Determination of Water Wells Location Based on Geophysical Investigations - An Example in an Alluvial Plain

In order to determine the best location of well for pumping drinking water in an alluvial plain, different non destructive geophysical methods (Ground Penetrating Radar (GPR), electrical prospecting, seismic refraction) are tested on the studied site. The goal of this study is to determine non destructive geophysical protocol for the lithological and geometrical characterization of the alluvial deposits (6 to 10 meters thick) and the bedrock constituted of clays. We have evaluated the efficiency of geophysical methods on the same site. The preliminary results are presented here. The results obtained with each method depend essentially of the lithology inside alluvial deposits and thick of vegetal soil. The combination of GPR and electrical measurements appears to be the best solution to have geometrical informations with good resolution for the top of the bedrock and informations about the lithological variations inside the alluvial deposits.