PREDICTION OF SUSPENDED BED MATERIAL TRANSPORT IN FLOWS OVER SILT AND VERY FINE SAND

Three equilibrium sand transport formulae were tested for prediction of the suspended bed material transport rate in the silt-laden Huanghe (Yellow River): Ackers and White (1973), Engelund and Hansen (1967), and Van Rijn (1984b). The best results were obtained with the Van Rijn function. However, at low flow stages better results were produced by the Engelund-Hansen equation. The Ackers-White formula seriously overpredicted the measured values. Some modifications of the Van Rijn formula were proposed for application in flows over very fine sand and silt. In a verification analysis it was demonstrated that these modifications slightly improve its predictive strength. Also, attention was paid to the effect of turbulence damping by sediment particles at high concentrations.