土库曼斯坦典型绿洲土地利用/覆被变化和景观格局的时空演变

当前开展遥感和GIS技术支持下的土库曼斯坦生态环境领域方面的研究,不仅可以保障中国的能源战略安全,同时也可为中国西北干旱区的生态环境演变及可持续发展研究提供一定的借鉴。本文以土库曼斯坦穆尔加布捷詹绿洲为研究对象,基于1976年、1988年、2001年和2011年的Landsat MSS、TM/ETM+的4期遥感数据资料,应用GIS和景观生态学方法定量分析了研究区近40年的土地利用方式及景观格局的时空变化动态特征。结果表明:(1)研究区LUCC变化明显,主要表现为林地、耕地、沙地和盐碱地呈现增加趋势,草地、水域和其他用地呈现减少趋势。土地利用在1976—1988年变化最快的是草地,1988—2001年是水域,2001—2011年是草地,1976—2011年是耕地。(2)研究区内整体景观的空间变化表现为蔓延度指数、散布与并列指数和斑块结合度指数均呈现降低趋势,分离度、SHDI和SHEI均呈现增加趋势,表明斑块数目增多,景观破碎化程度加大,连通性降低。总之,要保障土库曼斯坦穆尔加布捷詹绿洲土地资源与生态环境的可持续发展,必须注重土地利用格局最优化,确保景观格局与生态过程的连续性。

Change of LUCC and Characteristics of Landscape Pattern in a Typical Oasis in Turkmenistan

Using four sets of remote sensing images in 1976, 1988, 2001 and 2011, and with ecological quantity analytical method, we analyzed the change of land use patterns and landscape pattern in about 40 years in the Murghab-Tejen Oasis in Turkmenistan. The results were as follows: (1) There happened a significant land use/cover change in the studied area. The areas of woodland, arable land, desert and saline soil showed increased, while that of grassland, water region and other area decreased. The fastest change rates of land use occurred in grassland (in 1976-1988), water region (in 1988-2001), grassland (in 2001-2011), and arable land (in 1976-2011), respectively. (2) The Total Area(CA), Percentage of Landscape(PLAND), Number of Patch(NP), Edge Density(ED), Landscape Division Index (LPI), Interspersion and Juxtaposition Index(IJI), Splitting Index(SPLIT) and Patch Cohesion Index (COHESION) at class level, and the Shape Area-Weighted Mean(SHAPE_AM), Patch Density(PD), Landscape Division Index (LPI), (ENN_MN), Contagion Index (CONTAG), Shannon's Diversity Index (SHDI), Simpson's Diversity Index (SIDI), Interspersion and Juxtaposition Index(IJI), Splitting Index(SPLIT) and Patch Cohesion Index (COHESION) at landscape level all showed that the number of the patches increased and landscape fragmentation presented an increasing degree. The connectivity of patches reduced. It would be essential to optimize the land-use pattern and to maintain the continuity of landscape ecological process and pattern in the Murghab-Tejen Oasis if sustainable development of land resources and ecological environment protection were expected.