Location: Soil and Water Management Research
Title: An aerodynamic temperature-based regional ET model evaluation for Texas High Plains agrometeorological conditions Authors
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2007
Publication Date: November 1, 2007
Citation: Chavez Eguez, J.L., Gowda, P., Howell, T.A., Copeland, K.S. 2007. An aerodynamic temperature-based regional ET model evaluation for Texas High Plains agrometeorological conditions [abstract]. ASA-CSSA-SSSA Annual Meeting, November 4-8, 2007, New Orleans, Louisiana. 2007 CDROM. Technical Abstract: High groundwater pumping costs and rapidly declining water levels in the Texas High Plains makes it imperative to improve irrigation water management for sustainability and economic viability. In this area, agriculture uses approximately 90% of groundwater withdrawals. Accurate regional evapotranspiration (ET) maps would provide valuable information on crop water use, irrigation efficiencies and aid in estimating regional groundwater recharge and pumping. In this study, an Aerodynamic Temperature-Based Surface Energy Balance Model for estimating spatially distributed ET rates was evaluated. Data from four precise large-scale monolithic weighing lysimeters (two with irrigation crops and two with dryland crops) at the Conservation and Production Research Laboratory, USDA-ARS at Bushland, TX [35 deg 11 min N, 102 deg 6 min W; 1,170 m elevation MSL] were used to evaluate the model. A Landsat 5 Thematic Mapper image, with a path/row of 31/36 was acquired on 23 July 2006 at 17:19 GMT. The satellite image covered a major portion of the Texas High Plains. Lysimeter-measured ET rates varied from 2.4 to 7.8 mm d**-1. Good agreement was found between remote sensing ET estimates and lysimeter derived ET values. The model performance, under the climatic conditions encountered in the Texas High Plains, will be discussed and summarized.