Conditioning factors of the Açu Aquifer recharge on the southwest border of the Potiguar Basin, Rio Grande do Norte State, Brazil.

Abstract

The Potiguar Basin Southwest border, on Rio Grande do Norte State, is situated in the semi-arid region and the precipitation is about 765.1 mm/year. The Açu aquifer is the main water source of supply to the population and to land irrigation. The wells bored in the area, however presents very different production, whose yields go from less them 5 m3/h up to 60 m3/h. It is the main reason of limiting the use of the groundwater. As shown by the geological, structural e geophysical dates (vertical electrical profiles and longitudinal conductance) there are high and low geological structures. According to the studies carried out, these characteristics results in various sectors of different hydrogeologic potentialities. The aquifer transmissisvity increases following the flux direction from south to north, changing from less than 10 m2/d to 280 m2/d, characterizing the north zone of the area as the best hydrogeologic possibilities. The groundwater recharge was estimated in 54 millions m3/year, in which most of it (91.5%) is stored in the north zone of the area.

Keywords

• Semi-árido
• água subterrânea
• recarga
• fluxo subterrâneo