东北地区收缩城市识别及其建设用地扩张时空演变

Identification of shrinking cities in Northeast China and spatiotemporal evolution of construction land expansion

【目的】建设用地扩张是城市化在地理空间上的直接表现,剖析收缩城市建设用地时空演变特征,对于优化收缩城市土地资源配置具有参考价值。【方法】构建“一主两副三维度”的多指标模型,识别东北地区2000—2020年收缩城市;运用公共边测度法、PLUS模型等,探讨研究期内东北地区收缩城市建设用地的扩张特征、扩张模式与驱动机制。【结果】①东北地区收缩城市数量与收缩程度呈加剧态势。2000—2010年,东北地区仅识别出4个人口收缩城市、1个人口-经济收缩城市;2010—2020年,识别出3个人口-经济收缩城市、1个人口-活力收缩城市和17个全维度收缩城市,且在空间上呈现出“东多西少、北高南低”的特征。②2010—2020年,东北地区70.59%的收缩城市建设用地呈持续增长的趋势,且扩张速度的高值区均集中分布于哈(尔滨)-大(连)经济带沿线城市。③收缩城市新增建设用地填充式扩张面积占比逐渐增加,扩张格局由扩散趋向集聚。④收缩城市建设用地演变是自然环境、人口-经济与基础设施等因素交互作用的综合结果,不同类型、不同研究时段收缩城市的核心驱动因子既存在共性,也具有独特性。【结论】东北地区70%以上的收缩城市呈现出建设用地持续扩张的矛盾发展格局。建议收缩城市形成合理的建设用地扩张秩序,充分挖掘城市存量建设用地利用潜力,实现收缩城市的“精明增长”。

[Objective]Expansion of construction land is a direct manifestation of urbanization in geographical space.Analyzing the characteristics of the spatial and temporal changes of construction land in shrinking cities is an important reference for optimizing the allocation of land resources in shrinking cities.[Methods]This study constructed a multi-indicator model with“one subject,two subsets,and three dimensions”to identify shrinking cities in Northeast China in 2000-2020.On this basis,it used the common edge measure method and PLUS model to explore the characteristics,patterns,and driving mechanisms of construction land expansion in shrinking cities in Northeast China during the study period.[Results](1)The Northeast area experienced a significant increase in the number and extent of shrinking cities between 2010 and 2020.From 2000 to 2010,only four demographically and one demographically-economically shrinking cities were identified.From 2010-2020,the region identified three demographically-economically,one demographic-vitality,and 17 full-dimensional shrinking cities.Spatially,it was characterized by a greater presence in the eastern and northern regions than in the western and southern regions.(2)More than 70.59%of the shrinking cities’construction land showed a continuous growth trend from 2010 to 2020.Among these cities,those with the fastest expansion rate were mostly centered in the Harbin-Dalian economic belt.(3)The proportion of infill expansion of new construction land in shrinking cities has gradually increased,and the pattern of expansion has tended to agglomerate from diffusion.(4)The evolution of construction land in shrinking cities is a comprehensive result of the interaction of the natural environment,population-economic and infrastructure factors,and the core driving factors of shrinking cities across various study periods and types have both commonality and uniqueness.[Conclusion]Of the shrinking cities in Northeast China,70% showed the paradoxical development pattern of continued expansion of construction land.We recommend that shrinking cities should form a reasonable order of construction land expansion,fully explore the potential for utilizing the cities’stock of construction land,and ultimately achieve“smart growth”in shrinking cities.