Study of sediment transport by tsunami waves: Ⅴ:influence of mangrove

In recent years, frequent tsunami disasters have caused huge losses. Mangrove forests had significant effects to tsunami disaster mitigation. The laboratory experiments were conducted to investigate the changes of cross-shore beach profiles by the tsunami waves under the influence of mangrove. The mangrove models were made of polyvinyl chloride circular tubes. The 1/10-1/20 composite slopes were constructed using the non cohesive sand. A series of solitary waves was selected as incident wave in the flume. The results show that the mangrove has great influence on the beach profile evolution. The tsunami scouring could significantly decrease as plant distribution density appropriate increase and distribution of plants optimizing. Based on the experimental data presented in this paper, an empirical relation was obtained to express the relationship between trend of beach erosion/deposition area, dimensionless maximum of deposition/erosion depths and vegetation distribution density and mode, dimensionless tsunami wave height, dimensionless specific weight parameter, beach slope etc. The study shows the internal connection of between sandy beach profile evolution and mangrove, hydrodynamics of tsunami wave, sediment and beach slope. The findings of this study have the potential to assist the tsunami disaster mitigation.