Data for stream wise velocity in Y shaped confluence

Open-channel confluence is an important phenomenon in rivers, and the confluence of the vegetation within it has a significant impact on its hydrodynamics and the transport of pollutants in it. This study experimentally investigated the effects of submerged vegetation on the flow structure (in terms of flow velocity, secondary currents, and turbulent kinetic energy) and the mixing of contaminants in a Y-shaped confluence channel. The results showed that the velocity profile could be divided into three layers vertically and characterized as S-shaped within the vegetated system, where this was different from the J-shaped profile in the non-vegetated 35 system. The presence of vegetation thus reduced the scale of secondary currents, which hindered the mixing of contaminants and stratified the distribution of pollutants. The different discharge modes and locations of the contaminants led to different paths of transport in the vegetated confluence channel, and it became easier for the discharge in the inner bank of the tributaries to diffuse and mix. Finally, the turbulent kinetic energy within the vegetated system was higher than that in the non-vegetated system, and peaked at the top of the canopy. The interaction between flow and vegetation increased the intensity of turbulence.