Composição de uma cartografia de transmissividade hidráulica exploratória com a utilização do parâmetro resistência elétrica transversal

Composition of an exploratory hydraulic transmissivity map using the parameter transverse electrical resistance

Abstract

The Barreiras Aquifer, unconfined in hydraulic nature, has a high hydrogeological potential and supplies approximately 80% of the cities along the eastern coast of Rio Grande do Norte, Brazil. In this context, the research area is located on the left bank of the Boa Cica Stream, in Nísia Floresta, RN. This study aimed to develop an exploratory hydraulic transmissivity (T) map based on aquifer test data and the geoelectric parameter of transverse electrical resistance (RT), the latter obtained from inverse models of vertical electrical soundings (VES). Additionally, sub-areas with higher hydrogeological potential were characterized based on the direct correlation between RT and T. The results demonstrated the satisfactory application of this methodology for determining transmissivities from transverse resistance, provided that prior hydrogeophysical calibration is considered, involving lithological-constructive profiles, aquifer testing, and the inverse model of the VES performed adjacent to the well. The highest RT values were identified in the central and western sub-areas, reaching 58,860 Ohm.m², associated with greater hydrogeological potential zones. In this regard, the analysis of the predominant factor in the calculation of RT, through linear regression, revealed an R² coefficient of 0.89, highlighting the predominance of the aquifer's average resistivity (linked to its hydraulic conductivity) over its thickness in RT values.