The drought that gripped the Southeast from 2005 to 2007 was not unprecedented and resulted from random weather events, not global warming, Columbia University researchers have concluded. They say its severe water shortages resulted from population growth more than rainfall patterns.

The researchers, who report their findings in an article in Thursday’s issue of The Journal of Climate, cite census figures showing that in Georgia alone the population rose to 9.54 million in 2007 from 6.48 million in 1990.

“At the root of the water supply problem in the Southeast is a growing population,” they wrote.

Richard Seager, a climate expert at the Lamont-Doherty Earth Observatory who led the study, said in an interview that when the drought struck, “people were wondering” whether climate change linked to a global increase in heat-trapping gases could be a cause.

But after studying data from weather instruments, computer models and measurements of tree rings, which reflect yearly rainfall, “our conclusion was this drought was pretty normal and pretty typical by standards of what has happened in the region over the century,” Mr. Seager said.