Graphical determination of the height of surge waves

This study deals with the propagation of surge waves in open channels. The governing equations are derived for an arbitrary cross-section and specific solutions are given for rectangular, parabolic, and trapezoidal cross-sections. The method can be applied in each case, where the relation between the level and the area is known in advance. The hypotheses are the same as in classical treatises of surge waves, but the derived equations in dimensionless parameters show the possibility of plotting graphs for the given profile, which allows the finding of the solution in each case without a trial-and-error procedure, as with the classical method.The same equations show that (a) in the case of positive waves generated at the upstream side of a channel, two of the three defined parameters can have any prescribed value and the third can readily be found; (b) in the case of positive waves generated at the downstream end, an inequality must hold in order that the third parameter has a physical interpretation.