Climate change and Urban Vulnerability in Africa

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Climate change and Urban Vulnerability in Africa

• Assessing vulnerability of urban systems,
  population and goods in relation to natural and
  man-made disasters in Africa

Training on the job Course on Hazards, Risk and
(Bayesian) multi-risk assessement Napoli,
24.10.2011 11.11.2011
12/10/2015
Fatemeh Jalayer
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Risk assessment The engineering point of view
R H V E
R risk H hazard V vulnerability E
exposure
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What is hazard?

• 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.

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Risk assessment The engineering point of view
R H V E
R risk H hazard V vulnerability E
exposure
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What is the vulnerability?
... a human condition or process resulting from
physical, social, economic, and environmental
factors which determine the likelihood and scale
of damage from the impact of a given hazard
(United Nations Development Programme,
2004) The fraction of the total value at risk
that could be lost after a specific adverse event
(Principles of multi-risk assessment, EU, EUR
23615, 2009). ... Vulnerability is the
characteristics and circumstances of a community,
system or asset that make it susceptible to the
damaging effects of a hazard (2009 UN
International Strategy for Risk Reduction)
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What is the climate change vulnerability?

• ... Vulnerability is the degree to which a
  system is susceptible to, or unable to cope with,
  adverse effects of climate change, including
  climate variability and extremes (United States
  Environmental Protection glossary for climate
  change).
• ... Vulnerability is a function of the
  character, magnitude, and rate of climate change
  and variation to which a system is exposed, its
  sensitivity, and its adaptive capacity (United
  States Environmental Protection glossary for
  climate change).

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The concept of Vulnerability seems always to
involve a system.
Some general aspects of the vulnerability
The system is a set of interacting or
interdependent components forming an integrated
whole.
boundary
system
surroundings
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Some general aspects of the vulnerability

• The definition of a system is very broad it can
  stand for the environment, the community, the
  assets, the buildings, the roads and so on.

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And hence, different types of vulnerability
Technical (Physical) Vulnerability of urban
structures and life-lines Environmental Vulnerabi
lity of agriculture Environmental fragility
(e.g., groundwaters, land) Social The specific
social inequality of people in the context of a
disaster in broad terms, how susceptible people
are to a hazard Economic Vulnerability of
different economic sectors Institutional Effectiv
eness and failure of organized structures and
institutions
12/10/2015
Fatemeh Jalayer
Slide 9
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Some general aspects of the vulnerability

• A system is consisted of many components. It is
  not trivial to take into account the interaction
  of the components.

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Some general aspects of the vulnerability

• Vulnerability is subjected to variability
• Temporal
• The hazard on the system can change with time
• The system can change in time.
• Spatial
• The system is usually distributed spatially.

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Some general aspects of the vulnerability

• Vulnerability assessment is usually characterized
  by incomplete information and its assessment is
  a probability-based procedure.
• Incomplete information regarding the hazard
  evaluation
• Incomplete information regarding the system
  parameters

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Some general aspects of the vulnerability

• The concepts of hazard, vulnerability and risk
  have quite a dynamic nature. What is called
  vulnerability from a point of view, would be
  called risk by some and hazard by some other at
  the same time and nobody is wrong!

R H V E
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Capacity
Before to start we need the definition of
capacity

• The combination of all the strengths, attributes
  and resources available within a community,
  society or organization that can
• be used to achieve agreed goals.
• Capacity may include infrastructure and physical
  means, institutions, societal coping abilities,
  as well as human knowledge, skills and collective
  attributes such as social relationships,
  leadership and management.

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A quantitative definition for vulnerability
rooted in engineering

• The vulnerability of a system or its components
  can be defined as the probability of its failure

• C is the system capacity
• D is the demand a system can be subjected to
• C and D are attributes of the same property or
  quantity (they have the same units)

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What is the system demand and how its
related to hazard

• Demand An urgent requirement or need
• Demand can be interpreted as the requirements
  imposed to the system by the hazard.

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Linking hazard and vulnerability

• In order to link vulnerability to hazard in an
  efficient way it is useful to introduce a
  variable that links hazard to system demand.
• In the earthquake engineering jargon, this
  variable is called an intensity measure (IM).
• It can be thought of as an interface variable
  representing the intensity of hazard .

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Vulnerability and Hazard

• Vulnerability can be calculated by expanding for
  all possible intensities of hazard

• p(IM) represents hazard
• P(DgtCIM) is called the system fragility

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System vulnerability vs Component
vulnerability

• The system vulnerability is a function of the
  vulnerability of its components. There are
  different ways to calculate the system
  vulnerability
• Employing a generalized definition of demand and
  capacity (the cut-set theory) for the system.
• Calculating the vulnerability of the system as a
  function of components vulnerability.
• Using simulation methods and calculating directly
  the system vulnerability.