Modeling Attenuation of Storm Surge over Deformable Vegetation: Methodology and Verification

Abstract

This study extended and unified resistance formulations for rigid and deformable plants under both emergent and submerged conditions. Three approaches were examined in detail and implemented into a numerical model. First, the flow resistance formulations for rigid plants were critically reviewed. By introducing plant deformation relations with a given vegetal stress and vegetation properties, the formulation for rigid plants was extended to flexural rigid plants. Second, a flow resistance formulation directly derived from submerged, flexible plants was examined and extended. Both approaches to simulating deformable vegetation solve a set of two equations, a vegetation deformation relation and a resistance law, iteratively. The methodology and numerical algorithm for rigid and deformable plants were implemented into an operational storm surge model and tested against laboratory data. Good agreement has been found. The verified model can be used to study the spatial and temporal variations of deflected vegetation heights and equivalent Manning’s coefficient under realistic hurricane and wetland conditions.