优化都市圈空间结构:小城镇和乡村发展的视角

Optimizing the Spatial Structure of Metropolitan Areas:A Perspective of Small Town and Rural Development

科学认识小尺度空间要素流动的演化趋向,对优化都市圈空间结构和细化区域政策尺度具有重要意义。本文从小城镇发展空间分化的角度,以城镇化潜力大的中部地区为研究对象,考察都市圈空间结构及其对乡村发展的影响。研究发现,小城镇人口增长率与其到中心城市距离之间表现为“∽”形曲线关系,毗邻省会城市的小城镇具有更快的人口增速。使用夜间灯光数据测度小城镇增长,这种“∽”形曲线关系仍然存在。研究结果表明,都市圈具有由大都市区、都市区、小都市区构成的多中心空间结构,以及大都市区→都市区→小都市区的演化过程。以自然地理条件和明清时期古城墙规模等数据构造工具变量的实证研究发现,以县城为核心建设小都市区以及促进其融入(大)都市区有利于促进乡村发展。进一步利用多时点DID模型检验高铁开通产生的扩散效应对县城的影响,结果显示,高铁开通对区位优势较好、发展潜力大和拥有较大城市辐射力的县城,具有更为明显的规模提升作用。本文的研究结论为国家支持都市圈发展、推动以县城为重要载体的城镇化和提升潜力地区城镇化水平提供了经验证据。

Scientific understanding of production factor mobility trends in small-scale space is critical for optimizing the spatial structure of metropolitan areas and refining the scale of regional policies.From the perspective of differentiated small town development,this paper studies the spatial structure of metropolitan areas and its impact on rural development,focusing on the central regions with significant urbanization potential.The study finds a""curve relationship between the population growth rate of small towns and their distance to the central city,with small towns adjacent to provincial capital cities having faster population growth.Using night light data to measure small towns'growth,the results show the"co"curve relationship stillexists.The findings reveal that metropolitan areas have a multi-center spatial structure composed of large metropolitan regions,metropolitan regions,and small metropolitan regions,with an evolution process of large metropolitan regions→metropolitan regions→small metropolitan regions.Using the scales of ancient city walls in the Ming and Qing Dynasties and natural geographical conditions to construct instrumental variables for endogeneity problems,empirical analysis finds that county town-centered small metropolitan areas and promoting their integration into(large)metropolitan areas are conducive to rural development.Further utilizing the multi-period Difference-in-Differences(DID)model to examine the diffusion effects of high-speed rail(HSR)opening on county towns,the study finds HSR opening has a more pronounced scale-enhancing effect on county towns with better location advantages,great development potential,and large urban radiation.This paper provides empirical evidence for the relevant national policies to support the development of metropolitan areas,promote urbanization with county towns as an important carrier,and enhance urbanization levels in potential regions.