ESTIMATION OF ANNUAL GROUND WATER RECHARGE IN THE SEDIMENTARY BASIN OF THE RIVER PEIXE,PARA(I)BA,BRAZIL

摘要

This paper presents the application of a water balance model to estimate the annual ground water recharge for the sedimentary river basin of Peixe located in the semiarid region of the Paraiba State in the northeast of Brazil. The model developed by Paralta et al., is based on US Soil Conservation Service (SCS) Method of Curve Number (CN) to calculate the runoff" generated during a precipitation event and hence the infiltration. By applying a sequential daily water balance to the root zone of the basin, taking into account the field capacity and wilting points of the soil moisture, any excess over and above the daily evaporation and maximum storage capacity is determined and the cumulative total of this excess is would be considered as the best estimate of the potential recharge of the aquifer. The results obtained in the Peixe basin for two years, show that the model is capable of producing reasonable estimates of the recharge and is capable of adequately accounting for the variations in soil type, land use and the vegetal cover as well as the aerial distribution of rainfall in each of the events.