Thomas D. Smith

SWIMS HAWAII HURRICANE WAVE, SURGE, AND RUNUP INUNDATION FAST FORECASTING TOOL

The Surge and Wave Island Modeling Studies (SWIMS) fast forecasting tool employs high-resolution, high-fidelity wave and surge models to simulate hundreds of hurricanes for the island of Oahu, Hawaii. The simulations are run on High-Performance Computers and results are stored in a database of storm response. The database is then used to forecast potential waves, surge, and inundation very quickly when a storm is approaching Hawaii by employing response-surface surrogate modeling. The hurricanes are characterized by five parameters: landfall location, angle of approach, central pressure, forward speed, and radius of maximum winds. The fast forecasting system can produce the storm response for deterministic assessment or probabilistic assessment based on the error cone of possible tracks and error characteristics of the forecasts. The high-fidelity simulation requires a few thousand computational hours and the surrogate model requires a couple of seconds for predicting each hurricane response.

Understanding regional shoreline change and coastal processes at the Sunset Beach Region, Oahu, Hawaii

PURPOSE: This U.S. Army Corps of Engineers (USACE) Regional Sediment Management Technical Note (RSM-TN) reviews the development of a conceptual understanding of the complex regional coastal sediment processes at the Sunset Beach region on the island of Oahu, HI, which is a component of the USACE Hawaii Regional Sediment Management investigations. This document discusses the numerical modeling and volume change rate methodology used to identify sediment pathways in the region. This conceptual understanding of the sediment processes for the Sunset Beach region was developed to help inform future sediment management planning and decisions and to aid in identification of potential RSM actions within the region.

TWAVE MODELING PACKAGE FOR SIMULATION OF COASTAL INUNDATION IN ISLAND REGIONS

This paper describes the coastal modeling package TWAVE (Typhoon and Wave) developed under the U.S. Army Corps of Engineers (USACE) Surge and Wave Island Modeling Studies (SWIMS) project. TWAVE is a PC-based modeling package that provides nearshore estimates of wave runup and inundation caused by tropical storm events (typhoons and hurricanes). TWAVE consists of regional models and nearshore wave models. The TWAVE modeling system is implemented in a Microsoft ® Excel worksheet format, which serves as the user interface to visualize the systems input and output files. The example in this paper demonstrates the data products derived from TWAVE for a hypothetical hurricane, based upon the 1992 Hurricane Iniki passing directly through downtown Honolulu, Hawaii. TWAVE was used to develop estimates of coastal wave parameters, runup, and inundation caused by tropical storms. Though there was no validation data available for the hypothetical hurricane considered in this example, this storm event was used to demonstrate the overall capabilities of TWAVE for island applications.