Cohesionless, Fine Graded, Flaked Sediment Transport by Water

A kNOWLEDGE of the transport of fine graded sediments (that is, nearly uniformly sized sediments of less than about 150 µm particle diameter) by flowing water is of importance to engineers, geologists and geographers. Since considerable experimental difficulties exist in the investigation of this subject, only a minor amount of research has been previously recorded ; this research has been confined to the transport of cohesionless sediments composed of almost equidimensional particles. For example, White1 estimated the tangential fluid stress, at the surfaces of a flat bed of sediment, when the individual particles just begin to move. This condition is defined as the incipient motion stress and was estimated for fourteen different szes of fine, well sorted granular sediments. In addition, Rees2 observed the modes of transport of a 10 µm cohesionless, natural granular silt and also postulated the existence of a second incipient motion stress which occurred when a suspended load in the fluid was in equilibrium with the bed.