Stage-discharge Curves Research Articles

Resistance Relationships for Alluvial Channel Flow

The problem of resistance to flow over alluvial beds has received considerable attention during the post-war years. Almost all the problems associated with alluvial channels—e.g., preparation of stage-discharge curves, determination of sediment transport rates, design of stable channels, prediction of aggradation and degradation due to the presence of hydraulic structures—require an accurate resistance law for their solution. The resistance of channels with a rigid bed has been defined accurately by relationships given by Keulegan and Manning. But the extensive data collected an alluvial channels in recent years have indicated large variations in the values of n, Manning's coefficient, and K S , the equivalent sand-grain roughness of the bed, for a particular channel under different flow conditions; also, the variation of these parameters with the flow conditions has not yet been satisfactorily predicted.