Bushland Reference ET Calculator with QA/QC Capabilities and An Iphone/Ipad Application.

Accurate daily reference evapotranspiration (ET) values are needed to estimate crop water demand for irrigation management and hydrologic modeling purposes. The Bushland Reference ET (BET) Calculator was developed by the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas for calculating hourly and daily grass and alfalfa reference ET. The user-friendly interface for the calculator was developed using .NET programming for Windows-based computers. The calculator uses the ASCE Standardized Reference (ET) Equation for calculating both grass and alfalfa reference ET at hourly and daily time steps. Users have the option of using a single set or time-series weather data to calculate reference ET. Daily reference ET can be calculated either by summing the hourly ET values for a given day or by using daily averages of the climatic data. New enhancements to the BET Calculator include graphic capabilities to conduct QA/QC of climatic data as well as calculated reference ET. In addition, efforts are being made to add predictive modeling capabilities using ordinary least square and advanced statistical learning regression methods. Further, a smart phone version of the BET Calculator was developed for calculating a single hourly or daily grass/alfalfa reference ET for current location using the nearest weather station or any other geographic location. This paper demonstrates use of Windows-based and iPhone/iPad versions of the Bushland Reference ET Calculator that being distributed through the USDA-ARS web site and Apple's App store to interested users at no cost.