Controlling the flow and bed morphology in a river confluence is important in training and navigation works. The flow in river confluence is highly complex due to crucial and rapid changes associated with flow dynamics, sediment transport, and geomorphology. The flow in Malaysia’s rivers has many confluence junctions in natural drains of catchment areas. The confluence between Kurau and Ara Rivers, in Perak, Malaysia, is selected to investigate the scour hole that usually forms in the erosion zone and the bar that forms in the deposition zone. A 2D numerical model is used in simulating hydro-morpho dynamics in the rivers confluence to mitigate the erosion and deposition zones by adopting vanes as control structures. Simulation results suggest that the most effective location, dimension, and angle of vanes can be decided based on their performance in scouring and deposition zones. The distribution velocity and flow vectors can help in deciding the location of the vanes.

Natural rivers have many branching junctions. The flow in branching junctions is complex, owing to significant changes associated with flow dynamics and sediment transport that result in erosion and deposition problems. A branching channel of the Tigris River in Missan, Iraq, was selected for investigation of the scouring and deposition zones. A two-dimensional (2D) numerical model was used to simulate the hydro-morphodynamics in the branching channel, where hypothetical vanes as control structures were included at the junction to control the scouring and deposition zones. The simulation results suggest the most effective location, dimension, and angle of the introduced vanes. For the studied junction, controlling morphological features was achieved by introducing a single vane with an inclination angle of 90° on the flow direction of the Tigris River. The most effective location of the introduced vane was the location that caused considerable enhancement in the flow depth and velocity distribution.

Controlling erosion and deposition zones that are usually forming at rivers confluences are important for improving river hydraulic efficiency. The flow in rivers confluences is highly complex, due to rapid changes associated with the river flow dynamics, sediment transport, and morphology. A two-dimensional (2D) numerical model was used to simulate the confluence between Kurau and Ara rivers, Perak, Malaysia. The numerical model has been calibrated and validated by using field data. The model was used to investigate the effectiveness of different shapes and sizes of 30 o obstacles/vanes in controlling erosion and deposition zones at the confluence of Kurau and Ara rivers. The simulation results show that the best performance of 30 o obstacles/vanes was found when a single obstacle/vane was introduced in the flow.