收缩城市的形态控制:断面模型与精明收缩的耦合框架

城市-乡村建成环境之间的过渡是连续且分阶段的过程,"精明增长"策略建立了一个"断面模型"来控制和规范不同类型的城市形态,并使各"生态区"断面之间产生连续的平滑衔接。基于这一认识,本文探索将"断面模型"与"精明收缩"结合的可能,即城市在收缩阶段进行"空间资源的优化重组"和"低效资源的整合退出"的过程中,用该模型控制和调整空间形态中"空间要素的合理分配"和"生态区的平滑过渡"。首先,文章通过解析断面模型与精明收缩的概念和内涵,从核心价值、控制对象、运作方式等层面建立两者的耦合框架。框架为断面模型应用于精明收缩提供了依据,也描绘出基于断面模型的精明收缩与精明增长的技术路径。其次,文章通过案例研究,分析与探讨美国相关收缩地区基于断面模型的规划实践,以此证明将断面模型应用于精明收缩的可行性。本研究希望通过耦合框架的提出以及相关案例的解析,确立精明收缩目标与形态控制手段之间的对应关系,完善"增长管理"和"收缩管理"理论,引导并管控城市形态的正向(增长期)与反向(收缩期)有序演变。

To Regulate the Urban Form of Shrinking City:A Coupling Framework of Transect Models and Smart Shrinkage

The transformation of landscape/townscape from the rural area to an urban area is a continuous and phased process,for which a transect model is used in the smart growth strategy to depict as well as to regulate the changing urban form,ensuring a smooth transition between different ecological zones.Inspired by this,we try to apply the"transect model"to"smart shrinkage",using the abilities of the former to"allocate spatial elements"and to"smooth transition between ecology zones",in order to fulfill the needs of the latter(i.e."to optimize the spatial pattern"and"to rightsizing the city").Firstly,this paper introduces the concepts and meanings of the transect model and the smart shrinkage and builds a coupling framework based on their similar aims,objects,and operations.Secondly,this paper analyzes three case studies in the USA,where the framework was partially implemented in the specific planning practices of these shrinking cities.Using the coupling framework and case studies,this research aims to develop a method/theory for the control of urban form in both growing and shrinking cities.By doing so,it prepares the urban planners and decision-makers with effective tools to manage growth and shrinkage using the same model for both urban and rural areas,ensuring a sustainable urban form in either positive(regional growth)or reversed(regional shrinkage)evolution of the ecological transects in urbanization.