Coastal Hazard and Risk Modeling

Storm surge, a primary cause of coastal flooding during tropical and extratropical storm systems, occurs when a storm’s winds push water toward land. The water mass encounters shallower water as it moves toward shore and increases in height. Additional factors like a storm’s pressure and the waves generated by storm winds also contribute to the total surge that impacts a coast.

RENCI’s Earth Sciences and Software group conducts research into coastal hazards and risk through a suite of diverse yet synergistic projects, with nationally recognized subject matter experts. Collaborations with universities, federal agencies, and industry have resulted in research outcomes and applications that are advancing fundamental science as well as having substantive impacts on decision makers in coastal hazards and risk.

The primary computational tool is the storm surge and wind-wave model ADCIRC, co-developed at the University of North Carolina at Chapel Hill and the University of Notre Dame. ADCIRC is used for fundamental research in coastal oceanography, engineering and flood protection design studies, and for coastal hazard assessments for the Federal Emergency Management Agency’s National Flood Insurance Program.

RENCI’s Role

The North Carolina Forecast System connects the surge and wave model ADCIRC+unSWAN with several atmospheric prediction models, including the National Centers for Environmental Prediction’s operational weather forecasting model and tropical cyclone forecast advisories from the National Hurricane Center. Hydrological river discharges are imposed as boundary conditions on the upper Tar and Neuse Rivers.

The system runs on RENCI’s Dell cluster, Hatteras, two times a day under normal operations and on four times a day during the tropical, cyclone events. The primary outputs of the system (water level and wave height) are published as graphic images to the website, where end users such as state and county emergency management managers can access the forecast results to help in their decision making process.

ADCIRC+unSWAN models depth-averaged circulation, water level, and the irregular, wind-driven wave field, coupling the long- and short- wave fields using a common unstructured model grid. The coupling occurs in real-time, through exchange of water level and currents from ADCIRC to unSWAN, and wave radiation stresses from unSWAN to ADCIRC.

Current and recent projects using ADCIRC and related software include:

  • Data access and visualization of storm surge models for NOAA’S National Hurricane Center
  • Statistical Modeling of storm surge for North Carolina
  • Optimal, risk-based evacuation routing for coastal North Carolina during hurricane events
  • Storm surge hazard assessment for New Jersey waste water facilities
  • Application of the ADCIRC modeling system for the North Carolina Sea Level Rise Impacts Study