新疆喀什噶尔河流域1990-2010年土地利用/覆被及景观格局的变化特征

Changing characteristics of land use/cover and landscape pattern from 1990 to 2010 in the Kaxgar River basin,Xinjiang

采用新疆喀什噶尔河流域1990、2000和2010年的Landsat-TM影像数据和中巴资源卫星数据,结合GIS技术,分析了喀什噶尔河流域近20 a土地利用/覆被及景观格局动态变化特征,并对其变化原因进行探讨.结果显示:在1990-2010年喀什噶尔河流域耕地、建设用地、盐碱地、水域湿地、裸土地和其他未利用地面积呈不断增加趋势,变化幅度分别为73.92%、51.44%、24.27%、10.24%、6.47%和2.98%;林地、草地和沙地面积减少,变化幅度分别为-4.13%、-17.16%和-0.73%;裸石岩砾面积近20 a基本维持不变.利用转移矩阵可知,流域新增耕地面积主要来自于16.46%的草地和3.36%的林地;新增建设用地主要来自于1.46%的耕地和0.22%的草地;新增水域湿地面积主要来自于0.18%的草地;新增盐碱地面积主要来自于0.28%的草地.1990-2010年的20 a里喀什噶尔河流域耕地和水域湿地分布趋于集中,景观优势度增强,且斑块之间的联系不断增强.林地和草地面积减少,景观趋于破碎化,景观优势度降低.喀什噶尔河流域土地利用类型及景观指数的变化受人口、经济、政策和技术的多重影响,导致流域耕地面积增加、植被退化.因此,合理利用流域水土资源对流域生态环境安全十分重要.

In this paper, the change of land use and landscape pattern, along with the changing reasons, in the Kaxgar River basin from 1990 to 2010 are analyzed, based on Landsat-TM and CBERS images in 1990, 2000 and 2010, combined with GIS technology. It is revealed that （ 1 ） the land use in the basin had changed signifi- cantly from 1990 to 2010, for example, cultivated land, construction land, saline, naked land, wetland and other unused land had increased, with the changing rates of 73.92%, 51.44%, 24.27%, 6.47%, 10.24% and 2.98%, respectively; the woodland, grassland, mad sandy land had decreased, with the changing rates of -4.13%, -17.16% and -0.73% ; the area of bare gravel had basically unchanged; （2） in the 20 years, 16.46% of the grassland and 3.36% of the woodland transferred into cultivated land; 0.18% of the grassland shifted into water wetland; 0. 28% of the grassland shifted into saline land; （3） during this period, the cultivated land and water wetland had concentrated and gradually become dominant landscape types; the wood- land and grassland had reduced and the fragmentation had also reduced, landscape dominance had decreased, landscape shape had become simple; （4） there were multiple effects on land use and landscape index in the Kaxgar River basin, such as growing population, economic interests, policy and technology factors, resulting in cultivated land expanding with some hidden dangers to the region ecological environment security, so rational use of water resources is very important for watershed ecological environment security.