CONSIDERING A NEW WAY TO SOLVE SAINT-VENANT EQUATIONS.

A new method to calculate the formation and propagation of flood waves is presented. It combines the advantages of recent dynamic methods while still providing computational efficiency. In the developed implicit method of characteristics (IMOC) the problem of lateral inflow or outflow can be solved with the same precision as in the classical method of characteristics. In using the theory of characteristics, the system of the St. Venant Equations is transformed into a scheme of nonlinear algebraic equations, which is solved by simple iteration. The computation of the variables is done in a rectangular grid and is not bound by R. Courant's condition. An application of IMOC to a rectangular channel with tributaries using conservation of mass as a test of accuracy shows the method to be extremely effective.