Effect of Channel Meanders on Flood Stage in Valley

Results of this study indicate that for a meandering channel in a valley there is an interaction between the channel flow and valley flow. The nature of the interaction varies with stage, in that channel flow remains dominant when the overbank flow is relatively shallow, but may become insignificant when the overbank flow is deep. Once the valley flow becomes dominant, the presence of the meandering channel can actually produce greater stages than would occur if the channel were absent. The tests showed that the method recommended for straight channels with irregular cross sections applies with good accuracy, but that it would be totally erroneous to apply this method to a meandering channel in a valley. Although not tested, there is little doubt that the effects noted for a sinusoidal channel would be even more pronounced for a channel with a convoluted meander pattern.