Modelling of the Wave Generated in an Irrigation Canal by Gate Opening on the Basis of the Saint-Venant Equations

The paper models the wave that propagates along an irrigation canal when the gate at the canal entrance is opened and the discharge increases sharply, using the one-dimensional Saint-Venant equations. The equations are solved by the finite volume method with the Rusanov scheme. The arrival time of the wave at canal cross-sections, the rise of the water level and the transition of the canal to a new steady state are determined. The numerical results are confirmed by the theory of characteristics.