 |
GET - Geosciences -Environnement- Toulouse |  |
|
GET - Geosciences -Environnement- Toulouse | |
| HAL : hal-00330845, version 1 |
| Fiche détaillée |  Récupérer au format |
 |
| Hydrology and Earth System Sciences Discussions 7, 1 (2003) 97-107 |
|
|
|
|
| Nitrogen dynamics in the shallow groundwater of a riparian wetland zone of the Garonne, SW France: nitrate inputs, bacterial densities, organic matter supply and denitrification measurements |
|
|
| J. M. Sánchez-Pérez 1P. Vervier 1 |
|
|
| (2003) |
|
|
|
| This study highlights the role of interactions between surface and sub-surface water of the riparian zone of a large river (the Garonne, SW France). Information is given about the role of surface water in supplying Dissolved Organic Carbon (DOC ) to the riparian zone for nitrate removal processes. The densities of bacteria (up to 3.3 106 cell m L-1) in groundwater are strongly conditioned by the water moving during flood events. Total bacterial densities in groundwater were related to surface water bacterial densities. In sediment, total bacteria are attached mainly to fine particles (90% in the fraction < 1 mm). Spatial variations in organic carbon and nitrate content in groundwater at the site studied are correlated with exchanges between the groundwater and the river, from the upstream to the downstream part of the meander. Total bacterial densities, nitrate and decressing organic carbon concentrations follow the same pattern. These results suggest that, in this kind of riparian wetland, nitrate from alluvial groundwater influenced by agricultural practices may be denitrified by bacteria in the presence of organic carbon from river surface water. Keywords: riparian zone, nitrate removal, spatial variations, alluvial groundwater |
|
|
|
|
|
|
|
|
|
|
|
| 1 : | Laboratoire d'écologie des hydrosystèmes (LEH) |
|
|
|
CNRS : UMR5177 – Université Paul Sabatier [UPS] - Toulouse III |
|
|
| 2 : | Laboratoire des Mécanismes et Transfert en Géologie (LMTG) |
|
|
|
CNRS : UMR5563 – Observatoire Midi-Pyrénées – Université Paul Sabatier [UPS] - Toulouse III – Institut de recherche pour le développement [IRD] : UMR154 |
|
|
| 3 : | Biogéochimie et écologie des milieux continentaux (Bioemco) |
|
|
|
CNRS : UMR7618 – Université Pierre et Marie Curie [UPMC] - Paris VI – Université Paris-Est Créteil Val-de-Marne (UPEC) – Ecole normale supérieure de Paris - ENS Paris – Institut de recherche pour le développement [IRD] – AgroParisTech – Institut national de la recherche agronomique (INRA) : UMR1122 |
|
|
| 4 : | Bureau de recherches géologiques et minières (BRGM) |
|
|
|
Bureau de Recherches Géologiques et Minières (BRGM) |
|
|
|
|
|
|
|
|
|
| Domaine | : | Planète et Univers/Interfaces continentales, environnement Planète et Univers/Océan, Atmosphère Planète et Univers/Sciences de la Terre |
|
|
| Liste des fichiers attachés à ce document : | |||||
|
|||||
|
|
|
| hal-00330845, version 1 | |
| http://hal.archives-ouvertes.fr/hal-00330845 | |
| oai:hal.archives-ouvertes.fr:hal-00330845 | |
| Contributeur : Publication EGU | |
| Soumis le : Mercredi 1 Janvier 2003, 08:00:00 | |
| Dernière modification le : Mercredi 15 Octobre 2008, 12:27:35 | |
