库尔勒市城市空间扩展特征及其驱动因素研究

以库尔勒市1990年、1995年、2000年、2005年、2010年以及2015年6个时期的Landsat TM/ETM+影像作为基础数据,借助ENVI 4.5、Arc GIS 10.1等专业软件对影像进行监督分类和空间分析。在此基础上,分析库尔勒市近25 a来土地利用时空变化规律、城市空间扩展趋势及演变过程、城市重心转移方向及距离和城市空间扩展形态变化特征等。研究表明:近25 a间库尔勒市建设用地面积大幅度增加,所占比例不断上升,年均增加速率为15.18%。耕地和未利用地对城市建设用地扩展贡献较大。城市向东南方向扩展,城市重心向东南方向转移了总共2 118.46 m。城市空间扩展紧凑度呈下降趋势,分形维数呈上升趋势,表明城市空间扩展趋于结构疏散化、形状复杂化。针对于以上特征及扩展趋势,分析了库尔勒市城市空间扩展的驱动因素并提出一些对策建议,为城市可持续发展提供科学依据。

Characteristics of urban spatial expansion and its driving factors in Korla City

Based on the LandsatTM/ETM+ imagery data of Korla City in 1990,1995,2000,2005,2010 and 2015,the urban land was classified by using of supervised classification method in ENVI 4.5 software and spatial analysis was employed by using of ArcGIS 10.1 software.The spatial-temporal changes of land use mode,urban expansion trend and evolution process,the shifting directions of urban center of gravity and its moving distance and extend pattern features of urban expansion were analyzed.The result indicates:1) Over the past 25 years,the area and proportion of construction land were substantially increased,annual average growth rate was 15.18％.2) Farmland and unused land contributed greatly to urban expansion.3) City extended to southeast,city gravity center shifted to the southeast about 2 118.46 meters.4) Urban compactness trend to decrease and fractal dimension index trend to increase,this indicated the spatial structure of city is losing and becoming more complex and unstable.Based on the above features and extension trends,this study analyzed the driving factors of urban spatial expansion and puts forward some suggestions and provides scientific bases for sustainable development of Korla City.