Forecasting suspended sediment discharge by using time series transfer function model in selected stations of Gorganrood, Golestan Province

Since information about temporal variation of suspended sediment establishes a basis for watershed and river management, it is crucial to utilize a method for modeling and forecasting suspended sediment that takes all influential factors into account. In this research, the transfer function model is used to study temporal variation of suspended sediment on seven selected stations in Gorganrood river. In order to evaluate the performance of the model in forecasting suspended sediment compared to the sediment rating curve, only flow discharge is considered as a highly effective factor in variation of suspended sediment. Although this comparison reveals that these two variables are mainly related at the same time but to develop into a more precise and accurate set of forecasts, the values of suspended sediment and flow discharge at past time should be taken in the model. Based on the validation criteria, the transfer function model was accurately fitted in both stations. Finally, comparing two models from forecasting point of view revealed that the transfer function model with model efficiency 98 and 97 for Hajighoshan and Voshmgir stations, respectively and with the bias less than 1 for both stations presents more accurate and precise forecasts compared to sediment rating curve.