Time Series Evapotranspiration Mapping Using Landsat-TM and Terra-MODIS Satellite Data.

Evapotranspiration (ET) is an important process in ecosystems′ water budget and energy balance, and is closely linked to ecosystem productivity. The aim of this work is to generate daily time series ET maps using moderate (Landsat) and coarse resolution satellite (MODIS) data for the states Kansas, Oklahoma and Texas. A single source algorithm SEBS (Surface Energy Balance System) was employed on MODIS data while a two source model (TSM) was used with Landsat data. An extensive network of weather stations were utilized to generate spatially interpolated inputs of air temperature, relative humidity, wind speed, solar radiation, pressure, and reference ET. Validations of the ET maps done against eddy covariance data from grassland sites at El Reno, OK suggested good performance. Results indicated that the proposed ET mapping framework is suitable for deriving accurate daily ET maps at regional scale.