The western coastline of Alaska spans over 10,000 km of diverse topography ranging from low lying tundra in the north to sharp volcanic relief in the south. Included in this range are areas highly susceptible to powerful storms which can cause coastal flooding, erosion and have many other negative effects on the environment and commercial efforts in the region. In order to better understand the multi-scale and interactive physics of the deep ocean,continental shelf, near shore, and coast, a large unstructured domain hydrodynamic model is being developed using the finite element, free surface circulation code ADCIRC.This model is a high resolution, accurate, and robust computational model of Alaska’s coastal environment capable of simulating tides, storm surges and the effect of wind waves. ADCIRC has been extensively used and validated in the Gulf of Mexico, east coast of the United States, the Great Lakes and many other regions worldwide. These models are extensively applied by FEMA, the United States Army Corps of Engineers,the USNRC and NOAA.
The ability of ADCIRC to use high resolution, flexible, unstructured grids is vital to accurately modeling tides and storm surge in this region. The geographic and topographical complexity of the Alaskan coastline can only be captured with very high model resolution. Hydrodynamically, the tides in in this region arevery complex with a large number of amphidromic points for the many of the tidal constituents and up to a 10 meter tidal rage in certain locations. Correctly modeling this tidal response locally requires a largescale, yet spatially very well resolved tidal model. Using historical wind and pressure fields, the model is also capable of simulating storm events and the resulting storm surge. With a high resolution grid, this storm surge can be modeled in coastal areas and estuarine and deltaic systems where coastal erosion and flooding are significant problems. This high resolution also allows for the model to capture where there may be strong localized amplification of storm surge. Accurate knowledge of tidal and storm surge response in water elevation and currents is vital to providing preventative measures against the coastal erosion and flooding problems occurring along the Alaskan coast. Both the tidal and surge model have an extensive number of observed data points collected by NOAA to be used for validation. In this talk we will present on the development of the model as well as results from the tidal and storm simulations.
