Submitted to: Proceedings of the World Environmental and Water Resources Congress Conference
Publication Type: Proceedings
Publication Acceptance Date: February 9, 2011
Publication Date: May 22, 2011
Citation: Gowda, P., Howell, T.A., Paul, G., Colaizzi, P.D., Marek, T.H., Copeland, K.S. 2011. SEBAL for estimating hourly ET fluxes over irrigated and dryland cotton during BEAREX08. Proceedings of the World Environmental and Water Resources Congress Conference. Paper No. 2787. 2011 CDROM. Interpretive Summary: Numerous remote sensing based models are available for estimating and mapping evapotranspiration (ET) from field to regional scale. Resulting ET maps can be used to assist producers to manage irrigation on their cropland. Before employing any remote sensing based ET model for irrigation management, they should be thoroughly evaluated with different cropping systems. In this study, we evaluated one of the most commonly used ET models in the world, SEBAL, for its ability to estimate ET on cotton canopies in the Texas High Plains using Landsat Thematic Mapper data. Results indicated good performance by the SEBAL model.
Technical Abstract: Numerous energy balance (EB) algorithms have been developed to make use of remote sensing data for mapping evapotranspiration (ET) on a regional basis. Adopting any or a combination of these models for an operational ET remote sensing program requires thorough evaluation. The main objective of this paper was to evaluate the Surface Energy Balance for Land (SEBAL), an EB based ET estimation algorithm, using lysimeter data and three Landsat TM images covering a major portion of the Texas High Plains acquired during the Bushland Evapotranspiration and Agricultural Remote Sensing Experiment 2008 (BEAREX08). Performance of the SEBAL was evaluated by comparing estimated surface temperature, net radiation, soil heat flux, and hourly ET, with measured data on four large lysimeters at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas [350 11 deg N, 1020 06 deg W; 1,170 m elevation MSL]. Crops grown on the lysimeter fields include irrigated and dryland cotton. Performance statistics indicated that SEBAL performed well estimating hourly ET rates for both irrigated and dryland cotton surfaces. Currently, more evaluation is being done to evaluate the SEBAL for other major summer crops grown in the Texas High Plains.