1998—2016年古尔班通古特沙漠南缘景观格局变化及驱动力

Changes and driving forces of landscape pattern in southern Gurbantunggut Desert during 1998-2016

为探究古尔班通古特沙漠南缘土地利用及景观格局的时空演变规律,以1998、2007和2016年遥感影像数据为基础,借助ArcGIS和Fragstats等软件,对其进行了分析,并运用主成分分析法探讨景观变化驱动力。结果表明:(1)沙地在整个研究区所占比例最大,但是其优势度逐渐降低,农田/草地和建设用地所占比例不断增加,水域面积持续减小,其他未利用地面积减幅最大。(2)从景观斑块水平来看,沙地和其他未利用地的破碎化程度不断加大,农田/草地类型面积扩大且形状愈加复杂不规则。(3)从景观整体水平来看,古尔班通古特沙漠南缘景观斑块数量、密度增加,形状趋向不规则与复杂化,蔓延度降低、分离度与分散度升高,景观斑块趋于离散、间断分布。(4)研究区景观格局演变受到自然和人为因素的双重影响,且人类活动为主导因素。通过对景观格局变化及其驱动力的研究,揭示出人类活动对古尔班通古特沙漠南缘景观格局演变具有巨大影响,对于今后开展荒漠植被的保护与恢复具有重要的指导意义。

Based on the remote sensing data in 1998,2007,and 2016,the spatiotemporal chan- ges of land use and landscape pattern as well as the driving forces in southern Gurbantunggut Desert in recent 19years were analyzed from the aspects of land use structure,changing speed, and landscape patterns using ArcGIS and Fragstats software.The results showed that:(1)The proportion of sand land was the largest,but its dominance decreased.The proportion of farmland/ grassland and construction land increased,while that of water area decreased.The decrease rateof other unused land was the largest.(2)At the level of landscape patch,the fragmentation degree of the sand land and other unused land increased,and the farmland/grassland area was enlarged with a more complicated and irregular shape.(3)At the overall level of landscape,the number and density of landscape patch increased,the shape was more irregular and complicated, the contagion decreased,and the degree of separation and dispersion increased.The landscape patches tended to discretely and discontinuously distribute.(4)The changes of landscape pattern were influenced by both natural and human factors,with human activities being dominant.Our results revealed that human activities had a great impact on the landscape pattern evolution in the southern margin of the Gurbantunggut Desert,which has an important guiding significance for the protection and restoration of desert vegetation in the future.