石羊河流域城镇化用地空间扩展分析

石羊河流域是流域经济社会可持续发展研究的重点区域之一。为找出流域城镇化用地空间扩展的机理，从社会经济、区位交通、生态约束出发，开展了城镇空间扩展用地评价与预测研究。首先，利用改进的土地适宜性评价方法，找出城镇扩展可能性和各乡镇适宜性高值区的空间格局，发现其主要位于流域中部绿洲生态功能区，沿G30高速公路和312国道分布，以县城/城区为中心呈星形扩散。然后，利用经过精度检验的土地转化模型（LTM），在适宜性评价因子的基础上模拟城镇扩张。结果表明：凉州区和金川区为流域发展的"两核"，312国道天祝至永昌段、211省道凉州至民勤段、212省道永昌至金川段为流域发展的"三带"。上述结果可为政府制定流域发展规划提供参考。

Analysis of spatial expansion of urban land in the Shiyang River basin

The Shiyang River basin is one of the key area,of which the economic and social sustainable development needs to pay more attention.In this article,viewing from the perspectives of socio-economic,regional transportation and ecological environment,the land evaluation and prediction of urban spatial expansion are discussed.First,using improved land suitability evaluation method,a high-value area of urban expansion possibility and townships suitable development are identified.It is found that the high-value area is mainly located in the ecological function zone of the central oasis of the basin,which distributes along the G30 expressway and G312 highway,taking the county town as the center.Then,the land transformation model (LTM),which had passed accuracy test,was applied to simulate urban expansion on the basis of the suitability assessment.The results show that there are two development cores,Liangzhou and Jinchuan Districts,and three development belts,G312 highway from Tianzhu to Yongchang,S211 highway from Liangzhou to Minqin,and S212 highway from Yongchang to Jinchuan.It is revealed that the LTM has good efficiency and is useful for simulating urban spatial growth.