2. LITERATURE REVIEW
Often the terms risks, hazards, and vulnerability are not well
understood and consequently are repeatedly misused or used with different
meanings (Schmidt-Thomé et al. 2006). In that vein, it is worthy to
elucidate these concepts, which will further clarify the phenomenon we intend
to assess.
2.1 Risk
A risk is perceived as: the losses derived from a specific hazard
to a defined element at risk, over a certain time period (UNDRO 1979); the
chance that a particular hazard will actually occur or the probability of
experiencing loss from a hazard (Smith 1996); or simply the product of the
vulnerability of a community or people to the effects of a specific event, and
the potential for the occurrence of that event (Ferrier and Haque 2003). From
these approaches, it is possible to express risk either as an average expected
number of deaths, economic loss, or physical damage to property, or as the
probability of the occurrence of an event. This probability is then dependant
on social, physical, economic and environmental factors or processes, which
increase the likelihood for people or communities to be harmed.
2.2 Hazards
Common definitions offered in the literature describe a hazard as
a physical event, natural or man-made, that may cause damages to human life,
property, assets and generate social and economic disruption or environmental
degradation. It is also perceived as conditions that increase the probability
of losses (UNISDR 2004, UNDP 1994, Smith 1996, Corvalan et al. 1999, City of
Long Beach 1998). These definitions imply that natural hazards are normal
phenomena that do not set nature necessarily to risk (Schmidt-Thomé
2006a). Risks and hazards are linked through vulnerability.
2.3 Vulnerability
The social, physical, economic, and environmental parameters that
we referred to earlier and which boost the chance for the occurrence of a
disaster embody the characteristics of the elements at risk, i.e. their
vulnerability. The Stockholm Environment Institute (SEI) (2005) characterizes
vulnerability as a lack of security from environmental threats and as the
result of a mixture of processes that profile the exposure to a hazard,
susceptibility to its impacts, and ability to recover in the face of those
effects. As Schmidt-Thomé (2006a) noticed, vulnerability must be seen
in a human perspective, since human beings put themselves at risk by their
exposure to hazardous areas. Other definitions adhere to the concept of
exposure to hazard but go one step further by adding the coping ability of
people to adjust and reduce the negative impacts. Shortly, it is the potential
for a geographic area and its belonging to experience losses from events
(Hossain and Singh 2002, UNDP 1994, Chambers 1989, Cutter 1996, Clark et al.
1998, Liverman 2001). Though three categories of vulnerability are suggested
(Cutter 2003, Weichselgartner 2001), namely the risk/hazard exposure, the
social response, and the vulnerability of places, our perspective in this study
is limited to the first and third approach. Yet the social response determined
by the characteristics of the population studied can not be dissociated from
the other elements (Cutter et al. 2003).
The concepts above suggest that hazards and vulnerability
represent the two components of risk. How risk is assessed is another
methodological aspect that we want to bring forward.
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