Interferências atrópicas na recarga de aqüíferos no Vale do Cariri-Ceará

Abstract

Parameters soil moisture, apparent density, total porosity, and hydraulic conductivity for soils of the Cariri Valley are linearly well correlated with organic matter. The higher the concentration of organic matter is, the lower are apparent density and hydraulic conductivity and the higher is porosity. A negative correlation between conductivity and organic matter suggests a higher protection of organic matter in soils of clayey texture. The majority of soil samples from the Cariri Valley present organic matter und moisture inferior to the worst category of anthropized soils of the Araripe Plateau. The variation of water storage from wet to dry season is much higher in valley soils than in anthropized ones on the plateau, indicating higher losses through evapotranspiration in the first. Apparent density and porosity are similar to values for deforested areas on the plateau. Hydraulic conductivity in some valley samples is close to that of preserved plateau areas; however, low organic matter inhibits soil moisture conservation, thus reducing soil percolation and, consequently, aquifer recharge.