Assessment of minimum variance unbiased estimator and beta coefficient methods to improve the accuracy of sediment rating curve estimation

Because of the requirement to just one input data, the basic sediment rating curve (SRC) method is the most recognised method for the study of river sediment load. Beside its advantages, this method suffers from low accuracy, especially for upper limit of sediment load values which is leading to the reduction of its reliability. In this study, sediment data recorded in four hydrometry station located in Gorgan Gulf basin are used to investigate and compare the accuracy of minimum variance unbiased estimator (MVUE) and beta coefficient as two correction methods. Visual criterion and two goodness of fit tests, namely mean square error (MSE) and model efficiency (ME) were applied to compare the results of SRC estimations. Visual and goodness of fit tests showed both correction methods particularly beta coefficient method improve the SRC estimation especially for upper limit of river sediment load in three of the four understudy stations.