In order to adjust a rain-flow model capable of estimating Santa Barbara river minimum flows, the authors analyzed the historical flow series and identified the base flow recession phase. The daily rainfall data observed at the stations Fazenda Aliança, Joviânia, Ponte Sul Goiana, Maurilândia and Ponte Meia Ponte were used to determine the total rainfall during the five months preceeding the dry season (P5). The average P5 for Santa Barbara River Basin was obtained using the Thiessen method. The rain-flow model produced in this work presented little errors compared with the minimum flows actually observed in the river during the dry season. The model allowed the authors to estimate the referrence flow Q7,10. The method studied in this work made it possible to simulate the hidrogram corresponding to the base flow recession phase starting from P5 rainfall. This allows the public water manager in Goias to prevent possible conflicts over water in the river basin using different rainfall distribution scenarios.
minimum outflow; underground flow; water resources
