Analysis of Histological features of Sarbaz River sediments and Estimation of river sediment load in Pishin dam Drainage basin, east of Sistan and Baluchestan province

River sediments are the major component of the aquatic ecosystems and play an important role in the nutrients cycle and contaminants transformation in river systems. Therefore, in this study, Analysis of Histological features of Sarbaz River sediments and Estimation of river sediment load in Pishin dam Drainage basin, east of Sistan and Baluchestan province, has been studied. For sedimentation, in this study, extrapolation method or sediment measurement curve has been used. According to the relevant data to stream discharge and sediment discharge, their relationship is evaluated as (Qs=22/89 * QW 1/939). Annual average of sediment load in the river is obtained as 425021 ton of suspended load and 42500 to 85000 ton of bed load. Other results also showed that the change in mean particle size and sediment sorting in the form of a discontinuous exponential increase from the point of entry of tributaries to the estuary of the river, well shows the role of feeding tributaries in the sediment logical status of the main tributary.