Estimation of regional evapotranspiration in the mu us sandland

In this paper, the evapotranspiration in Wushen County, located in the Mu Us Sandland, was estimated by Advection-Aridity Model with meteorological data and 1km resolution reflectance of NOAA/AVHRR from 1981 to 2000. Then the spatial and temporal distributions of the evapotranspiration in Wushen County were analyzed. The results show: (1) Advection-Aridity Model combined with remotely sensed data could estimate regional evapotranspiration better. (2) The annual mean evapotranspiration during 19812000 in Wushen County is 264mm increasing from northwest to southeast while the annual mean precipitation is 320mm. (3) The temporal variation of evapotranspiration is in agreement with that of precipitation. (4) The relative variance of annual evapotranspiration is between 8% and 16%, which is the smallest in the eastern headwaters, bigger in the middle and the biggest in the north and southwest. Keywordsevapotranspiration; Wushen County; AdvectionAridity Model;