Particle Size Characteristics of Suspended Sediment Transported in River Base and Flood-Flows

Document Type : Technical Note


1 Graduated Student of Watershed Management, Dept. of Natural Resources and Marine Sciences, Tarbiat Modarres Universicy, Noor

2 Assoc. Prof. of Watershed Management, Dept. of Natural Resources and Marine Sciences, Tarbiat Modarres University, Noor


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%.


1- Woodward, J. C., and Walling, D. E. (2007). “Composite suspended sediment particles in river systems: Their incidence, dynamics and physical characteristics.” J. Hydrological Processes, 21, 3601-3614.
2- Williams, N. D., Walling, D. E., and Leeks, G. J. L. (2008). “An analysis of the factors contributing to the settling potential of fine fluvial sediment.” J. Hydrological Processes, 22, 4153-4162
3-Williams, N. D., Walling, D. E., and Leeks, G. J. L. (2007). “High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended Sediment.” J. Water Research, 41, 1081-1093.
4- Beuselinck, L., Govers, G., Poesen, J., and Degraer Froyen, G. (1998). “Grain-size analysis by laser diffractometry: Comparison with the sieve-pipette method.” J. Catena., 32, 193-208.
5- Walling, D. E., Owens, Ph. N., Waterfall, B. D., Leeks, G. J. L., and Wass, P. D. (2000). “The particle size characteristics of fluvial suspended sediment in the Humber and Tweed catchments, UK.” J. The Science of the Total Environment, 251/252, 205-222.
6- Mahdavi, M. (2002). Applied hydrology, University of Tehran Pub., Vol. 2, Tehran.
7- Edwards, T. K., and Glysson, G. D. (1999). Field methods for measurement of fluvial sediment, USGS Open-File Report, Book 3 Chapter 2, USA.
8- Fernández, S., Villanueva, U., de Diego, A., Arana, G., and Madariaga, J. M. (2008). “Monitoring trace elements (Al, As, Cr, Cu, Fe, Mn, Ni and Zn) in deep and surface waters of the estuary of the Nerbioi-IbaizabalRiver(Bay of Biscay, Basque Country).” J. Marine Systems, 72, 332-341.
9- Sadeghi, S. H. R., Aghabeigi, S., Vafakhah, M., Yasrebi, B., and Esmaeili, S. A. (2006). “Suitable drying time for suspended sediment samples, Iran.” Proc., International Sediment Initiative Conference, Khartoum, Sudan, 12-16.
10- Gasparotto, E., Malo,D.D., and Gelderman, R. H. (2003). “Impact of organic matter removal on particle size analysis by pipette and hydrometer.” Soil/Water Research. Available at <> (May 2008).
11- Chaudhari, S. K., Singh, R., and Kundu, D. K. (2008). “Rapid textural analysis for saline and alkaline soils with different physical and chemical properties.” J. Soil Science Society of America, 72, 431-441.
12- Gavlok, R., Horneck, D., Miller, R. O., and Kotuby-Amacher, J. (2003). Soil, plant and water reference methods for the western region, 2nd Ed., WCC-103 Pub., USA.
13- Mousavi Herami, R. (2004). Sedimentology, Astan Ghods Razavi Inc., Mashhad, Iran. (In Persian)
14- Blott, S. S., and Pye, K. (2001). “Gradistat: A grain size distribution and statistics package for the analysis of unconsolidated sediment.” J. Earth Surface Processes Land Forms, 10 (26), 1237-1248.