Confluence of open-channel flows

River confluences are important due to their role on transport of sediments, erosion, transport of nutrients and flood events. Bathymetric surveys show that, typically, in nature, two flows merging into a confluence have discordant beds. The main goal of this paper is to analyse the effect of difference in bed elevations of the tributary and main channel onto the confluence hydrodynamics. A total of four Large Eddy Simulations (LES) are carried out, with four different discordance bed ratios. The simulations reproduced the experimental case of Weber et al. (2001). It turns out that the presence of a bed discordance has a pronounced effect on the recirculation zone dimensions and distribution of the turbulent kinetic energy