Wave transformation in the nearshore waters of Jeddah, west coast of Saudi Arabia

Many specific problems in the coastal zones require an accurate description of the wave field and knowledge of wave parameters. The studies on the spectral characteristics of wind-waves in the Red Sea are very much limited. In this study, the spectral characteristics of nearshore waves in the central Red Sea, specifically the Jeddah coast has been investigated utilizing a third generation spectral wave model, SWAN. The model results were validated against the available measured data. The seasonal and monthly characteristics and the diurnal variability of wave spectra were analysed and discussed. The wave transformation between deep, intermediate and shallow water depths were assessed at three transects - northern, central and southern regions off Jeddah. The results indicate that multi-directional swells are present in the Jeddah nearshore regions, which are propagated from the northern and southern Red Sea. The diurnal variability in the wave spectra is persistent throughout the year, although it fluctuates among the seasons according to the prevailing wind conditions. Significant attenuations in wave heights were identified in the intermediate and shallow waters, with the highest attenuation occurred in the central Jeddah coast.