Simulating typhoon waves by SWAN wave model in coastal waters of Taiwan

The SWAN wave model is typically designed for wave simulations in the near-shore region and thus is selected for evaluating its applicability on typhoon waves in the coastal waters around Taiwan Island. Numerical calculations on processes of wave heights and periods during the passages of four representative typhoons are compared with measured data from field wave stations on both east and west coasts. The results have shown that waves due to typhoons of paths 2, 3 and 4 can be reasonably simulated on east coastal waters. However, discrepancies increase for the simulated results on west coastal waters because the island's central mountains partly damage the cyclonic structures of the passing-over typhoons. It is also found that the included nested grid scheme in SWAN could improve the accuracy of simulations in coastal waters to facilitate further engineering practices.