国道312酒泉-嘉峪关段公路沿线景观格局变

公路作为一种特殊的土地利用类型，对其周边景观格局起着“通道-障碍”双重作用。在RS和GIS技术支持下，以甘肃酒泉-嘉峪关市1986、1996、2006年和2010年Landsat TM/ETM+影像为数据源，应用景观格局指数分析法，对比分析近25 a来，酒泉-嘉峪关段国道312公路两侧不同缓冲区内景观格局变化。结果表明：① 1986-2010年，公路沿线景观格局变化显著，建设用地增加迅速，未利用地明显减少，且主要转化为建设用地；公路辐射作用在不同缓冲区内影响程度存在差异。② G312线酒泉-嘉峪关段交通道路廊道结构特征变化突出，公路连通度和通道作用不断加强。③ 公路及相关设施建设使得沿线景观斑块密度增加，景观异质性增强，部分斑块类型在不同缓冲区表现出一定程度的聚集效应；公路沿线景观格局趋于破碎化、多样化和均匀化。④ 公路沿线以2 000 m内缓冲区影响最大，而公路起始两端的市中心地带影响范围超过3 000 m。两城市扩张与经济发展以及原有景观格局特征是导致公路沿线生态效应差异明显的重要原因。

Change of Landscape Pattern along the Jiuquan-Jiayuguan Section of National Highway 312

As a special land use in landscape, road plays a “corridor barrier” role and affects surrounding landscapes. The research on road landscape ecology is of an important significance in arid area where the ecology is fragile. Based on the results interpreted from the Landsat TM/ETM+ images of Jiuquan and Jiayuguan cities in 1986, 1996, 2006 and 2010, the land use change and landscape change along the Jiuquan-Jiayuguan section of National Highway 312 (G312) and its ecological effects in different road buffers including 1 000, 2 000 and 3 000 m in width were analyzed using the means of GIS and landscape ecology. The results were as follows: (1) Landscape pattern was significantly changed during the period from 1986 to 2010. The area of construction land was rapidly enlarged, that of unused land was reduced, unused land was promptly converted to construction land, and the dominance of unused land was weakened. The aggregation and radiation effects of the G312 were quite difference from different road buffers; (2) Change of the corridor structure of the Jiuquan-Jiayuguan section of the G312 was significant, and the connectivity and channel function of the Jiuquan-Jiayuguan section of the G312 were increased; (3) Because of the infrastructural construction of G312 and its neighboring highway G30, the patch density and heterogeneity of landscapes along these highways were increased. A certain aggregation of some patches in different buffers was brought about, and the fragmentation, diversification and homogenization of landscapes along the G312 occurred; (4) Effects of the G312 on landscape pattern were the most significant within a buffer width zone of 2 000 m but over 3 000 m in central Jiuquan and Jiayuguan cities. Urban expansion, economic development and landscape pattern change were the important factors affecting the ecology along the G312.