土地覆被变化是表明人类活动和生态环境之间相互作用的一个最敏感的因素之一.以天水藉河流域为研究区,基于多源遥感影像数据,提取研究区流域内土地利用/覆盖格局动态变化信息,并利用景观生态学中的景观指数定量的分析格局变化特征,同时对土地利用/覆盖格局变化的主要驱动力进行初步探讨,找出其与当地水土保持生态工程措施之间的关系.结果表明:基于多源遥感的土地利用变化监测所得土地利用变化规律与现实具有较大的符合度,研究区1992～2001年间水土保持措施基本上没有得到有力的加强,管理力度较弱,致使生态环境没有得到较好的改善,甚至遭到进一步破坏,林草覆盖率呈较大幅度的下降趋势.而由于国家政策引导,2001～2008年间当地居民水土保持意识的增强,天水藉河流域进行了大范围的水土保持生态工程建设,尤其是藉河示范项目开始实施,对生态环境的改善起到了不可估量的作用.%Land use/cover change (LUCC) is one of the most sensitive factors that show the interactions between human activities and ecological environments. Taking Xihe watershed as the study area, based on multi-source remote sensing images, the dynamci change information of land use and cover in the studying area was extracted and the change characters of land use/cover pattern was analyzed by using landscape metrics and the main driving force for the changes was probed and the relationship between the driving force and soil conservation measures taken in the study area was found out. Results show that land use/cover change rules monitored by multi-source RS images agreea with the reality greatly. During 1992 - 2001, soil conservation measures were seldom strengthened greatly with poor management, so that geological environment was little bettered or was further damaged, leading to the sharply decreasing of the total degree of coverage for forest and grass. Owing to the guidance of the government, during 2001 - 2008, consciousness of soil conservation of local people were greatly enhanced, and large-scaled soil conservation ecological engineering constructions were carried out, especially the project of Xihe watershed demonstration area, which played an inestimable role in improving the ecological environment.
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