An Analysis of Land-use Change in Changchuan Watershed, a Soft Sand-Rock Area at the Middle Reach of Yellow River

Changchuan Watershed in Inner Mongolia is located in a soft sand-rock area at the middle reach of Yellow River. Based on the image data from Landsat-MSS in 1976, the image data from Landsat-TM in 1998 and in 2000, the land use/cover patterns and their changes in the watershed have been analyzed in this paper by means of RS and GIS techniques. The preliminary results are as follows: 1) Changchuan Watershed is dominated by three land use types, i.e. shrub-land, grassland and the unusable land, covering over 75% of the watershed in total. 2) During the period from 1976 to 2000, through integrated measures of soil and water conservation, woodland and shrub-land areas greatly increased, but some woodland and shrub land have been transformed into unusable land, sandy land or farmland. In the meanwhile, the area of water body distinctly decreased. 3) The biological measures of soil and water conservation such as forestation and grass planting, the cultivation expanding and the variation of annual precipitation might be the main factors leading to the land use changes in the area.