CHAPTER II: LITERATURE REVIEW
2.1. Hazards, Disasters, and Vulnerability
The concepts of hazard, disaster and vulnerability have been
extensively used in various disciplines with different meanings. Even for
natural hazards, such as floods, no unique definitions and assessment
procedures have been widely accepted (Pistrika and Tsakiris, 2007, p 1). Hazard
is the probability of occurrence within a specified period of time and within a
given area of a potentially damaging phenomenon (Maiti, 2007, p 10). This
definition adds both spatial and temporal components to the definition of
hazards while another definition from UNISDR (2009, p 17) refers hazard to "a
dangerous phenomenon, substance, human activity or condition that may cause
loss of life, injury or other health impacts, property damage, loss of
livelihoods and services, social and economic disruption, or environmental
damage." Hazard is, in the case of river-floods, a natural event that is
perceived as a threat and not as a resource by humans (Fekete,
2010, p 31). For the author, hazard is revealed in the state of exposure, when
the natural event actually hits the vulnerable elements. In technical settings,
hazards are described quantitatively by the likely frequency of occurrence of
different intensities for different areas, as determined from historical data
or scientific analysis.
Hazard becomes a disaster when it hits a vulnerable community.
It causes disaster when large numbers of people are killed, injured or affected
in some ways (Maiti, 2007, p 10). In the same line of thought FAO (2008, p 16)
points out that disasters of all kinds happen when hazards seriously affect
communities and destroy temporarily or for many years the livelihood security
of their members. Another definition from ISDR refers disaster to «a
serious disruption of the functioning of a community or a society causing
widespread human, material, economic or environmental losses which exceed the
ability of the affected community or society to cope using its own resources".
A disaster results then from the combination of exposure to a hazard,
socio-ecological vulnerability that are present, and the limited capacities of
households or communities to reduce or cope with the potential negative impacts
of the hazard.
Assessing and measuring vulnerability in the context of natural
hazards and climate change requires first and foremost a clear understanding of
the concept (s) of vulnerability (Birkmann, 2013, p 9 ). Vulnerability is an
important concept in human environment research, its conceptualization has been
interpreted in many different ways, according to the perception of the
researchers. The word "vulnerability" has created important links between
different research communities, particularly disaster risk management (DRM),
climate change adaptation (CCA), development and resilience research (Birkmann
,2013, p 9).
Cannon (1990) refers vulnerability only to biophysical exposure,
where vulnerability is described as a measure of the degree and type of
exposure to risk generated by different societies in relation to hazards.
Some studies found that vulnerability only refers to the
susceptibility of a given system; United Nation/ISDR (2004) and the United
Nation Development Programme (UNDP, 2004) view vulnerability as a human
condition or process resulting from physical, social, economic and
environmental factors, which increase the susceptibility of a system to be
damaged from impact of a given hazard.
Other authors, like Blaikie et al.(1994) and Wisner, et al.
(2004) relate vulnerability of a system or a community only to its capacity to
anticipate, cope with, resist and recover from the impact of a hazard.
Adger (1999) views vulnerability as a function of two
components: the effect that an event may have on humans, referred to as social
vulnerability and the risk that such an event may occur, often referred to as
exposure.
According to Chamber (1983), vulnerability has two sides: an
external side of risks, shocks to which an individual or household is subjected
to climate change and an internal side, which is defencelessness, meaning a
lack of means to cope without damaging loss.
Numerous studies define vulnerability as being a function of
exposure, susceptibility or sensitivity, coping capacity or resilience. Watson
et al. (1996), defines vulnerability as the extent to which climate change may
damage or harm a system, depending not only on a system's sensitivity but also
on its ability to adapt to new climatic conditions. Kasperson et al., (2000)
defines vulnerability as the degree to which an exposure unit is susceptible to
harm due to exposure to a perturbation or stress and the ability or lack of the
exposure unit to cope, recover or fundamentally adapt to become a new system or
to become extinct. According to Tuner et al. (2003, p 8075), vulnerability
refers to the degree to which a system, subsystem or system component is likely
to experience harm due to exposure to a hazard be it perturbation or stressor.
For Balica (2007 p 26), vulnerability is the extent to harms, which can be
experienced by a system under certain conditions of exposure, susceptibility
and resilience. For Damm, (2010), the term vulnerability is taken as a function
of exposure, susceptibility, and capacities. According to Fekete (2010, p 31),
vulnerability is both a state and a degree: everyone is vulnerable in the state
of exposure to a hazard and is vulnerable to a certain degree: vulnerability
changes in time and space and aims at identifying and explaining why the object
of research is at risk and how risk can be mitigated.
While, IPCC (2007) relates vulnerability to the character, the
magnitude and the rate of climate change and variation in addition to the
susceptibility and limited coping capacity of a system and IPCC (2012a, p 32)
shows how the concept of vulnerability has served as a guiding element to
address disaster risk in the context of climate change and climate
variability.
The similarity between all of these studies is that
they agree on the three factors that define vulnerability. Thus, the
vulnerability of a system is not only a function of exposure to hazards,
perturbations and stresses alone but also resides in the sensitivity or
susceptibility and in resilience or capacity of the system experiencing such
hazards. Birkmann (2013, p 10) reviews vulnerability concept from various
researchers and concludes that the concept of vulnerability stresses the
fundamental importance of examining the preconditions and the context of
societies and communities and elements at risk to effectively promote risk
reduction and climate change adaptation.
Based on the various views on vulnerability shown above, flood
vulnerability in the current study is viewed as the degree of experienced flood
harms under certain condition of exposure, susceptibility and resilience
factors within the human-environment systems. Therefore, flood vulnerability is
taken here as a function of exposure, susceptibility and resilience.
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