Published on 07/24/01

Rainy Summer Giving Way to Drought?

Julian Williams is facing an old enemy that just won't go away: drought. "We're in bad need of some rain now," Williams said as he cut a customer's pasture for hay.

University of Georgia weather experts say pastures will signal the familiar agricultural drought's return. Williams already sees some hay fields needing water, as well as other crops.

That wasn't the case two weeks ago.

The state had more rain than it usually gets, about 2 inches more during June, when Tropical Storm Allison made a rainy and much-welcome visit. Temperatures, too, averaged about 1.5 degrees cooler.

The storm clouds gave way to dust clouds, though, and much warmer weather in July. The July Georgia sun boiled out the moisture that remained after the storm.

Green Plants Misleading

The plants look green, giving the impression they have plenty of water.

"Just because things look green doesn't mean the drought is gone," said Pam Knox, assistant state climatologist with the University of Georgia.

Agricultural drought, Knox said, is a short-term water deficit caused by limited rainfall, high temperatures and low humidities. The combination depletes the soil moisture, stressing plants, particularly those with shallow root systems.

Technically, the early-summer rains broke the agricultural, or short-term, drought in June. But it was more of a hair-line fracture than a clean break.

Crops wilt, cotton leaves sag and peanut leaves fold in a desperate effort to save the little water the plants have. After a little leave of absence, the short-term drought threatens to return.

Need an Inch per Week

"You have to have an inch a week or you start to go back into a short-term drought," Knox said.

Many areas haven't had anywhere close to an inch of rain since the first of July. The whole state needs about 3 inches of rain spaced out over the next two to three weeks. If it doesn't come, the official agricultural drought will be back.

Some areas could get scattered thunderstorms, and while they help those lucky enough to get them, the UGA weather experts say the scattered thunderstorms won't stave off a drought.

Julian Williams knows. He farmed for 35 years, worrying about the weather. Now, he cuts hay for other people who would like the rain to stay away even longer.

Most Hoping for Rain

"Folks that have hay to cut want it to be dry a day or two, you know," says Williams. But most farmers search the skies hoping for rain.

Knox said the state will need months of rain, even years, to break the long-term, hydrologic drought.

"Most people think of droughts as hot, severe, short-term events that cause plants to wilt and grass to brown," Knox said. "That's agricultural drought."

Georgia is in the fourth year, she said, of an unbroken hydrologic drought, which happens when the long-term water balance is negative. In other words, the soil and plants lose more water than comes back as precipitation.

Long-term Water Balance

The negative long-term water balance, she said, draws down the soil moisture. Over the long haul, it will reduce the replenishment of groundwater, leading to drops in well-water levels and in the base flow in streams.

"Base flow is the water in streams which comes out of the ground, rather than from rainfall," she said. "It's especially important in preserving the health of streams in dry spells."

The only way to recover from hydrologic drought, Knox said, is to have months or even years of above-normal precipitation. Cooler temperatures help, too, she said, because they reduce water losses.

In the short term, Georgia farmers need timely rains to provide the moisture they need for their shallow-rooted crops. In the long term, Knox said, the state needs a long period of rain-soaked days.