hi,

A precipiton method to calculate river hydrodynamics, with applications to flood prediction, landscape evolution models, and braiding.. The rivers are grouped by sea or ocean. The rivers flowing into the sea are sorted along the coast. The now grand river passes through Tours, at the region's heartland in what is known as the garden of France.  

If you know Flow rate (Q) and Area (A), then you can know/calculate (mean or average) velocity (v):

v = Q/A