Research on the cold-island effect with desertification process ----base on the QiTai oasis

摘要

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, 1999and 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.