密度、距离及分割视角下长三角区域城市韧性逻辑建构与实证分析

Logical construction and empirical study of urban resilience from density,distance and division perspective in the Yangtze River Delta

风险影响的跨区域性凸显了城市网络在增强城市韧性中的重要性。立足新经济地理学理论中密度-距离-分割三大要素(3D要素),从区域及城区层级上构建包含生态密度、空间距离及社会分割指标的城市韧性综合指数模型,以长三角41市为例,运用空间计量方法研究韧性指数特征、均衡发展状态及3D要素对韧性水平的影响效应。结果显示:①区域中城市韧性水平总体偏低,在空间上呈现以“苏锡常”为核心向外梯度递减的圈层式+轴线型韧性发展格局;韧性等级与区位条件、规划衔接以及内外均衡发展状态高度相关。②随着城市韧性水平的提升,城区层级上的抵御恢复力及区域层级上的适应转型力均衡趋势增强。高水平韧性城市中两者趋向均衡发展,中低水平韧性城市中两者存在失衡;③不同层级的3D要素对韧性水平的影响存在差异性,区域层级上的主导要素为距离,而城区层级上则为密度,二者交互后的影响更加显著。

The impact of regional cities’risks is continuously becoming more cross-regional and multi-scale,highlighting the importance of exploring pathways to enhance resilience by leveraging urban network connectivity.Based on the connotation and features of density,distance and division elements(3D elements)in the new economic geography theory,we have developed an Urban Resilience Index model using the Pressure-State-Response framework and the coupling coordination degree model.This comprehensive model incorporates six indicators,encompassing three elements of ecological density,spatial distance and social division at both urban and regional scales.Taking 41 cities in the Yangtze River Delta Urban Agglomerations as a case study,the balanced development degree model and the geographic detector model methods are used to explore the spatial distribution characteristics of the Urban Resilience Index,the balance status of urban internal and external development,and the effect of 3D elements on resilience levels at regional and urban scales.The results are as follows:1)The overall resilience level of the Yangtze River Delta cities remains low,exhibiting a“spindleshaped”top-down quantitative structure.Resilience levels gradually decrease outward,with the Suzhou-Wuxi-Changzhou Metropolitan Area serving as the concentric and axial core.The resilience level is closely correlated with location conditions and planning connection,as well as the balance between internal and external resilience development.2)As the level of urban resilience increases,there is a trend towards greater balance between the Resist-Restore Ability at the urban scale and the Adapt-Transform Ability at the regional scale.The leading scale of regional urban resilience development shifts from the urban scale to the regional scale,ultimately forming a dual-scale linkage.Most high-level cities show balanced internal and external resilience development.More than half of the medium-level cities demonstrate balanced development,with better balance observed in southern region.However,among the low-level cities,only a few achieve balanced development.3)The effect of 3D elements on the level of resilience varies across different scale.Distance is the dominant element affecting resilience levels at the regional scale,while the dominant element at the urban scale is density.The interaction between the former two elements has an even more significant impact.Furthermore,the impact of social division at the urban scale is notably enhanced when interacting with other elements.Therefore,greater emphasis should be placed on the integrating and optimizing multiple elements across different scales.