Experimental Investigation On Irregular Wave Attenuation Under The Effects Of Vegetation With Roots,Stems And Canopies

With global warming,rising sea level and frequent occurrence of marine disasters,coastal erosion has been becoming more and more serious,which seriously threatens the lives and property of people in coastal areas.As a new coastal ecological protection tool,coastal vegetation can not only maintain the balance of coastal ecosystems,but also significantly reduce wave energy,which plays an important role in coastal protection.It is necessary to study the reduction of natural disasters.Wave attenuation by aquatic vegetation is down to the interacton between plants and water waves.In reality,ocean waves have strong randomness,and the wave dissipation characteristics of roots,stems and leaves of plants are quite different.Therefore,it is of great academic value and practical significance to study the interaction between plants and irregular waves,taking into account the effects of root,stem and crown of vegetations.In this paper,a vegetations model with quantifiable roots,stems and leaves is used.Through the wave flume experiment,the mechanism of wave dissipation by vegetation patch composed of different types of plants.By changing water depth,incident wave height,period and plants distribution density,the effects of hydrodynamic factors and plant factors on wave decay along vegetation field and transmitted coefficients in different plant forms are investigated.At the same time,spectral analysis and FFT transform are used to analyze the spectral changes of irregular waves in different plant forms.With experimental data,the relationships between transmitted coefficients and dynamics factors and vegetation factors are established,providing scientific instruction on the coastal protection.