Wetlands as a nature-based coastal defense: a numerical modeling and field data integration approach to quantify storm surge attenuation for the Mid-Atlantic region

This paper has presented the objectives and broad methodology of a 2-year effort to combine field work and numerical modeling to quantify storm surge attenuation of wetlands in the Chesapeake Bay region. The criteria considered in selection of marsh sites included exposure to storm surge based on simulations of historical storms, presence of salt marsh vegetation, topography and internal marsh geometry. Three sites have been identified and have been instrumented with pressure transducers deployed over transects of 200 to 750 m. Future work will present methods used in calibrating ADCIRC-SWAN using the water level data collected and processed from these sites, as well current profiler data. Of particular consideration in numerical modeling efforts for this study is that of computation cost. A high-resolution computational mesh (~10m) is necessary to capture the complex hydrodynamics in marsh systems. Furthermore the computational domain must stretch far enough from the coastline to adequately capture the propagation of waves and storm surge. The mesh employed here is a 1.2 million node mesh extending to the 15m inland contour, and to the 60 degree Prime Meridian in the Atlantic Ocean. To reduce computational costs significantly, while allowing for adjustments to the mesh, and to the vegetation parameterization at the chosen marsh sites, a subdomain modeling method developed by Baugh et al. will be utilized [20].