新疆焉耆盆地近40年土地利用与土地覆被演化

Land Use and Land Cover Change of Yanqi Basin, Xinjiang in the Resent 40 Years

焉耆盆地是塔里木盆地广博荒漠背景下的一个绿洲,盆地内各种景观分异十分显著,其中心的博斯腾湖在当前西部大开发之际担当着向塔里木油田供水和向塔里木河生态输水的重要任务。因而了解焉耆盆地土地利用与覆被格局及其变化是博斯腾湖及其下游地区今后规划和发展的前提。该文通过利用各种景观指数以及斑块转移矩阵分析了20世纪60年代、90年代以及2000年焉耆盆地的土地利用与覆被类型的演化特征。结果显示从20世纪60年代到2000年,研究区土地利用与土地覆被结构经历了复杂的演化,盆地内各种景观变得越来越破碎,异质性明显增加;但是总的来说,盆地中绿洲和荒漠仍呈现出鲜明的分异。而人口的增加、农业的发展模式、以及由于自然和人为因素所产生的水资源的动态变化等是导致盆地土地利用与覆被变化的主要影响因子。

Yanqi Basin is an oasis in the background of the arid area in Xinjiang. Discrimination of all kinds of landscape is very conspicuous in the basin. The Bosten Lake, which transports water to Tarim river and supplies water to Base of the Tarim oil field, so far, is mainly water resource. The former studies usually focus on the change of water, the quality of water of the lake, however, few studies the land use and land cover pattern of Yanqi Basin using integrated synthetic methods. The pattern of the land use and land cover and the dynamic evolution of the patterns of Yanqi Basin control directly the distribution and dynamic changes of substance, energy,environments and ecosystem safety, so the study about the land use and land cover pattern and dynamic changed of the pattern is necessary. Yanqi Basin disturbed by human being and the nature, which make the types and structure of the land use and the land cover very complexity. As a result, Yanqi Basin is a very good example for the study of relative fields and the study of the northwest of China.By means of GIS, landscape pattern and land use and land cover dynamic evolution of Yanqi Basin are analyzed with the diversity index, the fragmentation index. The landscape became more and more fragments and increased landscape heterogeneity have been observed, as a whole, it still displayed a pattern of sharp contrast between oasis and desert landscape. The land use and land cover change in Yanqi Basin of Xinjiang during 1960s, 1990s and 2000 are analyzed by using various landscape metrics and the transition matrix of the land use types. The results can be gotten that the change of Basin is mainly embodied in the expanding of oasis, methods of expanding of oasis and nature succession because of the change of status of water. The scale of expanding of oasis is bigger and the oasis comes from the grassland usually in 1960s to 1990s. The scale of expanding of oasis is small and the oasis comes from the interlaced zone between oasis and desert from 1990s to 2000. The land use and land cover within the study area has undertaken a complicated evolution in structure and composition in Yanqi Basin, Xinjiang, from 1960s to 2000, The human activities and the changes of water resource have significantly influenced the evolution and distribution of land use and land cover.