城市功能中心时空分化及其规划政策驱动机制——以苏州市中心城区为例

Spatio-Temporal Differentiation Characteristics of Urban Functional Centers and Planning Policy-Driven Mechanisms:A Case Study of Suzhou Central Urban Area

以苏州中心城区为例,运用长时间跨度的城市兴趣点数据,采用核密度估计、区位熵等方法,识别城市功能中心的时空分化特征,进而探讨其驱动机制。研究发现:1)城市功能中心的空间分布由单中心向多中心演化,主副差序格局显著。功能中心的功能呈现公共性向生活性主导转变,并逐渐转化为消费性主导的特征,且主导功能的空间分异显著。2)驱动机制方面,多尺度空间、多层级政府的规划政策共同建构嵌套式的演化驱动机制。其中,宏观政策层面,经由国家战略落位和区域规划向下传导,指引空间和功能的整体演化方向;中观政策层面,有为政府通过构建蓝图式规划,联动市场机制,推动城市多功能中心的生成;微观政策层面,城市功能疏解、空间更新和新城特色空间营造等行动政策协同,推动城市各功能中心的功能疏解与集聚。城市功能中心的主导功能类型演化有其客观规律,有必要加强多案例对比研究,注重从功能中心体系视角出发,探讨功能中心的联系与分工,以促进规划政策的精细化供给。

Knowledge of the evolutionary characteristics of urban functional centers and their formation mechanisms is a prerequisite for promoting urban renewal and optimizing these centers.Taking the central urban area of Suzhou as an example,the driving mechanisms of spatial-temporal differentiation were determined through examining long-term data of urban points of interest,kernel density estimation,and location entropy.The findings are as follows.First,the spatial distribution of urban functional centers evolves from a monocentric to a polycentric pattern,with a significant pattern of primary and secondary differential order.In the case of Suzhou,the city has evolved from a single center to a multi-center functional system with one main center and four sub-centers,which is in accordance with the layout of the functional centers determined by the urban master plan.Second,The services of functional centers shift from public function to a dominance of lifestyle function and then to consumer dominance,which supports the trend of the transformation into a consumption-oriented city.The spatial differentiation of the dominant function types of each center is significant,with both a complementary division of labor and a corresponding trend of functional specialization.Under China's unique governance system,the intervention of planning policies is bound to have a significant impact on the spatial and temporal differentiation of urban functional centers.Therefore,based on the perspective of urban planning and policy,we have constructed an analytical framework for the evolution of functional centers at multiple scales and with multiple actors acting together.Macro policies are transmitted downward through national strategies and regional plans to guide the overall evolution of space and functions;at the meso policy level,the active local government builds a blueprint plan through planning tools,such as development plans and urban master plans,links with market mechanisms,and carries out urban management to promote the generation of multiple functional centers in the city.At the micro-policy level,action policies such as urban function relocation,spatial regeneration,and the creation of special spaces in new towns are coordinated to promote the function relocation and agglomeration of functional centers in the city.Multi-scale planning policies jointly construct a nested mechanism to drive the evolution of functional centers;however,the degree of spatial and temporal matching between planning policies and market mechanisms determines the formation and evolution paths of functional centers.The mismatch between the"blueprint"approach of urban planning and the flexibility of the market mechanism,the failure of the transmission of planning policies at the upper and lower levels,or the change of planning can cause a bias in the generation and evolution of functional centers.The contribution of this study is,first,to establish a spatial and temporal cognitive framework for the evolution of functional centers and to explore the evolutionary pattern of the dominant function types of functional centers based on fine-grained data.We found that the dominant functions of urban functional centers in the case study area go through an evolutionary process of"public function-living function-consumption function".A similar process has not yet been documented in other cities,underscoring the need to verify the model through multi-case comparisons.Second,the special urban governance environment in China requires that researchers and planners view policy interventions at multiple scales in order to fully understand the spatial and temporal evolution of urban functional centers and so establish a policy cognitive framework for the evolution of functional centers.Understanding the role of planning policy interventions forms the basis for the subsequent implementation of targeted planning interventions.