Thanks to advances in geoelectrical resistivity method over the past two decades, researchers can now gather
massive geophysical data sets encompassing long distances and depths, at reasonable cost. The enhanced resolution
and spatial coverage of these techniques make them, now, very attractive for use in geological engineering
applications, an area for which they were previously charged to be unsuitable. The study shows the capability of
electrical resistivity imaging (ERI) to identify key subsoil features that might affect a future tailings dam slated for
construction at the Zaruma-Portovelo Mining District, Ecuador. The ERI profiles were gathered and processed
with the aim of obtaining resistivity images of a sufficiently resolution for geotechnical use. A geophysical
modelwas created based on these images. The resistivity imageswere calibrated according to geomorphological,
hydrogeological and geotechnical data in order to translate geophysical information into rational geological information.
The ERI results, supported by the geomorphological and geotechnical work, suggested that the rock
massif is composed of weathering horizons of different rock qualities, slopes are affected by sliding surfaces
and these features exert a control on the groundwater flow. These results indicated that the original site selected
to construct the dam dike was susceptible to land sliding and an alternative construction site was suggested.
Based on the sameresults, a geomorphological–hydrogeological conceptualmodel for layered weathered granitic
massif in mountainous areas was also proposed.