|P.v., Vara Prasad|
Submitted to: Proceedings of the World Environmental and Water Resources Congress Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/9/2011
Publication Date: 5/22/2011
Citation: Paul, G., Gowda, P., P.V., V.V., Howell, T.A., Staggenborg, S.A. 2011. Evaluating surface energy balance system (SEBS) using aircraft data collected during BEAREX07. In: Proceedings of the World Environmental and Water Resources Congress Conference, May 22-26, 2001, Palm Beach, California. Paper No. 2777. 2011 CDROM. Interpretive Summary: Numerous evapotranspiration (ET) models have been developed to use remote sensing data for mapping ET on a regional scale. Adopting any one of these models for an operational ET remote sensing program requires thorough evaluation. In this study, we evaluated the Surface Energy Balance System (SEBS) for estimating hourly ET. Eleven very high resolution images acquired during the 2007 summer growing season over the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas, were used for this purpose. Comparison of estimated hourly ET values with lysimeter measurements indicated that SEBS may provide good ET estimates. Considering the minimal amount of data required, SEBS was found to be a promising tool for operational ET remote sensing programs. More efforts are being made to thoroughly evaluate the SEBS model.
Technical Abstract: Evapotranspiration (ET) is an essential component of the water balance and a major consumptive use of irrigation water and precipitation on cropland. Remote sensing based surface energy balance algorithms are now capable of providing accurate estimates of spatial-temporal ET. Uses of these spatial ET estimates are innumerable, including hydrological modeling, irrigation scheduling, drought and flood monitoring, and global climate change studies. The objective of this study was to evaluate the ability of the Surface Energy Balance System (SEBS) to estimate hourly ET fluxes, using very high resolution (0.5-1.8 m) aircraft images acquired during the BEAREX07, (Bushland, Texas ET and Agricultural Remote Sensing Experiment 2007). Accuracy of the predicted ET fluxes were investigated using observed data from four large weighing lysimeters, each located at the center of 4.7 ha field in the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas. The uniqueness and the strength of this study comes from the fact that it evaluates the SEBS for irrigated and dryland conditions simultaneously with each lysimeter field planted to irrigated forage sorghum, irrigated forage corn, dryland clumped-grain sorghum, and dryland row-grain sorghum. Eleven images acquired during early and mid-cropping seasons (June 24 - July 27, 2007) were used in the study. The SEBS algorithms performed equally well for both irrigated and dryland conditions in estimating the hourly ET with overall mean bias error and root mean square of -0.01 and 0.11 mm h 1 (-1.53% and 20.27%), respectively.