基于夜间灯光数据的呼包鄂城市群空间扩张特征及驱动力研究

Spatial Expansion Characteristics and Driving Forces of Hohhot-Baotou-Ordos Urban Agglomeration Based on Night Light Data

为了揭示呼包鄂城市群时空演化特征和主导因素并明确其所处发展阶段,利用夜间灯光数据提取城市群1997年、2002年、2007年、2012年和2017年5个时期建成区轮廓,运用规模扩张指数、重心偏移模型和景观格局指数对其扩张过程、扩张方向和空间格局特征进行量化描述,在此基础上构建驱动力模型,探究其时空扩张驱动力。结果表明:(1)呼包鄂城市群呈现“先快后慢、先强后弱”的中心圈层式扩张的空间形态演变特征;(2)扩张方向上呈现“顺势转移、逐心而动”和“大幅东进、加速南移”的空间重心迁移特征;(3)空间格局上呈现核心-边缘分布以及“由极化转向集聚”的组织结构特征;(4)动力机制上以行政力和内源力平行驱动为主,市场力和外向力对城市群空间扩张影响作用依次递减。区域城镇化进程较快,总体处于快速发展的低级一体化阶段。

In order to reveal the spatio-temporal evolution characteristics and dominant factors of the Hohhot-Baotou-Ordos Urban Agglomeration and clarify its development stage,the contour of urban agglomeration built-up areas in five periods of 1997,2002,2007,2012 and 2017 was extracted by using nighttime light data.Based on the scale expansion index,gravity center migration model and landscape pattern index,the process,direction and spatial pattern characteristics of its expansion were quantitatively described.Based on this,a driving force model was established to explore the driving forces of its spatial and temporal expansion.The results show that:(1)The spatial morphology evolution of the central circle is characterized by“first fast and then slow”,“first strong and then weak”in the expansion process.(2)In the direction of expansion,the spatial center of gravity migration is characterized by“moving along with the trend”and“moving sharply eastward and accelerating southward”.(3)The spatial pattern showed a core-edge distribution,with the organizational structure characteristic of“shifting from polarization to agglomeration”.(4)In terms of the dynamic mechanism,administrative force and internal force are the main driving forces,while the influence of market force and external force on the spatial expansion of urban agglomeration decreases in turn.Regional urbanization process is fast,and overall is in the rapid development of low-level integration stage.