ABSTRACT
Any flow-induced deformation of an alluvial channel (or only of its bed) is by means of the grain motion en mass, i.e. by means of sediment transport. This chapter considers some aspects of sediment transport and related topics. The grains forming the boundary of an alluvial stream have a finite weight (in fluid) and a finite coefficient of friction. The laws of sediment transport correspond to the simplest case of a steady and uniform two-dimensional turbulent flow in a straight open-channel. In the present context, “two-dimensional” means that the flow characteristics do not vary along the third dimension y (perpendicular to the vertical (x; z)-planes). For the case of fully rough flows, it has since long been established that, as long as h >> ks, the vertical velocity profile exhibits properties similar to those of hydraulically smooth flows – in the sense that the profile follows the logarithmic law within the inner region down to some distance from the bed.
