Study On The Influence Of Vegetation And Artificial Sand Bar On The Evolution Of Sandy Beach Profile

Many countries around the world are suffering from coastal erosion especially in areas that experience extreme weather events such as storm surges.Therefore,coastal protection and erosion reduction have been becoming the research focus for many years.In recent years,vegetation and artificial sand bars are found to be effective defense measures to protect sandy coasts.The research of the effect of vegetation and artificial sand bars on sandy beach profile evolution is thus important.This paper mainly includes two parts.The first part is the numerical study of wave height attenuation and beach profile evolution in the presence of vegetation.The second part is the physical model experiments studying wave transformation and beach profile evolution under the protection of artificial sand bar.Firstly the vegetation and artificial sand bar's background and significance were introduced and the research progress of vegetation effect on wave attenuation and artificial sand bar on the evolution of beach profile,the XBeach model has also been introduced briefly.Secondly,wave height attenuation of two groups physical model experiments are verified using XBeach model considering the existence of the vegetation and then coastal evolution in one of experiments is verified using XBeach sediment transport model.On the basis of the verification,the effects of the drag coefficient,distribution density,height and diameter of vegetation on the attenuation of wave height and coastal evolution are further analyzed by numerical simulation.Finally,a physical model test is carried out to study the effect of artificial sand bar on coastal erosion and protection.The influence of artificial sand bars on coastal evolution is analyzed through the different characteristics of artificial sand bars,including the distance from shore,the top elevation of sand bars and the difference of the median diameter of sand filled in the sand bars.Through processing and analyzing the experimental data of the physical model,the influences of various characteristics of the sand bar on wave propagation deformation and beach profile are obtained.