Friction Factors and Bed Forms in Fluvial Channels

Bed-form geometry in a curved channel and a straight flume which are subject to the same nominal flow conditions is investigated by statistical analysis of records of stream bed profiles. A quantitative comparison between bed geometry in curved and straight channels is made in terms of the autocorrelation, spectral density and probability density function of a process defined by the bed elevation. The same statistical functions are used to evaluate the bed-friction factor and ripple celerities. It has been found from experiments that the total rate of sediment transport in the curved channel is approximately 15 times as much as that of a straight flume which is subject to nominally identical flow conditions.