ABSTRACT
Non-uniform bed load transport is a common and complex physical process in river. This study was conducted to investigate the transport laws and the accurate prediction formula of non-uniform bed load. Series of flume experiment on non-uniform bed load transport were conducted based on the real time sampling system of bed load and image recognition technology. By means of fitting and dimension analysis, key parameters and the new calculation formula of the non-uniform bed load transport rate were proposed based on the river sediment data. By introducing a comprehensive flow intensity Ψb reflecting the mixture ratio of the bed material η, properties of the viscous sublayer and the characteristic Froude number Fr b, the transport characteristics of the bimodal bed load under several flow and sediment conditions were analyzed. It also indicated the combined effect of non-uniformity of sediment and particle interaction is the mechanism of the hump curve rule of bimodal bed load was analyzed.
