甘肃民勤绿洲的景观格局变化及驱动力分析

Landscape changes of Minqin oasis in Gansu Province and its driving force

应用GIS、RS技术与景观格局分析软件FRAGSTATS研究了甘肃省民勤绿洲近 14年间的景观格局变化 .结果表明 ,该绿洲的各类景观拼块体在此期间发生了十分复杂的时空转换 ,荒漠化过程与开荒过程同时存在 ,绿洲毁林、毁草开荒过程主要发生在 1994～ 1998年期间 ,并集中分布在绿洲南部水资源条件较好的地带 ,土地弃耕化过程主要发生在 1998～ 2 0 0 1年期间 ,集中分布在绿洲北部水资源条件较差地带 ;Shannon多样性指数、Shannon均匀度指数的下降与蔓延度指数的上升表明了人类对绿洲景观改造程度的不断加强 ,绿洲仍然维持着以耕地与居民地为主的强烈人为干扰的人工绿洲景观 .人类不合理的土地利用方式改变了绿洲景观的空间格局 ,水资源条件的变化进一步促进了景观结构的演变 .

Based on the technology of GIS, RS and using FRAGSTATS, studies on the landscape changes of Minqin oasis during 1987 to 2001 showed that the transitions of landscape patches were complex, and open up wasteland took place during 1994 to 1998 in the south of the oasis where the condition of water was better and desertization took place during 1998 to 2001 in the north of the oasis where the condition of water was worse.The decreasing of the Shannon's diversity index and the Shannon's evenness index and the increasing of Contagion index showed that human beings reconstructing the landscape of the oasis began stronger than before.Unreasonable land use was changed the landscape pattern, and the condition of water resource accelerated the landscape change.