城市形态结构对空间紧凑发展的影响机制分析——以上海为例

Impact of urban morphological structure on space compact development:A case study of Shanghai

基于空间紧凑发展内涵,构建综合指数模型,分析2005—2020年上海空间紧凑度的演变特征并与国内外城市进行比较,进一步利用时空地理加权回归模型分析城市形态结构对空间紧凑度的影响效应。研究发现:①空间紧凑度呈现中心高外围低的圈层式分布特征,中心城区普遍趋于稳定,外围城区增长较快,且与其他同类城市比较处于高紧凑发展水平;但受政策及规划影响,紧凑度分指标在空间格局上存在显著差异。②城市密度与空间紧凑度呈倒“U”型关系,功能混合度和用地形态与空间紧凑度呈近线性关系,且城市密度与之关联性最强。③整体上城市密度和功能混合度均对空间紧凑发展产生促进效应,而用地形态表现出抑制效应;分区尺度上形态、功能和密度要素对空间紧凑度的影响效应存在显著差异。④通过中心城区与外围城区的差异性空间结构调整,控制国土空间规划形态结构指标来提升城市紧凑发展水平。

The disorderly sprawl of land hinders the effectiveness of urban operations.Achieving compact development through optimized territorial spatial planning tools has become a crucial issue for high-quality urban development.This is particularly true for large cities where there is a significant disparity in land expansion rates between the suburbs and the central urban areas.Thus,this study emphasizes the importance of targeted zoning optimization suggestions to achieve efficient space utilization.Based on the connotation of spatially compact development,a comprehensive index model is constructed to analyze the evolution characteristics of spatial compactness in Shanghai during 2005-2020 and compare it with domestic and foreign cities.In addition,a polynomial functional relationship regression model is used to explore the correlation between the sub-indices of urban form structure and spatial compactness,as well as the factors contributing to any differentiation observed.Finally,a Geographically and Temporally Weighted Regression model is used to analyze the effect of urban morphological structure on spatial compactness from the perspective of different city districts.Research Findings:1)Shanghai is at a high level of compact development compared to similar cities.The pattern of spatial compactness is circular.It shows a high center and a low periphery,with the central region generally tending to be stable and the peripheral region growing faster.However,there are significant differences in the spatial pattern of compactness sub-indicators due to the influence of policies and planning.Compared with domestic and foreign cities,Shanghai presents the characteristics of highly compact development.2)Urban density has an inverted"U"-shaped relationship with spatial compactness,and correlation is the strongest.In contrast,the mix degree of urban function and land-use form have a nearly linear relationship with spatial compactness,respectively.3)Overall,it is evident that land-use form can inhibit spatially compact development,though both urban density and the mix degree contribute to it.At the zoning scale,the impacts of form,function,and density on spatial compactness vary dramatically.In the peripheral urban areas,the impacts of the three types of factors on spatial compactness align with the overall findings.However,in the central urban areas,urban density tends to have a negative effect on improving spatial compactness,while land-use form has a notable positive impact.4)An adjustment to the spatial and morphological structures associated with territorial spatial planning may facilitate compact development within core and periphery areas.Specifically,the central urban areas should prioritize reducing urban density and optimizing land use structure,while the peripheral urban areas should focus on improving urban attractiveness and reducing land use fragmentation.