42. MODIS-based Estimates of the Regional Evapotranspiration

The spatial distribution of the regional MODIS-based evapotranspiration (ET) based on surface energy balance and DEM (Digital Elevation Model) and limited weather data is presented. Considering the remotely-sensed sun radiation is higher than actual sun radiation, two calibration factors are introduced with the measured ET, and the results are validated when the instantaneous ET is converted to the diurnal ET. In the process of calibration and validation, the mean value of 3 x 3 pixels, including the observed “point” value, is calculated as the “pixel” value to fit the remotely sensed pixel value to improve the representation of the observed “point” data. At the end of this paper, some common existing concerns are considered and analysed, and some suggestions are put forward.