Cities are one of humanity’s crowning achievements. However, as cities and regions grow, they become more interconnected and complex while adapting to an ever-changing social, political, and natural environment. More recently, cities have to deal with increasing uncertainty which is brought about by radical changes such as social, economic and political instability, climate change, environmental degradation and global health crises. Under such circumstances, urban planners and designers have realised that the current planning and design approaches are often inadequate to deal with the rapidly changing and increasingly complex environments (Hes and Du Plessis, 2015).
In response to these challenges, resilience thinking has been proposed as an alternative paradigm to challenge the current ‘business and usual approach’ (Walker and Salt, 2006). Resilience thinking embraces uncertainty and encourages planning with and for change. Moreover, because of these qualities, urban resilience is rapidly being viewed as one of the critical factors to achieving the goals of sustainable urbanism (Salat, 2011; UN Habitat, 2016a). Consequently, the rate at which urban resilience concepts have been included in many plans, strategies and assessments has steadily been growing (Zhang and Li, 2018). However, despite the growing acceptance of urban resilience in the urban discourse (Coaffee and Lee, 2016), the spatial aspects of urban resilience have been neglected. More specifically, there is still very little understanding of how the physical form of cities impacts their overall capacity to adapt to change, and therefore, their potential resilience (Feliciotti, 2018; Garcia and Vale, 2017; Romice et al., 2020).
In response to this gap in our knowledge, this study investigates the relationship between the urban form and the manifestation of resilience in cities through addressing four research objectives. First, this study explored how urban form impacts and contributes to the potential adaptive capacity of cities. Secondly, it sought to develop and test a methodological protocol that can describe and assess the potential spatial adaptive capacity of any location within a city. Third, through the application of the protocol on case studies, this study set out to extract a range of typologies that reflect the morphological traits most likely to improve a city’s spatial adaptive capacity. Fourth, using the created typologies, this study proposed a range of urban design principles to promote urban forms that can contribute to more spatially resilient urban settlements.
To address these research objectives, six directives for spatial resilience, which contribute to the formation of spatial-morphological resilience, were derived from a review of urban resilience and urban design literature. Additionally, the conceptual relationships between the directives were explored using a conceptual framework. To operationalise the framework a Spatial Resilience Assessment (SRA) protocol was proposed. The SRA protocol included two sub-protocols which incorporated new and existing methods and metrics that are used to (a) assess, at multiple scales, the extent to which each spatial resilience directive is present for any location within a study area; (b) to evaluate the relative spatial adaptive potential of a location and (c) to extract the morphological typologies that are most likely to improve the potential spatial adaptive capacity of a study area.
Through the application of the proposed SRA protocol in two case studies, Manhattan (NYC) and Hong Kong, this study not only identified which locations within each case study had higher spatial adaptive potential but was also able to extract the morphological qualities of the best performing areas though the creation of the spatial adaptive urban types for each case study. Through the application of the protocol, this study produced over 100 maps per case study as both a quantitative assessment of the quality of the adaptive potential of an area, but also as a means of visually exploring the physical manifestation of the concept of spatial resilience through the morphology of the city. The results from both case studies suggest that variation in the size, shape and configuration of the constituent elements of urban form can greatly impact the potential adaptive capacity of a location. In addition to geometric and configurational characteristics, the relative position of a location (plot or building) within the broader urban context also plays a role in the locations multi-scale adaptive potential within a city. The finding of this study were summarised into a set of spatial resilience urban design principles that, could be used to guide the development and transformation of urban settlements to be more spatially resilient.