Integrating Time-Domain Electromagnetic Soundings into a Geomatic Platform to Generate a Pseudo-3D Geoelectrical Model for Groundwater Exploration: The Alfaro Case Study (La Rioja, Spain)

Time-Domain Electromagnetic (TDEM) soundings are widely recognized as an effective method for subsurface characterization at intermediate depths. This study applies TDEM surveying to the municipality of Alfaro (La Rioja, Spain), where ten stations with 200 × 200 m loops were acquired and processed using Occam 1D inversion. The resulting models were integrated into a 3D environment in geomatic software (Seequent, Oasis montaj 2025.1) to generate a continuous geoelectrical volume of the subsurface. Three major resistivity domains were identified: a shallow resistive unit (40–80 ohm·m), an intermediate unit (20–40 ohm·m), and a deep conductive domain (<20 ohm·m). The pseudo-3D model revealed a thickening of the intermediate–resistive domain toward the central and western sectors, interpreted as the most favorable zone for groundwater extraction. This workflow demonstrates that integrating 1D TDEM inversion results into a pseudo-3D geoelectrical framework improves the spatial interpretation of resistivity distributions and provides a practical decision-support framework for identifying optimal drilling sites.