Aplicação de imageamento elétrico para a locação de poços em aquíferos fissurais na região de Campina Grande, PB.

Abstract

The present work analyzes the effect of the adoption of different configurations of the eletroresistivity method to investigate the occurrence of potential fissural aquifers in three areas in the region polarized by the municipality of Campina Grande. In these areas there are subvertical fractures in the crystalline basement, as well as altered rocks and / or alluvial sediments. In order to recognize such potentially groundwater accumulating structures, multiple vertical electric sounding technique (VES) using the Schlumberger array and the electric profiling (EP) using the total or partial multilevel gradient array were applied. Different configurations were tested in profiles whose direction is approximately perpendicular to the planes of fractures and / or foliation. The results obtained show that the multilevel electric profiling through the gradient array showed greater clarity in the detection of fracture zones in relation to the configurations using VES. However, such subvertical structures could still be detected by VES, provided that an adequate spacing between the VES centers was adopted. The geoelectric sections obtained by the tested configurations indicate the presence of accumulating structures of groundwater defined by the anomalies of low electrical resistivity, correlated to fractures and / or changes in the permeability of the medium. The gradient array presents operational advantages in relation to the other configurations, and the total gradient array provides a higher resolution image than the partial gradient array, whose image loses resolution in the shallower part of the geoelectric section.