Qualidade das águas subterrâneas da bacia sedimentar do município de Lavras da Mangabeira, Ceará

Abstract

The sedimentary basin studied, with about 60.3 km2 in area, is composed of three small sub-basins localized in the township of Lavras da Mangabeira, in the Southeast of Ceará State. This research characterizes, with respect to chemical quality, groundwaters collected during two campaigns, one at the end of the dry season, the other at the end of the rainy one. In samples from seven wells, we measured electric conductivity “in loco” and cation concentration Ca2+, Mg2+, Na+ e K+ and the anions Cl-, SO4 2- e HCO3 -. Results show that groundwaters from the sub-basins Riacho do Meio and Riacho do Rosário are hydrochemically different. One well in each of these two subbasins produces, during the rainy season, water unfit for human consumption. The wells of the Rosário basin were found to produce water inappropriate for irrigation in one campaign.