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International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 12, No. 2, 2015, pp. 775-788
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Bioline Code: st15070
Full paper language: English
Document type: Review Article
Document available free of charge
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International Journal of Environment Science and Technology, Vol. 12, No. 2, 2015, pp. 775-788
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Sediment transport during flood event: a review
Karimaee Tabarestani, M. & Zarrati, A.R.
Abstract
Flow unsteadiness in flood events has a significant
effect on the structure of the flow field and motion
of sediment particles, thereby affecting dispersion of pollutants
and river ecology. The aim of the present article
was to evaluate state-of-the-art research efforts concerning
flow characteristics and sediment transport in unsteady
flow condition. The paper is organized in four sections: The
first section deals with the unsteady parameters which
affect sediment transport. In the second section, the flow
characteristics in unsteady open channel flow are presented.
Different studies showed that the flow characteristics
which affect sediment transport including velocity
distribution or shear stress during passage of a hydrograph
differ from steady flow condition. In addition, measurements
during passage of a hydrograph show that turbulence
intensity is generally larger in the rising limb of the hydrograph
rather than in the falling limb. This causes the peak
of sediment load and pollutants occur during the rising
limb of the storm hydrograph. The third and forth sections
deal with bed load and suspended load in unsteady flow
condition, respectively. Studies show that the methods
which are based on steady flow conditions generally
underestimate the sediment transport rates in unsteady
flows. The larger the unsteadiness, the bigger is the difference.
Finally, with considering different findings from
previous studies, suggestions are presented for further
research.
Keywords
Unsteady flow; Bed load; Suspended load; Unsteady parameter; Flow characteristics; Pollution; dispersion; Review
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