) in 2008. The level of peak discharge during flood events did not control peak nitrate concentrations, since similar nitrate peaks were produced by different peak discharges. Statistically strong correlations were found between nitrate transport and total precipitation, flood duration, peak discharge and total water yield. These four variables may be the main factors controlling nitrate export from the Save catchment. The relationship between nitrate and discharge (hysteresis patterns) investigated through flood events in this study was mainly dominated by anticlockwise behaviour.

Item Type:Article
Additional Information:Thanks to Elsevier editor. The definitive version is available at http://www.sciencedirect.com
HAL Id:hal-00720728
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Laboratory name:
Deposited On:24 May 2012 09:54

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