A universal in tailing wave-train generation of forced soliton generation over topography is found theoretically as the flows are at the resonant points and it is examined with the numerical calculation of the corresponding fKdV equation. From the comparisons, it is shown that theoretical and numerical results on the invariance is in good agreement and the theory given in this paper does not include the modulus truncation, any free constant and unknown function. A universal in tailing wave-train generation of forced soliton generation over topography is found theoretically as the flows are at the resonant points and it is examined with the numerical calculation of the corresponding fKdV equation. From the comparisons, it is shown that theoretical and numerical results on the invariance is in good agreement and the theory given in this paper does not include the modulus truncation, any free constant and unknown function.