The Chezy-Manning equation as well as several other equations used in the calculation of the uniform flow in channels does not represent satisfactorily the shape effect of the flow cross-sectional area, which results in little precision. A methodology developed by Kazemipour & Apelt (1980), considering the von Karmam Prandtl equation for pressurized tubes, denominated as method of Kazemipour, has showin quite efficient in the calculation of the flow in smooth circular channels. In this research, the method of Kazemipour, numerically adjusted was confronted with the Manning equation. In the analysis, discharge values calculated by the two methodologies and reliable experimental data were used. According to the evaluated parameters, the method of Kazemipour showed to be superior to Manning's equation for flow calculation in smooth circular channels.
irrigation; discharge; hydraulics
