Ocean Systems Engineering

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Monsoonal sediment transport along the subaqueous Mekong Delta: An analysis of surface sediment grain-size changes

  • Thanh C., Nguyen (University of Science, Ho Chi Minh City) ;
  • An T., Dang (University of Science, Ho Chi Minh City) ;
  • Khuong N.T., Tran (University of Science, Ho Chi Minh City)
  • Received : 2022.06.05
  • Accepted : 2022.11.28
  • Published : 2022.12.25
⟨ Previous Next ⟩

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.

Keywords

Acknowledgement

This research is funded by Vietnam National University Ho Chi Minh City (VNU-HCM) under grant number C-2020-18-01 project entitled "Hydrodynamics processes driving the sediment transport along the coast of the Mekong Delta". In addition, we wish to express our sincere thanks to the anonymous reviewers for their helpful comments, which helped us to improve this draft.

References

  1. Anthony, E.J., Brunier, G., Besset, M., Goichot, M., Dussouillez, P. and Nguyen, V.L. (2015), "Linking rapid erosion of the Mekong River Delta to human activities", Scientific Reports, 5, 14745. https://doi.org/10.1038/srep14745.
  2. Besset, M., Gratiot, N., Anthony, E.J., Bouchette, F., Goichot, M. and Marchesiello, P. (2019), "Mangroves and shoreline erosion in the Mekong River Delta, Viet Nam", Estuar. Coast. Shelf S., 226, 106263. https://doi.org/10.1016/j.ecss.2019.106263.
  3. Brunier, G., Anthony, E.J., Goichot, M., Provansal, M. and Dussouillez, P. (2014), "Recent morphological changes in the Mekong and Bassac river channels, Mekong eelta: The marked impact of river-bed mining and implications for delta destabilisation", Geomorphology, 224, 177-191. https://doi.org/10.1016/j.geomorph.2014.07.009.
  4. Darby, S.E., Hackney, C.R., Leyland, J., Kummu, M., Lauri, H., Parsons, D.R., Best, J.L., Nicholas, A.P. and Aalto, R. (2016), "Fluvial sediment supply to a mega-delta reduced by shifting tropical-cyclone activity", Nature, 539(7628), 276-279. https://doi.org/10.1038/nature19809.
  5. Kondolf, G.M., Rubin, Z.K. and Minear, J.T. (2014), "Dams on the Mekong: cumulative sediment starvation", Water Resour. Res., 50(6), 5158-5169. https://doi.org/10.1002/2013WR014651
  6. Kummu, M. and Varis, O. (2006), "Sediment-related impacts due to upstream reservoir trapping, the lower Mekong River", Geomorphology, 85(3-4), 275-293. https://doi.org/10.1016/j.geomorph.2006.03.024.
  7. Li, X., Liu, J.P., Saito, Y. and Nguyen, V.L. (2017), "Recent evolution of the Mekong Delta and the impacts of dams", Earth-Science Reviews, 175, 1-17. https://doi.org/10.1016/j.earscirev.2017.10.008.
  8. Liu, J.P., DeMaster, D.J., Nittrouer, C.A., Eidam, E.F. and Nguyen, T.T. (2017), "A seismic study of the Mekong subaqueous delta: proximal versus distal sediment accumulation", Cont. Shelf Res., 147, 197-212. https://doi.org/10.1016/j.csr.2017.07.009.
  9. Loisel, H., Mangin, A., Vantrepotte, V., Dessailly, D., Ngoc Dinh, D., Garnesson, P., Ouillon, S., Lefebvre, J.-P., Meriaux, X. and Minh Phan, T. (2014), "Variability of suspended particulate matter concentration in coastal waters under the Mekong's influence from ocean color (MERIS) remote sensing over the last decade", Remote Sens. Environ., 150, 218-230. https://doi.org/10.1016/j.rse.2014.05.006.
  10. Manh, N. Van, Dung, N.V., Hung, N.N., Kummu, M., Merz, B. and Apel, H. (2015), "Future sediment dynamics in the Mekong Delta floodplains: Impacts of hydropower development, climate change and sea level rise", Global Planet. Change, 127, 22-33. https://doi.org/10.1016/j.gloplacha.2015.01.001.
  11. Marchesiello, P., Nguyen, N.M., Gratiot, N., Loisel, H., Anthony, E.J., Dinh, C.S., Nguyen, T., Almar, R. and Kestenare, E. (2019), "Erosion of the coastal Mekong Delta: Assessing natural against man induced processes", Cont. Shelf Res., 181, 72-89. https://doi.org/10.1016/j.csr.2019.05.004.
  12. Milliman, J.D. and Farnsworth, K.L. (2011), "River discharge to the coastal ocean", Cambridge University Press.
  13. Milliman, J.D. and Meade, R.H. (1983), "World-wide delivery of river sediment to the oceans", J. Geology, 91(1), 1-21. https://www.jstor.org/stable/30060512. https://doi.org/10.1086/628741
  14. Nguyen, T.T., Stattegger, K., Unverricht, D., Nittrouer, C., Phung, V.P., Liu, P., DeMaster, D., Bui, V.D., Le, D.A. and Mai, D.D. (2017), "Surface sediment grain-size distribution and sediment transport in the subaqueous Mekong Delta, Vietnam", Vietnam J. Earth Sci., 39(3), 193-209. https://doi.org/10.15625/0866-7187/39/3/10266.
  15. O'Malley, J. (2007), "U.S Geological Survey ArcMap Sediment Classification Tool: Installation and User Guide".
  16. Rasanen, T.A., Someth, P., Lauri, H., Koponen, J., Sarkkula, J. and Kummu, M. (2017), "Observed river discharge changes due to hydropower operations in the upper Mekong Basin", J. Hydrology, 545. https://doi.org/10.1016/j.jhydrol.2016.12.023.
  17. Shepard, F.P. (1954), "Nomenclature based on sand-silt-clay ratios", J. Sedimentary Petrology, 24, 151-158. https://doi.org/10.1306/D4269774-2B26-11D7-8648000102C1865D.
  18. Szczucinski, W., Jagodzinski, R., Hanebuth, T.J.J., Stattegger, K., Wetzel, A., Mitrega, M., Unverricht, D. and Van Phach, P. (2013), "Modern sedimentation and sediment dispersal pattern on the continental shelf off the Mekong River Delta, South China Sea", Global Planet. Change, 110, 195-213. https://doi.org/10.1016/j.gloplacha.2013.08.019.
  19. TCVN4198:2014 (2014), "Soils - Laboratory methods for particle - size analysis", Viet Nam Standards and Quality Institute. (in Vietnamese)
  20. Unverricht, D., Nguyen, T.C., Heinrich, C., Szczucinski, W., Lahajnar, N. and Stattegger, K. (2014), "Suspended sediment dynamics during the inter-monsoon season in the subaqueous Mekong Delta and adjacent shelf, southern Vietnam", J. Asian Earth Sci., 79, 509-519. https://doi.org/10.1016/j.jseaes.2012.10.008.
  21. Unverricht, D., Szczucinski, W., Stattegger, K., Jagodzinski, R., Le, X.T. and Kwong, L.L.W. (2013), "Modern Sedimentation and morphology of the subaqueous Mekong Delta, Southern Vietnam", Global Planet. Change, 110, 223-235. https://doi.org/10.1016/j.gloplacha.2012.12.009
  22. Walling, D.E. (2008), "The changing sediment load of the Mekong River", AMBIO: A J. Human Environment, 37(3), 150-157. https://doi.org/10.1579/0044-7447.
  23. Wang, J.J., Lu, X.X. and Kummu, M. (2011), "Sediment load estimates and variations in the lower Mekong River", River Res. Appl., 27(1), 33-46. https://doi.org/10.1002/rra.1337