Urban Systems during Disasters: Factors for Resilience

With a focus on modern cities, this article considers both the strong ties that exist between individuals in a social network, and the weak ties between different social networks themselves, recognising that a resilient human system relies on the density of both. As a socioeconomic system however, cities also contain richer and poorer neighbourhoods, all of which are dependent upon each other for the continued resilience of the city. The authors offer 5 key recommendations to help increase urban resilience.

Date added 2 November 2020
Last updated 5 November 2020

The article commences with a brief overview of different aspects of the concept of 'ecosystem resilience', noting how it was this body of research that has informed our understanding of resilience in human systems.

From an ecosystem perspective, resilience is usually concerned with how quickly or how well a system bounces back from a disaster. Such resilience can be measured by examining, for example, the tightness of the connections within the ecosystem, and how much more of an impact a disaster might have on an ecosystem with loose connections, or by measuring the magnitude of the impact of a disaster.

When it comes to human systems, the article focuses mainly on those systems that are in evidence in modern cities, while recognising that in many cases the city will also be reliant upon the continuing resilience of natural ecosystems to provide services such as food and water for its citizens regardless of whether they come from richer or from poorer neighbourhoods.

The notion of resilience, especially for human systems in cities, becomes of great importance as these cities grow, with larger and denser populations exposed to more potential disasters:

“The dense urban neighborhood, defined as an area that one can walk across in one-quarter to one-half hour (approximately 2.5 km), may contain as few as 3000 or as many as 250,000 people … and is the primary unit of contagious urban processes, whether they be infectious disease in epidemics … fire ... or contagious behavioral patterns such as the abuse of illegal drugs".

While a city’s various neighbourhoods are physical entities, they are also socioeconomic entities with many disparities between them. However, resilience can be found when there is a density of both strong ties between individuals in a social networks, and interactions between different social networks themselves (weak ties). So, for example, during a disaster that may impact more on poorer citizens “the dense fabric of weak and strong ties facilitates … the sharing of resources to tide over affected families and individuals”.

The article offers a number of examples of urban renewal programmes in the United States, finding that “neighborhoods with a high prevalence of small, tight, isolated social networks”, for example segregated ethnic neighborhoods, are perceived to be brittle, and therefore less resilient to disasters. On the other hand, neighbourhoods with very strong ties and high resilience might also be so enduring that they may be resistant when any policies attempting change are implemented.

One key issue raised in this paper is regarding the comparison of the highly successful 1947 Small Pox vaccination programme in New York, with the failure of the 1976 Swine Flu vaccination programme. 'Brittle neighbourhoods' such as those identified above, are slow to share information, and tend to lack trust in authority. In 1947 the public were used to working together for the common good during the Second World War, and the entire community mobilised to spread the news about the vaccine so that millions were vaccinated within two weeks. However, by 1976, urban populations were more segregated and fragmented, and the message just simply could not get through clearly or strongly enough.

Based on the above, the authors make 5 key recommendations for increasing urban resilience, as summarised below.

5 recommendations for increasing urban resilience

  1. Apply techniques to multiply weak ties; e.g., form alliances of houses of worship of all faiths
  2. Encourage the ethnic and economic integration of neighborhoods; e.g., deliberately construct new housing and refurbish old housing for a mix of families and individuals;
  3. Provide adequate municipal and private services to prevent contagious urban processes; e.g., allocate housing preservation services that fit the heaviest demand of each neighborhood, as defined by ecological analyses;
  4. Plan for the pandemic by providing for adequate municipal and private services; and
  5. Ensure adequate services, especially in poor neighborhoods, which are the keystone populations of metropolitan regions.

The main conclusion of this article is that:

“the ability of a municipality and its dependent suburban counties to weather a disaster such as an avian flu pandemic depends on the size of social networks in its neighborhoods and on the interconnection between the social networks. Diversity such as gained by social and economic integration influences the strength of the loose ties between social networks.”