Three-dimensional numerical study of flood-building interactions to assess the efficiency of flood adaptation strategies

Abstract

The conventional assessment of flood adaptation strategies often emphasizes the depth–damage relationship, overlooking the complex interactions between floods and buildings in damage modeling. This study uses a three-dimensional unsteady Reynolds-averaged Navier–Stokes equation with a standard 𝑘-𝜀 turbulence closure model to investigate the role of wetlands/ponds in moderating hydrodynamic impacts and extreme loads on buildings. The modeled scenarios consider a dry pond, a filled pond, a dry pond with rigid emergent vegetation, and a dry pond with rigid submersible vegetation. The simulations in the present study aim to discern variations in water surface elevation, velocity, bed shear stress, and impact forces on buildings within floodplains. The findings reveal that certain wetland configurations can reduce the impact forces on buildings by up to 50%, along with reducing the elevation of the water surface and the shear stress of the bed in the proximate areas. Finally, a relationship between the Froude number and the drag coefficient is developed to broaden its application to diverse adaptation scales.