地理学报 ›› 2022, Vol. 77 ›› Issue (10): 2514-2528.doi: 10.11821/dlxb202210007

• 城市地理与区域发展 • 上一篇    下一篇

1988—2018年中国城市实体地域与行政地域用地扩张对比

徐智邦1,2(), 焦利民1,2(), 王玉1,2   

  1. 1.武汉大学资源与环境科学学院,武汉 430079
    2.武汉大学地理信息系统教育部重点实验室,武汉 430079
  • 收稿日期:2021-09-29 修回日期:2022-04-28 出版日期:2022-10-25 发布日期:2022-12-25
  • 通讯作者: 焦利民(1977-), 男, 河南安阳人, 教授, 博士生导师, 研究方向为城市化与国土空间优化, 地理空间分析与建模等。E-mail: lmjiao@whu.edu.cn
  • 作者简介:徐智邦(1991-), 男, 山东淄博人, 博士生, 研究方向为城市土地动态建模。E-mail: xzbang@whu.edu.cn
  • 基金资助:
    国家自然科学基金项目(41971368)

Comparison of urban land expansion between urban physical and administrative areas in China from 1988 to 2018

XU Zhibang1,2(), JIAO Limin1,2(), WANG Yu1,2   

  1. 1. School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, China
    2. Key Laboratory of Geographic Information System, Ministry of Education, Wuhan University, Wuhan 430079, China
  • Received:2021-09-29 Revised:2022-04-28 Published:2022-10-25 Online:2022-12-25
  • Supported by:
    National Natural Science Foundation of China(41971368)

摘要:

城市边界是城市演化认知和城市规划决策的空间依据。中国不少研究实践将地级市等行政地域范围视为城市,与物理上主要由连续人造不透水面构成的城市实体地域相比,存在较大的空间边界差异。然而,鲜有研究定量分析“实体”视角下长时间序列的城市用地演化,特别是对实体和行政两种统计单元视角下的城市扩张差异缺乏系统认识。本文基于30 m空间分辨率的多源遥感产品识别了1988—2018年8期的城市实体地域边界,分析其用地扩张过程,进一步与行政地域相对比,系统识别了两种统计视角下城市用地扩张的认知差异和空间模式。主要结论为:① 1988—2018年间,中国面积5 km2以上的城市实体地域单元数量增长了378%,以华东和华中地区的增长最为显著;城市实体地域中,88%为独立增长型,分布广泛但面积大都小于50 km2;12%为空间聚合型,主要分布在发达地区,面积普遍较大。② 相比行政地域,城市实体地域的位序规模更符合幂律分布,其Zipf指数30年来逐渐上升趋向于1,城镇体系发展愈发均衡;相比城市实体地域,行政地域单元在平原地区的城市扩张面积普遍偏高,在沿海地区的城市扩张强度普遍偏低。③ 和城市实体地域单元在拓扑关系上无法一一匹配的1327个行政单元大多分布在人口密集或发达的平原地区;结合实体和行政边界识别了“跨政区同城化”和“政区内集群化”两种扩张模式,前者多发生在省会区域,后者主要分布在华北平原,两者反映了城市化的空间重构。本文研究结果有助于深化中国土地城镇化时空过程的认识,并可对土地资源的科学配置、统一协调及行政区划的优化整合提供空间依据。

关键词: 城市扩张, 城镇化, 城市用地, 实体城市, 城市实体地域, 中国

Abstract:

Urban boundaries are the spatial basis for the cognition of urban evolution and urban planning decision-making. In China, "city" usually refers to a legally defined administrative unit, whose spatial boundary does not coincide with that of physical entity consisting of a continuous artificial impervious surface. However, few studies quantitatively analyze the temporal and spatial evolution of urban physical areas over long time series, especially lacking a systematic understanding of the spatial differences in urban land expansion from the views of physical and administrative areas. Based on the multi-source remote sensing products with a spatial resolution of 30 meters, we identified the physical urban boundary from 1988 to 2018 and analyzed the land expansion process of the physical area. Further, we identified the cognitive differences and spatial patterns of urban land expansion from the above two views and found the following conclusions: (1) In the past 30 years, the number of urban physcial areas in China with an area of more than five square kilometers has increased by 378%, and the most significant growth is in East and Central China. Among the physical areas, 88% of them belong to the type of "independent growth" widely distributed but most of them are smaller than 50 km2, while the other 12% belongs to the type of "spatial aggregation", mainly distributed in developed areas and the area is generally large. (2) Compared to administrative units, the rank-size distribution of urban area is more complying with the power-law model. Its Zipf's exponent has gradually increased to 1 in the past 30 years, indicating development of the urban system has become more and more balanced. Compared to physical areas, administrative area have larger land expansion area in plain areas and lower land expansion intensity in coastal areas. (3) The 1327 county-level administrative units that cannot topologically match the urban physical area are mostly distributed in densely populated or developed plain areas. Combining two views, two types of spatial expansion have been further identified, namely "inter-districts co-urbanization" and "intra-district clustering". The former occurs in provincial capital area, while the latter is mainly distributed in the developed areas of the North China Plain. Both reflect the spatial reconstruction of urbanization. This research is helpful to deepen the understanding of the spatiotemporal process of China's land urbanization and provide decision support for scientific land resource management.

Key words: urban expansion, urbanization, urban land, natural cities, urban area, China