BRGM, Orléans meeting, June 2002 PEGASE – Pesticides in European Groundwaters : detailled study of representative Aquifers and Simulations of possible Evolution scenarios (European project ) Martigny Site (Switzerland) : Hydrogeological Contribution Dr Mahmoud BOUZELBOUDJEN, Ing. Dipl. University of Neuchâtel, Switzerland In collaboration with Kirsten Meiwirth & Marc Soutter Swiss Federal Institute of Technology and Pascal Ornstein & Jean-Daniel Rouiller Centre de Recherche Alpin, Sion, Switzerland Prof. André Mermoud, PEGASE Swiss Team Leader, Swiss Federal Institute of Technology, Lausanne

STUDY AREA Léman Lake Rhône river Rhine river Konstanz Lake SWITZERLAND Valais canton Porous aquifer

1. STUDY PURPOSE (Suite)

HYDROGEOLOGICAL DATABASE

THE POROUS AQUIFER OF THE VALAIS CANTON IN THE CONTEXT OF POROUS SWISS AQUIFERS L B V S C Rhône river B = Brig C = Crêtelongue F = Feldsberg K = Konstanz Lake L = Léman Lake V = Vétroz S = Sierre Rhine river K F SWITZERLAND Valais canton study area Geneva Porous aquifer Piezometer National Database

(Fig. 3) H Brig-Léman Experimental variogram

3-D Groundwater Pegase Model Area (~14 km 2 )

PIEZOMETRY : 832 measurements stations location Piezometric measurements were taken twice every year, in July (high water) and in February (low water).

Apports latéraux Groundwater maximal fluctuation (in meters) resulting of Rhône rising from 10 to 13 october 2000

Groundwater detph (in meters) the 16 th octobre 2000 Zone réellement inondée Rupture de la digue Flooded Area

FullyD FullyG MAR Rhône river and aquifer relations : examples

Legend : Precipitations (in black) Rhône river (in blue) Piezometers (in red) Rhône river and aquifer relations

Legend : Precipitations (in black) Rhône river (in blue) Piezometers (in red) Rhône river and aquifer relations

4.1 Aquifer system structure

Results of piezometric campaigns used for 3-D groundwater modelling (Feflow and FEN codes) Results of piezometric campaigns used for 3-D groundwater modelling (Feflow and FEN codes)

Detail in Feflow of Time-varying function of MAR3 limnimeter ( )

Pesticides Study Area (~4 km 2 )

Fagerlund G. (dec. 2001) Chroniques piézométriques 2000 de la nappe alluviale du Rhône de Viège au Léman - Interprétations des réponses de laquifère face à la crue doctobre Travail de diplôme postgrade en hydrogéologie, cycle , Université Neuchâtel, inédit Fagerlund G. (février/mars 2002) Potentiels hydrauliques de la nappe alluviale du Rhône, de Sierre au lac Léman et plus particulièrement dans la région de Martigny. Stage à lUniversité de Neuchâtel (du 11 février au 15 mars 2002), responsable M. Bouzelboudjen, Rapport inédit Jaquet O., Ornstein P., Rey J.-M., Rouiller J.-D. & Bouzelboudjen M. (2000) Optimisation Géostatistique de Réseaux de Mesures Piézométriques: le Cas de la Nappe Alluviale dans la Vallée Alpine du Rhône, Suisse, Bulletin d'Hydrogéologie No 18, Centre d'Hydrogéologie, Université de Neuchâtel, Editions Peter Lang, pp Kimmeier F., Bouzelboudjen M., Ornstein P., Weber I., Rouiller J.-D. (2001) Geohydrological parameter identification and groundwater vulnerability to pollution: A Swiss case study. 3rd International Conference on Future Groundwater Resources At Risk, Lisbon, Portugal, 16 p., 12 fig., 1 tab., 1 ann. Kimmeier F., Bouzelboudjen M., Ababou R., Ribeiro L. (2001) Travel path uncertainty : a case study combining stochastic and deterministic hydraulic models in the Rhône valley, Switzerland. 3rd International Conference on Future Groundwater Resources At Risk, Lisbon, Portugal, 15 p., 9 fig., 1 ann. Lambelet C. (dec. 2000) Synthèse hydrogéologique de la région de Fully. Travail de diplôme postgrade en hydrogéologie, cycle , Université Neuchâtel, inédit References :