Within the sustainability field, resilience has become a new buzzword. There are an increasing number of programmes and guides on resilient cities, resilient architecture and resilient infrastructure being developed by organisations such as the World Bank and the United Nations. To understand these developments it is useful to review definitions and the development of the original concept.
There are many different definitions of resilience (Adger 2000, Perrings 1998, López-Ridaura, 2005, Zhou 2009, Holling 1973, Pimm 1984, Lele 1998). The concept has its origins in ecology and Holling describes resilience in terms of relationships within a system, the ability of a system to absorb changes and the capacity of these relationships to persist after this change (Holling 1973).
Since its application to ecology, the concept of resilience has evolved and been applied to a wide range of fields including anthropology (Vayda et al 1975), ecological economics (Perrings et al 1992), environmental psychology (Lamson 1986) cultural theory (Thompson et al 1990), management literature (King 1995), property rights and common property research (Hanna et al 1996) and social sciences (Davidson-Hunt and Berkes 2003).
Defining resilience in the urban context is a relatively new and this tends to be multi-faceted. For instance, the World Bank defines resilience in cities in terms of social, infrastructural, economic and institutional resilience:
- Social resilience refers to the demographic profile of a community including by sex, age, ethnicity, disability, socio-economic status and other key groupings, as well as a community’s social capital. Social capital, although it is difficult to quantify, refers to a sense of community, the ability of groups of citizens to adapt, and a sense of attachment to a place.
- Infrastructural resilience refers to the vulnerability of built structures including property, buildings and transportation systems. It also refers to sheltering capacity, health care facilities, the vulnerability of buildings to hazards, critical infrastructure, and the availability of roads for evacuations and post-disaster supply lines. Infrastructural resilience also refers to a community’s capacity for response and recovery.
- Economic resilience refers to a measure of a community’s economic diversity as well as to the overall employment, number of businesses, and their ability to function following a disaster.
- Institutional resilience refers to the governmental and non-governmental systems that administer a community (World Bank 2012).
A review of resilience definitions reveals that while these may differ, there are two enduring themes. The first relates to an ability, to maintain particular aspects of a system, in spite of change. Thus the characteristics of the system in terms of function, structure, identity and feedback are retained during, and after, change (Folke 2006).
The second relates to the capacity of a system to recover after a change. This refers to self-organising, regenerating and reorganising characteristics of a system that enables it to reform and maintain itself (Folke 2006).