An evapotranspiration model based on the energy balance for different vegetation types in arid area was built in the study,
and applied to the natural ecological system of Lake Ebinur wetland nature reserve in Xinjiang. The spatial-temporal dynamic change of the vegetation evapotranspiration in the study area was computed, and the evapotranspiration of three typical vegetations was analyzed and compared. The ground meteorological data were used to test the model. The results show that the evapotranspiration of all the natural system is about 10mm/d, and the maximum is over 20mm/d and occurs between May and August. The evapotranspiration of three typical arid vegetations was estimated in sequence of
<i>Populus euphratica Oliv</i>. <i>Tamarix chinensis Lour</i>. <i>Haloxylon ammodendron (Meye)Bge</i>. Finally, it is suggested that the ground surface vegetation types and arid characteristics are most important in the establishment of the evapotranspiration
model of natural ecological system based on energy balance in arid areas.
Because of the special weather characteristic and the land surface properties, the field uniformity of the land surface in
the arid area causes that the oasis is the cold source in its surroundings. It is the typical cold-island effect in oasis. But
use the remote sensing means what to acquire is the land surface radiation temperature (brightness temperature).
Therefore, withdraw the technique method of temperature information of thermal field in ground from the remote
sensing and the research of the relation between the air temperatures with the brightness temperature, are important
contents in cold-island effect research by the means of the remote sensing. The traditional temperature measurement by
using the observation data from fixed stations can not reflect the land surface temperature correctly, so it is of great
significance to supply the parameter of the ecological model and the climate model to recognize the interaction between
the eco-system and the climate system .The remote sensing data have great capacity, strong objectivity and rich quantity.
It is not seen much to make use of the remote sensing data to retrieve the ecological factors of the oasis in the arid area.
This paper makes use of the thermal radiation recorded by the Band 6 of LANDSET TM/ETM in 1986, 1990, 1994,
1997, 1999, and 2002 to deal with the land surface temperature in Qitai oasis and dynamically analyze the distribution
characteristic and the influential factors of the surface temperature.