A Multidisciplinary Hydrogeophysical Approach Applied to the Chalk Aquifer Using MRS (North of France)

For several years LaSalle Beauvais has regularly carried out hydrogeological and hydrogeophysical measurements in order to characterize the chalk aquifer in the vicinity of Beauvais (Picardie, France), in terms of geometry, behavior and development (Zouhri and Lutz, 2010). A multidisciplinary approach has been chosen: piezometric and meteorological measurements, near surface geophysics measurements (electrical resistivity tomography, seismic refraction…), logging (gamma-ray, water conductivity, temperature), and since June 2014: Magnetic Resonance Sounding. The main hydrogeophysical results obtained on the experimental site of LaSalle Beauvais are displayed in order to show how geophysics methods can improve the hydrogeological knowledge. We insist in particular on the results of Magnetic Resonance Soundings. This method, little used in France because of its susceptibility to electromagnetic noise, allows us to estimate the water content, the permeability and the transmissivity. All of these results, which will be complemented by pumping tests and water samples study in the future, will be of great interest for the water management in the Beauvais area.