Comparison of Empirical and Numerical Methods in the Prediction of Wave Characteristics in AmirAbad and Bushehr Ports

In this article, the accuracy of empirical and numerical methods in prediction of wind wave characteristics in AmirAbad and Bushehr Ports have been studied, evaluated and compared. First, the wave characteristics have been calculated using Babolsar and Bushehr synoptic stations and employing empirical methods including SMB, SPM and CEM. Moreover the errors of empirical methods have been determined by comparing the predicted values of wave heights and periods with wave characteristics recorded by wave buoys of AmirAbad, Neka and Bushehr. Then the results of empirical methods have been compared with the wave characteristics obtained from Iranian Seas Wave Modeling Project. This modeling has been implemented using the modified ECMWF wind field and the SW module of MIKE21 software. A more complete assessment of the results has been carried out by extreme value analysis of the predicted and recorded wave height and calculating the significant wave height with 2~10 years return periods, totally and in dominant directions. Results show that the SPM method is the most suitable method among the empirical models for determining the wave characteristics of AmirAbad Port and the SMB and SPM methods are more suitable for predicting the wave heights and periods in Bushehr Port, respectively. The accuracies in predicting wave parameters were found to be compatible for numerical and empirical methods in Bushehr Port and agreed with recorded characteristics. However, in comparison to numerical method, the empirical method yields to poor prediction in Amirabad Port. According to the investigations the errors of empirical methods are mainly due to unsuitable wind data and it is predicted that in the presence of reliable wind data, the results of empirical and numerical methods would be comparable.