|Water Science and Engineering 2013, 6(2) 178-188 DOI: 10.3882/j.issn.1674-2370.2013.02.006 ISSN: 1674-2370 CN: 32-1785/TV|
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Mechanism of back siltation in navigation channel in Dinh An Estuary, Vietnam
Viet-Thanh NGUYEN1, 2, 3, Jin-hai ZHENG*1, 2, Ji-sheng ZHANG1, 2
1. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, P. R. China
The Dinh An Estuary is one of the Nine Dragon estuaries of the Mekong River. An international navigation channel was built in the estuary for vessels traveling from the South China Sea to the southwestern area of Vietnam and then to Phnom Penh, Cambodia. The morphological evolution of the navigation channel is complicated and unstable. The back siltation intensity in the navigation channel has largely increased and been concentrated in the curvature segments of the channel since 1980. In this study, based on simulation results and measured data, five key factors that influence the back siltation in the navigation channel were systematically analyzed. These factors included the increasing elevation gap between the channel and the nearby seabed, the disadvantageous hydrodynamic conditions, sediment transport, mixing of saltwater and freshwater, and wave effects in the navigation channel. It is shown that the back siltation to a large extent results from the low current velocity of the secondary ocean circulation, which often occurs in the curvature segments of the channel. Suspended sediment also settles in the channel due to the decrease of the current velocity and the sediment transport capacity when flow passes through the channel. The changes of hydrodynamic conditions are responsible for the majority of the severe siltation in the curvature segments of the navigation channel.
|Keywords： back siltation hydrodynamics navigation channel sediment transport Dinh An Estuary|
|Received 2012-08-31 Revised 2013-02-21 Online: 2013-04-05|
This work was supported by the 322 Project of Vietnam International Education Development, Ministry of Education and Training, Vietnam (Grant No. 322), the Qing Lan Project, the 333 Project of Jiangsu Province (Grant No. BRA2012130), the Fundamental Research Funds for the Central Universities (Grant No. 2012B06514), and the 111 Project (Grant No. B12032).
|Corresponding Authors: Jin-hai ZHENG|
An, N. N. 1994. Numerical Model to Simulate the Hydrodynamic and Proposed Regulation Scheme to Improvement Navigation Channel in Dinh An Estuary.
An, T. V. 2005. Study the Solutions to Stabilized Bed of Channel in Dinh An Estuary Service to Waterway Transport.
Hau, L. P. 2005. Estuarine Hydrodynamic and Engineering.
Hung, L. M. 1988. Morphological Evolution of Dinh An Estuary Before and After Dredging.
Nguyen, T. V., and Tanaka, H. 2007. Study on the effect of morphology change on salinity distribution in the Dinh An Estuary, Lower Mekong River of Vietnam. Journal of Coastal Research, (50), 268-272.
Nguyen, V. T., Zheng J. H., and Luong, P. H. 2011. Morphological evolution of navigation channel in Dinh An estuary,
Nguyen, T. V. 2012. Morphological Evolution and Back Siltation of Navigation Channel in Dinh An Estuary,
Portcoast Consultant Corporation. 2006. Feasibility Project of Waterway for Heavy-Tonnages Ships to Enter the
Portcoast Consultant Corporation, Nippon Koei
Savenije, H. G. 2005. Salinity and Tides in Alluvial Estuaries. The
Shao, Y. Y., Yan, Y. X., and Maa, J. P. Y. 2011. In situ measurements of settling velocity near Baimao shoal in Changjiang Estuary. ASCE Journal of Hydraulic Engineering, 137(3), 372-380. [doi:10.1061/(ASCE) HY.1943-7900.0000312]
Thuy, N. N. 1989. Hydrodynamic Modeling of the Propagation of Tidal Waves in the River System of the
van Rijn, L. C. 2004. Estuarine and coastal sedimentation problems. International Journal of Sediment Research, 20(1), 39-51.
Warner, J. C., Schoellhamer, D. H., Burau, J. R., and Schladow, S. G. 2006. Flow convergence caused by a salinity minimum in a tidal channel.
Wolanski, E., Nguyen, N. H., Le, T. D., Nguyen, H. N., and Nguyen, N. T. 1996. Fine-sediment dynamics in the Mekong River Estuary,
Zhang, C., Zheng, J. H., Wang, Y. G., Zhang, M. T., Jeng, D. S., and Zhang, J. S. 2011. A process-based model for sediment transport under various wave and current conditions. International Journal of Sediment Research, 26(4), 498-512. [doi:10.1016/S1001-6279(12)60008-0]
Zhang, W., Wei, X. Y., Zheng, J. H., Zhu, Y. L., and Zhang, Y. J. 2012. Estimating suspended sediment loads in the Pearl River Delta region using sediment rating curves. Continental Shelf Research, 38, 35-46. [doi:10.1016/j.csr.2012.02.017]
Zheng, J. H., Yan, Y. X., and Zhu, Y. L. 2002. Three dimensional baroclinic numerical model for simulating fresh and salt water mixing in the Yangtze Estuary.
Zheng, J. H., Mase, H., Demirbilek, Z., and Lin, L. H. 2008. Implementation and evaluation of alternative wave breaking formulas in a coastal spectral wave model. Ocean Engineering, 35(11-12), 1090-1101. [doi:10.1016/j.oceaneng.2008.05.001]
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