Potentiometric and Bedrock Map Drawn from Vertical Electrical Soundings (VESs) and Considerations on the Investigation Depth

Abstract

The article presents considerations on the depths achieved by Vertical Electrical Soundings (VES) as a function of electrode distances, and also on their quantitative interpretation. Besides the distances among electrodes, the effective achieved depths will depend on the resistivity distributions. At the request of environmental agencies, resistivity geophysical surveys were carried out in an area designed to the implementation of a residential complex which, would have to present a site hydrogeological study, including a potentiometric map among other requirements to be met. For the referred map elaboration, 18 VES were carried out in order to determine the depth of the water level at these points. In addition to this information, the works provided another additional data: the determination of the bedrock depth. Based on VES results, the potentiometric map and the bedrock depth map were elaborated in the study area. The cost reduction with the use of this indirect technique is significantly lower when compared to the costs of mechanical soundings, besides the reduction of the execution time.