Resilient infrastructure: adapting to an uncertain future?

Much has been written and said about resilience over the last couple of decades. It is one of those concepts that users each adapt to their message. Sadly, the result is that it means everything and nothing to many. Yet, it is fundamental to our understanding of infrastructure systems. As with sustainability, it may be useful to look at its origins and the foundational concepts that gave rise to its application.

In 1973, Buzz Holling published a paper in the Annual Review of Ecology and Systematics entitled ‘Resilience and stability of ecological systems’. He distinguished between resilience and stability. Stability, he explained, ‘represents the ability of a system to return to an equilibrium state after a temporary disturbance; the more rapidly it returns and the less it fluctuates, the more stable it would be.’ Conversely, resilience is a ‘measure of the persistence of systems and of their ability to absorb change and disturbance and still maintain the same relationships between populations or state variables.’ This idea can be developed to reflect a system's ability to self-organise, learn and adapt (Gunderson and Holling 2002).