半干旱区城乡接合部景观镶嵌结构研究--以兰州市西固区为例

在RS与GIS的技术支持下，以地处西北半干旱区的城乡接合部-兰州市西固区为区域背景，利用景观生态学方法研究了在不同的坡度、高程下景观镶嵌结构的空间布局与空间镶嵌作用的机制。结果显示：随着坡度的增加景观镶嵌结构的多样性指数减小，斑块数量、破碎度先增加后减少，优势度先增加后减少；随着高程的增加，多样性指数，斑块数、破碎度先减少后增加，优势度则相反。景观镶嵌体在坡度与高程的分布上具有一致性，综合坡度与高程分区的景观分形模型模拟结果显示：人类活动影响较小的自然景观类型的复杂性远高于人工景观类型，而稳定性后者高于前者。由此得到以下结论：⑴影响本区景观格局最主要的因素是气候因素；⑵景观格局分布的垂直变化明显；⑶河流廊道在构建本区景观格局中也扮演重要角色；⑷2 类有可能通过改变景观类型的复杂性和影响着自然生态环境。

A Study on the Mosaic Structure of the Landscape in the Semi-arid Urban-rural Junctional Areas--A Case Study in Xigu District, Lanzhou City

Based on the research in Xigu District, Lanzhou City, the characteristics of the mosaic structure of the regional landscape are studied by using RS and GIS technology, quantitative analysis and fractional model. Then the main factors that control and impact the pattern of regional landscape are revealed. In the regions with the low altitude, gentle slope and various kinds of landscape, there are the characteristics of large index of lanscape diversity, weak dominance, high fragmentation, and the regions are easy to become the centers of human activities because of their smooth terrian, convenient communications, and being near to the rivers. but in the regions with the high altitude and steep slope, there are the characteristis of strong dominance, small index of landscape diversity and low fragmentation. In the mountainous regions, however, the landscape changes with the increase of altitude and the steepening of slope. The diversity of the natural landscape is much higher than that of the artificcal one, but the stability of the latter is higher than the former. Thus, the conclusions can be obtained: a. Climatic factors are the main factors influencing the landscape pattern in this area; b. The vertical change of the landscape distribution is obvious; c. Valleys play an important role in the landscape formation; d. The natural ecological environment may be impacted by human activities through changing the complexity of the landscape.