| Based on three sets of TM data (1997, 2002 and 2005) , the land use information was extracted by the method of unsupervised classification.Using the tools of geographical information system (GIS) combined with statistics, this paper analyzed the quantitative change and the spatial change of the land use types, and also the dynamic change of land use on different slopes.The results are as follows: cultivated land, forest and grassland accounted for more than 97%, which were the main land use types of the study area.Compared to 1997, cultivated land decreased 1.2% in 2001 and decreased 11.1% continuously in 2005.The conversion of cropland to forest and grassland during the period from 2001 to 2005 was higher than that in the period from 1997 to 2001.In different slope gradients, the land use change mainly happened on the slope from 5° to 40°, and the greatest change were on the slope from 15° to 25°. |