Author(s): Caamano Diego; Goodwin Peter
Keywords: Velocity reversal hypothesis; Pool riffle sequences; Gravel bed rivers; Headwater streams
Abstract: Since Keller 1971 first proposed the velocity reversal hypothesis for pool-riffle channels, there has been considerable interest expressed in the literature about this phenomenon with a diverse range of opinions about whether this process exists and, if it does, the conditions under which it can be expected to occur. In order to help resolve this debate, an analytical criteria for the conditions for velocity reversal has been developed. Although a simplified one dimensional approximation is used to analyze the flow field through pool-riffle sequences, it is proven that the velocity reversal can take place and quantifies the physical characteristics of the channel morphology for this to occur. Expected errors and other uncertainties are currently been quantified through three dimensional model simulations and field observations.