Adel Zghibi

Modelling of Tracer Movement with Avection-Dispersion Scheme at the LaSalle Beauvais Experimental Site, Beauvais, France

Modelling of Tracer Movement with Avection-Dispersion Scheme at the LaSalle Beauvais Experimental Site, Beauvais, France In order to understand the tracer transport in a contaminant plume arising from an injection well in the Chalk aquifer, underground field experiments at the LaSalle Beauvais experimental site (France) was hydrogeological investigated and analysed by means of analytical and numerical approaches. Both advection and diffusion mechanisms are taken into account. We use an analytical solution for describing one-dimensional solute transport in a unidirectional steady-state flow tracer with scaledependent dispersion. Comparison between the breakthrough curves of the analytical and the numerical solutions shows excellent agreement for various ranges of scale-related transport parameters of interest.

Hydrogeology, Geoelectric Investigations and Conceptual Groundwater Flow Model within the Chalk Aquifer of Beauvais (Paris Basin, France)

Hydrogeology, Geoelectric Investigations and Conceptual Groundwater Flow Model within the Chalk Aquifer of Beauvais (Paris Basin, France) A groundwater investigation including several boreholes lithologs, electrical resistivity tomography (ERT) has been carried out to improve the understanding of the distribution of hydraulic properties of the Chalk aquifer of Beauvais (North of France). The ERT study is conducted at 3 locations, using 64 electrodes deployed at an inter-electrode spacing of 5 m, and the data were recorded using Schlumberger vertical electrical sounding. The results of ERT are interpreted in terms of subsurface geology and aquifer characteristics revealing the presence of three prominent lithologic layers under prevailing hydrodynamic conditions. The main objectives of the hydrogeological investigation are their ability to display the underground in 3D space, to help characterize and to visualize the soil stratigraphy and water table level at the site. In addition, geological data and hydrological studies are used to produce a conceptual model for regional groundwater flow in the combined unsaturated and saturated zones of the chalk aquifer of Beauvais.