Comparative Study on Different Schemes for Treatment with Multi-Islands and Complex Coastlines in Wave Numerical Computation

In order to describe complex multi-island terrain and coastlines adequately in ocean wave numerical model, basing on the optimization of computing grid by using depth and high resolution coastlines, the method of introducing sub-grid effect into WAVEWATCH-III model has been established. Comparing the results of computation with this scheme and with the scheme for improving grid resolution to distinguish out islands, it shows that: The effect of multi-islands and complex terrain on wave spreading is adequately described by sub-grid effect of islands and the results are much better; The computational precision of significant wave height obtained by introducing the scheme for sub-grid effect of islands into computation with low resolution grid is equivalent with the precision of results obtained by computation with high resolution grid, but the efficiency of former scheme is greatly improved.