Channel confluences are universally present in nature.
They can be divided into two types: asymmetrical river confluences and symmetric river confluences.
The latter is also called as the Y-shaped confluences.
Most of previous work has paid more attention to the asymmetrical river confluences, but few studies have been conducted on the Y-shaped confluences.
In this article, the effects of bed discordance on the flow patterns at “Y” shaped open-channel confluences were studied
by using a 3-D numerical simulation. It is proved that the
model can undertake quantitative assessment of the flow at
confluences. The results indicate that there are a lot of
differences between the Y-shaped confluence and asymmetrical
confluence. The discordant bed height plays an important role
at the Y-shaped junction.