Mapping daily evapotranspiration using ASTER and MODIS images based on data fusion over irrigated agricultural areas

In this study, the continuous daily ET at 90 m spatial resolution was estimated from the Surface Energy Balance System (SEBS) by using the land surface temperature and land surface reflectance of VNIR combining the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Space-borne Thermal Emission Reflectance Radiometer (ASTER) spatiotemporal characteristics obtained from the Temporal Adaptive Reflectance Fusion Model (STARFM). Performance of this scheme used to estimate ET at high spatiotemporal resolution was validate over a heterogeneous oasis-desert regions by using in-situ observations from automatic meteorological systems (AMS) and eddy covariance (EC) systems in the middle reach of Heihe River Basin of Northwest China. The error introduced during the data fusion process based on STARFM is in an acceptable range for the predicted LST at 90 m spatial resolution. The surface energy fluxes estimated from SEBS using predicted remotely sensed data combing MODIS and ASTER spatiotemporal characteristics are agree well with observed surface energy fluxes from EC systems for all land cover types. The continuous daily ET estimated based on SEBS and STARFM seems to produce the general ET trends reasonably well for all land covers.