Evaluating Three Evapotranspiration Mapping Algorithms with Lysimetric Data in the Semi-arid Texas High Plains
2007
Chávez, José L. | Gowda, Prasanna H. | Howell, Terry A. | Copeland, Karen S.
Ground water levels are declining at unsustainable rates in the Texas High Plains. Accurate evapotranspiration (ET) maps would provide valuable information on regional crop water use and hydrology. This study evaluated three remote sensing based algorithms for estimating ET rates for the Texas High Plains. Data from four large-scale weighing lysimeters (two each irrigated and dryland crops) at the Conservation Production Research Laboratory, USDA-ARS at Bushland, TX, were used to evaluate the remote sensing methods. ET algorithms evaluated include Mapping Evapotranspiration at High Resolution using Internalized Calibration model (METRIC), Two-Source Energy Balance model (TSM), and an Aerodynamic Temperature based Energy Balance model (ATEB). A Landsat 5 TM image acquired on July 23, 2006 was used for estimating ET. Predicted ET values were compared with lysimetric data to determine how well the different ET models worked. A discussion of each model's strength and weaknesses, under the climatic conditions encountered in the Texas High Plains, is provided.
显示更多 [+] 显示较少 [-]