南京城市边缘增长速率空间分异的驱动机制

Driving mechanisms of spatial differentiation in the growth rate of urban fringe area of Nanjing, East China

为深入理解城市增长的驱动机制,本研究利用1998、2003和2008年3期LandsatTM遥感影像,应用空间分析技术和广义线性模型从多个尺度对南京城市边缘区内聚落规模的变化及增速分异的驱动机制进行了分析。结果表明,研究期间聚落占地率持续增长,不同时期、不同区位的聚落分布及增长率存在显著差异。南京城市的边缘增长受到多种因子的共同作用,影响因素的构成依赖于研究的时空尺度。1998—2003年期间主要影响因子为水体占地率、公交站点数量、与国道、省道、县道的最近距离、林业用地占地率等;2003—2008年期间包括与国道、省道、县道的最近距离、公共绿地占地率、公交站点数量等。交通可达性以及人居环境质量对城市边缘增长速率的影响普遍存在于2～4km不同研究尺度上,但不同尺度上具有显著作用的具体因子具有明显差别。总体上,交通可达性表现出最高的相对重要性。城市基础设施规模、公共绿地占地率等因子的负效应反映了城市增长空间的制约作用,这种制约作用先期只发生在较小尺度上,后期在较大尺度上也有所体现。

To better understand the driving mechanisms of urban growth, a multi-scale analysis was made on the changes of the settlements in the urban fringe area of Nanjing and the driving mechanisms of the spatial differentiation in the urban growth rate, by using the spatial analysis and generalized linear models and based on the Landsat TM images in 1998, 2003, and 2008. In 1998-2008, the settlement coverage in the urban fringe area of Nanjing had a continuous increase, and there existed significant differences in the settlement distribution and its growth rate among different locations and time periods. The settlement growth in the urban fringe area was affected by a variety of factors, which depended on the spatial and temporal scales of interest. In 1998-2003, the main affecting factors were the water body＇s coverage, bus stop number, nea- rest distance to main roads, and forest coverage. In 2003-2008, the affecting factors included nearest distance to main roads, public green land, and bus stop number. Overall, the transporta- tion accessibility and the quality of living environments affected the urban growth rate at all stud- ied scales, but the specific factors were scale-dependent. Transportation accessibility generally had the highest relative importance in affecting urban growth. The negative effects of urban infra- structure and public green land reflected the constraint of growing space, and the constraining effect only occurred at a small scale in 1998-2003 but turned to be significant at both small and large scales in 2003-2008.