The impact of metropolitan authorities and supra-local strategic spatial planning on land-use patterns: a comparative analysis between Barcelona and Milan metropolitan areas, 1950s-2010s

在过去的70年里，人口和地貌的戏剧性变化极大地影响了这个欧洲领土的传统城市结构。这些人口和形态的转变通常被称为大都市进程，给政策制定者带来了紧迫的制度和政治挑战。在整个欧洲，自上世纪50年代以来，对这些挑战的一个典型(但渐进的)回应是建立大都市当局。通常，发布区域范围的战略性空间规划是为了为超越和跨越地方行政边界(即超地方层面)的未来发展提出一个全面的指导方针。但是，一个关键的问题仍然是，大都市当局如何以及在多大程度上通过这些战略性空间规划有效地指导地方空间政策，以遏制城市遏制，特别是遏制城市蔓延。城市蔓延或郊区化可以被定义为“管理不善、规划不善的城市增长(...)，其特征是城市土地使用过度增加，城市密度下降，家庭和经济功能在空间上分散分布”(Siedentop and Fina 2012：2765-2766)。这项研究的论点是，欧洲大都市当局随着时间的推移对土地控制政策产生了重大影响。主要假设是，尽管空间规划作为超地方空间发展的指导方针具有战略性质，但在大都市和地方治理行为者之间已经启动了具体的日常空间规划做法，使超地方战略性空间计划得以有效实施。研究土地控制政策如何在大都市层面的实践中应用显得尤为有意义，因为它可以提高我们对如何支持和引导超地方尺度上的可持续发展的理解。本研究将大都市治理过程(即大都市当局的角色)与(郊区)土地利用扩展模式联系起来。这项研究考察了大都市尺度上的制度因素、治理动态和空间规划实践在多大程度上可以(并且已经)对土地利用模式产生(间接和非因果)影响。在我之前研究的基础上，本研究考察了西班牙巴塞罗那和意大利米兰大都市当局在引导当地空间发展朝着遏制城市蔓延方向发展方面的作用。之所以选择巴塞罗那和米兰这两个城市地区，是因为这两个地区的体制结构和空间规划系统相似，但空间发展模式不同。本研究提案专门针对总体研究的第二个目标(O2)，工作方案以及所申请的资金仅涉及这一目标。第一个和第三个目标(O1和O3)已经实现。

In the past 70 years, dramatic demographic and morphological changes have greatly affected the traditional urban structure of the European territory. These demographic and morphological shifts are generally referred to as metropolitanisation processes, and have posed pressing institutional and political challenges to policy-makers. Across Europe, a typical (but gradual) response to these challenges since the 1950s has been the establishment of metropolitan authorities. Typically, area-wide, strategic spatial plans were issued to propose a comprehensive guideline for future development beyond and across local administrative boundaries (i.e. supra-local level).However, a key question remains about how and to what extent metropolitan authorities have been effective through these strategic spatial plans in steering local spatial policies for urban containment, in particular for the containment of urban sprawl. Urban sprawl, or suburbanisation, can be defined as "a poorly managed and poorly planned urban growth (...) characterised by an excessive increase in urban land uses, decreasing urban densities, and a spatially dispersed distribution of households and economic functions" (Siedentop and Fina 2012: 2765-2766).The argument of this research is that European metropolitan authorities have had a substantial impact on land containment policies over time. The main hypothesis is that, despite the strategic character of spatial plans as guidelines for supra-local spatial development, specific day-by-day spatial planning practices have been set in motion between metropolitan and local governance actors that enabled the effective implementation of supra-local strategic spatial plans. Investigating how land containment policies are applied in practice at the metropolitan level appears to be particularly meaningful nowadays because it can improve our understanding on how to support and direct efforts towards sustainable development at the supra-local scale.This study connects processes of metropolitan governance (i.e. the role of metropolitan authorities) with patterns of (suburban) land-use expansion. This research examines to what extent institutional factors, governance dynamics and spatial planning practices at the metropolitan scale can have (and have had) an (indirect and non-causal) impact on land-use patterns.Building on my previous research, this study examines the role of the metropolitan authorities of Barcelona (Spain) and Milan (Italy) in steering local spatial development towards urban sprawl containment. The urban regions of Barcelona and Milan were selected because they have similar institutional structures and spatial planning systems, but present divergent spatial development patterns.This research proposal specifically targets the second objective of the overall study (O2), and the work programme as well as the requested funding concerns this objective only. The first and third objective (O1 and O3) have already been carried out.