Researcher reviews a thousand years of drought in Kansas

LAWRENCE — If you think the ongoing Kansas drought that started in 2010 is bad, you should have been around here during the Medieval Warm Period. That’s the era between the years 900 to 1,300 A.D. that saw slightly higher global temperatures and resulted in harsher dry spells in Kansas than the notorious Dust Bowl years or the still worse 1950s drought.

“The Medieval Warm Period really shows up in the drought record, particularly for Kansas, as a time where droughts were much longer and more severe,” said Anthony Layzell, doctoral student in geography and research assistant with the Kansas Geological Survey.

Layzell recently surveyed data on tree rings going back roughly a thousand years. (Tree rings are telling of precipitation for a given year, because a tree grows more and generates a thicker ring in a wet year, versus a thinner ring in a dry year.)

The researcher aims to put modern memories of harsh droughts such as those from the 1930s and mid-1950s into the context of the longer historical record. Layzell said such information could be helpful to policymakers, farmers and other stakeholders in planning for inevitable drought conditions in Kansas and managing vital water resources such as the Ogallala Aquifer that underlies much of the western half of the state.

“Policymakers should keep in mind that there’s a natural range of variability in terms of droughts, and things change over time,” said Layzell. “It seems commonsense that you should always plan for the worst. That’s exactly why we use the 1950s drought for planning, because it’s the worst on record. However, the record of the last 100 years isn’t necessarily representative in terms of drought occurrence. In fact, the longer-term record for Kansas shows that the 1930s and 1950s droughts are not that unusual and that droughts have been much worse in the past. So, it might be wise to take a longer-term perspective.”

On Friday, Layzell will share his research and data with interested Kansans, policymakers and fellow experts as a presenter at the 2013 KU NSF IGERT Water Symposium, Beyond the Long Hot Summer: The Future of Water in Kansas.

“It’s an opportunity for the general public and academics at KU and policymakers to hear about climate, water and agriculture — three themes that intertwine,” said the KU researcher.

Those are quite relevant subjects, given that the region has been suffering though an ongoing drought. But where does Layzell say the current drought ranks historically?

“It’s been as severe as some other recent droughts we think about,” he said. “2002 was a bad drought year — and 2012 was just as severe. However, it’s not been as severe as the 1930s and 1950s droughts nor, for that matter, a large number of other historic droughts over the past thousand years.”

The researcher cautioned that a drought’s duration is more important than its severity over just a few months.

“If this drought continues, well — we’ll see,” Layzell said.

As for predicting the future of droughts, beside the historical frequency found in the tree rings, Layzell said the Pacific Ocean might hold clues to better understanding why droughts occur in Kansas.

“Sea-surface temperatures tend to crop up a lot,” said Layzell. “Changes in sea-surface temperature in the equatorial Pacific can affect how much rainfall we get in Kansas. During El Niño years, when sea-surface temperatures are warm, conditions tend to be wet, while cold sea-surface temperatures during La Niña years tend to induce droughts, particularly for the southern U.S. but also up into Kansas.”

The 2013 KU NSF IGERT Water Symposium is from 4 p.m. to 7 p.m. Friday, Feb. 22, followed by a reception at The Commons, Spooner Hall, on KU’s main campus. The event is free and the public is invited to attend. See more information here.