Multifunctionality of Urban Green Space -- An Analytical Framework and the Case Study of Greenbelt in Frankfurt am Main, Germany

This research emphasizes the significance of multifunctionality in urban green space planning practice and builds an analytical framework of multifunctionality for the holistic interpretation of the studied case, the Greenbelt Frankfurt am Main. Multifunctionality has been widely used in the context of urban green space planning practice and evaluation in recent years. It is considered as a key characteristic in several contemporary concepts like Green Infrastructure, Ecosystem Services and Landscape Planning. However, the applied range and meaning of the term is becoming too broad while the specific definition is still an elusive description. With the spreading of the new concepts and the transition of urban green space planning to a more critical role, the lack of clarification of this term may lead further confusion and misuse. This research aims at the clarification and application of multifunctionality in the context of urban green space planning practice, as a necessary entry point for the future researches on urban green infrastructure planning. Based on literature review on the development of related topics, this study argues that most component functions of multifunctionality have long traditions in planning history and multifunctionality is more about a new holistic perspective instead of a new term; moreover, the ecosystem services should be seen as the theoretical base for multifunctionality because it provides so far the most rational and overall classification for the component functions as well as multiple analyzing approaches; furthermore, the interactions among functions are the unignorable parts of multifunctionality and distinguish it from only multiple functions. In a word, multifunctionality is a comprehensive status of urban green space and represents the overall performance of the place. Thus it is not comparable between different contexts but can be used as a framework for the holistic understanding of urban green space. Based on the theoretical study, an analytical framework is built and applied on the Greenbelt in Frankfurt am Main, Germany. The methodology combines both semi-quantitative and qualitative approaches and targets on the analyses in both planning process and land use performance status, to discuss how multifunctionality of urban green space is influenced by planning efforts. The results on urban level analyses illustrate that the spatial distribution of functions in reality is quite uneven while the main planning efforts were made without specific focus. These results together indicate the mismatch of supply and demand of multifunctionality in the Greenbelt. Furthermore, at local level, three cases are used for the in-depth discussion of interactions between functions. They point out the significant role of positive synergy effects on the efficient delivering of multifunctionality, as well as illustrate possible ways to generate such positive effects. The overall result of case study clearly indicates the advances and potential directions for the future development of Greenbelt. Multifunctionality is a significant term for the holistic interpretation and systematical analyses of the urban green space. In this study, it has been proved to be a useful framework to understand the functions and interactions from the perspective of human-nature system, as well as to provide insights for the features of current development, which is critical for the future. As a term that has connected multiple topics and has been applied in both theoretical researches and planning practice, multifunctionality has further potential in assisting the development of urban green space, especially in urban Green Infrastructure Planning.