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Ocean Systems Engineering Volume 12, Number 4, December25 2022 , pages 403-411 DOI: https://doi.org/10.12989/ose.2022.12.4.403 |
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Monsoonal sediment transport along the subaqueous Mekong Delta: An analysis of surface sediment grain-size changes |
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Thanh C. Nguyen, An T. Dang and Khuong N.T. Tran
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| Abstract | ||
| Annually, about 48-60% of sediment discharge of the Mekong River is delivered near the mouths of the Mekong River branches which is mostly coinciding with the southwest (SW) monsoon. This sediment budget in turn will be southwestwardly transported along the coast of the Mekong Delta (MD) during the northeast (NE) monsoon. Analysis of monsoonal changes in grain-size distribution (GSD) of surface sediment contributes to a better understanding of erosion and deposition processes along the MD. This study aims to figure out changes in GSD and sediment textures along the MD between SW and NE monsoons based on 183 surficial sediment samples collected along the MD during two field surveys carried-out in October 2016 and February—March 2017. Compared to the GSD during the SW and NE monsoon, the GSD along the MD changed significantly, especially in the estuary areas and along the coast of Bac Lieu and Ganh Hao. Whereas, in the west coast of the MD, GSD seem no changes between the two seasons. These changes in seabed sediment suggest that sediment with grain-sizes ranging from silt to fine sand can be transported during only a NE season. | ||
| Key Words | ||
| bathymetry; eroding; fine sand; grain-size distribution; Mekong Delta | ||
| Address | ||
| Thanh C. Nguyen, An T. Dang and Khuong N.T. Tran: University of Science, Ho Chi Minh City, Vietnam; Vietnam National University- Ho Chi Minh City, Vietnam, 227 Nguyen Van Cu Str., Dist. 5, Ho Chi Minh City, Vietnam | ||
