The case we have studied is the confluence of two rivers. The next figure describe this confluence with an Y form.

__Description of the confluence system.__

In our tests,
the flows are imposed at the top of each rivers and the water height is
imposed at the end of the zone. We made two tests. The first one is quite
simple, the value of each flow at the entrance was constant during the
simulation and **Q1=Q2=cte**. During the second test, our aim was to
simulate a flood, then the flows at each entrance follow the following
graphs:

Indeed, in the two cases, there were
a pic of **Q1** and **Q2**, to simulate the flood at the top of each
confluent.