A NEW APPROACH FOR THE EVALUATION OF SEDIMENT TRANSPORT PREDICTORS IN ALLUVIAL STREAMS AND DEVELOPMENT OF THE NEW EQUATIONS FOR SPECIAL SITUATIONS

摘要

The transport of sediments along alluvial channels is of importance to the river engineering problems. Bed load transport in alluvial channels has been extensively studied and a number of theoretical semi-empirical or empirical equations have been proposed (Meyer-Peter and Mueller (1948), Einstein (1950, 1952), Ackers and White (1973) and others. They relate the rate of sediment transport either to the average velocity of flow or to the bed shear. Each author contributes with his very personal approach to find the equation. Therefore, prediction of sediment transport rate, using different equations, results in wide range of predicted values, which always are not reliable. In the present study, first some data from 210 observations in natural rivers and 5620 observations from different series of experiments were used to compare a number of existing formulae for the description of sediment transport in alluvial channels. The results show that none of the equations predicts well within the range of observations. Though, the Ackers and White, Van Rijn and Toffaleti equations give somewhat more accurate prediction than the others. Then, from the available data, 2243 series of the experimental data were analyzed using statistical methods to implement some relationships for the prediction of bedload transport rates for various sediment and hydraulic conditions. The remaining observations were used to verify the proposed relationships.