Flow and Sediment Laboratory Measurements over Unsubmerged Roughness Elements

The overarching objective of this investigation was to evaluate the role of relative submergence on the formation and evolution of cluster microforms in gravel bed streams and its implications to bedload transport. The methodological component of this study was founded on the recent research findings of Papanicolaou et al. and Strom et al. about cluster formation, disintegration, and the effects of cluster evolution on bedload transport. An enhancement of the methodology was attempted to account for the role of relative submergence on cluster microtopography, a very important feature in gravel-bed rivers that few to none have researched in a systematic way. Specifically, the methodology and experimental design of this research was based on the premise that in natural gravel bed streams, where the height of clast-obstacles is generally of the same order of magnitude with the flow depth, the processes between the interaction of the flow and clasts play a dominant role in eddy taxonomy and flow prevailing mechanisms.