Movement of sediment as bed load in rivers

Abstract

The movement of sediment which rolls and creeps along the bed of a river, and is known as bed load, is analyzed using basic physical principles of fluid dynamics. The conditions for the start of sand‐grain movement are set down and form an important part of the analysis. The turbulence mechanism in the flow above the bed plays a most significant role in the analysis of rate of bed‐load movement. The final equation developed for the rate of sediment transport is not empirical; all the numerical constants in it are definite physical measures either of the sediment or of the hydraulic and turbulence characteristics of the river. The equation fits laboratory and field data obtained for a wide variety of conditions by various experimenters.