Imaging of subsurface hydraulic flows using Self-Potential, Electrical Resistivity, and Induced Polarization Data: Application to a Dam and a Landslide

Geoelectrical methods are increasingly used to characterize subsurface hydraulic flows and the hydraulic properties of the subsurface. This study presents an integrated approach combining Electrical Resistivity Tomography (ERT), Induced Polarization (IP), and Self-Potential (SP) to (1) map water content, cation exchange capacity (CEC), and permeability, and (2) estimate the distribution of Darcy velocities through inversion of SP data. The methodology uses permeability estimates to build a groundwater flow model, which is then refined by inverting the SP data. Two case studies illustrate this approach: a masonry dam founded on weathered granite with a localized leakage zone, and a large landslide affecting a carbonate syncline overlain by clay-rich sediments and morainic material. In both contexts, the ERT–IP–SP framework provides coherent 2D–3D images of preferential flow paths and hydraulic barriers, as well as Darcy velocity fields consistent with independent observations. These results demonstrate the effectiveness of the methodology for studying subsurface hydraulic processes and for managing water resources and geological risks.