Discharge-Sediment Relative Approach (DSRA) to Estimate of the Annual River Sediment Delivery

Estimating river sediment delivery is one of the important issues for researchers in hydrological studies because of its complexity. In a river that has sediment data in a few days per month، estimating of river sediment delivery is carried out by using sediment rating curve method. In this study in order to exactly estimation for such rivers، a new approach has been developed which it can be called as «Discharge-Sediment Relative Approach (DSRA)». It is developed based on expanding sediment concentration continuity curve based on individual sediment concentration data in a few days of each month. In this method، the fluctuation of sediment concentration between two continuous measurements is reconstructed based on the ratio of the measured sediment concentration and water discharge. In this paper the DSRA method has been applied to estimate of Dez river sediment delivery as a case study. Also the amount of sediment inflow to Dez reservoir were calculated by using the USBR rating curve method. Comparison of calculated results with measured data obtained from Dez reservoir bathymetry showed that errors of the DSRA method to estimate of the annual sediment inflow to Dez reservoir was obtained as 8. 5% while this value for USBR rating curve method was about 27%. This means that the DSRA Method could be considered as a good approach to estimate of river sediment delivery for gauged basins.