Understanding the Role Coastal Marshes Play in Protecting Communities from Storm Surge and Flooding - NERRS/NSC(NERRS Science Collaborative)

The research team developed a vegetation-resolving three-dimensional surge-wave model to simulate storm impacts on Piermont Marsh and the adjacent Village. The model incorporated locally collected data on plant distribution and structure, as well as observed and simulated wind and water level data from the Hudson River. By modeling the impacts of Superstorm Sandy, they found that marsh vegetation with predominantly invasive common reed, Phragmites australis, reduced 66% of the wave energy, but less than 1% of the flood, at the Village. The marsh vegetation also significantly prevented transport of debris from the southeastern corner of the marsh. If managers were to replace Phragmites with the shorter, native cattail, Typha angustifolia , simulations of Sandy, which occurred in October, suggest that Piermont Marsh’s wave and debris buffering capacity would be preserved. However, had Sandy occurred in May/June when Typha is much shorter and sparser, the marsh would have been unable to buffer the wave and debris as effectively. The Piermont Marsh Coastal GeoTool allows Village of officials and resource managers to explore how homes and buildings would be impacted under marsh management and sea-level rise scenarios.