Geophysical characterization of an artificial water basin for seepage detection

This thesis investigates the structural integrity and potential seepage within the embankments of an artificial water basin in the alpine region, specifically designed to support snowmaking for a ski resort. The study utilizes electrical resistivity tomography (ERT), seismic refraction and surface wave analyses to process two survey lines along the embankments. The geophysical data acquisition was carried out in the framework of the spoke “Digital and sustainable mountain” of the project NODES, funded by the National Recovery and Resilience Plan. The ERT results reveal varying saturation levels within the embankment materials, identifying a thin surface layer with high resistivity, indicative of unsaturation, followed by a deeper layer with potential water content. Notably, a high resistivity anomaly near the drainage system suggests the presence of concrete structures or large boulders. A significant anomaly indicating possible seepage was detected along the same line. Seismic data provided estimates of the mechanical properties of the materials, showing reduced shear modulus and Young's modulus in areas with identified anomalies, confirming potential weak spots and saturation zones. In comparison, the second line exhibited more homogeneous material with fewer resistivity anomalies and less significant mechanical property variations. The integrated geophysical approach proves effective in detecting potential leakage and assessing the embankment's condition, offering valuable insights for the maintenance and safety of artificial water basins in alpine environments. The study underscores the importance of combining geophysical techniques for comprehensive site characterization and risk mitigation in similar infrastructures.