科尔沁沙地的土地利用与沙漠化

根据1985年和2000年的土地利用数据和从相同时期的TM影像上提取的土地沙漠化数据,运用ARC/INFO软件和Access统计软件,分析科尔沁沙地近20年来土地利用和沙漠化土地的构成及变化特点、土地利用与土地沙漠化之间的关系。主要结论草地和耕地是土地利用的主要类型,未利用地面积较大,其它利用类型面积较小;15年来,耕地和林地增加幅度最大,草地减少幅度最大,土地利用转移的主要方向是草地变为耕地和林地。科尔沁沙地沙漠化土地比例大,占一半左右,以中度类型为主;变化趋势是沙化面积增加,程度减轻。在持续强度利用条件下,面积广大的草地和耕地发生退化,由潜在沙漠化土地发展为轻度和中度为主的沙漠化土地;而土地利用方式变化所形成的沙漠化土地面积较小,在新增沙漠化土地中的比例亦很小。所以,草地、耕地等土地利用强度的增大是沙漠化土地面积扩大的最主要原因,而土地利用方式的改变能加快土地沙漠化的进程。

Land Use and Desertification in Korqin

Based on the digital land use data and the desertification data obtaining from TM image from 1985 to 2000, land use structure and desertified land structure and its changes are studied, the relationship between land use and desertification are analyzed. The conclusions as follows: the cultivated land and pasture land are the main land use types, and the unused land area is much and other land use area is small. In fifteen years, cultivated land and woodland increased much and pasture land reduced. The main change patten is that pasture land become cultivated land and woodland. The desertified land in Kerqin is large and the main type is moderate. The change trend is that the desertified land enlarged and desertification degree reduced. Under continuously intension land using, much of the pasture land and cultivated land degraded which developing light and moderate desertified land from potential desertified land, and on the other land, the desertified land induced by land use change is small and its ratio in new desertified land is little, so the increase of land use intension, such as pasture land and cultivated land, is the most important reason of desertification. Comparing with the desertified land in the area of land use patten unchanged, the average annual increase ratio of desertified land in the area of land use patten changed is large, and thus the change of land use patten may accelerate the process of desertification.