Bed Topography and Sediment Sorting in Channel Bend with Unsteady Flow
Publication: Journal of Hydraulic Engineering
Volume 121, Issue 8
Abstract
Bed topography and transverse sediment sorting in an alluvial channel bend were investigated under unsteady-flow conditions with nonuniform sediment. Five experiments, each having the same initial sediment-size gradation but a different inflow hydrograph, were done in a 180° channel bend with a constant radius of curvature. In addition, bed elevations across various sections of the bend were measured, and bed-surface sediment were sampled at the peak and end of the hydrograph in each experiment. Experimental results indicated that the characteristics of the hydrograph have prominent influences on bed topography and transverse sediment sorting. Those cases with a higher ramping rate of the hydrograph have greater deposition heights near the inner bank and larger scour depths near the outer bank. Furthermore, the sediment is finer near the inner bank and coarser near the outer bank in cases with a higher ramping rate. The bed deformation and sediment-size variation correlated well with the unsteady-flow parameter defined in this study. Furthermore, regression relations for transverse bed profile, transverse variation of sediment size, and total amount of sediment discharge were established in terms of the unsteady-flow parameter.
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References
1.
Allen, J. R. L.(1970). “A quantitative model of grain size and sedimentary structures in lateral deposits.”Geological J., 7, 129–146.
2.
Bridge, J. S.(1976). “Bed topography and grain size in open channel bends.”Sedimentology, 23(3), 407–414.
3.
Dietrich, W. E., and Smith, J. D.(1984). “Bed load in a river meander.”Water Resour. Res., 20(10), 1355–1380.
4.
Engelund, F.(1974). “Flow and bed topography in channel bends.”J. Hydr. Div., ASCE, 100(11), 1631–1648.
5.
Falcon, M. A., and Kennedy, J. F.(1983). “Flow in alluvial-river curves.”J. Fluid Mech., 133, 1–16.
6.
Graf, W. H., and Suszka, L. (1985). “Unsteady flow and its effect on sediment transport.”Proc. 21st Congress, International Association for Hydraulic Research, Delft, The Netherlands, 540–544.
7.
Griffiths, G. A., and Sutherland, A. J.(1977). “Bedload transport by translation waves.”J. Hydr. Div., ASCE, 103(11), 1279–1291.
8.
Ho, S. Y. (1987). “Flow characteristics and evolution of bed topography in meandering channels with fixed banks,” PhD thesis, National Taiwan University, at Taipei, Taiwan.
9.
Ikeda, S., Yamasaka, M., and Chiyoda, M.(1987). “Bed topography and sorting in bends.”J. Hydr. Engrg., ASCE, 113(2), 190–206.
10.
Kikkawa, H., Ikeda, S., and Kitagawa, A.(1976). “Flow and bed topography in curved open channels.”J. Hydr. Div., ASCE, 102(9), 1327–1342.
11.
Lee, K. T. (1991). “The effects of unsteady flow characteristics on bed topography and sediment gradation in river bends,” PhD thesis, National Taiwan University, at Taipei, Taiwan.
12.
Little, W. C., and Mayer, P. G. (1972). “The role of sediment gradation on channel armoring.”ERC-0672, School of Civ. Engrg., Georgia Inst. of Technol., Atlanta, Ga.
13.
Nouh, M. (1989). “Self armoring process under unsteady flow conditions.”Proc. 23rd Congress, International Association for Hydraulic Research, Delft, The Netherlands, B49–56.
14.
Odgaard, A. J.(1982). “Bed characteristics in alluvial channel bends.”J. Hydr. Div., ASCE, 108(11), 1268–1281.
15.
Rozovskii, I. L. (1961). “Flow of water in bends of open channels.”No. OTS 60-51133, Y. Prushansky, translation, Office of Technical Services, U.S. Dept. of Commerce, Washington, D.C.
16.
Yen, B. C. (1965). Characteristics of subcritical flow in a meandering channel . Iowa Inst. of Hydr. Res., Iowa City, Iowa.
17.
Yen, C. L. (1967). “Bed configuration and characteristics of subcritical flow in a meandering channel,” PhD thesis, University of Iowa, at Iowa City, Iowa.
18.
Yen, C. L., and Lee, K. T. (1991). “Effects of reservoir on bed topography and sediment gradation of downstream channel bends (III).”Research Report No. 126, Hydr. Res. Lab., Nat. Taiwan Univ., Taipei, Taiwan (in Chinese).
19.
Yen, C. L., and Lin, Y. L.(1990). “Bed material and bed topography in channel bend.”Proc. 7th Asian and Pacific Div. Congress, International Association for Hydraulic Research, Delft, The Netherlands, 1, 213–218.
20.
Zimmermann, C., and Kennedy, J. F.(1978). “Transverse bed slopes in curved alluvial streams.”J. Hydr. Div., ASCE, 104(1), 33–48.
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Copyright © 1995 American Society of Civil Engineers.
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Published online: Aug 1, 1995
Published in print: Aug 1995
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