Abstract
This paper describes how the NDVI-based evapotranspiration estimation changes as the spatial resolution of the remote sensing image becomes coarser, and estimates the past or future evapotranspiration using land use data. With the 20-m SPOT/HRV image, the simulated images are produced using the degradation algorithm on the MTF. The images have resolutions of 30, 50, 80, 250, 700, 1100 and 2000m. The authors investigate the effect of the spatial resolution on the estimated evapotranspiration using these images, and show that the mean of estimated evapotranspiration does not change remarkably as the spatial resolution become coarser. This paper also proposes the F-C-U diagram to estimate regional evapotranspiration using the land use data. The F-C-U diagram can estimate easily the future or past evapotranspiration using the future or past land use data. The authors estimate the evapotranspiration change from the 1900s to the 1985s using the F-C-U diagram and LUIS (Land Use information System), which is the 2-km grid digital land use data set.
