Development of Parameterized Surge Response Functions for Coastal Bays
In the past few years, there has been an increase in the number of hurricanes hitting the Gulf of Mexico coastline. These hurricanes have caused damage in the billions of dollars, and hundreds of people have been killed during these events. The damage from hurricanes is caused by four main factors: storm surges, waves, strong winds and rain. At the coast, the damage due to the storm surge and waves is dominant. Numerical simulation models like ADCIRC are available for estimating storm surge, but high computational time makes it impossible to use them for evacuation planning purposes. Public perception of storm surge hazard is based upon the Saffir Simpson scale. As demonstrated by Hurricanes Katrina and Ike, the Saffir Simpson scale does not work well for surge prediction. The accurate and timely prediction of storm surge is very important. For this purpose, dimensionless Surge Response Functions (SRFs) for the open coast of Texas has been developed (Irish et.al 2008a and Song, 2009). The surge inside bays tends to be different from that at the open coast due to local geometric factors like shape, center of gravity, and characteristic size of the bay. To predict accurately the surge levels inside the bay, scaling laws are developed based upon the above mentioned factors. These scaling laws are used along with SRFs for the open coast (Irish et. al. 2009) to develop dimensionless SRFs for bays. The SRFs for 3 bays, Matagorda, Galveston and Corpus Christi have been explored. Results have shown that the Surge Response method works reasonably well for Matagorda, Corpus Christi and Galveston Bay. For these bays the dimensionless surge lies within the 95% confidence interval of Surge Response Functions.