Hazardous Environments

1
Hazardous Environments

• Introduction

2
Curriculum
3.1 Hazardous Environments resulting from Crustal
(tectonic) Movement

• Global distribution and the relationship of
  hazards to plate tectonics (convergent,
  divergent, conservative plate margins, hot
  spots)
• earthquakes and resultant hazards (shaking,
  landslides, tsunami)
• volcanic hazards types of eruption and their
  products (nuées ardentés, lava flows, mudflows,
  pyroclastic and ash fallout)
• prediction and monitoring of hazard perception
  of risk.
• Effects on lives and property.

3
3.2 Hazardous Environments resulting from Mass
Movements

• Nature and causes of mass movements on slopes
  leading to hazards that result from slope
  instability, level of impact
• the nature and causes of avalanches and the
  hazards produced
• prediction and monitoring of the hazard and the
  perception of risk.
• Effects on lives and property.

4
3.3 Hazard resulting from Atmospheric Disturbances

• Distribution of areas most at risk from tropical
  storms and tornadoes
• processes causing the development of tropical
  storms and tornadoes
• related hazards (Coastal flooding, severe river
  floods, landslides, storm surges, high winds,
  pressure imbalances).
• Prediction, monitoring of hazards and perception
  of risk.
• Effects on lives and property.

5
3.4 Sustainable Management in Hazardous
Environments

• A case study illustrating some of the problems of
  sustainable management of a hazardous environment
  and an evaluation of attempted or possible
  solutions.

6
What Is a Hazard?

• A Hazard is an event that threatens life and/or
  property.

Extreme Natural or Cultural Events
People and/or their property
HAZARD
7

• Natural Hazards
• Extreme natural events that originate in the
  lithosphere, the atmosphere or hydrosphere
  (tectonic/geologic, surface or atmospheric) that
  risk damage to people and/or property.
• Cultural Hazards
• Events caused by humans technological
  (explosions, contamination etc) and social
  (riots, crime, terrorism) that risk damage to
  people and/or property.
• Disaster
• John Whittow in his book Disasters The Anatomy
  of Environmental Hazards suggested that
• a hazard is a perceived natural event which
  threatens both life and property a disaster is
  the realisation of this hazard

8

• Disasters are therefore extreme events that
  normally cause great loss of life and/or damage
  to the built environment and create severe
  disruption to human activities.
• Risk Assessment
• The process of establishing the probability that
  a hazard event of a particular magnitude will
  occur within a given period.
• Integrated Risk Management
• The process of considering the social, economic
  and political factors involved in risk analysis
  determining the acceptability of
  damage/disruption deciding on actions to be
  taken to minimise damage/disruption.

9

• Vulnerability
• Is the potential for losses or other adverse
  impacts. People, buildings, ecosystems and human
  activities threatened with disaster are
  vulnerable.
• IDNDR
• (International Decade for Natural Disaster
  Reduction)
• Set up by United Nations in 1989 with a
  multisectoral framework of action with the aim
  to reduce the loss of life, property damage and
  socio-economic disruption caused by natural,
  technological and environmental disasters

10

• IDNDR conclusions
• Recent hazards impacts have dramatically
  increased (however frequency of extreme natural
  events has not).
• Risk has increased due to increasing cultural
  exposure to extreme natural events.

Population Growth
Urbanisation
Increased Impacts of ENEs
Economic Growth
Government inability to cope
Pressure to develop marginal land
Failure to recognise potential hazards
11
Common Characteristics of Natural Hazards

• Natural hazards and their effects on people tend
  to have common characteristics
• The origin of the hazard is clear and produces
  characteristic effects.
• Warning time is normally short (except for
  drought) i.e. they are rapid-onset unscheduled
  events.
• Most loss of life and property are suffered
  during or soon after the event.
• The risk is involuntary (although this applies
  mainly to LEDCs as most people in MEDCs are
  aware of risks and choose to minimise or ignore
  them)
• The impact on the human population has an
  intensity and scale to justify an emergency
  response.

12
Risk levels LEDCs vs MEDCs

• LEDC
• Large / poor populations
• Inadequate infrastructure
• Ineffectual governments
• Extreme climate

• MEDC
• Large built environment
• (greater risk of damage)
• Larger investment risk
• Highly urbanised

13
Hazard Classification

• Hazards have been classified using a wide range
  of criteria and approaches, and for a variety of
  purposes and user groups.
• Purposes of classification
• Assessing risk
• Understanding spatial patterns
• Understanding how hazards impact on people
• Aiding our understanding of processes and how
  they are inter-related
• Helping to manage responses to hazards
• Classification groups include
• Spatial distribution e.g. MEDC/LEDC, Continents
  or climate region
• Origin/causal process e.g. tectonic, atmospheric
• Impact on people e.g. levels of damage

14
Hazard Frequency Magnitude(Scale)

• Hazards are commonly classified using their
  frequency and magnitude.
• Magnitude (size)
• most commonly seen with earthquakes (Richter and
  Mercalli scales) or tropical cyclones (Beaufort
  scale for wind speed Saffir-Simpson scale)
• Frequency (how often they occur)
• Storms and floods are often classified using a
  recurrence interval e.g. 100 year flood. This
  is a probability statement not a temporal
  staement.
• There is a statistical relationship between
  magnitude and frequency
• as magnitude increases frequency decreases.

15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
Saffir Simpson Scale
20
Effects, Risk Perception

• Effects
• Effects can be split into environmental
  cultural or primary secondary
• Risk
• People put themselves at risk because
• Hazards are essentially unpredictable
• Lack of alternatives (due to social, political,
  economic or cultural factors)
• Changing levels of risk
• Cost/benefit (benefits outweigh the risk/cost)
• Perception
• Perception
• Fatalism (acceptance of hazard Gods will)
• Adaptation (modify lifestyle to minimise effects)
• Fear (forces people to relocate away from risk)

21
Management of Hazards

• Response to hazards has shifted from just coping
  to a sophisticated integrated risk management
  approach.
• This approach supported by the UN IDNDR
  combines Prediction, Prevention Protection.
• Britton (1998) defined Integrated Risk
  Management as
• the process of considering the social, economic
  and political factors involved in risk analysis
  determining the acceptability of
  damage/disruption deciding on the actions to be
  taken to minimise damage/disruption
• This approach thus has 2 essential elements
• Risk Assessment
• Risk Communication (between all concerned)

22
(No Transcript)