Unsteady flows in channels and rivers combine a number of very complex naturalphenomena, particularly phenomena related to the wave propagation caused by gravity orfloods. The free surface flows relative to flows are regulated by the dynamic equilibrium ofthe forces of gravity, inertia and friction (Hervouet, 2003).In this present research study thefocus is primarily on the dynamic behavior of flows in an open channel, which occurs afterthe opening of a partition in the case of an enlargement and finally an abrupt drop. Thenumerical integration of the governing hyperbolic partial differential equations allowed usto better understand the phenomenon studied in the three cases cited above. Solving theseequations could be realized by using a FORTRAN calculation program that we developed.
