SAND DUNES AND MEGADROUGHTS OF KANSAS

 
 
Alan Halfen*

Department of Geography, The University of Kansas

 
 

“Megadroughts” were long-duration, prehistoric droughts more severe than historic droughts such as the Dust Bowl droughts of the 1930s. Megadroughts resulted in widespread desimation of vegetation and in the formation and reactivation of dune fields across the Great Plains. Kansas, located in the Central Great Plains, has several dune fields which have recorded these prehistoric megadroughts. This research applies landform analysis and dating methods to the dune fields of Kansas in order to investigate the timing, severity and areal extent of prehistoric megadroughts. In order to reconstruct the history of megadroughts, dunes in two areas of Kansas are being studied: the Hutchinson Dunes in east-central Kansas and the Arkansas River Dunes in western Kansas, along the Arkansas River. In general, both dune fields were stable (vegetated) prior to a global warming event around 1000 AD, but activated in response to one or more megadroughts shortly thereafter. Dune activity slowed towards 1500 AD as climate became wetter, but again intensified due to megadroughts that followed a global cooling event around 1600 AD. Megadroughts continued into the 1800s followed by a short period of stability and, most recently, dunes rectivated in response to the 1930s and 1950s historical droughts. Data gathered from dune fields in Kansas present evidence of past megadroughts and raise the spector that megadroughts will occur in the future, especially given current scenarios under greenhouse warming. Future megadroughts, more severe than those of the 1930s, will have widespread impacts on the agriculture, economy and overall well-being of Kansas citizenry.