<b>Quantitative analises of the river discharge int the Patos Lagoon Estuarine System</b>

Abstract

The main objective of this paper is to establish the mean monthly contribution of each one of the tributaries of Patos Lagoon. A specific methodology was applied to recover missing data and 3 time series covering 57 years of monthly data for Jacuí, Taquari and Camaquã rivers could be formed. A seasonal behavior that presents a peak in late winter/early spring was depicted from the records. The sum of the annual mean flow of Jacuí, Taquari and Camaquã rivers is 1770 m³/s. When the mean flow of São Gonçalo channel (700 m³/s) is included, the total river discharge of Patos Lagoon attains 2400 m³/s. Large year-to-year variations are likely to occur and they are mostly tied with events of “El Niño”, when above normal values are recorded, and “La Niña” that presents river flows well below average.