Surges in open channels was computed by using Ameins' four-point difference scheme which is the most efficient method for flood routing problems. The method bas been applied to surges, which suggested the optimum value of θ=0.6, however, the effect of change of Δx/Δt was not discussed. Price has proposed, comparing the results with exact analytical solutions for the monoclinal wave, that the optimum value of Δx/Δt is equal to kinematic wave speed. In this paper, comparisons are made between the results of numerical solutions and laboratory experiments. The results of calculations demonstrated good agreement with results of laboratory experiments. The numerical instability is observed for the large value of Δx compared to Δt.
