2.4. The Index Approach to Study
Vulnerability
In literature, quantitative assessment of vulnerability is
usually done by constructing a vulnerability index. This index is based on
several sets of indicators that result in the vulnerability of a region. It
produces a single number, which can be used to compare different regions.
Literature on index number construction specifies that there should be good
internal correlations between these indicators.
Different methodologies have been used to compute a Flood
Vulnerability Index (FVI). All FVI equations have factors for exposure to
hazard, sensitivity or susceptibility of the people, and their resilience or
coping capacity to the hazard. Vulnerability is the result of the combination
of exposure, susceptibility and resilience.
Atkins et al. (1998) studied the methodology for measurement of
vulnerability and constructed a suitable composite vulnerability index for
developing countries and island states. Their composite vulnerability indices
were presented for a sample of 110 developing countries for which appropriate
data were available. The index suggests that small states are especially prone
to vulnerable events when compared to large states. Among the small states,
Cape Verde and Trinidad and Tobago are estimated to suffer relatively low
levels of vulnerability and majority of the states estimated to experience
relatively high vulnerability; and the states like Tonga, Antigua and Barbados
being more vulnerable to external economic and environmental factors.
Chris Easter (2000) constructed a vulnerability index for the
commonwealth countries, which is based on two principles. First, the impact of
external shocks over which the country was affected and, second, the
resilience of a country to withstand and recover from such shocks. The analysis
used a sample of 111 developing countries of which 37 small and 74 large for
which relevant data were available. The results indicate that among the 50
most vulnerable countries, 33 were small states with 27 being least developed
among them.
Moss et al. (2001) identified ten proxies for five sectors of
climate sensitivities which are settlement sensitivity, food security, human
health sensitivity, ecosystem sensitivity and water availability. They equally
established seven proxies for three sectors of coping and adaptive capacity:
economic capacity, human resources and environmental or natural resources
capacity. These proxies are aggregated into sectoral indicators, sensitivity
indicators and coping or adaptive capacity indicators and finally help in
constructing vulnerability resilience indicators to climate change.
Dolan and Walker (2003) discussed the concept of vulnerability
and presented a multi-scaled, integrated framework for assessing
vulnerabilities and adaptive capacity. Determinants of adaptive capacity
include access to and distribution of wealth, technology and information, risk
perception and awareness, social capital and critical institutional frameworks
to address climate change hazards. These are identified at the individual and
community levels and situated within larger regional, national and
international settings.
Katharine Vincent (2004) created an index to empirically assess
relative levels of social vulnerability to climate change-induced variations in
water availability that allow cross-country comparison in Africa. An aggregated
index of social vulnerability was formed through the weighted average of five
composite sub indices, which are economic well-being and stability, demographic
structure, institutional and strength of public infrastructure, global
interconnectivity and dependence on natural resources. The results indicate
that using the current data, Niger, Sierra-Leone, Burundi, Madagascar and
Burkina-Faso are the most vulnerable countries in Africa.
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