Green infrastructure and urban resilience

With 70% of the world’s population likely to be living in cities by 2050, it is important that urban infrastructure is well equipped to manage the wide variety of potential environmental, social, technological and economic challenges. In order to increase urban resilience to chronic stresses and acute shocks, we need new design approaches that take into consideration the multi-dimensional challenges that cities will likely face or are already facing.

In partnership with the University of Arizona, Monash South Africa, Arcadis, and the University of Science and Technology Beijing (China), we are conducting a scoping study on the contributions of green infrastructure (GI) to urban resilience for the Joint Programme on Resilience Engineering (now relaunched as The Resilience Shift). For the purpose of this study, we define GI as the clever combination of natural and artificial (green and grey) structures intended to achieve specific functional resilience goals (e.g. flood management, public health, etc.), developed and regulated through inclusive and transparent consultation processes. Green roofs on buildings are an often cited example of GI, but in our view unless these specifically involve beneficiary, maintenance, finance and other communities they may not realise their full potential as resilience-enhancing initiatives.

GI has the potential to enhance resilience to climate change impacts – including flooding, increased temperatures and drought – in cities, while also removing air pollutants, reducing energy demands, providing amenities to residents, and mitigating climate change. Moreover, cities are increasingly focussing on the contribution of GI to socio-economic resilience, on citizens’ empowerment (particularly women, children and disadvantaged communities), and on improving decision-making through active engagement of citizens with GI. A good example is the Climathon initiative where citizens, students, start-ups, big thinkers and technical experts meet to come up with innovative solutions to climate challenges in cities. In other words, resilience not just about the structures – grey, green, grey-green – that are engineered, but also how these are conceived, (co)created and integrated into complex socio-ecological systems. Resilience emerges out of the ‘how’ as well as the ‘what’ of infrastructural design choices.

Overview of Rio Tietê Linear Park scheme, São Paulo, Brazil (Courtesy: Arcadis).

Another example of GI that may be socially-sensitive is the development of a ‘linear park’ along the Rio Tietê in São Paulo, Brazil. Developed in three phases between 2016 and 2022, the scheme will eventually stretch to 75km. Displaced riverbank communities will receive new homes in less risky areas whilst the entire urban region will benefit from improved floodwater attenuation, health and leisure opportunities, and moderation of the urban heat island effect through the attendant greening up and removal of impermeable, highly reflective, surface coverings.

In conducting this overview study, we are focussing less on technical innovations in GI engineering and more on the importance of integrating considerations of inclusion and appropriateness into all stages of the lifecycle of resilient urban infrastructure. Inclusive public participation applies across the lifecycle of GI interventions and requires designers, planners, engineers and others to engage with all sectors of the communities that they purport to serve. The principle of appropriateness indicates that any GI project aiming at increasing urban resilience must be tailored to the needs and the capacity of the local context to maintain it across its planned lifecycle.

In light of this, we are reviewing urban GI projects that have resulted or may result (for new or ongoing initiatives) in increased resilience in a selection of cities around the world. We are specifically reaching out to Resilience Officers who are responsible for overseeing the development of a city resilience strategy under the 100 Resilient Cities (100RC) initiative (which was pioneered by the Rockefeller Foundation and aims at helping cities become more resilient to the challenges of the 21st Century).

This scoping study will result in a report that will inform prioritisation of subject areas for subsequent rounds of grant funding by The Resilience Shift. Our aim is to make sure that GI will be an integral part of the next call for proposals.