Resilient Communities are the Foundations of a Resilient America.

Sustainability and Community Resilience: III. The Evolution of a Community

In previous posts in this series, I’ve tried to look at the relationship between sustainability and resilience, first in terms of time, then looking at how perceived self-interest impacts both. In this post, I’m going to look at what the evolution of a community can tell us about this relationship (Apology – this is a bit longer than normal due to graphics).

As mentioned in the last post, community sustainability means a wise use of resources,

• Discriminating between wants and needs so that needs are met first, and
• Using resources efficiently – the least necessary to meet the maximal amount of needs.

As a sidelight, if a community cannot provide one or more of the services that its members perceive as essential at an acceptable level, it risks loss of those members. Thus, if the community’s capacity is at too low a level, then the community either collapses or reorganizes itself into something different (Lance Gunderson would call this a domain shift.). As I’ve argued in a previous blog, this is what has happened in New Orleans.

In practice, a community may not have all of the resources it needs to fill every need, but may trade resources from one area (usually economic) to “buy” resources in another. As an example, an isolated rural community might not be able to afford its own hospital, or even be able to support a full-time medical professional, but could forge an agreement with a regional medical facility to operate a clinic.

I have tried to represent the thoughts above in a graphic (see Figure 1). For each community service area (e.g., water, health care), the community receives a certain level of service. Taken together at any time, these define the state of the community, let’s call it F(t). Since I’m not a very good artist, I’ve collapsed all of the community service areas into three – infrastructural (including the built and natural environment), economic, and social. Also seen in the figure is a rendering of a 3-dimensional surface, D. This represents the region in community state space in which the level of service provided is no longer acceptable – if the community cannot provide an acceptable level of service (F(t) remains within D), the community will either reorganize or collapse (I think of D as the Dome of Doom.). We do not know the exact shape of D, nor do we know much about where its boundaries lie; however, we can infer its existence from phenomena such as the disappearance of rural American towns.


Figure 1. Evolution of a community

This diagram is also consistent with the idea that a community can “barter” for services that it may otherwise lack, e.g., using economic strength to overcome infrastructural weakness. This is represented as the narrow extensions of the dome along each axis (As a side note for those who get off on things thermodynamic, F(t) is related to the free energy of the community.).

As seen in the figure, the state of the community changes over time: in good times, the community can provide more services, i.e., move away from the origin. However, because of the interdependence among the services, a community rarely moves straight out from the origin. As an example, while the capture of a new airplane manufacturing facility may be a huge economic plus for the community, it will reduce the capacity of the community’s infrastructure because of the new demands for water, electric and transportation services. As discussed in the previous blog in this series, the location of D will also change over time; if the community members prosper, they will want additional services that they may not have had before. Thus, our isolated rural community initially might be satisfied with a clinic, but – at least in more prosperous times – would demand more complete medical services.

Evolution of a Community Service Area

If we look at a single facet of a community (let’s pick water services), we see little change during normal times (see Figure 2). There are changes due to the seasons, but not huge ones. Small events like a line break (the dip in the autumn) may cause a minor disruption in service, but generally the level of service provided is relatively constant over time. It also is greater than that actually needed – after all, we don’t really need our lawns to be green! It is important to note, however, that almost always the level of service provided reflects what the community wants and not necessarily what it needs. In this case, the seasonal changes in water usage reflect the difference between what’s wanted and what’s needed.


Figure 2. Normal water usage

Impact of a disaster

Suppose an earthquake occurs at time t (Figure 3) that causes major disruption to the water system (for this example, I’ll treat the pre-disaster service as a constant). The amount of water provided to the community will fall precipitately and this community is unable to reach the same level of service as before the earthquake. In this case, one could argue that the community’s water usage is now more sustainable than prior to the disaster, since the difference between the amount of water actually needed and that used is less, i.e., the community is meeting its need for water more efficiently. However, one also has to admit that the community wasn’t very resilient to the earthquake.


Figure 3. Impact of a disaster

Thus, a community’s evolution – particularly the impact of a disaster – further illuminates the relationship between sustainability and resilience. Both are related to use of resources to provide service. Sustainability is more about filling needs; resilience is more about providing the services the community wants. Wants can change dramatically over time, needs likely change more slowly. During a disaster, the community will want essential services to resume quickly, at least at the same level as before – efficient use of available resources will be important only if those resources are limited. For the community, speed is of the essence. Conversely, sustainability is all about efficient use of available resources – as long as needs are being met there is no need for additional resources.

In this series I have tried to determine the relationship between sustainability and resilience by answering
• Is a sustainable community resilient?
• Is a resilient community sustainable?
• Are resilience and sustainability at opposite ends of a continuum, or at right angles to each other?”
We’ve looked at the relationship between sustainability and resilience in terms of time, in terms of perceived self-interest, and in terms of the evolution of the community.

The relationship is clearly complex; the concepts are intertwined. As we have just seen, greater sustainability may not mean greater resilience – and the converse is equally true. A community’s sustainability is the integration over time of all of the actions the community takes and reflects the efficiency of its use of resources. A community’s resilience is demonstrated by how well the community continues to meet its citizens’ expectations even in the face of adversity. Sustainability is about maximizing efficiency; resilience is about optimizing the balance between efficiency and redundancy. In this sense, sustainability and resilience are not antipodes, nor at right angles, but complementary concepts both important to community success.