An inter-comparison study of green and gray structure effects on overland flow flooding and force on coastal buildings

Coastal communities have been prone to extreme inundations generated by storm surges and tsunamis. Especially inundated overland flows adversely impact low-lying areas. Therefore, mitigation solutions are essential in protecting human lives and infrastructures. So far, hard structures (gray structures) have been widely used to protect coastal communities against severe flooding. Recently, Natural and Nature-Based Features (NNBF, green structures) also have been studied for flood hazard mitigation, such as mangroves (Tomiczek et al., 2020), dunes, reefs, etc. However, the inter-comparison studies of gray and green structures in the flooding and force reduction have not been investigated sufficiently. Therefore, the present study investigated the physical and numerical model comparison of gray and green structures regarding flooding hydrodynamics and forces on the buildings.