分水后黑河干流中游地区景观动态变化及驱动力

综合利用GIS、RS技术和景观生态学方法,分析了黑河干流中游地区1985～2005年,尤其是黑河干流水量统一调度实施后(即2000年以后)的景观动态变化及驱动机制.结果表明:(1)研究区景观发生了较大变化,1985～2000年,耕地、林地、城乡工矿居民用地逐渐增加,而草地、水域、未利用土地不断减少;2000～2005年耕地、城乡工矿居民用地逐渐增加,而草地、林地、水域、未利用土地不断减少.(2)在类型水平上,分水后,耕地和城乡工矿居民用地呈连片趋势发展,破碎度降低,形状更为规则,空间连接性增强;林地、草地、水域和未利用土地破碎度增加,分布更为分散,连通性和优势度降低.(3)在景观水平上,分水后,研究区景观多样性水平提高,异质性在增加,破碎化程度越来越大,景观中斑块空间连接性下降,优势度在减少,斑块类型在景观中趋于均匀分布,土地利用向着多样化和均匀化方向发展.(4)研究区景观变化的驱动力主要包括人口增长、经济社会发展,2000年以后,可利用水量的约束直接影响着研究区的景观变化.

Dynamic change of landscape and its driving forces in midstream of Heihe mainstream basin after water redistribution

Based on the techniques of GIS/RS and the methods of the landscape ecology, the characteristics of the landscape changes and driving forces in midstream of Heihe mainstream basin from 1985 to 2005 were analyzed in the paper, especially the changes of landscape after water redistribution scheme in Heihe River basin was executed. The results showed as follows: (a) The landscape had changed greatly in Heihe River basin from 1985 to 2000, the farmland, woodland, resident and industry land increased, while grassland, water area and unused land decreased; the farmland, resident and industry land continued to increase from 2000 to 2005, and the changes of other patch type was adverse. (b) After 2000, at the class level, farmland and resident and industry land have become more fragmented, along with the area increasing, and patch shape has tended to be more regular, and the spatial connectedness of these two types increased gradually. The fragmentation, spatial connectedness and landscape dominance of woodland, grassland, water area and unused land had similar change trends. The fragmentation increased, but the spatial connectedness and landscape dominance of these four types decreased respectively. (c) At the landscape level, the diversity, heterogeneity and fragmentation of landscape increased after 2000, while the spatial connectedness and landscape dominance decreased. (d) The main forces of landscape change included population growing and the economic development. However, the reduce of available water resources in Heihe River has become the main force since 2000 which caused the significant changes of the landscape change.