Abstract:

As one of constituents of land surface moisture balance and energy balance,the land surface evapotranspiration is a key driving factor of land use/cover change. The amount of evapotranspiration influences the process of land use change and vice versa. In order to make clear how they interact each other and reveal the effects of land surface evapotranspiration on the process of environment changes, the land surface evapotranspiration amount in western Jilin Province in 1986,1996 and 2000 had been calculated based on surface energy balance theory, and the relationship between evapotranspiration distribution and grassland degradation, land salinization and soil desertification had been also discussed by overlaying the evapotranspiration data and land use data. The calculating results shows that the annual average evapotranspiration(AAE) amount in grassland,sand land and salinization land in western Jilin Province increases from 1986 to 2000. The AAE amount in sand land increases at the highest rate, the grassland follows, and the salinization land AAE was the lowest,which provides a desirable condition for transforming from natural land to sand land and salinization land and the evapotranspiration can aggravate grassland degradation, land salinization and soil desertification, in the area at a certain extent.

Key words: land surface evapotranspiration, land use/cover change, entironment, land surface energy balance, the west of Jilin Province