Suspended load transport
Particles in the water column of a turbulent flow can be carried over long distances as long as the net balance between upward suspending forces and gravity remains positive.
Sediment concentration profiles typically show a two-layer structure: the inner layer above the bottom is characterized by low-Reynolds conditions (developing turbulence) and high concentrations, while the turbulence in the outer layer is fully-developed and the concentrations are low, typically smaller than 0.1%, corresponding to dilute conditions. Since the inner layer usually is thin, of the order of a few centimetres, it often falls outside the depth range where measurements are collected, and therefore largely remains undetected and little known. The transport capacity of the outer layer is controlled by that of the inner layer.
Please note that others may also have edited the contents of this article.