Investigation of stage-discharge relationship in compound channels

Various methods are available in the literature for discharge calculation in compound channels. In this study, discharge calculations were performed in symmetrical compound channels using the Single Channel Method (SCM) and the Divided Channel Method (DCM), which are among the traditional discharge estimation methods. The discharges obtained from these methods were compared with the experimental data given in previous studies, and the validity of the methods was evaluated by calculating the error rates. As a result of the study, among the six different equivalent roughness formulas used in the SCM, the best result was obtained with the formula proposed by Cox (1973). In the DCM, the channel cross-section was divided into sub-areas by different virtual dividing lines. The calculations were performed for a total of 10 different cases where each virtual line was included and not included in the wetted perimeter, and the best result was obtained when the diagonal dividing line was in the middle of the main channel and was not included in the wetted perimeter.