CHARLESTON, S.C. (AP) — People along the coast have a few options in an era of global warming expected to bring more frequent, intense storms and the kind of devastation recently seen with Superstorm Sandy: They can move back from the shore, elevate buildings or build levees to keep the floods at bay.
But a pair of scientists at Georgia Tech and Clemson suggest another alternative, although it sounds a bit like science fiction. Their research shows it is possible to raise the coastline itself.
Leonid Germanovich of Georgia Tech and Lawrence Murdoch of Clemson, both environmental engineers, have worked out the math and are proposing a method of flood protection they call SIRGE, or solid injection for raising ground elevation.
The idea is relatively straightforward. They envision injecting sediment-laden slurry into hydraulic fractures in the ground. If repeated in adjacent areas and over a wide area, it works to push up the surface of the earth. They suggest a series of pumps and wells to force the material underground.
The proposal, and the extensive scientific equations that accompany it, were published in 2010 in the prestigious Proceedings of the Royal Society. The Society, dating to the 1660s, is the national academy of science in the United Kingdom and has 1,400 fellows worldwide.
After a 1900 hurricane devastated Galveston, Texas, killing an estimated 8,000 people, the city rebuilt after the ground level was raised as much as 17 feet.
"It's been shown with the Galveston example, if you can increase elevations, that is your best bet in safeguarding areas against flood," Murdoch said.
While you can't elevate every building in a community, another approach might be to raise the level of the ground below it. A similar technique has been used on smaller scales.
For example, when a tunnel is drilled under a city, a technique called compensation grouting is used above it, injecting material to keep the surface above stable so it doesn't sink. Perhaps the best-known example is the grouting done under Big Ben in London when a subway tunnel was built, Germanovich said.