以松嫩平原西部的典型沙漠化区泰来县为例,利用遥感、地理信息系统和野外调查获取了3期土地利用和沙漠化分布数据,分析了土地利用变化及其沙漠化动态响应。结果表明:①土地利用程度变化大多趋于加重趋势,其中1986~2000年加重趋势迅猛,2000~2005年加重趋势有所减缓;②沙漠化土地面积总体趋势逐渐增加,前期以40.7hm²/a的速度增加,后期以8hm²/a的速度增加,增加速度明显减慢,其中低覆盖度草地和林地发生沙化的几率最高;③土地利用方式未变化的土地以沙漠化减轻为主,而土地利用方式发生变化的土地,前期以沙漠化加重为主,后期以减轻为主,与土地利用程度变化相一致。

The Songnen Plain is an important grain production base in China. As a typical vulnerable area of eco-environment, its west part is one of the foci of land use and sandy desertification study. In this paper, Tailai County, a typical sandy desertification region in the Songnen Plain was taken as an example, and a method integrating remote sensing, Geographic Information System (GIS) and field survey was employed to build the dataset of land use and sand desertification for analysis. Remote sensing images included the Landsat Thematic Mapper (TM) image in 1986 and 2000, and the image with the Charge-Coupled Device Camera (CCD) on the China-Brazil Earth Resources Satellite (CBERS) in 2005. Moreover, the land use change and dynamic response of sandy desertification were further analyzed by spatial analysis model of GIS. Results showed that quantity and degree of land use remarkably changed at a region level, and the response of sandy desertification was also remarkable. First, the degree of land use change was mainly aggravated, and it increased by leaps and bounds in the period 1986-2000, and slowed down in the period 2000-2005. Second, the general trend of sandy desertification was gradually increasing, at a rate of 40.7 hm²/a in the former period and 8 hm²/a in the latter period. Furthermore, low coverage grassland and forest were distributed in the highest risk region of sandy desertification, and had an increasing trend. Third, the transformation of land use had great impacts on sandy desertification. Although sandy desertification degree of land use unchanged was mainly mitigated, the transformation area of cultivated land and low coverage grassland to sand land was much larger than the area of sand land converted to them, thus it was still at the risk of further increase. The region of land use changed has been suffering sandy desertification since 1986 with two different desertification periods identified. The first period (1986-2000) saw severe sandy desertification, and in the second period (2000-2005) the sandy desertification was weakened greatly. On the whole, land use tended to be unreasonable, although the trend was mitigated, it was still at the risk of further increase in the sandy desertification.