Numerical simulation of seasonal currents in the Mekong Coastal Area: a case in 2019

Thanh Duong Nguyen; Duy Vinh Vu; Minh Hai Nguyen

doi:10.15625/1859-3097/22266

Author affiliations

Authors

Nguyen Thanh Duong Institute of Science and Technology for Energy and Environment, VAST, Vietnam
Vu Duy Vinh Institute of Science and Technology for Energy and Environment, VAST, Vietnam https://orcid.org/0000-0002-4500-027X
Nguyen Minh Hai Institute of Science and Technology for Energy and Environment, VAST, Vietnam

DOI:

https://doi.org/10.15625/1859-3097/22266

Keywords:

Seasonal currents, Mekong, Delft3D, hydrodynamics, modeling

Abstract

This study, employing the Delft3D numerical model, investigated the Mekong Delta’s seasonal current dynamics by simulating its hydrodynamic regime in 2019. Using Nash-Sutcliffe Efficiency and Root Mean Square Error metrics, the model’s accuracy in replicating measured water levels (cm) and currents at various stations was validated, achieving acceptable simulation results. This allowed for a reliable analysis of the delta’s current patterns. The study revealed that while the overall direction and peak velocity of current remain relatively consistent throughout the year, their spatial distribution undergoes significant shifts, particularly during the transitional periods between seasons. Monthly flow velocities reflect this seasonality, with strong (up to 1 m/s) and consistent northeast-southwest surface flows during the low flow season (minimal stratification), driven by northeasterly winds. Conversely, the flood season exhibits greater regional variability in velocity and direction due to strong freshwater input and fluctuating winds, with surface velocities reaching 1 m/s in the Mekong estuary in October but decreasing sharply with depth (strong stratification), and flow directions shifting dynamically throughout the season.

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References

[1] H. Hein, B. Hein, and T. Pohlmann, “Recent sediment dynamics in the region of Mekong water influence,” Global and Planetary Change, vol. 110, pp. 183–194, 2013.

[2] N. M. Nguyet, V. D. Duong, D. T. Le, L. D. Tu, C. D. San, P. N. Truong, N. Quyen, T. Bang, D. P. Wright, A. H. Tanim, and D. T. Anh, “Wave efficiency for three classes of breakwaters on the coastal Mekong Delta,” Applied Ocean Research, vol. 129, 103362, 2022.

[3] V. D. Vinh, S. Ouillon, N. Van Thao, and N. N. Tien, “Numerical simulations of suspended sediment dynamics due to seasonal forcing in the Mekong coastal area,” water, vol. 8, 255, 2016.

[4] V. D. Vinh, S. Ouillon, T. D. Thanh, and C. V. Chu, “Impact of the Hoa Binh dam (Vietnam) on water and sediment budgets in the Red River basin and delta,” Hydrology and Earth System Sciences, vol. 18, pp. 3987–4005, 2014.

[5] T. Q. Tuan and M. T. Luan, “Monsoon wave transmission at bamboo fences protecting mangroves in the lower Mekong Delta,” Applied Ocean Research, vol. 101, 102259, 2020.

[6] D. Unverricht, T. C. Nguyen, C. Heinrich, W. Szczuciński, N. Lahajnar, and K. Stattegger, “Suspended sediment dynamics during the inter-monsoon season in the subaqueous Mekong Delta and adjacent shelf, southern Vietnam,” Journal of Asian Earth Sciences, vol. 79, pp. 509–519, 2014.

[7] T. D. Dang, T. A. Cochrane, and M. E. Arias, “Quantifying suspended sediment dynamics in mega deltas using remote sensing data: A case study of the Mekong floodplains,” International Journal of Applied Earth Observation and Geoinformation, vol. 68, pp. 105–115, 2018.

[8] N. N. Tien, “The influence of hydrodynamic factors on characteristics of suspended sediment distribution in the Mekong River Mouth Area,” Vietnam Journal of Marine Science and Technology, vol. 15, pp. 150–158, 2015.

[9] N. Taniguchi, C. F. Huang, M. Arai, and B. M. Howe, “Variation of residual current in the Seto Inland Sea driven by sea level difference between the Bungo and Kii Channels,” Journal of Geophysical Research: Oceans, vol. 123, pp. 2921–2933, 2018.

[10] T. T. N. Nguyen, D. S. Shih, L. Chua, H. N. Kieu, L. H. Ha, L. H. Nguyen, N. V. Luu, T. V. Huynh, L. M. Duong, and A. T. Ngo, “Identifying flow eddy currents in the river system as the riverbank scouring cause: A case study of the Mekong River,” water, vol. 14, 2022.

[11] T. D. Dang, T. A. Cochrane, M. E. Arias, P. D. T. Van, and T. T. de Vries, “Hydrological alterations from water infrastructure development in the Mekong floodplains,” Hydrological Processes, vol. 30, pp. 3824–3838, 2016.

[12] C. A. Nittrouer, D. J. DeMaster, E. F. Eidam, T. T. Nguyen, J. P. Liu, A. S. Ogston, and P. V. Phung, “The Mekong continental shelf: The primary sink for deltaic sediment particles and their passengers,” Oceanography, vol. 30, no. 3, pp. 60–70, 2017.

[13] A. Snidvongs and S. K. Teng, Global International Waters Assessment, Mekong River, GIWA Regional Assessment 55. Kalmar, Sweden: University of Kalmar, 2006.

[14] X. X. Lu and R. Y. Siew, “Water discharge and sediment flux changes over the past decades in the Lower Mekong River: possible impacts of the Chinese dams,” Hydrology and Earth System Sciences, vol. 10, pp. 181–195, 2006. DOI: 10.5194/hess-10-181-2006.

[15] R. Costanza, R. de Groot, P. Sutton, S. Costanza, S. van der Ploeg, S. J. Anderson, I. Kubiszewski, S. Farber, and R. K. Turner, “Changes in the global value of ecosystem services,” Global Environmental Change, vol. 26, pp. 152–158, 2014.

[16] G. P. Allen, J. C. Salomon, P. Bassoullet, Y. Du Penhoat, and C. Grandpré, “Effects of tides on mixing and suspended sediment transport in macrotidal estuaries,” Sedimentary Geology, vol. 26, pp. 69–90, 1980.

[17] E. Wolanski, N. N. Huan, L. T. Dao, N. H. Nhan, and N. N. Thuy, “Fine-sediment dynamics in the Mekong River estuary, Vietnam,” Estuarine, Coastal and Shelf Science, vol. 43, pp. 565–582, 1996.

[18] A. Sottolichio, P. Le Hir, and P. Castaing, “Modeling mechanisms for the stability of the turbidity maximum in the Gironde estuary, France,” Proceedings in Marine Science, vol. 2–3, pp. 373–386, 2000.

[19] H. Loisel, A. Mangin, V. Vantrepotte, D. Dessailly, D. D. Ngoc, P. Garnesson, S. Ouillon, J. P. Lefebvre, X. Mériaux, and P. M. Thu, “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 Sensing of Environment, vol. 150, pp. 218–230, 2014.

[20] A. S. Ogston, M. A. Allison, R. L. McLachlan, D. J. Nowacki, and J. D. Stephens, “How tidal processes impact the transfer of sediment from source to sink: Mekong River collaborative studies,” Oceanography, vol. 30, no. 3, pp. 22–33, 2017.

[21] P. Weatherall, K. M. Marks, M. Jakobsson, T. Schmitt, S. Tani, J. E. Arndt, M. Rovere, D. Chayes, V. Ferrini, and R. Wigley, “A new digital bathymetric model of the world’s oceans,” Earth and Space Science, vol. 2, no. 8, pp. 331–345, 2015.

[22] Delft Hydraulics, Delft3D-FLOW User Manual, 2003.

[23] J. A. Battjes and J. P. F. M. Janssen, “Energy loss and setup due to breaking of random waves,” in Coastal Engineering 1978, pp. 569–587, 1978.

[24] J. E. Nash and J. V. Sutcliffe, “River flow forecasting through conceptual models part I—A discussion of principles,” Journal of Hydrology, vol. 10, no. 3, pp. 282–290, 1970.

[25] R. L. Sapra, “Using R² with caution,” Current Medicine Research and Practice, vol. 4, no. 3, pp. 130–134, 2014.

[26] T. C. Nguyen, K. Schwarzer, and K. Ricklefs, “Water-level changes and subsidence rates along the Saigon-Dong Nai River Estuary and the East Sea coastline of the Mekong Delta,” Estuarine, Coastal and Shelf Science, vol. 283, 108259, 2023.

[27] A. V. Vu, L. J. Baumgartner, G. S. Doran, M. Mallen-Cooper, J. D. Thiem, J. A. Howitt, K. E. Limburg, B. M. Gillanders, and I. G. Cowx, “Variability in water chemistry in the Lower Mekong Basin: considerations for fish life history reconstruction,” Estuarine, Coastal and Shelf Science, vol. 255, 107355, 2021.

[28] H. M. Nguyen, S. Ouillon, and V. D. Vu, “Sea level variation and trend analysis by comparing Mann–Kendall test and innovative trend analysis in front of the Red River Delta, Vietnam (1961–2020),” water, vol. 14, no. 11, 1709, 2022.

[29] Z. Xue, J. P. Liu, and Q. Ge, “Changes in hydrology and sediment delivery of the Mekong River in the last 50 years: connection to damming, monsoon, and ENSO,” Earth Surface Processes and Landforms, vol. 36, no. 3, pp. 296–308, 2011.

[30] P. S. Hoan and N. K. Vinh, “Current characteristics in the waters of Khanh Hoa Province during Southwest monsoon period,” Vietnam Journal of Marine Science and Technology, vol. 12, no. 3, pp. 57–66, 2012.

[31] C. Chen, Z. Lai, R. C. Beardsley, Q. Xu, H. Lin, and N. T. Viet, “Current separation and upwelling over the southeast shelf of Vietnam in the South China Sea,” Journal of Geophysical Research: Oceans, vol. 117, no. C3, 2012.

[32] A. M. Maxam and D. F. Webber, “The influence of wind-driven currents on the circulation and bay dynamics of a semi-enclosed reefal bay, Wreck Bay, Jamaica,” Estuarine, Coastal and Shelf Science, vol. 87, no. 4, pp. 535–544, 2010.

[33] A. Jalil, Y. Li, W. Du, W. Wang, J. Wang, X. Gao, H. O. S. Khan, B. Pan, and K. Acharya, “The role of wind field induced flow velocities in destratification and hypoxia reduction at Meiling Bay of large shallow Lake Taihu, China,” Environmental Pollution, vol. 232, pp. 591–602, 2018.

[34] J. Yang and K. Chen, “The role of wind stress in driving the along‐shelf flow in the northwest Atlantic Ocean,” Journal of Geophysical Research: Oceans, vol. 126, no. 4, 2021, e2020JC016757.

[35] N. M. Hai, V. D. Vinh, and T. D. Lan, “Impact of sea level rise on current and wave in Van Uc coastal area,” Vietnam Journal of Marine Science and Technology, vol. 19, no. 3, pp. 313–325, 2019.

[36] M. Yahya Surya, Z. He, Y. Xia, and L. Li, “Impacts of sea level rise and river discharge on the hydrodynamics characteristics of Jakarta Bay (Indonesia),” Water, vol. 11, no. 7, 1384, 2019.

[37] D. Khojasteh, W. Glamore, V. Heimhuber, and S. Felder, "Sea level rise impacts on estuarine dynamics: A review," Science of The Total Environment, vol. 780, 146470, 2021.

[38] J. M. Valentim, L. Vaz, N. Vaz, H. Silva, B. Duarte, I. Caçador, and J. M. Dias, “Sea level rise impact in residual circulation in Tagus estuary and Ria de Aveiro lagoon,” Journal of Coastal Research, vol. 65, no. SI, pp. 1981–1986, 2013.

[39] C. L. Lopes and J. M. Dias, “Tidal dynamics in a changing lagoon: Flooding or not flooding the marginal regions,” Estuarine, Coastal and Shelf Science, vol. 167, pp. 14–24, 2015.

[40] A. R. Carrasco, T. Plomaritis, J. Reyns, Ó. Ferreira, and D. Roelvink, “Tide circulation patterns in a coastal lagoon under sea-level rise,” Ocean Dynamics, vol. 68, no. 9, pp. 1121–1139, 2018.

[41] M. T. Vu, C. Luu, D. Q. Bui, Q. H. Vu, and M. Q. Pham, “Simulation of hydrodynamic changes and salinity intrusion in the lower Vietnamese Mekong Delta under climate change-induced sea level rise and upstream river discharge,” Regional Studies in Marine Science, vol. 78, 103749, 2024.

[42] V. D. Vinh, N. M. Hai, S. P. Purayil, G. Lacroix, and N. T. Duong, “Seasonal variation of coastal currents and residual currents in the CAT BA–HA long coastal area (VIET NAM): Results of coherens model,” Regional Studies in Marine Science, vol. 80, 103874, 2024.

[43] V. D. Vinh and T. D. Thanh, “Characteristics of current variation in the coastal area of Red River Delta—results of research using the 3D numerical model,” Vietnam Journal of Marine Science and Technology, vol. 14, no. 2, pp. 139–148, 2014.

[44] J. P. Lefebvre, S. Ouillon, V. D. Vinh, R. Arfi, J. Y. Panché, X. Mari, C. V. Thuoc, and J. P. Torréton, “Seasonal variability of cohesive sediment aggregation in the Bach Dang–Cam Estuary, Haiphong (Vietnam),” Geo-Marine Letters, vol. 32, no. 2, pp. 103–121, 2012.

[45] V. D. Vinh and S. Ouillon, “The double structure of the estuarine turbidity maximum in the Cam–Nam Trieu mesotidal tropical estuary, Vietnam,” Marine Geology, vol. 442, 106670, 2021.