Flow and Sedimentation Characteristics of Tidal Waterways – with the Kouanzhi Waterway in the Lower Yangtze River as an Example

Abstract River flow in the Lower Yangtze (LYR) is influenced by combined effect of runoff and tides, complex conditions tend to cause sediment deposition waterways, which turn affects navigation conditions. In order improve understanding river mechanism tidal reaches, this study selected a typical reach LYR – Kouanzhi Waterway (KW) as an example investigate characteristics that affect transport processes. Sedimentation annually occurs at entrance KW large sidebar constantly increases size, causing reduction depth width, but causes sedimentation are still unclear. study, three-dimensional (3D) model was established based on Delft3D, k-epsilon chosen simulate turbulent flow. The simulates processes during flood tides dry seasons. results numerical simulation show significant difference exists large-scale structures between season, extremely vortex shedding phenomenon formed downstream channel entrance, great rate entrance. addition, because width widens middle part KW, circulation structure developed near Sanyiqiao sidebar. supposed trap deposit intensity turbulence greatly reduced, decreases accordingly. disappeared, thus be under erosion period. provide vital reference for engineering works waterway regulations reaches.