Numerical Simulation Of Typhoon Wave Propagation In Coastal Vegetation Field

In recent years,due to the global climate change,typhoon waves,storm surges and other marine disasters have caused great economic and social losses to the inshore areas.The observation shows that the use of vegetation revetment can not only reduce the typhoon surge energy,but also help to improve the local ecological environment and have a positive impact on the ecosystem.Therefore,it is of great significance to understand the influence of vegetation on Typhoon wave and storm surge,to reduce the damage of storm tide and Typhoon wave,to reduce the economic loss caused by storm surge and typhoons,to ensure the safety of people's life and property,to promote the development of coastal economy and to improve the ecological environment.Based on the SWAN Wave model and the ECOMSED tidal current model,the propagation characteristics of typhoon waves in vegetation waters are studied numerically,and the main contents are as follows:(1)The simulation model of typhoon wave propagation in vegetation waters is constructed.The reliability of SWAN model vegetation module was validated by the Lovas model experiment of the vegetation waters,and the wind wave module of the SWAN model was validated by using the "Ramasun" typhoon field data in 2014.On the basis of model verification,the influence of typhoon wind speed on the wave height of vegetation in different vegetation densities and vegetation heights,the proportional relationship between the high attenuation rate of random wave and typhoon wind speed was analyzed.The results show that with the increase of typhoon wind speed,the attenuation coefficient of wave height in vegetation waters is exponential attenuation trend.(2)Based on the ECOMSED model,the storm surge simulation model of the vegetation waters was constructed.Based on the vegetation area of the Louisiana Breton Sound estuary in the United States,the reliability of the model in storm surge propagation in simulated vegetation waters was validated by the storm surge triggered by the 2012 "Iassc" Typhoon.On this basis,the influence of vegetation on storm tide water level is analyzed.Through numerical flume experiment,the influence of flow velocity on the wave height of the typhoon in the vegetation is analyzed under different vegetation parameters.The study shows that the variation rule of effective wave height under different vegetation densities is similar to that of effective wave height under different vegetation heights,that is,the wave height increases gradually with the increase of flow velocity,but the increase amplitude is not obvious.Based on the two working conditions of different vegetation densities and vegetation heights,the proportional relationship between the high attenuation rate of random wave and the flow velocity in the flat bottom vegetation was analyzed.The results show that with the increase of flow velocity,the wave height attenuation coefficient shows linear attenuation trend.