Numeric Simulation of Suspended Sediment Transportation during Dredging of Harbor Basin

Abstract

Huang, Y.; Sheng, Y.H.; Min, X.Q.; He, Y.F., and Chen, P., 2020. Numeric simulation of suspended sediment transportation during dredging of harbor basin. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 276–280. Coconut Creek (Florida), ISSN 0749-0208.Maintaining the safe water depth of the harbor basin is important to ensure the safety of ships, while dredging is the major method to accomplish this task. However, the dispersion and transportation of suspended sediment during the degrading process, may change the seawater quality. This research utilizes the 2D tidal flow model and 2D sediment numerical model to simulate the distribution of suspended sediment during dredging, and then analyzes the influence on the nearby sea area. The major conclusions can be summarized as follows: (1) the equivalent roughness method can simulate well in the research area; (2) the dredging in Xiazhi Harbor basin has limited influence on the seawater quality. When the increased Suspended Sediment Concentration (SSC) reaches 10 mg/L, the impact distances of both flood current and ebb current are 1.66 km and 0.99 km, respectively; (3) since the tidal dynamic is stronger at the ebb current, the suspended sediment diffusion at this period is more significant, and has less impact on the water quality. Thus, it is recommended to dredge the harbor basin during ebb current.