Planning multifunctional green infrastructure for compact cities: What is the state of practice?

摘要

Urban green infrastructure planning aims to develop green space networks on limited space in compact cities. Multifunctionality is considered key to achieving this goal as it supports planning practice that considers the ability of green spaces to provide multiple benefits concurrently. However, multifunctionality is an elusive concept and little information is available on how it is perceived and actioned by planners. Therefore, this paper will examine the application of the multifunctionality concept in urban planning based on a semi-quantitative study, including interviews with chief planners and analyses of planning documents, in 20 European cities as well as three qualitative good practice case studies. The semi-quantitative study revealed a broad awareness of the variety of social and ecological functions provided by green spaces in planning. Yet, the analysed strategic plans contained little information on how to enhance multifunctionality. Regardless of the lack of details, cities facing growth were more likely to consider promoting multifunctionality as a planning aim. The qualitative case studies in Germany (Berlin), the United Kingdom (Edinburgh) and Denmark (Aarhus) provided a detailed insight into how multifunctionality is handled on different spatial scales and revealed great differences from academic multifunctionality approaches that were developed in the context of ecosystem service assessments. The approaches applied in practice include audits based on indicators for multiple green space functions or the purposive design and management of multifunctional parks. Based on the findings, we arrive at five recommendations for promoting multifunctional urban green infrastructure in densifying urban areas: 1) undertake systematic spatial assessments of all urban green (and blue) spaces and their social, ecological and economic functions; 2) include standards and guidelines for multifunctionality in city-wide strategic planning; 3) encourage design and management for multifunctionality at the site-level while considering that not all sites must deliver the same set of functions. Further, spatial assessment, strategic planning and site design need to 4) consider synergies, trade-offs and the capacity of urban green spaces to provide functions as part of the wider green infrastructure network; and 5) largely benefit from cooperation between different sectors and public departments. These recommendations can also be instructive for research on ecosystem service assessments in order to develop approaches that more strongly correspond to the demands of planning practice.