Modeling of suspended sediment concentration - case study in Can Gio, Ho Chi Minh city

Hoa Tien Le Nguyen; Hong Phuoc Vo Luong

doi:10.15625/1859-3097/18016

Author affiliations

Authors

Le Nguyen Hoa Tien Department of Oceanology, Meteorology and Hydrology, Faculty of Physics and Engineering Physics, University of Science, Ho Chi Minh city, Vietnam; Vietnam National University, Ho Chi Minh city, Vietnam
Vo Luong Hong Phuoc Department of Oceanology, Meteorology and Hydrology, Faculty of Physics and Engineering Physics, University of Science, Ho Chi Minh city, Vietnam; Vietnam National University, Ho Chi Minh city, Vietnam

DOI:

https://doi.org/10.15625/1859-3097/18016

Keywords:

Suspended sediment concentration, diffusion coefficient, settling velocity, one-dimension model, the mudflat, Can Gio.

Abstract

The dynamics of suspended sediments are complicated due to the influence of hydrodynamic factors and the characterization of cohesive sediment properties. A one-dimensional model is built to calculate the vertical distribution of suspended sediment concentration (SSC). In the model, parameters that influence the vertical distribution of SSC include the settling velocity (w_s) and the diffusion coefficient (K_z). The settling velocity depends on the cohesive sediment properties, and the diffusion coefficient depends on the wave-current dynamics. The model applies measured data in June 2014 on the mud flats in Can Gio, Ho Chi Minh city, Vietnam. In this study, the settling velocity w_s is a constant of 0.64 × 10^-6 m/s. The diffusion coefficient depends on water depth, wave action, and tidal currents. Under strong wave - medium current conditions, the average K_z is 2.88 × 10^-3 m²/s. Under medium wave - strong current conditions, the average K_z is 6.11 × 10^-3 m²/s, while under strong wave - strong current conditions, the average K_z can reach 6.59 × 10^-3 m²/s. The resulting simulations demonstrate that the SSC increases rapidly near the bottom layers. Here, the clay sediments are easily disturbed by dynamic conditions. At the bottom layer, the SSC is strongly influenced by the current factor, while the role of the wave factor has not been clearly shown.

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References

Li, Y., and Parchure, T., 1998. Mudbanks of the southwest coast of India. VI: Suspended sediment profiles. Journal of Coastal Research, 14(4), 1363–1372.

van Leeuwen, B., Augustijn, D. C., Van Wesenbeeck, B. K., Hulscher, S. J., and De Vries, M. B., 2010. Modeling the influence of a young mussel bed on fine sediment dynamics on an intertidal flat in the Wadden Sea. Ecological Engineering, 36(2), 145–153.

Li, D., Yang, Z., Sun, Z., Huai, W., and Liu, J., 2018. Theoretical model of suspended sediment concentration in a flow with submerged vegetation. Water, 10(11), 1656.

Bay, N. T., and Phung, N. K., 2007. Study on the tendency of accretion and erosion in the Can Gio coastal zone. Vietnam Journal of Marine Science and Technology, 7(4), 50–63. (in Vietnamese).

Hong Phuoc, V. L., Massel, S., An, D. T., and Thanh, N. C., 2008. Concentration of suspended sediments in mangrove forests. Journal of Geology, Series B, (31–32), 155–163. (in Vietnamese).

Le Nguyen, H. T., and Vo, L. H. P., 2021. Calculating the settling velocity of cohesive sediment based on semi-empirical method. Vietnam Journal of Marine Science and Technology, 21(4), 481–491.

Lee, W., 2011. Tridiagonal Matrices: Thomas Algorithm. MS6021. Sci. Comput. Univ. Limerick, 1–3.

Wolanski, E., 1995. Transport of sediment in mangrove swamps. Hydrobiologia, 295(1), 31–42.

Hwang, K. N., 1989. Erodibility of fine sediment in wave-dominated environments. Master’s thesis, University of Florida.

Phuoc, V. H., and Massel, S. R., 2006. Experiments on wave motion and suspended sediment concentration at Nang Hai, Can Gio mangrove forest, Southern Vietnam. Oceanologia, 48(1), 23–40.

Hong Phuoc, V. L., 2020. Research on litho-hydrodynamics in erosion-deposition processes in mangrove for the Southern of Vietnam. The report of the research project NCCB-ĐHƯD.2012-G/10, Ministry of Science and Technology. (in Vietnamese).

Le Nguyen, H. T., and Luong, H. P. V., 2019. Erosion and deposition processes from field experiments of hydrodynamics in the coastal mangrove area of Can Gio, Vietnam. Oceanologia, 61(2), 252–264.