Modeling Runoff and Sediment Yield Using of Hydro-Geomorphologic Characters in Samian Watershed, Ardabil Province

Runoff and sediment yield are important issues in water resource management that led to some problems in utilization of water structure and dams. Runoff volume, soil erosion intensity and sediment yield in watersheds are related to watersheds hydro-geomorphologic characteristics. Therefore, the aim of this research is to assess a relationship between watersheds hydro-geomorphologic characteristics with runoff and sediment yield in upstream of Samian hydrometer station with 42157 ha area. For this aim, the upstream watershed of this hydrometric station and 19 other sub watersheds were determined. The watersheds characteristics were divided in 6 groups and 76 parameters. Using of the correlation matrix, Ward clustering method and PCA method were determined parameters for modeling in three different scales that prepared 72 equations for estimation runoff and sediment yield. Also, the statistical coefficient consists of NS, R2 and RMSE were used for assessment of the obtained equations. Results showed that the obtained equations from total watershed scale with NS coefficient between 0. 95 and 0. 99, and R2 coefficient between 0. 97 and 0. 99 have the highest accuracy. Also, the equations obtained of selected parameters with PCA method have high precision than clustering method. Regarding importance of runoff and sediment yield estimation in ungauged stations, the regional modeling method can be used with high performance.