The increasing need for the characterization of hydrological conditions of catchments demands better and more practical research techniques. The streamflow characterization is fundamental for hydrological/ hydrogeological studies and it can be determined by several methods. This paper intends to analyze the portable weir technique, an alternative methodology for low flow determination, still relatively unknown in Brazil. Two to three streamflow measurements a day were manually taken in ten catchments of the Maracujá basin, a tributary of the Alto Rio das Velhas river in the State of Minas Gerais. Three kinds of weir were used: triangular, rectangular and trapezoidal Cipoletti, all of them constructed with 4-6 mm thick galvanized iron plate. The results showed that this is a practical, reliable and economic technique of measuring low flows. Even though the peak flows were occasionally not recorded, either because of the weir overflow or because of the long recording period. The recession period was always well recorded, allowing the determination of the baseflow, the recession coefficient and other hydrological indices, which are useful in the indirect method of hydrogeological characterization.
Hydrogeology; portable weir; stream flow; catchment; baseflow
