Assessment of groundwater quality recovery strategies using nitrate transport modelling. Application to the Saône alluvial formations (Tournus, Saône-et-Loire)

To assess the efficiency of different agro-environmental strategies used to reduce groundwater pollution by nitrates, transport modelling in soils and groundwater has been carried out on two withdrawal areas in an alluvial plain. In a first time, the agro-environmental model AgriFlux allowed the simulation of water and nitrates fluxes flowing to groundwater. This model was calibrated for each agro-pedological unit of the studied territory. In a second time, the application of the hydrogeological model MODFLOW-MT3D allowed the simulation of nitrate transport in groundwater for the 1980-2004 period. This soil-groundwater coupled modelling has shown that soil nature is the first factor that conditions the vulnerability to nitrates. Thus, nitrate leaching occurs preferentially under sandy soils. Efficiency of different agro-environmental operations for groundwater quality recovery was quantified. The best results are obtained by combination of (1) grassland re-installation on sandy agricultural lots located in near well protection perimeter and (2) fertilization reduction on sandy agricultural lots located in the well alimentation area upstream the near protection perimeter. On other soils, the effect of grassland on groundwater quality improvement is more limited. Nevertheless, the control of nitrate fertilisation remains essential and is justified in both near and far well protection perimeters. Modelling thus allows optimising and priorizing agro-environmental actions in alluvial agricultural zones. [Comte J.-C., Banton O., Kockmann F., Villard A., Creuzot G. (2006), Assessment of groundwater quality recovery strategies using nitrate transport modelling. Application to the Saône alluvial formations (Tournus, Saône-et-Loire), Ingénieries Eau-Agriculture-Territoires, 45, 15-28]

Monument au sénateur [de la Loire, Emile] Reymond [à Montbrison, Loire, inauguration, 24 mai 1920] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59390

Monument au sénateur [de la Loire, Emile] Reymond à Montbrison [Loire, inauguration, 24 mai 1920] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59391

Montbrison, 24/5/20, inauguration du monument au sénateur [de la Loire, Emile] Reymond, [MM.] Dupin, [Théodore] Steeg [ministre de l'Intérieur], [Pierre-Etienne] Flandin [sous-secrétaire d'Etat à l'aéronautique] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59393

24/5/20, inauguration du Monument du sénateur [de la Loire, Emile] Reymond à Montbrison [Loire] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 59396

Les administrateurs du département de la Loire, destitués par Reverchon, commissaire du gouvernement ([Reprod.]) / [signé : Courbon Saint-Genest, F. M. Vissaguet]

Collection : Les archives de la Révolution française ; 6.2.2671

Bassin houiller de la Basse-Loire. Atlas / par E. Bureau,... ; Ministère des Travaux publics, Service des topographies souterraines

Collection : Etudes des gîtes minéraux de la France