The original hyperbolic mild-slope equation can effectively take into accou
nt the combined effects of wave shoaling, refraction, diffraction and refle
ction, but does not consider the nonlinear effect of waves, and the existin
g numerical schemes for it show some deficiencies. Based on the original hy
perbolic mild-slope equation, a nonlinear dispersion relation is introduced
in present paper to effectively take the nonlinear effect of waves into ac
count and a new numerical scheme is proposed. The weakly nonlinear dispersi
on relation and the improved numerical scheme are applied to the simulation
of wave transformation over an elliptic shoal. Numerical tests show that t
he improvement of the numerical scheme makes efficient the solution to the
hyperbolic mild-slope equation, A comparison of numerical results with expe
rimental data indicates that the results obtained by use of the new scheme
are satisfactory.