Monday, May 24, 2010
A group of researchers at the Institute of Computational Engineering and Sciences (ICES) at The University of Texas at Austin is trying to answer to that question by running sophisticated computer simulations to see what would happen in various storm scenarios. Their research results will inform decisions on whether to proceed with a wall.
While the concept for such a wall has been around for decades, it gained currency after Hurricane Ike struck in 2008.
The idea is that a wall would offer extra protection to Galveston and the surrounding area from surging walls of water that cause much of the damage from hurricanes. A dike would include a gate at the mouth of the Houston Ship Channel that would prevent a storm surge from rolling up the channel.
Hurricane Ike was the most damaging hurricane to strike the Galveston area since the great hurricane of 1900. Following that hurricane, a 17-foot seawall was erected on Galveston Island. The Ike Dike, which would include the seawall, is the 21st century version of the seawall.
Is an Ike Dike structurally and economically feasible? How would it affect the environment, the economy and recreation? Would it do more harm than good?That’s where Clint Dawson at ICES and a team of researchers come in.
Dawson is a professor in the Department of Aerospace Engineering and Engineering Mechanics and head of the Computational Hydraulics Group at ICES
The project is an example of the impact that university research can have on current concerns while adding to the base of knowledge in computer models and simulations.
Dawson and his group collaborate with researchers at the University of Notre Dame, and also work with the Severe Storm Prediction, Education and Evacuations from Disasters Center (SSPEED) at Rice University in Houston.
Before a computer model can be trusted to predict the future, it must prove that it can accurately repeat the past.
That is, can the computer model, loaded with data from Hurricane Ike, depict what happened with the actual storm?
“We have to do this because we have to show the larger scientific community that our computer model can reproduce reality because otherwise nobody would believe us,” Dawson said. “This is the whole crux of doing what is called predictive simulation.”
Dawson and his colleagues began modeling Hurricane Ike shortly after it passed and have been refining their model since then.
“After Ike we were doing simulations and we continued to improve and refine our model to the point that now we’re very confident in the results we’re getting,” he said. “We’re getting fantastic matches with data. So we can use the computer model to look at various scenarios of what might happen.”
One of the 32 simulations that the Dawson group has run is a repeat of Hurricane Ike with the Ike Dike in place.
He said the results show that the “dike would actually substantially reduce the surge throughout Galveston Bay. From that perspective it looks like it might be feasible. However, that’s just one scenario.”
They’ve also run scenarios in which the storm makes landfall at another place.
“If the storm had hit further down Galveston Island, say 10 or 20 miles down the coast, it would have been much more devastating for Galveston and Houston,” he said. “They would have taken the brunt of it.”
There are more scenarios to run, but in the end, Dawson said, the goal is to provide the people who will make decisions concerning the Ike Dike, or other proposed mitigation strategies, with the best information.
“What we hope is that policy makers will make decisions based on informed science, on the best science we can do,” Dawson said.