Comparing Inundation Maps Developed Using WHAFIS and STWAVE: A Case Study in Washington County, RI
Date of Original Version
In 2010, a report, Mapping the Zone, Improving Map Accuracy, was prepared by a FEMA flood map committee appointed by the National Academies' Water Sciences and Technology Board, which discussed theoretical and practical issues related to FEMA map accuracy. The present analysis presents a case study, which addresses in particular one of their major concerns: The use of a 1-D model to solve a 2-D problem. Finding #2 in the report stated: "Coastal flood maps can be improved significantly through use of coupled two-dimensional storm surge and wave models and improved process models, which would yield more accurate base flood elevations". The study re-computes the 100-year inundation maps in Washington County, using two-dimensional models. The initial and boundary conditions for wave simulations are based on results of fully coupled 2-D surge and wave models, the advanced circuulation model (ADCIRC) and the phase-averaged steady state spectral wave model (STWAVE), respectively, from the North Atlantic Coast Comprehensive Study (NACCS) performed by the U.S. Army Corps of Engineers. Waves are simulated using STWAVE over a series of high-resolution grids in nearshore and overland areas. Results are mapped and compared with FEMA's maps and transects.
Coastal Structures and Solutions to Coastal Disasters 2015: Resilient Coastal Communities - Proceedings of the Coastal Structures and Solutions to Coastal Disasters Joint Conference 2015
Grilli, Annette R., Malcolm L. Spauding, Lauren Schambach, Jane Smith, and Mary Bryant. "Comparing Inundation Maps Developed Using WHAFIS and STWAVE: A Case Study in Washington County, RI." Coastal Structures and Solutions to Coastal Disasters 2015: Resilient Coastal Communities - Proceedings of the Coastal Structures and Solutions to Coastal Disasters Joint Conference 2015 , (2015): 147-160. doi:10.1061/9780784480304.016.