Efficient integration of a storm surge model into a multidisciplinary agent based model framework

Multiple hurricanes have impacted coastal areas of the USA and they represent one of the most costly natural hazards in the country. In an effort to comprehend the regional vulnerability and resilience to these hazards, a multidisciplinary team is developing an novel framework, the Integrated Hazard, Impact, and Resilience Model (IHIRM). Storm surge modelling is a key role of this framework and inundation from multiple scenarios will be estimated by using a hydrodynamic model (ADCIRC) and a wave model (SWAN). Simulating a large number of storm surge scenarios requires a considerable computational effort and therefore the trade-offs between cost and accuracy must be investigated. Initially, model response sensitivity to numerical mesh resolution was performed for Hurricanes Irene (2011) and Sandy (2012). Results from the moderate and high resolution meshes provided similar values, while the increase of computational time was substantial. Secondly, we explored the difference between the maximum water levels simulated with ADCIRC and with the coupled version ADCIRC+SWAN (i.e., contribution of wave setup during the peak of the storm). The contribution of wave setup to the overall water levels was less than 0.1 m inside the Chesapeake Bay and 0.5 m outside the Bay. Additionally, the computational time significantly increased for the coupled version simulation. Hence, neglecting the contribution of wave setup in areas like the upper Chesapeake Bay would not have a significant impact on the surge estimates and a considerable amount of resources would be saved. Conversely, wave setup must be considered at open coast areas.