Sea waves are one of the main characteristics of water areas in the world, which are mainly produced by Wind. waves are the main boundary condition in the dynamic loading and hydraulic calculations of coastal structures. Numerical models are being developed to bring the sea and ocean conditions closer to the real conditions. In this research, the SW model from MIKE21 software is used to simulate Wind waves in the Chabahar Bay and the energy extracted from these waves is estimated. The SW model simulates the growth, transmission and decay of Wind waves in offshore and coastal areas. Chabahar Bay is a semi-closed and subtropical bay with an average depth of 7. 5 m, which is located in the southeast of Iran. The model was implemented for a period of one year (2017) with a spatial resolution of maximum 5 km for offshore regions and less than 500 m in the interior parts of Chabahar Bay. ECMWF model Wind data with a time step of 6 hours and a spatial resolution of 0. 125 minutes were used. Comparison of model results for hourly averages with measured data shows a correlation coefficient of 0. 84 for significant wave height. The annually average and maximum of wave height due to Wind in the entrance of Chabahar Bay is 0. 82 m and 2. 19 m, respectively. The direction of the dominant waves is from south and the largest share of energy is related to waves with a period of around 11. The average of annual extractable power related to Wind waves in the southern parts of Chabahar Bay was calculated from the order of 3 kW/m.

This work regards the extension of the Miles’ and Jeffreys’ theories of growth of Wind-waves in water of finite depth. It is divided in two major sections. The first one corresponds to the surface water waves in a linear regimes and the second one to the surface water waver considered in a weak nonlinear, dispersive and antidissipative regime. In the linear regime, we extend the Miles’ theory of Wind wave amplification to finite depth. The dispersion relation provides a wave growth rate depending to depth. A dimensionless water depth parameter depending to depth and a characteristic Wind speed, induces a family of curves representing the wave growth as a function of the wave phase velocity and the Wind speed. We obtain a good agreement between our theoretical results and the data from the Australian Shallow Water Experiment as well as the data from the Lake George experiment. In a weakly nonlinear regime the evolution of Wind waves in finite depth is reduced to an anti-dissipative Kortewegde Vries-Burgers equation and its solitary wave solution is exhibited. Anti-dissipation phenomenon accelerates the solitary wave and increases its amplitude which leads to its blow-up and breaking. Blow-up is a nonlinear, dispersive and anti-dissipative phenomenon which occurs in finite time. A consequence of anti-dissipation is that any solitary waves’ adjacent planes of constants phases acquire different velocities and accelerations and ends to breaking which occurs in finite space and in a finite time prior to the blow-up. It worth remarking that the theoretical amplitude growth breaking time are both testable in the usual experimental facilities. At the end, in the context of Wind forced waves in finite depth, the nonlinear Schrö dinger equation is derived and for weak Wind inputs, the Akhmediev, Peregrine and Kuznetsov-Ma breather solutions are obtained.

Nowadays, sea operations require accurate prediction of the characteristics of the waves in the coastal and offshore areas. For modeling wave characteristics, there are various methods such as empirical methods, numerical methods and soft computing methods. In this research, the SWAN numerical model for modeling of wave characteristics in Hormuz Strait area was used. First , a global model for modeling the characteristics of the waves in the Persian Gulf domain was built. Then, the boundary condition obtained from the global model for local modeling with a larger resolution in the area of ​​Hormuz Strait was used. The local model constructed in the Hormuz Strait area was calibrated using the recorded waveforms of the buoy deployed in that area and then was validated. Comparison of the results with the measured data of the Hormuz Strait buoy shows that the modeling has been carried out in this area has very precision results.

In this study, the evolution and dependency of infragravity waves (IGWs) on Wind waves for breaking and nonbreaking conditions is separately investigated.The efficiency of two constant cutoff frequencies (0.125 and 0.14 Hz) is compared for wave data measured in the sandy beaches of Nowshahr at the Southern Caspian Sea. It is found that the frequency of 0.125 Hz results higher correlation coefficients between IGWs energy content and two Wind wave groups. Two pair different correlation patterns between IGWs in one side and Wind waves higher and lower than 0.125 Hz in another side were recognized for breaking and nonbreaking conditions. It can be concluded that the IGWs excitation is controlled by the frequency distribution of Wind wave energy.According to 0.125 Hz as more successful option, the correlation of IGWs with swell waves is generally more significant than sea waves. In the nonbreaking wave condition, the IGWs are well correlated with sea waves, whereas no considerable correlation between IGWs and sea waves is found in the breaking condition. It is resulted that IGWs energy is approximately linearly proportional of both swell and sea waves in nonbreaking condition. In the high and moderate conditions of incident wave energy, the density of IGWs energy grows shoreward, while energy attenuation can be detected for IGWs in very low energy waves.