Date of Award
Master of Science in Ocean Engineering
M. Reza Hashemi
The Northeast Coast of the United States faces the possible damaging effects of storm surge, waves, and wind due to Atlantic tropical and extratropical storms each year. Historically, there have been several significant storm events that produced substantial levels of damage to the region, most notably the Great Atlantic Hurricane of 1938, Hurricane Carol, Hurricane Bob, and most recently Hurricane Sandy (2012). The objective of this study was to develop an integrated modeling system that could be used as a forecasting tool to evaluate and communicate the risk coastal communities face from these aforementioned hazards. This system utilizes the ADvanced CIRCulation (ADCIRC) model for storm surge predictions and the Simulating WAves Nearshore (SWAN) model for the wave environment. The two models are tightly coupled, passing information to each other and computing over the same unstructured domain, allowing for the most accurate representation of the physical storm processes. The coupled SWAN+ADCIRC model was extensively validated for Rhode Island coastal waters, and has been set up to perform real-time forecast simulations. Modeled storm parameters are then passed to a coastal risk assessment tool. This tool is universally applicable, and generates spatial structural damage estimate maps on an individual structure basis for a specific study area. The required inputs are detailed information about the individual structures, inundation levels, and wave heights for the selected region. Additionally, an option for estimating wind damage to structures was incorporated.
Once developed, the integrated coastal risk assessment system was tested and applied to Charlestown, a small vulnerable coastal town along the southern shore of Rhode Island. The developed system was tested for Hurricane Sandy and a synthetic 100-year storm. In both storm cases, a dune intact and dune eroded scenario were simulated. For the dune intact scenario the current dune profile present was used, while for the dune eroded case a 100-year storm dune eroded profile was used. The resulting damage maps for Charlestown clearly show that the dune eroded scenarios affected more structures, and increased the severity of the estimated damage. The system was also tested in forecast mode for two large Nor’Easters, Stella (March 2017) and Riley (March 2018). The results showed the coupled model performed well in forecast mode when compared to observations. Neither Nor’Easter produced damage to the study area, which was why the 100-year storm was used as a hypothetical future storm. This coastal risk assessment system is unique because of its ability to provide real-time forecasting of structural damage to a region. Ideally, this system’s estimated damage maps will be used by coastal zone and emergency managers to identify high risk areas in coastal communities, allowing for the determination of the best adaptation and mitigation strategies.
Small, Christopher J., "DEVELOPMENT OF AN INTEGRATED HYDRODYNAMIC AND COASTAL RISK ASSESSMENT MODEL FOR CHARLESTOWN, RI" (2018). Open Access Master's Theses. Paper 1283.