Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2009
Publication Date: 10/13/2009
Citation: Gowda, P., Senay, G.B., Howell, T.A., Marek, T.H. 2009. Lysimetric evaluation of simplified surface energy balance approach in the Texas High Plains. Applied Engineering in Agriculture. 25(5):665-669. Interpretive Summary: The Simplified Surface Energy Balance (SSEB) model is one of the most simplified approaches available for mapping evapotranspiration (ET) at a regional scale. This approach requires only reference ET in addition to satellite imagery. Performance of the SSEB approach was comparable with other data-intensive ET techniques. Considering the minimal amount of ancillary data and excellent performance in predicting daily ET, the SSEB is a promising tool for mapping ET in semiarid regions.
Technical Abstract: Numerous energy balance (EB) algorithms have been developed to make use of remote sensing data to estimate evapotranspiration (ET) regionally. However, most EB models are complex to use and efforts are being made to simplify procedures mainly through the scaling of reference ET. The Simplified Surface Energy Balance (SSEB) is one such method. This approach has never been evaluated using measured ET data. In this study, the SSEB approach was applied to fourteen Landsat TM images covering a major portion of the Southern High Plains that were acquired during 2006 and 2007 cropping seasons. Performance of the SSEB was evaluated by comparing estimated ET with measured daily ET from four large monolithic lysimeters at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Tex. Statistical evaluation of results indicated that the SSEB accounted for 84% of the variability in the measured ET values with a slope and intercept of 0.75 and 1.1 mm d**-1. Considering the minimal amount of ancillary data required and excellent performance in predicting daily ET, the SSEB approach is a promising tool for mapping ET in the semiarid Texas High Plains and in other parts of the world with similar hydro-climatic conditions.