Studied by 35 people
Case studies used in this are: L'Aquila, Nepal, Typhoon Haiyan, and Somerset Level floods
What is a natural hazard?
Events that are naturally occurring and non-preventative with a negative effect on life.
What is a risk?
Probability of a hazard occurring
What is a hazard perception?
The way that people view the risk caused by the hazard
What is hazard impact?
The actual impact of the hazard
Tectonic hazards
Earthquake, volcanic eruption, tsunami
Geomorphological hazards
Avalanche, landslide
Biological hazard
Locust swarm, forest fire
Atmospheric hazard
Floods, heatwaves, drought
Low risk factors
Good education
Money available
high quality infrastructure
Small population
High risk factors
Poor education
Little money
Low quality infrastructure
Large, dense population
How climate changes increases risk
Warmer areas lead to more energy gained, leading to hurricanes
Some parts get wetter and more prone to flooding
Hotter areas get more droughts leading to famine
How poverty increases risk
Poor people forced to live in high risk areas, leading to people building houses in dangerous areas
How urbanisation increases risk
Some of the world’s largest cities are at risk of hazards
Densely populated areas are at greater risk
How farming increases risk
Floodplains are good for farming but are prone to flooding
Oceanic crusts
6-8km thick
Heavier and denser
Newer
Basalt
Continental crusts
30-50km thick
Lighter
Older
Granite
Constructive plates
Move away from each other
Volcanoes, small earthquakes
Destructive
Move towards each other
Mountains, Earthquakes, Volcanoes
Conservative
Moves alongside each other
Hills, earthquakes
Ash clouds
Ash blasted into the atmosphere
Disrupts air transport
Smothers farmland
Suffocates people
Lava
Liquid magma on the Earth’s surface
Destroys property, forests and fields
Pyroclastic flow
Deadly mix of rocks ash and gas surging quickly down volcano’s side
Extremely dangerous
Burns everything in path
Social reasons for living near volcanoes
It’s scenic
Well developed areas have good prep for minimising risk
Economic reasons for living near volcanoes
Good for tourism
Many jobs for mining minerals, e.g. sulphur
Environmental reasons for living near volcanoes
Volcanic soil is fertile
Volcanic activity is rare
How does remote sensing reduce risk from volcanoes?
GPS satellites and other machinery detect ground deformations
Some phones have GPS receivers and accelerators built in to detect movement in the ground
How does seismology reduced risk from volcanoes?
Devices are used to detect radon gas that escape from cracks in the Earth’s surface
L’Aquila: Primary impacts
300 people died and 1500 people were injured
Up to 15000 buildings were damaged, including the hospital
L’Aquila: Secondary impacts
Fewer applications for the University of L’Aquila
Transport was damaged due to landslides and rock falls
L’Aquila: Immediate responses
Temporary shelter was provided
The EU provided $550 million
L’Aquila: Long-term responses
No taxes were paid by residents of L’Aquila in 2010
University fees were dropped for 3 years
Nepal: Primary impacts
9000 people died and 22000 people were injured
7000 schools were destroyed
Nepal: Secondary impacts
Kali Gandabi river got blocked causing floods
250 people missing from Langtang
Nepal: Immediate responses
500000 temporary shelters were set up
The UN and the WHO provided medical supplies
Nepal: Long-term responses
Buildings were constructed with safety in mind
Base camp at Mt. Everest was repaired since it is an important source of Nepal’s economy
Global atmospheric circulation
Movement of air around the Earth in cells to balance the temperature.
Insolation
Incoming solar radiation
Which pressure zones do winds blow from and to?
From high pressure to low pressure
High pressure
Cold air sinks - dry skies
Low pressure
Warm air rises - rainy
Coriolis effect
Distortion of winds on the ground caused by the Earth’s rotation
Cells from north to south
Polar, Ferrel, Hadley, Hadley, Ferrel, Polar
What are tropical storms called in each area?
East Asia - typhoons
US and Caribbean - hurricanes
South Asia - cyclones
Australia - Willy-willies
What are the conditions to form a tropical storm?
From 5-30° north and south of the equator - temp are higher here so pressure is low and air rises
In the summer and autumn - sea temps are at their highest
Over warm oceans above 27°C, 60-70m deep - provides heat and moisture
What are the features of a tropical storm?
Between 482-644km wide
6-8km high
As fast as 65km/h
What is the structure of a tropical storm?
The central part is the eye, it has no rain and light wind speeds.
It is surrounded by towering cumulonimbus clouds, has heavy rain and wind speeds of up to 320km/h
How do tropical storms develop?
Air is heated above the ocean surface, causing warm air to rise rapidly.
More warm, moist air is drawn up, causing strong winds.
As it rises, it cools and condensed to form towering cumulonimbus clouds which make torrential rainfall.
Coriolis effect causes it to spin up around the eye to create an eye wall where it is most intense.
Cool air sinks in the eye so t is calmer and drier.
It travels across the ocean in the direction of the prevailing winds.
When it meets land, it loses power as there is no more moisture from the ocean to fuel it.
How might climate change affect the distribution of tropical storms?
May affect areas outside of the current hazard zones as the seas will get more warmer.
How might climate change affect the frequency of tropical storms?
It is unsure whether it will increase or decrease but the intensity will increase.
How might climate change affect the intensity of tropical storms?
Intensity may increase due to warmer temps and higher sea levels.
What are the primary effects of Typhoon Haiyan?
6,300 people died across the Philippines, Vietnam, China, and SP Islands.
Nearly 600,000 people were displaced.
There was over 400mm rain
What are the secondary impacts of Typhoon Haiyan?
Raw sewage was spread by flood waters.
14 million affected, many homeless and lost income.
Cost the government at least $5.8 billion to repair and for lost earnings.
What are the immediate responses to Typhoon Haiyan?
Over 1,200 evacuation sites were set up.
UK government sent shelter kits to families.
Philippines red cross delivered basic food aid.
What are the long-term responses to Typhoon Haiyan?
Immunised people against diseases.
UN donated financial aid, supplied and med support.
Thousands of home are being built away from areas at risk.
How to reduce the effect of tropical storms through prediction?
TV, radio and social media will broadcast storm warnings days in advance.
Scientists use satellites to predict the track of the hurricane
How to reduce the effect of tropical storms through protection?
Storm-proof building adaptation shelters, e.g. shutters over windows, made of strong concrete
Storm shelters
Sea walls and levees
How to reduce the effect of tropical storms through planning?
National awareness program - activities in school and on social media
Signposts - evacuation routes and shelters are clearly marked around the city.
Extreme weather
When weather events are significantly different from the average or usual weather pattern, and is severe or unseasonal
Weather vs Climate
Weather is day to day atmospheric condition while climate is the average
What are the different types of weather hazards in the UK?
Thunderstorms
Prolonged rainfall
Droughts and heatwaves
Snow and extreme cold
Strong winds
Somerset Levels 2014: Location
Somerset is a county in south-west England. It is bordered by the Bristol Channel, Quantock Hills and Mendip Hills
Somerset Levels 2014: Why is the area prone to flooding?
The Somerset Levels and Moors are very flat and low-lying, with many slow-flowing rivers suffering from silt. The ground becomes easily saturated
How were the Somerset level floods caused?
Caused by low pressure systems as 13 storms hit the south-west in short periods of time.
Rainfall was 3x the average and was the wettest winter in 200 years.
What were the social impacts of the Somerset level floods?
Power supplies cut
Over 600 houses flooded
16 farms evacuated
What were the economic impacts of the Somerset level floods?
Bristol to Taunton railway line closed at Bridgewater
Over 1000 livestock evacuated
Cost of damage was more than £10 million
What were the environmental impacts of the Somerset level floods?
Floodwaters were heavily contaminated with sewage and pollutants
Stagnant water needed reoxygenating before being pumped back into rivers
Large amounts of debris had to be cleared
How was the risk reduced at the Somerset Levels?
Riverbank height was raised
8km of rivers have been dredged to increase capacity
£20 million Flood Action Plan launched by Somerset County Council
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