黑河下游土地利用与景观格局时空特征分析

TemporaI-SpatialFeatures of Land Use and Landscape Pattern in Lower Reaches of Heihe River

基于研究区1986年Landsat TM和2000年Landsat ETM+遥感影像资料,综合运用遥感与GIS技术手段,结合景观格局分析软件,就近15年来黑河下游额济纳流域土地利用与景观格局变化进行了分析,并探讨了引起变化的驱动因素。结果表明:①研究区草地、林地、水域、耕地面积减少,‘居民工矿建设用地和未利用土地面积显著增加:土地利用动态转化过程以草地转化为未利用土地、林地转化为草地和未利用土地逆转为草地为主要特征:土地利用的空间位置转换面积大于其数量变化。②景观的破碎化程度降低,景观多样性及景观异质性程度减小,景观的稳定性降低。③气候的暖千化趋势,黑河下泄水量的持续减少,加之人类不合理的经济活动,是黑河下游土地利用和景观格局变化的主要原因。

With the aid of remote sensing techniques, GIS, and landscape pattern analysis software FRAGSTATS, changes in land use and landscape pattern of the Ejina Basin, the lower reaches of the Heihe River were studied based on 1986 Landsat TM images and 2000 Landsat ETM Plus images. And driving factors of the changes were explored. Results showed that （l） the areas of grasslands, forestlands, water surface and cultivated lands were decreased in the 14 years, whereas the areas of alienated lands and deserted lands were remarkably increased. The dynamic changes in land use were characterized mainly by transformation of grasslands into deserted land, forestlands into grassland, and deserted lands back into grasslands. The change in spatial location of land use was greater than that in area. （2） Landscape fragmentation, diversity, heterogeneity and stability were obviously reduced. （3） Climatic warming-drying trend, reduction of the flow into the lower reaches of the Heihe River, and irrational human activities were the main driving forces accelerating this progress.