It is challenging to assess the efficacy of countermeasures against channel burial by siltation through model experiments. Therefore, numerical analysis is a crucial verification method. However, conventional analytical models are low-resolution hydrostatic approximations that cannot accurately depict the topography of the navigation channel and surrounding structures and eddies. Consequently, it is impossible to analyse and verify the effectiveness of anti-siltation measures by installing depressions and submerged dikes around the navigation channel. This study employed a high-resolution vertical two-dimensional non-hydrostatic model with a grid size of approximately 0.25 m to calculate the flow velocity and suspended solids concentration (SS) around the channel and examine the siltation distribution. The results demonstrated that the eddy generated upstream of the channel causes a high concentration of SS to sink obliquely downwards at the outer edge of the clockwise eddy, with a horizontal-to-vertical flow velocity ratio. This accumulation occurs in the low-flow region directly below the eddy. Implementing countermeasures reduced SS deposition in the depression and the layer below the eddy, with a 50-70% reduction in the amount of SS buried in the channel.