Analysis of the relationship between electrical resistivity, hydraulic conductivity and physico-chemical parameters for the Aquifer Free of the Corumbataí (SP)

Abstract

Brazil is a privileged country in relation to their mineral resources, but have problems in diagnosis the situation about the surface water and groundwater, because the quality and the quantity of water. Questions about physico-chemical parameters as high as salinity or low hydraulic conductivity can affect the use of this underground water resource. The study of procedures for diagnostic directly or indirectly in salinity in groundwater can assist the selection of sites for acquisition. In this direction, this study describes a comparative analysis between geochemical analyzes and tests on geophysical study of saline free aquifer, in an attempt to establish correlations between data, whether direct or indirect, in addition to providing an analysis of the limitations of the DC Resistivity geophysical method as indicator tool of degrees of salinity in an indirect way. The geological site consist in clay soils settled on siltstone and argillites of the Corumbataí Formation, of the Basin of Paraná Sedimentary Basin in Brazil. This unit represents an aquiclude regional, the occurrence of level free aquifer in the contact soil/rock characterized by variable salinity and is widely used as a source of supply for rural properties. The physical-chemical parameters measured in samples collected in wells were: total dissolved solids (TDS), electrical conductivity (CE), in addition to measures of hydraulic conductivity (k). The data of TDS and CE were widely variable, but resulted in a direct correlation. The comparison between the data from electrical resistivity with TDS and electrical resistivity with hydraulic conductivity do not result in satisfactory correlations perchance the complexity geological and a high variable in salinity. Factors that control electrical resistivity in the geological environment.