Monsoonal patterns of wave reflection from rubble mound breakwater of Chabahar Bay

This paper presents the results of a one-year field study on the monsoonal reflective response of the rubble mound breakwater (RMB) of Chabahar Bay, located on the northern coast of the Gulf of Oman, Iran. Measurements show that, in general, the correlation between the reflection coefficient and Iribarren number during the winter monsoon period is more remarkable than that of the summer monsoon period. The difference in wave reflection behavior during monsoonal periods is mainly due to the energy proportion of incoming sea and swell waves. Various characteristic wave periods by means of power- and hyperbolic-law prediction functions are explored to enhance the wave reflection prediction, highlighting the significant performance of negative-moment spectral periods Tm−1 and Tm−2 compared with peak and mean spectral periods. Statistical comparison of the performance of Tm−1 and Tm−2 shows that Tm−2 considerably improves the prediction accuracy for moderated energy waves with bimodal sea and swell climates originating from different directions in the winter monsoon and pre-summer monsoon months. However, the prediction improvement is insignificant for unimodal energetic waves observed during the summer monsoon months. Generally, using Tm−2 increases the accuracy of the preexisting equations in predicting the observations of this study.