Friday, September 3, 2010

Hazards: The Complexity Approach

I was at a conference on water and risk at the start of the year. A very distinguished professor had delivered an extremely interesting talk on a key concept he had taken decades to get across to policy makers involved in development. As the presentations went on he became increasingly concerned and agitated that researchers should realise that they had to get their ideas across to policy makers who were not well versed in either the details of academic debate or the intricate nature of conceptual frameworks. He questioned a final year postgraduate about what the major new concept in hazard and risk was. Without hesitation the postgraduate replied ‘complexity’. The distinguished professor paused, audibly drew in a long breath and said ‘God help us!’

Complexity is, as the name implies, neither the easiest concept to get across nor the easiest one to illustrate. Part of this fogginess is because the concept is still evolving within hazard analysis. The fixed and clear definitions of what it is and how to use it are still in their infancy and still subject to intense academic debate (although a useful discussion of the concept is given in Smith and Petley, Environmental Hazards, 2009, Routledge). Different researchers from different field converge on a particular disaster and each applies their own view and meaning of complexity to the analysis of that disaster. So what follows is a partial interpretation of complexity thinking and hazards but one that I hope will nonetheless provide a flavour of how a new concept is starting to mesh and enhance hazards analysis.

Complexity theory is a borrowed, as most geographical concepts are, this time from physics and mathematics where it evolved from a detailed equation based theory into something that even geographers could begin to understand. The central idea is that a system of components operating together produces some output. This may not sound that dramatic but it is the type of output that is a little unexpected. Traditionally, it has tended to be assumed that you can understand something better if you start to pull it apart and study each component one by one, individually. Once you have a detailed knowledge of the components then you have a detailed knowledge of the system. Simplify the system to understand it. This is a highly reductionist view of reality and how you go about studying it. To understand a car you dismantle it and study each component in great detail then put the parts back together and you understand the car. Even with my limited mechanical knowledge, I can see this will not work! Complexity is a brake on this view of simplifying reality to study it.

Complexity recognises that real systems are complicate and intricate networks of components acting together in a variety of ways. Simply studying one component or even a small group, does nothing to help us understand how the system really works. It is the interactions, the relations, which drive the system that produce the emergent behaviour that we observe and try to study. In complexity theory the bits of the system, the actual components are still vital as without them the system would not exist, but to understand the system, to grasp how it works, it is the interactions, the relations and their changes that it is vital to understand. From these interactions there does tend to emerge some predictable forms of overall system behaviour. Sometimes, however, change the relations and the output can alter in unexpected and unpredictable ways. In this view of hazards, hazards and disasters occur not necessarily because of one factor but through a combination of and the complex interactions of a number of factors.

My earlier blog on the BP oil spill and the Swiss cheese model of hazards could be seen as an illustration of complexity in action. In this model, it is the interaction between specific ‘holes’ that results in the incident occurring, without this interaction there would be no incident, no explosion, no oil spill. This model is only one by which hazards can be understood however. My earlier blog on ash cloud again focuses on interactions, this time amongst a group of actants to start to form an understanding of how the system evolved and how the hazard itself became defined.

The compelxity approach is outliend albeit briefly in Petley adn Smith's book below.


  1. i believe it is the most effective approach to almost any problem. It allows you to look at the problem from the different angles. Interesting article, Rob

  2. I realize it's been a few years, but this just came in handy for me. good job.