Análise da hierarquia dos parâmetros espessura e resistividade média na composição da resistência transversal do Aquífero Barreiras - Área da Bacia do Rio Catu-RN

Abstract

The use of underground waters with no appropriate control can cause serious problems in urban and rural supply. The towns of the east coast of Rio Grande do Norte, for instance, have about 80% of their supplies credited to Aquifero Barreiras, this being of non-confined hydraulic feature. However, the lack of wells data makes it difficult to indicate promising areas for the exploration of this resource. In this context and considering the aforementioned source, the aim of this research was the River Catu basin, which is carved in the Cenozoic sequences of Barreiras Formation and their coverings. The objective was identify places of the greatest hydrogeological potential, using geoelectric data from surveys already accomplished particularly reinterpreting the Dar Zarrouk parameter, transversal electric resistence (TR). The northeast and central regions of the area showed TR values greater than 50.000 Ωm2, related to thickness sectors and/or higher average resistivities of the saturated zone and attesting these subareas as more promising in terms of hydrogeological potentials. The greater average thickness of saturated zone are located in the portions northeast and central, presenting alignment of the same in the direction of coast line, reaching 95 m. The highest values of the average resistivities of the saturated zone are located in the central and extreme northeast parts of the area, reaching up to 950 Ωm. However, linear regressions revealed that the average saturated thicness imposes a greater influence on the strength calculation transverse electric current, presenting a correlation factor of 0,70, while the factor of average resistivity was 0,47.