Laboratory Investigation On Wave Transformation Through The Emergent, Rigid Vegetation

Waves act directly on the beach; this may cause beach erosion degradation or even athreat to coastal buildings and people’s lives and property. The trees planting on the beach canplay the role of the wave absorbing; such as mangroves in coastal areas in Guangdong,Guangxi, Hainan and Fujian, the willow trees planting at the two sides of the Yangtze River,Yellow River and the Songhua River and breakwater forests planting on the Pearl River Deltadike.Most of the existing laboratory physical model experiments are carried out in regularwaves; and most just consider the impact of the influencing factors of water depth, incidentwave high and vegetation width on the wave dissipation effect of the breakwater forests;vegetation density and vegetation arrangement are not studied. And researches on thedeformation of the solitary wave propagation on non-submerged rigid vegetation, especiallyin our country are not often carried.PVC plastic pipes are used to simulate the rigid vegetation trunks in this experiment；the pipe diameter is 1.0cm, the height is 50cm. Wave flume model experiments on wavetransformation through the emergent, rigid vegetation under solitary and regular waves arecarried on.Through the wave flume experiment of vegetation model, the effect on wavetransformation of the ten vegetation models is studied. The water height and incident waveheight are varied; the change of wave height and wave form of solitary and regular wavesthrough vegetation model and the variation of the reflection, transmission and dissipationcoefficients with vegetation density and vegetation arrangement are studied. The experimentresults of the ten vegetation models are compared to acquire the proper models withreasonable vegetation arrangement.