In this paper the hydraulic characteristics of branching flow in open channel has been studied, a main channel was used with a branching channel connected with three angles (30°, 60°, 90°) with four bed slopes (0.001,0.0015,0.002,0.0025)and at each slope five values of discharge were pass in the mainchannel(13, 14, 15, 16 and 17.25) l/s. For each discharge five depths of water were allowed in the branching channel in each experiment. The results of the experiments indicated that the discharge ratio increases with increases bed slope of the branching channel. It was also found that the highest discharge ratio is obtained in the angle 60° then the angle 90° and then angle 30°. The results also showed that the relationship between thedischarge ratio and Froude number is linear and direct proportional to the Froude number in the upstream main channel and in the branching channel, and inversely with the Froude number in the downstream main channel. The relationship between discharge ratio and the ratio of water depth in the branching channel to water depth in the downstream main channel is linear and inverse. An empirical equation to calculate the discharge ratio was observed, with a coefficient of determination (R2) equal (0.953).
Key Word: Branching channel, Branching channel slope, open channel, Branching flow and Branching angle.