Friday, September 3, 2010

Hazards and Vulnerability

Media reports and images are full of vulnerable people being struck by disasters. Film of families being rescued by inflatable boat in Pakistan has been common staple on recent news reports. When Hurricane Katrina smashed into New Orelans, it appeared the most vulnerable people in a developed country were being targeted by the disaster. It seems so clear but what do we actually mean by vulnerable? Leading on from this question is another important one. If we can define does this help us take steps to ensure these people are not affected by such hazards and disasters?
In a previous blog (Floods in Pakistan: Vulnerability) I began to discuss the complex nature of any definition of vulnerability and illustrated some of the issues using this ongoing disaster. If you want a simple definition then vulnerability can be defined as the potential for loss of life or property in the face of environmental hazards or environmental disasters (or indeed any hazard or disaster). Loss susceptibility is another term often used in relation to vulnerability. Other definitions include vulnerability as a threat to which people are exposed; vulnerability as the degree to which a system acts adversely to a hazard (whatever adverse might mean?!); differential risk for different social classes; interaction between risk and preparedness; inability to take effective measures; capacity of group to anticipate, cope with, resist and recover from impact of natural disaster. There are others and any one interested in the range of definitions used should have a look at Susan Cutter’s book, Hazards, vulnerability and environmental justice (2006, Earthscan). A key point to bear in mind is both the physical and human environments can be vulnerable. Physical systems can be fragile and susceptible to impacts as much as human systems. Outlining how these can be studied together will be the subject of a future blog. This blog will focus on social vulnerability, the vulnerability of the human part of the equation, rather than physical vulnerability.
Some other terms borrowed from ecology also tend to be used when researching vulnerability. Adaptation refers to the ability of the actants in the socio-ecological system to find strategies to adapt to the hazard or disaster. Resistance is the ability of the actants to resist the impact of the hazard or disaster. Resilience is the ability of the system to absorb, self-organise, learn and adapt to the hazard or disaster. A useful resource for vulnerability can be found at the web pages of Neil Adger ( and at the Resilience Alliance website ( a site looking at research into resilience of socio-ecological systems and sustainability. As with most things borrowed, once you change the context the meaning changes as well, so the application and use of these terms does not necessarily match their original, potentially more limited definitions in ecological research.
An important aspect of vulnerability is that it evolves; it changes as the nature of the disaster or hazard unfolds and as the people who are vulnerable response and react to their situations. This also highlights the importance of scale for defining vulnerability. What scale is appropriate? The individual can be viewed as an important unit, but the individual usually operates within the context of a family or household, so is this a more appropriate unit for analysing vulnerability and resilience? What about larger entities such as communities and governments? As you change the unit of analysis would you expect the different units to have the same type of vulnerability, the same ability to resist or the same characteristics of resilience? Once these different spatial entities interact, such as the provision of aid by the government to individuals, does this cross scalar interaction affect vulnerability and resilience? In other words, what seems like a simple thing is very complex to unravel in detail.
At heart vulnerability is about the differential ability or power to access resources by individuals and groups in society. To escape a flood you need the power or ability to get out of the area. You need a car, you need early warning, you need a friendly policeman to wave you through and protect you from the other people trying to escape on foot. These material things require resources and access to them at the appropriate time. There are static and dynamic aspects to this access to resources. The static aspects of vulnerability, might be capable of identification before a disaster strikes. At the simplest level, mapping socioeconomic groups gives an indication to the availability of funds to gain access to resources. Likewise, mapping similar census data such as lone parent numbers or age (elderly and young are less able to escape floods for example) could also indicate the vulnerability of a place. A useful site that discusses such mapping and has developed a specific means of measuring it, the index of social vulnerability, can be found at the University of South Carolina at the Hazards and Vulnerability Institute ( of which Susan Cutter is the Director.
There is also a dynamic aspect to vulnerability; the manner in which relationships are organised and the manner in which they change through normal times and then during and after a disaster. Such flows could include the transport infrastructure; a key aspect that appears to have failed during this disaster and which has dramatically affected the ability of the institution of government to maintain an effective relationship with vulnerable groups. At a local level, however, if the transport infrastructure that remains intact sufficient for the local population to move to safety and then initiate community based activities that represent resilience at that level? Importantly this dynamic aspect is concerned with pathways and relations, both physical between locations and places and social and emotion between peoples and between individuals and organizations. From the above it is clear that trying to understand vulnerability also means trying to udnerstadd its geography; how it varies in space and time and how people succumb to, adapt or try to overcome this geography.

Two useful books on vulnerabiltiy are:

Measuring Vulnerabiltiy to Natural Hazards: Towards Disaster Resilient Socieites by the United Nations University (2007)

Hazards Vulnerability and Environmetnal Justice by Susan Cutter (2006)

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