This year’s particularly dry spring drove a large part of the Midwest, including Missouri and Illinois, into drought.
The lack of moisture has far-reaching implications, including on agricultural production and water levels on the country's largest rivers.
“Rain is essential—it is where drought starts and ends,” said Illinois State Climatologist Trent Ford. “As we were going into drought from April through June, we just weren’t getting rain.”
The present situation highlights the complexity of exiting drought when a state or region can slip into it relatively easily, Ford said. Rainfall across parts of the Midwest in recent weeks is helpful, but it may not be enough to alleviate the dryness, he said.
Different kinds of rain One complicating factor is the changing climate, which is causing increasingly sporadic rain events that can drop inches of rain in only a few hours, said Jason Knouft, a biology professor at St. Louis University who studies the impacts of human activities on freshwater resources.
“Those seem to be more common than these long, soaking rains,” he said. “When we get these intense rainfall events, you’ve got a lot of water hitting the landscape really quickly.”
The Northeast—especially Vermont—and parts of western Kentucky both experienced intense rain events this month, which spurred significant flooding. The ground often is unable to absorb all the water that comes in these kinds of storms, Knouft said.
“When you dump a huge amount of water onto a surface, even if you’re dumping it onto soil, there’s only so much the soil can absorb,” he said.
The rest runs off, meaning a local watershed is capturing only a fraction of the rain that fell, Ford said. He points to the St. Louis region as an example, which is close to the anniversary of historic rainfall last year.
The nine inches that fell in late July helped propel last summer to rank as the sixth-wettest all time for St. Louis, though the region was quite dry beforehand, Ford explained.
“Hydrologically, when we think about the plant’s response to that, we get very dry conditions, then we get this big burst of rainfall,” he said. “The majority runs off. It’s down the Mississippi, down to the gulf. It’s gone. You don’t have that water in your soil to deal with.”
Source: stlpublicradio.org
Photo Credit: gettyimages-banksphotos
Categories: Illinois, Weather