京津冀建设用地人口密度变化格局及影响机制

Spatial pattern and mechanism of population density change in the built-up areas of the Beijing-Tianjin-Hebei region

【目的】土地资源优化配置是协同社会发展、粮食安全与生态环境的重要议题。科学认知县域人口流动分异下人口与建设用地变化的耦合规律、空间特征及形成机制,完善多尺度多层次配置机制是集约利用土地资源的重要途径。【方法】以京津冀城市群为研究区域,借助GIS空间分析与计量经济模型,解析县级尺度建设用地人口密度变化格局、耦合类型及影响机制,探究区域城乡协同的集约用地应对路径。【结果】①2009—2018年京津冀人口增长格局向京津中心城市外围区县和河北中心城市集中;建设用地快速增长区主要位于京津廊道市县及河北中心城市,北京和天津建设用地增速持续下降。②京津冀建设用地人口密度平均下降323人/km2,85.2%的研究单元出现下降,大幅下降区集中在河北中心城市外围市县;人口和建设用地变化耦合类型以收缩粗放型为主,加剧了土地资源的空间配置矛盾。③人口流动和工业化模式显著影响建设用地人口密度变化;而受二元制度约束,城镇化率提高的节地效果还不显著。【结论】京津冀县级单元人口和建设用地变化关系差异明显,河北非中心城市县域土地集约利用压力增大,亟需创新省市县多尺度协同机制,健全城乡多层次闲置土地利用政策体系。

[Objective]The objective of this study was to scientifically examine the coupling rule,spatial characteristics,and formation mechanism of population and built-up area changes under the differential population flow in county units,and improve the multi-scale and multi-level allocation mechanism for the intensive use of land resources.[Methods]Taking the urban agglomeration of the Beijing-Tianjin-Hebei region as the study area and using GIS spatial analysis and econometric models,this study explored the pattern,coupling relationship,and driving mechanism of population density change in the built-up areas at the county level.[Results]The study found that:(1)From 2009 to 2018,population of 61%of the areas in the Beijing-Tianjin-Hebei region decreased.The population growth was concentrated in peripheral districts of Beijing and Tianjin and municipal districts of Hebei Province.Meanwhile,the corridor between Beijing and Tianjin and the central urban areas of prefecture-level cities in Hebei were the high-growth areas of the built-up areas in the region,and the growth rate of the built-up areas of both Beijing and Tianjin slowed down significantly.(2)Population density in the built-up areas of the Beijing-Tianjin-Hebei region declined by 323 people per square kilometer,and substantial decline areas were concentrated in counties in Hebei Province.The coupling relationship between population and built-up area changes was dominated by the pattern of“shrinkage and extensive”type from 2009 to 2018,which increased pressure on land resource allocation.(3)Population flow and industrial development model significantly influenced population density change in the built-up areas,but the increase of urbanization rate did not exhibit a significant effect on land use efficiency.[Conclusion]The relationship change between the populations and built-up areas of county-level units in the Beijing-Tianjin-Hebei region is significantly different,and the pressure of intensive use of the built-up areas in counties surrounding central cities,especially located in the central and southern plain farming areas of Hebei Province is increasing.Therefore,it’s urgent to innovate the multi-scale coordination mechanism of provinces,prefectural cities and counties,and optimize the multi-level policy system for reusing idle land in urban-rural areas.