The Influence of Urban Morphology on the Resilience of Cities Following an Earthquake

Abstract

This paper proposes a conceptual theory of resilience in urbanism and demonstrates its application through a case study. The theory's underpinnings are the attributes of resilience that have been developed in ecological sciences, but have clear parallels in urbanism. They suggest that it may be possible to enhance the resilience of a city through the design of its urban morphology. The paper explores these ideas by examining the relationship between the community's adaptive behaviour and the spaces of the city of Concepción after its 2010 earthquake. This empirical evidence suggests that the role of the urban designer in earthquake-prone cities is perhaps more critical before an earthquake happens and that the more the idea of a resilient urban morphology is embedded as part of daily life, the more effective it is likely to be in the aftermath of a major earthquake.

Notes

1. Sometimes referred to as the emergency period a period when communities must fend for themselves before organized help arrives and which most clearly reveals a city's spatial vulnerability.

2. Ecological resilience is “the capacity of a system to absorb disturbance and reorganize while undergoing change so as to still retain essentially the same function, structure, identity, and feedbacks” (Walker et al., 2004). Resilience depends on “1) the amount of disturbance a system can absorb and still remain within the same state … 2) the degree to which the system is capable of self-organization … and 3) the degree to which the system can build and increase the capacity for learning and adaptation” (Folke 2006, 259–260). It also depends on the capacity of a system to operate at a series of interconnected scales.

3. In this we have been influenced by Anne Vernez Moudon's research into urban morphology, where she refers to the city as a complex matrix of buildings, infrastructure, and open space, “constantly used and transformed over time” (1997), where individuals and communities exist in a tight and dynamic inter-relationship with that matrix.

4. Water-sensitive urban design strategies are an example of spatial designs that absorb environmental variability. Detention basins and rain gardens take up more space than traditional storm water pipe systems; from that perspective they are relatively inefficient. But the extra space can help to absorb flood peaks in wet years, insuring against environmental unpredictability or variability.

5. For example, later in this essay we talk about the widespread and spontaneous use of neighbourhood barricades to prevent looting in Concepción. While some members of our team were horrified at this evidence of a “siege mentality”, a closer examination of the practice through the lens of the resilience attributes suggests that by creating smaller, more manageable neighbourhoods, communities were, perhaps unwittingly, generating social capital, making it easier for them to organize and respond quickly and effectively.

6. One first-hand account describes “a community of 50 families with 15 children, camping in the same park at Laguna Grande for three days because of the fear of aftershocks” (C. Cifuentes, Boca Sur Viejo, San Pedro de la Paz, 2010).

7. “Some of us returned the next morning [to our houses] and then we returned to the hills to sleep. Others stayed longer in more established camps” (Cecilia Munos, president of the Talcahuano community, 2010). “For about a month … they were sleeping in tents during the night and then left during the day. This was because they had built their own houses and they were structurally unstable” (R. Pavez Hidalgo, Boca Sur Viejo, Villa Mora, Coronel, 2010).

8. “We were looking for elevated land above 20 metres. Everyone from Coronel was running to the hills” (A. Salazar Diaz, Coronel, 2010).

9. In San Francisco after the 1906 earthquake, the generous width of most of the streets allowed for a wide range of functions to be established in the recovery period, from domestic cooking to temporary rail lines and temporary commerce, and the hilly topography and widely distributed park network ensured that there were plenty of opportunities to shelter in local parks with good visual access.