Effect of Shallowness on Sediment Deposition in Recirculation Zones
Publication: Journal of Hydraulic Engineering
Volume 137, Issue 9
Abstract
Various hydrodynamic and sediment deposition experiments were conducted on a purpose-built, wide, shallow water table using a range of incoming flow and bed roughness conditions, including five flow rates, different inflow sediment concentrations, and different artificial roughness coefficients generated by four transverse string intervals. A recirculation zone was created behind a 0.5-m-wide backward-facing step on the left side of the table. Surface velocities, sediment concentrations, and processes and features of sediment deposition in recirculation zones were measured. Experimental results indicate that (1) as the value of the shallow stability parameter increased from 0.033 to 0.47, the length of the recirculation zone decreased to less than half, but the corresponding area and volume of sediment deposition increased about four times, and (2) it is the strength of the mixing layer rather than the size of the recirculation zone that dominates the process of sediment deposition as well as the final deposition feature.
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Acknowledgments
The writers thank the National Natural Science Foundation of China (NSFC), Science Fund for Distinguished Young Scholars program, for support of this study and support for Daoyi Chen in collaboration with Guangqian Wang at Tsinghua University (Grant No. NNSFC50428906). The writers also thank the reviewers very much for their constructive comments that improved the paper.
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Information
Published In
Journal of Hydraulic Engineering
Volume 137 • Issue 9 • September 2011
Pages: 976 - 985
Copyright
© 2011 American Society of Civil Engineers.
History
Received: Apr 23, 2010
Accepted: Dec 2, 2010
Published online: Dec 6, 2010
Published in print: Sep 1, 2011
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