Disaster Theory for Techies

I’ve had a number of conversations over the past few weeks on the delineation between pre- and post-disaster phases. We need to move away from this linear concept of disasters, and conflicts as well for that matter. So here’s a quick introduction to “disaster theory” that goes beyond what you’ll find in the mainstream, more orthodox literature.

What is a Disaster?

There is a subtle but fundamental difference between disasters (processes) and hazards (events); a distinction that Jean-Jacques Rousseau first articulated in 1755 when Portugal was shaken by an earthquake. In a letter to Voltaire one year later, Rousseau notes that, “nature had not built  [process] the houses which collapsed and suggested that Lisbon’s high population density [process] contributed to the toll” (1).

(Incidentally, the earthquake in Portugal triggered extensive earthquake research in Europe and also served as the focus for various publications, ranging from Kant’s essays about the causes of earthquakes to Voltaire’s Poème sur le désastre de Lisbonne).

In other words, natural events are hazards and exogenous while disasters are the result of endogenous social processes. As Rousseau added in his note to Voltaire, “an earthquake occurring in wilderness would not be important to society” (2). That is, a hazard need not turn to disaster since the latter is strictly a product of social processes.

And so, while disasters were traditionally perceived as “sudden and short lived events, there is now a tendency to look upon disasters in African countries in particular, as continuous processes of gradual deterioration and growing vulnerability,” which has important “implications on the way the response to disasters ought to be made” (3).

But before we turn to the issue of response, what does the important distinction between events and processes mean for early warning?

Blast From the Past

In The Poverty of Historicism (1944), the German Philosopher Karl Popper makes a distinction between two kinds of predictions: “We may predict (a) the coming of a typhoon [event], a prediction which may be of the greatest practical value because it may enable people to take shelter in time; but we may also predict (b) that if a certain shelter is to stand up to a typhoon, it must be constructed [process] in a certain way […].”

A typhoon, like an  earthquake, is certainly a hazard, but it need not lead to disaster if shelters are appropriately built since this process culminates in minimizing social vulnerability.

In contemporary disaster research, “it is generally accepted among environmental geographers that there is no such thing as a natural disaster. In every phase and aspect of a disaster—causes, vulnerability, preparedness, results and response, and reconstruction—the contours of disaster and the difference between who lives and  dies is to a greater or lesser extent a social calculus” (4).

In other words, the term “natural disaster” is an oxymoron and “phrases such as a ‘disaster hit the city,’ ‘tornadoes kill and destroy,’ or a ‘catastrophe is known by its works’ are, in the last resort, animistic thinking” (5).

The vulnerability or resilience of a given system is not simply dependent on the outcome of future events since vulnerability is the complex product of past political, economic and social processes. When hazards such as landslides interface with social systems the risk of disasters may increase. “The role of vulnerability as a causal factor in disaster losses tends to be less well understood, however. The idea that disasters can be managed by identifying and managing specific risk factors is only recently becoming widely recognized” (6).

A Complex System

Consider an hourglass or sand clock as an illustration of vulnerability-as-causality. Grains of sand sifting through the narrowest point of the hourglass represent individual events or natural hazards. Over time a sand pile starts to form, which represents the evolution of society or the connectedness of a social network. Occasionally, a grain of sand falls on the pile and an avalanche or disaster follows.

Why does the avalanche occur? One might ascribe the cause of the avalanche to one grain of sand, i.e., a single event. On the other hand, a systems approach to vulnerability analysis would associate the avalanche with the pile’s increasing slope and to the connectedness (or population density) of the grains constituting the pile since these factors render the structure increasingly vulnerable to falling grains.

Left on its own, the sand pile’s stability, or the social network, becomes increasingly critical or vulnerable. From this perspective, “all disasters are slow onset when realistically and locally related to conditions of susceptibility”. A hazard event might be rapid-onset, but the disaster, requiring much more than a hazard, is a long-term process, not a one-off event.

We must therefore “reduce as much as we can the force of the underlying tectonic stresses in order to lower the risk of synchronous failure—that is, of catastrophic collapse that cascades across boundaries between technological, social and ecological systems” (7).

Recall Rousseau’s comment on population density as a contributing cause of the earthquake disaster and Popper’s remark that adequate shelter or resilience could offset the impact of typhoons. The sand pile at the bottom of the hourglass is constrained by the glass’s circumference. While abstract, this image mimics the growth of densely populated cities that become increasingly vulnerable to hazards, either natural or technological.

Unlike the clock’s lifeless grains of sand, however, human beings can minimize their vulnerability to exogenous shocks through disaster preparedness, mitigation and adaptation. In doing so, individuals can “flatten” the structure of the sand pile into a less hierarchical system and thereby shift or diffuse the risk of an avalanche. In conflict prevention terms, this means structural prevention, which typically focuses on local livelihoods and local capacity building.


Clearly, early warning should seek to monitor both the falling grains and the vulnerability of the sand pile to determine the risk and magnitude of an avalanche. In more formalistic language, a dual approach is important because it is not always clear a priori whether a disaster is due to a strong exogenous shock, to the internal dynamics of the system or a combination of both (8).

As the disaster management community has learned, in “support[ing] good decision-making, the issue is not one of being able to predict the unpredictable. Rather, the fundamental question is that, given that we cannot have reliable predictions of future outcomes, how can we prevent excessive hazard levels today and in the future in a cost-effective manner?”

More on resilience:

  • Disaster Response, Self-Organization and Resilience [Link]
  • On Technology and Building Resilient Societies to Mitigate the Impact of Disasters [Link]
  • Social Media = Social Capital = Disaster Resilience? [Link]
  • Failing Gracefully in Complex Systems: A Note on Resilience [Link]
  • Towards a Match.com for Economic Resilience [Link]

21 responses to “Disaster Theory for Techies

  1. I’ve got nothing to ad, just wanted to express my gratitudude for your posts and this site. Kudos!

      • hey ,i must reccomend you for a job well done.would you help me in finding the answer to the following question as far as disaster management is concerned?EXPLAIN A THEORY AND DISCUSS THE IMPORNTANCE OF A THEORY IN DISASTER MANAGEMENT. i will highly appreciate your help.Thank you in advance as i wait for your response

  2. altough I sort of like the word gratiduded, I meant gratitude of course :) Tnx, keep up the good work!

  3. Really appreciate posts like this. Thanks!

  4. Patrick,

    A lucid, informative, and highly-applicable post, as always. You are a born teacher, Patrick.

    One point I’d like to emphasize here is the importance of modeling and simulation of events and their impacts. Event detection is important, but only insofar as it empowers communities to put plans into action.

    Back in 2006 I heard that research was underway to develop an index of social fragility. Do you know what kind of work is going on in this area today?

    Thanks, Robert

    • Thanks for your comments and very kind words, Robert.

      One of the main reasons I went to the Santa Fe Institute (SFI) back in 2006 was precisely to get up to speed on the latest modeling and simulation techniques from other disciplines that could be applied to crisis early warning/response because I was tired of standard regression analysis techniques. And as you know, the definition I use for people-centered early warning is the UN ISDR’s, i.e, to empower local communities to get out of harm’s way.

      In terms of a global social fragility index, there have been a number of initiatives. Colleagues at the Earth Institute’s Center for Hazards and Risk Research did a hotspot analysis back in 2005 that may be of interest:


      The most interesting and operational one I came across recently is GDAC’s. They calculate quasi real-time impact analysis of hazards based on a social vulnerability index they put together.

      All in all, however, the concept of fragility is still focused on states, ie, state fragility. We need more policy focus on social fragility *and* resilience. See my previous blog post on “Mapping Fragility and Conflict Early Warning” for more on this topic:


      Thanks again for your comments!

  5. Pingback: FutureGov » Useful links » links for 2009-05-19

  6. Excellent thinking on the points that a) no disaster is “natural” and b) that all disasters are slow onset.

    I also very much appreciate your hourglass model as a way of explaining these points, and the opportunities they imply.

  7. Oh and, fantastic image :)

  8. Amazing post. Great job discussing hazard management in terms of complexity science concepts. Or vice versa…

  9. Pingback: No Such Thing as a Natural Disaster » CUNY Institute for Sustainable Cities

  10. Pingback: On Building Resilient Societies to Mitigate the Impact of Disasters | iRevolution

  11. Pingback: The Best of iRevolution: Four Years of Blogging | iRevolution

  12. Very interesting post, Patrick. Emergency managers have been pushing mitigation since the 1990s and resilience policy more recently. The problem is too often a lack of political will to reduce the social components of hazard risk. We have spent hundreds of billions on homeland security/disaster prep but also continue to make society more vulnerable to cascading disruptions through development policy, economic integration, etc. Until we get serious about resilience and mitigation, it will remain an open question whether or not we are increasing or reducing disaster risk over time. This strikes me as a question that political science could contribute to.

  13. Fantastic post. The slow onset idea is the fuel to the engine for us who care about reducing vulnerability. I wish it were widely spread amongst society helping to make all of us aware how important being a grain of sand can be.

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