Tsunami Inundation and Sediment Transport in Vicinity of Coastal Mangrove Forest

Field measurements from Sumatra of tsunami wave height, erosion and deposition form a comprehensive data set that is tested against the Delft3D tsunami inundation and sediment transport model. Relative agreement between measured and modeled maximum water levels and sediment erosion and accumulation provides confidence that the model is reasonably characterizing the important processes of tsunami inundation. Adding a component to account for vegetation, the model is used to explore the effects of fringing mangrove forests on tsunami inundation and sedimentation. In model experiments, mangrove forests modify the water levels and flow speeds reached during tsunami inundation. Simulations with a mangrove forest result in sedimentation in the forest and not erosion, as occurs in the base case with no forest. This difference in sedimentation is important because the change in profile shape increases wave energy reflection off the beach and decreases wave energy penetration onto land.