Etablissement de la relation hauteur-débit de l’Amazone à Óbidos: Méthode de la dénivelée normale à“géométric variable“

Abstract

This paper describes the way in which the daily discharges of the River Amazon were calculated at Óbidos. The stage-discharge relationship is practically univocal in low and mean water. In high flow periods, the scatter of the stream gaugings compared to the univocal rating curve effects the correction of the discharges according to the levels at Santarém then at Parintins. The "normal difference in level" method is not well adapted for Óbidos: It was replaced by a "normal difference in level with variable geometry" method, a function of the water levels at Óbidos. While using only the Santarém station, the application of this new method reduced the scattering to 3.0% on the entire rating curve.