The eastern coastal areas of China are widely distributed with flexible vegetation due to the effect of climate, which have a great influence on wave attenuation. This paper used the XBeach model to simulate the the effect of wave attenuation under flexible vegetation on slope beach by respectively changing the relative height, diameter, density and vegetation coefficient of the plants. Results show that the effect of wave height attenuation by flexible vegetation increases with the increase of relative height, diameter, density and vegetation coefficient and with the increase of each parameter, the increasing tendency of attenuation gradually weakened.
With the development of society and the deepening of the process of industrialization, human activities have made more profound changes to the global climate. Among the marine disasters caused by climate change, storm surge disasters in coastal areas are more extensive and have certain research significance. Therefore, the exploration of methods for preventing waves and attenuating waves and protecting the embankments and the shoreline along the coast has also been a hot topic. Different from traditional invasive hard coastal engineering, aquatic vegetation distributed at the boundary of sea and land is of great significance for wave mitigation in coastal zones, especially in extreme weather such as storm surge (Feagin et al., 2011). In recent years, coastal areas have been increasingly demanding protection of the ecological environment and coastal vegetation has become a good material for ecological revetment due to its certain wave-reducing effect and environmental-friendly characteristics. Research on the effect of coastal wave vegetation on wave-revetment and protection needs to be studied further. In terms of field observation, Möller et al.(1999) have shown that after going deep into the Spartina alterniflora salt marsh 20-30m, the wave height attenuates to 29% and the energy loss is about 90%. Yang et al.(2012) measured the wave parameters of 13 continuous tides on the coast of the tidal reach of the Yangtze River estuary, and calculated the wave attenuation of S. alterniflora at the edge of the coastal salt marsh. The results showed that the wave height attenuation rate per unit distance on the coastal tidal flat covered with vegetation is 1 to 2 orders of magnitude higher than the attenuation rate at mudflats.