Hydrodynamic and hydrochemistry behavior of the Barreiras-Jandaíra-Açu aquifer system in the area of fazenda Belém, west of the Potiguar Basin, CE

Abstract

The evaluation of the hydrodynamic and hydrochemistry behaviour of the aquifers in areas under the influence of the oil exploration activity, are essential to the protection and management of the groundwater resource. The aim of this study was to analyse the relationships between the hydraulic loads of Açu and Barreiras-Jandaíra aquifers in the area of Fazenda Belém, sector west of the Potiguar basin, state of Ceará and its implications on the quality of groundwater. Regional and local studies in the area of Fazenda Belém were consulted, about the hydrodynamic and hydrochemistry properties of the two Aquifer systems. Hydrochemistry e static level data were obtained and the potentiometric surfaces of the two aquifers for different periods, since its original state, before the influence of the oil exploration activity, until the present day were set,. The Açu Aquifer presented a fall of approximately 110 m, while the Barreiras-Jandaíra Aquifer presented only minor variations, between 2m to 4m. The hydrochemistry data allow to affirm that in the study area, the waters stored in the Barreiras-Jandaíra Aquifer are classified as chlorine-bicarbonate - sodium-calcium (Na-Ca-Cl-HCO3) and the waters stored in the Açu Aquifer are classified as bicarbonate-chlorine - sodium (Na-HCO3-Cl). With this information it is possible to affirm that the Açu and Barreiras–Jandaíra aquifers correspond to individual aquifers systems. The fact that the fall of the static level in the Açu Aquifer, did not affect the hydraulic loads of the aquifer Barreiras-Jandaíra and the distinct chemical classes of the water of the two aquifers suggest the existence of a hydraulic isolation and indicating the absence of water mix between the two systems, since its original state until the present.