塔里木河干流区土地覆被变化与景观格局分析

Land Cover Change and Landscape Pattern in the Mainstream of the Tarim River

在GIS和遥感技术支持下,结合景观格局数量分析方法,利用1973年MSS、1983年航空遥感土地利用图、1990年TM、2000年TM和2005年CBERS遥感影像对新疆塔里木河干流区土地利用/覆被变化过程进行了定量分析。结果表明,1973-2005年塔里木河干流区土地利用/覆被发生了显著变化,耕地和城乡居民及建设用地面积显著增加,林地、草地和湿地面积减少,未利用地表现出先增加后减小的趋势。研究区土地利用类型转移的主要方向是林地和草地转化为耕地、耕地转化为城乡居民及建设用地、草地转化为未利用地。土地利用变化经历了"显著变化—缓慢变化—显著变化—急剧变化"的过程。景观格局分析表明,在人类活动的影响下,研究区景观破碎度、多样性增大,优势度减小。草地和未利用地对整个景观的控制作用减小,景观结构趋于多样和均匀。驱动力分析表明,人口增长和经济发展因素是塔里木河干流区土地利用/覆被变化的最直接驱动力,同时还受产业结构因素和政策因素及人类干扰强度的影响。

This study aims at revealing how land use and land cover changed in the mainstream of the Tarim River since 1973. Combining the integrated technology of ecological quantity analytical method with GIS technology, based on the MSS images in 1973, TM images in 1990 and 2000, CBERS images in 2005, and the land use data of 1983, the changes of land use/cover and landscape pattern were analyzed in this paper in the mainstream of the Tarim River from 1973 to 2005. The results showed that the areas of farmland and residential land increased obviously, areas of grassland, forest and wetland decreased, and that of unused land increased first then decreased. The major patterns of land use change were the conversions of grassland, forest and wetland to farmland, farmland to residential land, and grassland to unused land. Land use change underwent a process of obvious change - slow change - obvious change - tremendous change. The analysis of landscape index showed that due to the disturbance of human activities, landscape diversity index increased while landscape dominance index decreased. Simultaneously, landscape fragmentation index increased gradually.