The sensitivity analysis of daily ET to land surface parameters derived from satellite data in Northwestern Loess Plateau of China

Sustainable development of Northwestern Loess Plateau of China (102deg-108degE, 34deg-38degN) will largely depend on the availability of water resources. Evapotranspiration (ET) is one of important items in water resources assessment. Current remote sensing can not directly measure ET which need to be estimate using the land surface physical parameters that can be derived from remote sensing data (NOAA/AVHRR) in combination with meteorological information. But various land surface parameters, such as albedo, emissivity, land surface temperature (LST), and NDVI, are directly or indirectly derived from satellite remote sensing data and therefore associated with uncertainty. The effects of the land surface parameters on the daily ET obtained by applying SEBS (Zhan, 2003) are analysed in this paper. In the sensitivity analysis of the daily ET to surface parameters that are different with seasonal change, it was appointed that the sensitivity will be different not only in different area, but also in different season