Comparison of Statistical Methods for Long-Term Suspended Sediment Yield Estimation (Case Study: Babolrood River)

In the present study، by classifying the flow rate and dividing the time series، some statistical regression models are investigated and with the establishment of regression relationship between observed flow rate versus sediment rate and simulate it according to the least square error and USBR and FAO methods، the sediment rating curves are presented with the its statistical analysis. Then، the most appropriate model is selected according to statistical indexes viz. mean square error and determination coefficient. Moreover، the value of long term suspended sediment yield are estimated by combination of the proposed models and the type of flow rate such as flow integrated curve، mean daily flow rate and mean monthly flow rate. In this case، the daily measuring flow rate and sediment concentration for 23 years at Ghoran Talar Hydrometric station located in Babolrood River is used. Finally، the combined mid classes model according to FAO method with mean daily flow rate have been recommended as a suitable model.