Analysis on Land Use/Land Cover Changes of Small Drain Basin Based on RS and GIS

Based on remote sensing images, this paper discussed the land-use and land-cover change of Kechou watershed located in Pingba county, Guizhou Province from 1973 to 2000. The images include the MSS data in 1973 with the resolution of 57m, Landsat-TM data in 1989 with the resolution of 25m, and Landsat-TM data in 1995 and 2000 with the resolutions of 30m. Based on the spatial analysis techniques supported by Arc/Info software and other statistical methods, this paper analyzed the spatial-temporal change characteristics of land use in the small watershed, revealed the major patterns and trends of land use and land cover change, and discussed the relation between land use and topography factors. The results show that the major land covers in the watershed are cropland and grassland. During the period of 1973 to 2000, the forest and grassland decreased while the cropland, water area, residential area and road area increased. The conversions of forest to grassland, grassland to cropland and cropland to residential and road area are the major patterns of land use change. The spatial distributions of land use have close relation with the topography factors such as elevation and slope. The elevation and slope of cropland, forest and grassland increased during the period of 1973 to 2000, which are identical with the conversions of land use types.