Natural Disasters and Degg's Model in High School Geography

What We've Covered So Far

• Completed EQ1
• Homework - create a revision resource for EQ1 including details of case studies
• Additional reading resources available on teams for further reading
• EQ1 Knowledge test

Natural Disasters and Tectonic Hazards

SA

E

Why Tectonic Hazards Become Disasters

Today's lesson

EQ2: Why do some tectonic hazards develop into disasters?

Key Idea

1.4

Disaster occurrence can be explained by the relationship between hazards, vulnerability, resilience and disaster.

Detailed Content for Understanding Disasters

1. Define natural hazard.
2. Define disaster.
3. Understand the importance of vulnerability and community's threshold for resilience.
4. Recall the hazard risk equation.
5. Understand the Pressure and Release model (PAR) and the complex inter-relationships between the hazard and its wider context.
6. Describe and evaluate the social and economic impacts of tectonic hazards on the people, economy and environment of contrasting locations in the developed, emerging and developing world.

Defining Natural Hazards

• A natural or quasi-natural event which is perceived as a risk to human life and property.

'A perceived natural event formed by tectonic processes which has the potential to threaten both life and property.'

• Risk =
  The probability that exposure to a hazard will lead to a negative consequence.

Types of Natural Hazards

• Make a list of at least 10 different natural hazards

Categorizing Natural Hazards

Type of Natural
Hazard

Examples

Tectonic Hazards

Hydrometeorologic
Hazards

Mass movement
Hazards

Biological Hazards

Examples of Hazard Types

Type of Natural
Hazard

Examples

Tectonic Hazards

volcanoes, earthquakes and
tsunamis

Hydrometeorologic
Hazards

River floods, hurricanes (tropical
storms), extra-tropical storms/mid
latitude depressions, tornadoes,
droughts

Mass movement
Hazards

landslides, mudflows, avalanches

Biological Hazards

locust plagues, disease epidemics

Quasi-Natural Hazards

?Why are some "natural" hazards
only quasi-natural?

• Can humans sometimes cause:
• "wild" fires?
• Landslides?
• River floods?
• Hurricanes?
• Volcanic eruptions?

What is a Natural Disaster?

• There are many definitions but ultimately it is
  when:
• 'A hazard causes significant impact on a vulnerable
  population'

It's a disaster
Darling!

https://www.bing.com/videos/search?q=natur
al+hazards &&view=detail &mid=36A97B52BC2
4E9FEC5E536A97B52BC24E9FEC5E5&&FORM=
VRDGAR

What Constitutes a Disaster?

This can be further quantified by stating that a
hazard becomes a disaster when:

10 or more people are killed, and/or 100 or more
people are affected. (CRED)

Disaster Threshold Levels

• These are used to decide if the impact of a hazard event is
  large enough to be considered a natural disaster
• Centre for Research on Epidemiology of Disasters (CRED)
  defines a disaster as:
• >10 people killed and/or
• >100 people affected.

United Nations defines a mega-disaster as:

• >2000 deaths and/or
• >200,000 homeless and/or
• GDP is reduced by at least 5% and/or
• Dependence on aid from abroad for a year or more after the event
• Task - Worksheet

1. For each of the 8 natural hazards, decide on the level of
   development based on the table.
2. Apply disaster threshold to 8 tectonic hazard events.

Understanding Development Levels

Developed World Characteristics

The developed world is considered to be countries
who are wealthy, have good infrastructure, a stable
government and steady or low population growth.

These are often known as HICs (High Income Countries)

Emerging World Characteristics

An emerging country is a country that has some
characteristics of a developed country, but does not
meet standards in all areas. They may not have equality
or a democratic government. Their income may not be
high enough (over $10,000 per capita)

These are sometimes
known as NEEs
(Newly Emerging
Economy)

Developing World Characteristics

These are countries with low incomes. (often around
$2 per day) they sometimes lack infrastructure,
healthcare, education and have low human rights.

Many have unstable governments.

These are often
called LICs (low
income countries)

P

It is also worth noting that it is sometimes difficult to define the 'boundary' for
each country- why?

Degg's Disaster Model

• This model shows the interaction between hazards,
  disaster and human vulnerability.
• Importantly, disaster may occur when a vulnerable
  population is exposed to a hazard.

Vulnerability Factors

'A hazard causes significant impact on a vulnerable
population'

From the definition we know that there must be a
vulnerable population involved.

What does this mean?

In what ways can a population be vulnerable?

Think about whether
the factors are
human or physical
factors .....

Factors that will
affect the
vulnerability of
a population

In pairs come up with at least 5 factors that might make a population more vulnerable.

Degg's Disaster Model Diagram

Natural Hazard event
Eg earthquake,
volcano, tsunami

Natural
Disaster

Vulnerable
population eg
suffering from
poverty, lack of
preparedness

Degg's Model Details

Physical environment:
·Dangerous Locations
Floods
·Unprotected buildings

Socioeconomic environment:
Droughts
·Weak local economy (poverty)
·Lack of disaster preparedness
·Prevalence of hunger and
endemic disease

Disaster

Vulnerability

0-01

Hazard
Event

Landslides

t

Tsunamis

Local scale:
Volcanic Eruptions
·Lack of training, skills, food
security, ethical standards

Macro scale
·Rapid population change
·Rapid urbanisation
·Debt repayment issues
·Limited access to power,
structures and resources,
i.e poverty
·Failing political, social and
economic systems

Biohazards
and pests

Earthquakes and
secondary
landslides

·Over exploitation if
resources/deforestation

High Winds

The more vulnerable the
population, the higher the
risk for disaster.

Understanding Risk

Hazard Risk Equation

Hazard Risk Equation - handout

This equation aims to take all the key elements that turns a hazard into a
disaster to work out the amount of risk a certain group of people faces:

Risk (R) =

(H) X
(V)
(C)

Disaster Risk and Age Index

• Handout

Pressure and Release Model (PAR)

Progression of Vulnerability in PAR Model

Progression of Vulnerability

Root Causes

Dynamic
Pressures

Unsafe
Conditions

Low access to
resources

Limited influence
in decision
making

• Lack of
  investment
• Lack of press
  freedom
• Lack of ethical
  standards in
  public life

Rapid Change:
· Population
change
· Urbanisation

• Deforestation

Disaster
Risk = Hazard
X
Vulnerability

Natural Hazards

Earthquakes

Volcanic
eruptions

Tsunamis

Hurricanes

Floods

Weak economic
system

Low capacity:
•
Lack of
education &
skills

Unprotected
buildings &
infrastructure

Lack of disaster
preparation

Poor governance

No warning
systems

Fragile economy
& lack of social
safety net

Disease
epidemics

PAR Model: Socio-economic and Natural Environment Pressures

Socio-economic Pressures

Progression of Vulnerability >

Root Causes

Dynamic
Pressures

Unsafe
Conditions

Low access to
resources

Low capacity:
· Lack of
education &
skills

Unprotected
buildings &
infrastructure

Limited influence
in decision
making

• Lack of
  investment
• Lack of press
  freedom

Poor governance

• Lack of ethical
  standards in
  public life

Weak economic
system

Rapid Change:
· Population
change
· Urbanisation

• Deforestation

Fragile
economy & lack
of social safety
net

-Natural
Environment
Pressures

Natural Hazards

<

Earthquakes

Volcanic
eruptions

Tsunamis

Hurricanes

Floods

Disease
epidemics

Lack of disaster
preparation

No warning
systems

Disaster
Risk = Hazard
X
Vulnerability

ween the North
2010, an earthquake
The resulting high death
quakes on record.

Key
direction of plate movement
plate boundary
epicentre
~ complex strike-slip fault

Gulf of
Mexico

NORTH AMERICAN PLATE

CUBA

DOMINICAN
REPUBLIC

MEXICO

Atlantic Ocean

JAMAICA

Caribbean
Sea

CARIBBEAN
PLATE

N

• 18

COCOS
PLATE

VENEZUELA

km

Pacific Ocean

SOUTH AMERICAN PLATE

Figure 3 The complex plate boundaries affecting Haiti

Figure 4 The earthquake's intensity and the number of Haitians put
at risk

N

0

30
km

Caribbean
Sea

HAITI

108

Port-au-Prince

epicentre

to work.

ernment officials, police
is) just didn't know
erty, so they didn't
:h the effects of the

Key
estimated
MMI intensity

population exposed
to shaking

IV

moderate

5 887 000

V

slightly strong 7 261 000

VI

strong

1 049 000

VII

very strong

571 000

VIII

destructive

314 000

IX

ruinous

2 246 000

X

disastrous to
catastrophic

332 000

DOMINICAN REPUBLIC

nero

0

1000

NAZCA
PLATE

-

HAITI

Haiti Card Sort Activity

Haiti card sort

• You need to apply PAR Model to Haiti 2010
  Earthquake disaster.
• You will need to decide if the cards are:
• Root causes
• Dynamic pressures
• Unsafe conditions
• Hazard (natural pressures)

Kahoot Quiz

• https://create.kahoot.it/details/edexcel-alevel-geog-
  tectonics-1/2f474316-ca7a-4035-a967-
  4a5a2f824d84

Recap of EQ2 Learning Objectives

Recap

EQ2: Why do some tectonic
hazards develop into disasters?

Key Idea

Detailed content

a. Define natural hazard.

b. Define disaster.

1.4

c. Understand the importance of vulnerability and
community's threshold for resilience.

Disaster occurrence can be explained by the relationship
between hazards, vulnerability,
resilience and disaster.

d. Recall the hazard risk equation.

e. Understand the Pressure and Release model (PAR) and the
complex inter-relationships between the hazard and its
wider context.

f. Describe and evaluate the social and economic impacts of
tectonic hazards on the people, economy and environment
of contrasting locations in the developed, emerging and
developing world.

Today's
lesson

Understanding the PAR Model

• Handout

Answers to Questions

Question 1 Calculations

Answers

• Question 1 =
  Total = 988
  Number = 10
  Mean = 988/10 = 98.8
  NB no marks for 98
  99 is ok

1
2
3
8
10
12, 26, 156, 170, 600
3LQ
11Md
156 UQ
Interquartile range = 156-3 = 153

Question 2 Calculations

Q2
Ed2 = 118
= 1-6 X 118
103 - 10
=1-708
990 <
1-0.715
+ 0.285
(0.2848) OK
0.284 - not OK

Question 2B Correlation Analysis

Q2B
Since the calculated value of r (0.285) is not
greater than the critical value of r (0.48) at
the 0.1 significance level then we cannot be
90% confident that the correlation is not
simply due to chance.

We can therefore reject the alternative
hypothesis and accept the null hypothesis
that there is no significant correlation
between tsunamis height and number of
deaths.

Skills Handout: Global Volcano Distribution

• Skills handout

Figure 1: The global distribution of active volcanoes

22
7 .1 2
8 8
9
24
15
716
29
5
12
4
1
10
19 21
13
20
.
. 25
...
.17
3º
...
11
6 30 26
27.
23

• Plate boundary
• Active volcano
• Other volcano

1 Azores
6 Galunggung
11 Krakatoa
16 Mt St Helens
17 Nevado del Ruiz
18 Nyos
21 Popocatapetl
26 Tambora

2 Bardarbunga
7 Grimsvotn
12 Mauna Loa
22 Redoubt
27 Tristan da Cunha

3 Cotopaxi
8 Haeimaey
13 Soufrière Hills
23 Ruapehu
28 Unzen

4 Etna
9 Katmai
14 Mt Pelée
5 Fujiyama
10 Kilauea
15 Mt Rainier
19 Parícutin <
20 Pinatubo
24 Surtsey
25 Taal
29 Vesuvius
30 Meru

28
:. 14
18