In the paper the applicability of a numerical model based on the Boussinesq-type wave transformation model in shallow water, named the Nonlinear wave transformation model by Port and Airport Research lmstitute (NOWT-PARI for short), is described. This model is applicable to estimate wave transformation with good accuracy for the ports and hrbors planning and shore protection works.
　The nonlinearily and the dispersion relatlon of the model are similar to the improved Boussinesq equation. The calculation results of nonlinear wave shoaling and the wave transformation on submerged breakwater agree well with those obtained in the analytical works and in the model experiment. Especially, the error control terms on the alternating direction implicit method employed in the model are effective to the improvement of the calculation accuracy. In the three dimensional calculation, it is also assured that the model can reproduce wave refraction on spherical shoal and wave diffraction around breakwater of the result of model experiment and the sommerheld solution respectively.
　The perfect wave reflection boundary is set at sea wall. The partial wave reflection boundary and permeable boundary are represented by the Sponge laye, with the wave energy dissipating term. The parameter study for the wave reflection at the sponge layer is carried out in order to get the standard width and the energy dissipating strength of sponge layer. The newly developed sponge layer with high-order energy dissipating terms is capable to reduce the wave energy more effectively The Porous layer boundary newly developed for calculating partial wave reflection can reproduce the profiles of partial standing waves without adjusting any parameters. The latest NOWT-PARI estimates harbor oscillations surrounded wave absorbing breakwaters.
　Moreover, the developed nonlinear wave transformation model is utilized to improve the rnodel experiment technique in the large basin. Dual face serpent-type wave maker controlled in　the nonlinear wave generation signals is applicable to expand an effective test area of multi directional waves, and to reproduce double-peaked directional spectrum waves. Transient waves can be generated with using the radio wave theory.