Estimate of Sediment Transport Rate at Karkheh River in Iran Using Selected Transport Formulas

In this study, the capability of sediment transferring formulas of Bagnold, Engelund and Hansen, Ackers and White, Yang and Van Rijn in the Karkheh River of Iran had been tested. In pointed formulas about 90 series of field data, had been applied which their suspended load concentration had been measured. The best sediment load estimate of Karkheh River had been reach by Yang formula which was proper for rivers with high suspended load concentration. The Engelund and Hansen and Ackers and White methods estimated the total sediment load more than observation rate and the Van Rijn formula estimated the rate of sediment rate lower than observation rate. The high scattering in calculated sediment load results by Engelund and Hansen, Ackers and White and Van Rijn methods, cleared which this methods were not appropriate for estimate sediment load of Karkheh River. But Yang and the following Bagnold methods delivered the better results. The obvious difference between estimated sediment load rate, by various methods and its measured rate is the reason of wash load which has not been accounted in the experimental formulas.