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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Keywords
back siltation
hydrodynamics
navigation channel
sediment transport
Dinh An Estuary
Authors
VIET-THANH -NGUYEN
ZHENG Jin-Hai
PubMed
Article by Viet-Thanh,.N
Article by Zheng,J.H

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
2. College of Harbor, Coastal and Offshore Engineering, Hohai University, Nanjing 210098, P. R. China
3. Faculty of Civil Engineering, University of Transport and Communications, Hanoi, Vietnam

Abstract

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 
DOI: 10.3882/j.issn.1674-2370.2013.02.006
Fund:

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
Email: jhzheng@hhu.edu.cn
About author:

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