科尔沁沙地的土地利用与沙漠化

Land Use and Desertification in Horqin Sandy Land

根据1985年和2000年的土地利用数据和从相同时期的TM影象上提取的土地沙漠化数据,运用ARC/IN FO软件和Access统计软件,分析科尔沁沙地近20a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得出:草地和耕地是土地利用的主要类型,未利用地面积较大,其他利用类型面积较小;15a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;变化趋势是沙漠化面积增加,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则能加快土地沙漠化的进程。

Based on the digital land use data and the desertification data obtained from TM image from 1985 to 2000, land use structure and desertification land composition and its changes are studied, the relationship between land use and desertification is analyzed. The conclusions are as follows: 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 the past fifteen years, the area of cultivated land and woodland increased much and that of pasture land reduced. The main change direction is that pasture land transformed into cultivated land and woodland. The desertification land area in Horqin is large and the main desertification type is moderate. Desertification changing trend is that the desertification land area expanded and desertification degree reduced. Under continuously intensive land utilization, much of the pasture land and cultivated land degraded; the degraded lands developed into light and moderate desertification lands from potential desertification land. The area of desertification land induced by land use change is small and also its percentage in total new desertification land is little, whereas the increase of land use intension, such as pasture land use and cultivated land use, is the most important reason of desertification. To some extent the changes of land use pattern could accelerate the process of desertification.