油气管道建设对干旱荒漠区景观格局影响的比较研究

A comparative study of pipeline construction effect on landscape pattern in arid desert area

以新疆绿洲一荒漠过渡带为研究对象，利用ArcGIS和fragstats软件，选用快鸟遥感影像解译土地利用类型，以50～100m为宽度划分缓冲区，分别计算缓冲区及整体景观的几类代表性的景观指数，比较油气管道建设3个阶段景观格局的动态变化，分析其对区域景观格局的影响。结果表明：建设后草地面积逐渐减少，灌木林地和建设用地面积逐渐增加；在斑块类型水平上，原本占据优势的草地景观斑块数量增加，结构复杂程度增加，在景观中优势程度下降，以小斑块为主的灌木林地和建设用地复杂程度和优势程度提高；管道上方各景观类型的景观格局指数变化幅度较其他区域更加剧烈；在景观水平上，选取的6项景观格局指数反映出景观整体破碎化程度加剧，异质性增加，内部连通性下降，各景观类型比重更加均匀。总之，管道建设对所经过区域的景观格局和功能产生了明显的影响，原有结构发生变化，功能削弱。主要的影响区域为管道上方作业区，对于其他区域，影响强度随着距管道距离的增加而迅速降低，范围能够达到管道作业带两侧300m。研究结果可为西部地区管道建设的生态环境保护和更深入的研究工作提供参考依据和理论基础。

As a key part of landscape ecology, analysis of landscape pattern is frequently used to reflect landscape ecological functions and processes, and the influence of the human disturbance on environment as well. In this pa- per, the key point is focused on the pipeline construction in the arid desert area. Through statistics and buffer analy- sis, we investigate the selected landscape patterns changes in different period of the construction. These landscape metrics are used to analyze the landscape pattern and its dynamic change in the different construction stages, so as to reveal the influence of the oil and gas pipeline construction. Based on the land use types interpreted by the years of 2002,2006 and 2010 QuickBird image of oasis-desert ecotone in Xinjiang, the buffers are divided with the width in 50-100 meters, and selected landscape metrics are calculated by using ArcGIS and fragstats. The result shows that grassland area gradually decreased while shrub land and construction land gradually increased. Total 1.96 hm2 in- creased area of shrub land was transformed from grassland. The area of construction land was changed greatly, since there was only 0.03 hm2 area remaining the same from 2006 to 2010. At the class level, the grassland that was domi- nant in the landscape pattern in 2002 had more patch numbers （ NP ） than the other years. Its pattern got complex and its area was decreased step by step. On the other hand, both shrub land and construction land had LPI and LSI risen, indicating that although they became complex, their got better function and took more important roles. Above the pipeline, the landscape metrics of each class was varied greatly. Percentage of Landscape （ PLAND ） of grass- land decreased by 90%, and Patch Density （ PD ） got higher rapidly. On the converse, shrub land was the dominate landscape element in the construction area. PLAND of construction land were 13.35%, 7.13%, 4.36%, 3.81% and 1.81% respectively from pipeline to 200-300 m buffer in 2010, as the same with its Aggregation Index （AI）. Thatmeant the influence of the pipeline construction was gradually weakened in the other buffers. At the landscape level, a large increase of fragmentation, heterogeneity and reduction of connectedness was found through the selected land- scape metrics. PD and Perimeter-Area Fractal Dimension （PAFRAC） increased, while Largest Patch Index （ LPI ）, AI , CONNECT and Simpson＇s Diversity Index （ SIDI ） reduced in the whole study area. It demonstrated that the Integrity of the landscape dropped off, and fragmentation degree heightened. Human disturbances brought by pipeline construction reduced the stability in this area. Moreover, the proportion of each landscape types became more balanced. There were significant differences between the year of 2002 and 2010, as well as construction area and other buffers. In conclusion, pipeline construction influences observably the landscape pattern and its function. The original structure has changed and functions have declined. The main affected area is construction area. Al- though all the buffers are influenced by the pipeline construction in landscape pattern, the buffer which is farther from the pipeline gets less impact. This study could provide theoretical basis and reference for environment conser- vation and further study on pipeline construction in arid desert area.