University of Oklahoma researchers looking at “flash droughts”

NORMAN, Okla. — Most Oklahomans know about flash floods, but what about flash droughts?!

Just as flash floods are caused by heavy rainfall in concentrated areas in a short time span, flash droughts are rapid, unexpected periods without rain.

“Given that flash droughts can develop in only a few weeks, they create impacts on agriculture that are difficult to prepare for and mitigate,” said Jordan Christian, a researcher at the University of Oklahoma.

“Flash droughts can drastically reduce crop yields and lead to severe economic losses and potentially disrupt food security,” said Jeffrey Basara, an associate professor in both the School of Meteorology and School of Civil Engineering and Environmental Sciences at OU. “These impacts can have cascading effects, including increased risk for wildfires, depletion of water resources, reduction of air quality and decreased food security.”

Basara is the principal investigator for the OU-led study exploring the global distribution, trends and drivers of flash droughts.

“This study is really important because although here in the U.S. we can often mitigate some of the effects with irrigation and other tools, a number of these types of events happen in places where they can’t be mitigated,” he added.

The study identifies global “hotspots” for flash drought from 1980 through 2015.

“We often associate drought with a lack of rainfall. For these flash drought events, about half of the contributing factor is a lack of rainfall, the other half is what we call ‘hostile layer mass’ – it gets really hot and dry,” Basara says.

The research team says these regions include the “Corn Belt” in Oklahoma and across the midwestern United States, barley production in the Iberian Peninsula, the wheat belt in western Russia, wheat production in Asia Minor, rice-producing regions in India, maize production in northeastern China, and millet and sorghum production across the Sahel.

“While several regions across the world have seen increasing or decreasing trends in flash drought over the last four decades, it is also critically important to know which regions may become more susceptible to flash drought risk in the future,” Christian said. “This study provides a foundation to build off and explore key questions regarding future trends of flash droughts.”

In 2019, Christian and Basara developed a method to begin to identify flash droughts. That methodology has helped researchers begin to better understand these events.

Christian led a study published in Environmental Research Letters in 2020 that looked at the impact of a major heatwave in Russia in 2010. Preceding that heatwave was a flash drought. The impact of those weather events led to the decimation of Russia’s wheat crop, so much so that Russia stopped exporting.

“Russia’s biggest wheat importer were countries in the Middle East, so the price of grain went through the roof in the Middle East,” Basara said. “The social unrest of the Arab Spring was created, in part, because of the unusually high grain prices and the socioeconomic turmoil those prices caused.”

With this study, the researchers are expanding their understanding of where flash droughts are more likely to occur around the world.

“As we go into a changing climate system, as we have population growth and food security issues, this becomes one of those topics that’s important because of its really severe impact on agriculture and water resources,” Basara added. “If we can better understand these flash droughts, we might have a better understanding of their predictability and then we can better plan.”