This present study was conducted to determine particle size characteristics of suspended sediments transported by base and flood-flows in theKojurRiverin Kojur forest watershed with an area of 50000 ha. Sediment samples were analyzed based on Stokes’ law using a modified pipette and applying the GRADISTAT software. Results showed 81.1, 3.4 and 15.3% for sand, silt, and clay, respectively, in base flow conditions while under flood conditions, the same values were 56.5, 17.0 and 26.5%.
