The geometry and dynamics of low-relief bed forms in heterogeneous sediment in a laboratory channel, and their relationship to water flow and sediment transport

Pebble clusters are concentrated in relatively coarse areas of the bed such as in the troughs of bed-load sheets and bars. Asymmetric, sinuous-crested bed-load sheets ranged from one to two grain diameters up to 12 mm in height and 0.6-1.2 m in length. The migration of bars was associated with fluctuations in the water-surface slope and bed-load transport rate with periods of about two hours. Low-relief bed forms in heterogeneous sediments appear to be ubiquitous features of low-stage "plane' beds and those transitional to dune-covered beds where the bed is not completely mobile. -from Author