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Sociétés et environnement : des équilibres fragiles
THEME 1
Facing hazards and disasters UNIT 1
KEY QUESTIONS:
Are some societies more vulnerable than others?
How do societies respond to increasing risks?
1. Vulnerability to risks
1.1. Communities are exposed to natural and technological hazards
1.1.1. From hazard to disaster
risk = hazard x vulnerability
A hazard is a perceived event that threatens both life and property. A threat (whether natural or human) that has the potential to cause loss of life, injury, property damage, socio‑economic disruption or environmental degradation.
A hazardous event is the occurrence (realization) of a hazard, the effects of which change demographic, economic and/or environmental conditions.
A disaster is a major hazardous event that causes widespread disruption to a community or region that the affected community is unable to deal with adequately without outside help.
Vulnerability is a measure of the extent to which a community, structure, service or geographical area is likely to be damaged or disrupted, on account of its nature or location, by the impact of a particular hazardous event. Some people and places are more vulnerable to certain hazards than other people and places.
Risk is the exposure of people to a hazardous event presenting a potential threat to themselves, their possessions and the built environment in which they live.
1.1.2. Natural and technological hazardsNatural hazards
Technological hazards
Systems of hazards
Video - 2011 Earthquake and tsunami in Japan
JAPON
INDE
CHINERUSSIE
FRANCE
Windscale(1957)
Tchernobyl (1986)
Kyshtym (1957)
Bhopal(1984)
Minamata (1955)
Équa
teur
Fukushima (2011)
Toulouse (AZF, 2001)
DeepwaterHorizon (2010)
Exxon Valdez (1989)
Seveso (1975)Baia Mare (2000)
Three MileIsland (1979)
ÉTATS-UNIS
Amocco Cadiz (1978)
Castillo de Bellver (1983)
Nowruz (1983)
Espaces ayant été sujetsà de grandes marées noiresPrincipales routes maritimesAccidents et catastrophes
nucléaires
Catastrophes chimiques
Autres pays ayantdes centrales nucléaires
Pays possédant un grand nombrede centrales nucléaires(plus de 30 réacteurs)
Sour
ce :
Agen
ce in
tern
atio
nale
de
l'éne
rgie
ato
miq
ue.
Technological hasards are mostly found in developed or emerging countries.
1.2. Increasing the risks of disasters
1.2.1. An increasing exposure to hazards
World map of population density
1.2.2. Human activities increase exposure to hazards
Doc. 1 and doc.1-2 p.28 1. Describe the hazardous event that caused the 2017 disaster in Houston.2. To what extent is Houston's vulnerability due to its natural environment?
Global warming is the long-term warming of the planet’s overall
temperature. Global warming causes climate change.
Climate change refers to changes in weather patterns and growing
seasons around the world. It also refers to sea level rise caused by
the expansion of warmer seas and melting ice sheets and glaciers.
1.3. Development and vulnerability
1.3.1. The effects and responses to hazards in countries of contrasting levels of wealth
TASK 1. Summarise, using the ‘Give me 5’ diagram, the
information about the effects and responses to hazards in countries of contrasting levels of development.
2. Describe how the effects of an earthquake in an HIC can be different from the effects of an earthquake in an LIC
3. Evaluate the factors that affect the effectiveness of the responses to a disaster.
4.
CASE STUDYAn earthquake in a LIC - Haiti 2010
CASE STUDYAn earthquake in a HIC - Japan 2011
GDP per capita
1.3.2. An increasing vulnerability
2. Risk management: a transition?
1.3 How successful is themanagement of hazards and disasters?
15Answers at www.hoddereducation.co.uk/needtoknow/answers
Theoretical frameworksPrediction and forecastingTable 5 Prediction and forecasting of tectonic hazards
Hazard Predictability CommentsEarthquake Limited Areas at high risk identified, together with
those likely to suffer severe ground shaking and liquefaction
Seismic gaps can point to areas of especially high risk
Volcano Most give some form of warning
Monitoring equipment on volcanoes can measure changes as magma chambers fill and eruption nears
Tiltmeters record ‘bulging’ as magma rises
Seismometers record minor earthquakes that indicate magma movement
Gas spectrometers analyse gas emissions that can point to increased likelihood of eruption
Tsunami The earthquake cannot be predicted; the wave can be
Seismometers can tell that an earthquake has occurred and locate it
Ocean monitoring equipment can detect tsunamis in the open sea
This information can be relayed to coastal areas, which can be evacuated
The hazard management cycleKey points:n illustrates four stages of the management of hazards in attempting
to reduce the scale of a disaster (Figure 4)n the recovery (‘returning to normal’) stage depends on:
n the magnitude of the eventn the level of development and governance of the area affectedn the external help available
!
PREPAREDNESSCommunity education andresilience building includinghow to act before, during andafter a disaster, prediction,warning, and evacuationtechnology and systems
RESPONSEImmediate help in the form ofrescue to save lives and aid tokeep people alive, and provideemergency shelter, food andwater
MITIGATIONActing to reduce the scale ofthe next disaster: land-usezoning, hazard-resistantbuildings and infrastructure
RECOVERYRebuilding infrastructure andservices, and rehabilitating theinjured (physically and mentally)
Rehabilitation
Reconstruction
Prediction
Preparedness
Prevention
Mitigation
Response
Naturalhazard
Figure 4 The hazard management cycle
Key termsPrediction Knowing when, and where, a natural hazard will strike on a spatial and temporal scale that can be acted on effectively.
Forecasting Provides a ‘percentage chance’ of a hazard occurring, e.g. a 25 per cent chance of a magnitude 7 earthquake in the next 20 years.
Seismic gaps Areas that have not experienced an earthquake for some time and are ‘overdue’.
Synoptic linkScientists are key players in prediction and forecasting.
428515_01_Edex_A-level_geo_005-018.indd 15 27/04/18 5:01 PM
Copyright: Sample proof materialThe risk management cycle
Hazardous event
1 Tectonic processes and hazards
Need to know: Edexcel A-level geography16
The Park disaster response modelKey points:n illustrates how quality of life is impacted by a hazardous event
(Figure 5)n shows how a range of management strategies can be used over
time — from before the event to after the eventn highlights the roles of emergency relief agencies and rehabilitationn shows how different areas affected may have different response
curves, depending on their level of preparedness and economic development
ImprovementStage 1
Stage 2Hazardous event
Stage 4
Stage 3Search,rescueand care
Stage 5Nature of recoveryrelated to:UÊÌ�iÊ�ii`ÊÌ�ÊÀi`ÕVi vulnerabilityUÊÌ�iÊ�ii`ÊÌ�ÊÀiÃÌ�Ài normality as soon as possible
Normality
Deterioration
Quality of life,level of economicactivity, socialstability,communicationsand services
Modifyingthe causeand event
Use ofvulnerabilitystrategies
Strategies to modifyvulnerability to preventfurther disasters
Improvementor return tonormality?
Permanent rebuildingof physical and socialinfrastructure
Modify the loss(e.g. aid andtemporary housingand services)
Pre-disaster Relief(hours to days)
Rehabilitation(days to weeks)
Reconstruction(weeks to years)
Relief and rehabilitation period –may include outside help(national or international)
Figure 5 The Park disaster response model
ManagementModifying the eventTable 6 Modifying the event
Nature of modification Benefits Issues
Land-use zoning:n prevention of buildings on low-
lying coasts (tsunamis)n avoiding areas close to volcanoesn avoiding areas where liquefaction
is likely
Low cost
Relocates people from areas of high risk
Prevents economic development in some coastal areas
Requires strict enforcement
Aseismic buildings:n cross-bracingn using counterweightsn deep foundations
Protects people and property
Financially possible in the developed world
Basic design can be replicated in developing world
High costs for tall buildings
Older buildings and homes for people on low incomes are too difficult to protect
Exam tipAnalyse and compare case studies using the hazard management cycle and/or the Park model.
Synoptic linkNote how both of these models highlight the roles played by key players such as scientists, emergency planners and engineers.
428515_01_Edex_A-level_geo_005-018.indd 16 27/04/18 5:01 PM
Copyright: Sample proof material
The Park disaster response model
2.1. The need to develop prevention, prediction and preparedness
Mitigation: actions aimed at reducing the severity of an event and lessening its impacts.
Prediction: the ability to give warnings so that action can be taken to reduce the impact of hazard events. Improved monitoring, information and communication technology have meant that predicting hazards and issuing warnings have become more important in recent years.
Preparedness: this involves prearranged measures that aim to reduce the loss of life and property damage through public education and awareness programmes, evacuation procedures, the provision of emergency medical, food and shelter supplies and the taking out of insurance.
5 simple steps to be more prepared today
1 Identify an out of area contact.
Know your connections-who will you 2 rely on and who will rely on you?
Establish a meeting place for you and 3 your connections.
Take stock of the things you use every day 4 that also could be useful in an emergency.
These are the makings of disaster supplies.
5 Talk about what you've done to be pre-pared with the people you care about.
8 SF72 Make a Plan
Our meeting spot Out of area contact Where will we meet in an emergency? Who will we check in with, outside
the area?
Address:
Location: Location:
Address:
My people Identify a group of friends and family with whom you'll coordinate.
Name: Name:
.1',,10~ P. .. .il.e .. ~c,n.e.: tv1c,~ilE:1p~c,nE:1:
f-lc,111e.phc,n.e: f-l()111E:1p~()n.E:1:... Address: Address:
Important contacts What other numbers would be handy in an emergency?
Doctor:
Pediatrician:
Pharmacist:
Veterinarian: S2
San Francisco disaster preparedness campaign
2.2. The need to improve crisis management and resilience
Reconstruction in Minamisanriku, Japan, after the 2011 tsunami
a. levees built to protect against tsunami waves.
b. new shopping mall c. embankment d. disaster prevention centre, destroyed
by the 2011 tsunami, kept as a shrine to the victims.
e. construction of new homes, protected by the hills.
Resilience: the sustained ability of individuals or communities to be able to utilize available resources to respond to, withstand and recover from the effects of natural hazard events. Communities that are resilient are able to minimize the effects of the event enabling them to return to normal life as soon as possible.
CASE STUDY 2Risk management
The Boscastle flood of 2004
Developing extended writing skills – the Boscastle floods
© www.teachitgeography.co.uk 2016 25506 Page 1 of 2
Student tasks
1. Underline any geographical keywords. Do you understand what they mean?
2. Can you circle below all the causes of flooding? (These are your POINTS)
Extension: Can you differentiate between the human and physical causes?
3. Shade the boxes that show all the EXAMPLES.
4. Draw a line to link the EXAMPLES to the correct POINT.
5. In another colour, link the correct EXPLANATION to the correct POINT and EXAMPLE.
This shape means that the land acted as a funnel,
directing vast volumes of water into the village
The village of Boscastle is located within the Valency
valley Heavy precipitation
This flash flood meant that people had very little time to
prepare or evacuate
This meant that when the volume of water in the rivers
increased, it lead to huge volumes of water flowing
through the town
Urbanisation
This meant that surface runoff increased, as excess water could no longer soak
into the soil
Boscastle is at the confluence (where tributaries meet) of three rivers: the Valency,
Jordan, and Paradise
180 mm of rainfall fell in three hours
The entire south west of England had been battered
with stormy weather over the days leading up to the flood
The main car park in Boscastle is located right next to the
river Large drainage basin
This meant that impermeable surfaces like tarmac,
increased the spread of floodwater into the village
Steep valley sides Saturated ground
6. Complete a paragraph to explain one of the causes of flooding.
POINT: One of the causes of flooding in Boscastle was… EXAMPLE: An example of this is… EXPLAIN: This means that…
7. Complete another PEE paragraph using a different cause.
Boscastle before the floods © Matthew Hunt, 2003, flic.kr/p/Lh7B
Boscastle before the flood Boscastle after the flood
Bocastle Flood Management Scheme
2.3. Good governance is needed to reduce risks
Global governance: movement of political integration aimed at negotiating responses to problems that affect more than one state or region.
Conclusion
