Modelagem do escoamento no sistema Piranhas-Açu utilizando o modelo NAVMO.

Abstract

In this research the distributed model NAVMO was utilized to model the runoff at several catchments of the Piranhas/PB – Açu/RN river basin in the semiarid regions of the states of Paraíba and Rio Grande do Norte, since the time series in those regions are short and incomplete and influenced by deforestation, great variability of climate factors and population growing, which are factors that affect the parameters of simulation models. The model was calibrated by a trial and error procedure to fit daily hydrographs, annual volumes and peak of runoffs, and then verified through different criterions. The modelling results showed that the mean coefficients of determinations (R2) were 0.8 for the peak runoffs and 0.9 for the volumes. For the verification phase, the coefficients were poorer than those for the calibration (R2 = 0.34), but in general the simulated hydrographs approached well the observed ones.