Title: The Ogallala Agro-Climate Tool (Technical Description) Authors
Submitted to: Computers and Electronics in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 7, 2010
Publication Date: October 1, 2010
Citation: Mauget, S.A., Leiker, G.R. 2010. The Ogallala Agro-Climate Tool. Computers and Electronics in Agriculture. 74(1):155-162. Interpretive Summary: The Ogallala aquifer region is one of the United States most productive agricultural areas. Much of this productivity is dependent on the aquifer’s water, which lies under 111.4 million acres of the Great Plains. But in the recent past pumping from irrigated agriculture has led to water level declines that have not been compensated for by the aquifer’s natural refilling process. This drawdown of a basically irreplaceable water resource has led to questions about the long-term survival of the area’s agricultural economy. The area’s economy might be sustained by changing irrigation practices to conserve the aquifer as a water resource for as long as possible, or by preparing for the transition to mainly non-irrigated farming. Both responses require knowledge of the region’s climate and of the water requirements of the area’s major crops. The Ogallala Agro-Climate Tool is a Windows Visual Basic application that was developed to provide that information. The application reports crop evapotranspiration estimates for 83 crops, the probabilities of exceedance of cumulative rainfall, irrigation demand and growing degree days, the probability that minimum and maximum daily temperatures will exceed user-defined temperature thresholds, and the probability of heat stress, cold stress and dry periods of varying duration.
Technical Abstract: A Visual Basic agro-climate application capable of estimating irrigation demand and crop water use over the Ogallala Aquifer region is described here. The application’s meteorological database consists of daily precipitation and temperature data from 141 U.S. Historical Climatology Network stations during 1976-2005. From that daily data the program calculates climate and crop evapotranspiration (ETc) statistics over arbitrarily defined periods within summer or winter growing seasons at user-selected latitude-longitude coordinates. The statistics reported include: ETc estimates derived from the FAO-56 single crop coefficient algorithm, probabilities of exceedance of cumulative rainfall, irrigation demand and growing degree days, the probability that minimum and maximum daily temperatures will exceed user-defined temperature thresholds, and the probability of heat stress, cold stress and dry periods of varying duration.