Numerical modeling of wave diffraction-refraction in water of varying current and topography

A numerical model for wave diffracrion-refraction in water of varying curre nt and topography is proposed, and time-dependent wave mild-slope equation with a dissipation term and corresponding equivalent: governing equations a re presented. Two different expressions of parabolic approximations for the case of the absence of current are also given and analyzed. The influence of current on the results of simulation of waves is discussed. Some example s show that the present model is better than others in simulating wave tran sformation in large water areas. And they also show that the influence of c urrent should be taken into account, on numerical modeling of wave propagat ion in water of strong current and coastal areas, otherwise the modeling re sults will be largely distorted.