塔里木河下游垦区绿洲景观格局变化分析

Analysis on the Change of the Oasis Landscape Patterns in the Reclamation Area in the Lower Reaches of the Tarim River

以塔里木河下游垦区为研究区 ,对其 1986～ 2 0 0 0年的景观变化进行了研究。结果表明 ,景观变化主要体现在 :(1)随着人类土地开发利用的程度提高 ,区域景观趋于多样化和均匀化 ,主要是以人类活动造成的灌木疏林地、低质草地和草地的退化为主 ;其次 ,人工绿洲的开垦多在这三类用地上 ;此外 ,水库蓄水面积的增大 ,淹没了部分这类用地。 (2 )从斑块的绝对面积来看 ,始终是以荒地和低质草地为主 ,且荒地、水浇地、水田、水域和沼泽在两个灌区都是逐步增加的 ,荒地面积的增加反映了研究区生态退化趋势较为严重。 (3)从斑块转移概率来看 ,研究区居民地、荒地、低质草地以及水浇地至少有 94 %以上的面积是保持其原来状况的 ;而沼泽的转移概率达到 84 %以上 ,主要转移为水域。反映了区域绿洲景观的主体仍然是以荒漠为背景的强烈人为干扰的人工绿洲景观 ,以及人工绿洲对水资源的依赖。

In this paper,the change of landscapes and its driving factors in the reclamation area in the lower reaches of the Tarim River during the period of 1986～2000 are researched. The results are as follows: (1) The diversity and evenness of the landscapes in the reclamation area are increased along with the exploitation and utilization of land resources,which are dominated by the degeneration of the irrigated sparse shrubbery lands,low-quality grasslands and grasslands;most of the reclaimed lands are located in these three kinds of lands;some of these lands are submerged by the enlarged water areas of the reservoirs;the enlargement of the wastelands reveals that the ecology in the study area is seriously degenerated. (2) Viewing from the diversion probability of the spots in the study area,the diversion probabilities from residential areas to residential areas,from wastelands to wastelands,from low-quality grasslands to low-quality grasslands,and from irrigated lands to irrigated lands are as high as over 94%,these reveal that the oasis landscapes in the region are still dominated by the artificial oasis landscapes under the background of deserts. (3) The regional economy depends mainly upon the cotton production. Under the effects of the regional natural conditions,therefore,the desertification process and the reclamation process occur simultaneously in the lower reaches of the Tarim River.