f Application of borehole logging methods to quantify hydraulic conductivity and to characterize water circulation in a complez saturated porous aquifer pfynwald – Wallis - Switzerland

Within the framework of the research project entitled « Fluid and mass transport in porous medium : quantification and comparison of hydrogeological, geophysical and hydrochemical methods. Example of the alluvial aquifer in the Bois de Finges » financed by the Swiss National Science Foundation (project n°2100-043477.95/1), we have applied and developed geophysical methods in order to determine the hydraulic conductivity and to characterize groundwater circulation. Located in the Upper Rhône Valley (Figure 1), upstream the city of Sierre in Central Wallis, the Pfynwald complex aquifer is mainly composed of alluvial deposits of the Rhône River covering the fine deposits of the alluvial Illgraben fan who is covering lacustrine sediments. Four boreholes reaching from 15 to 30 meters of depth enable the use of different logging tools (fluid resistivity and temperature, natural gamma ray, gamma gamma, neutron-thermal neutron, heat pulse flowmeter).