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Unit 2Weather and its effects

This is the next unit

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The next 5 weeks

• Week 1: What is a hurricane? What is it like for people in an MEDC?

• Week 2: What was cyclone? What is like for people in an LEDC?

• Week 3: British weather systems: What is an anticyclone like?

• Week 4: Why was our summer so wet?

• Week 5: Why is El Nino so important?

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What is a hurricane?• It is a weather system that forms out over the

ocean, and develops into a whirling, very windy storm with heavy rain

How are they different from typhoons and cyclones?

• They aren’t – it depends where you are in the world. If you are in the Atlantic, they are called hurricanes, if you are in the Pacific Ocean they are called typhoons and if you are in the Indian Ocean they are called Cyclones.

• Did you know that in Australia they are called willy-willies?

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Here is a hurricane

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Now shut your eyesTry and draw a picture in your head

Because when I have finished I want you to make an annotated sketch or several of them if you like about how

the hurricane forms

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• Hurricanes all start over the sea where, for reasons that we do not fully understand, a patch of ocean has a surface temperature of more than 260C. The hot air rises taking a lot of water vapour with it. As the water vapour rises up it cools to form big cumulus clouds. This creates low pressure at sea level. Wherever you have low pressure, air with higher pressure tends to move in to replace it.

• The winds that travel around the Earth (called the Trade Winds) at this point are pulled in to fill the gap left by the rising air. But due to the turning effect of the earth, air does not move straight into a low pressure zone but whirls in around and towards it – just like the water going down the plug hole – for the same reason. Remember the world is turning at about 1700 km an hour!

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• We have the hot air rising, the air coming in from outside and coming under the cloud in a spin, picking up more water vapour and spiralling upwards as it warms. This has 2 effects; the first is that the storm clouds begin to be pulled into a spin by the incoming wind. The second effect is that the spinning storm is pulled outward – leaving a low pressure funnel at the centre. Now way up high there is cold air which is under higher pressure so this is sinks down into the centre – at the bottom this begins to warm and gets pulled in to the warm spinning stormy mass, and so more cold air follows in after it. As everything is spinning faster and faster the storm begins to drift sideways because of the trade winds.

• Not only that but this huge bundle of energy depresses the sea level under it, so there is a backup ridge of water all around it – this gives rise to surges both before and after the hurricane has passed.

• So the hurricane brings surges and high winds and heavy rain all together! This why they cause so many problems to the countries they cross.

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This gives a really neat intro See if this is like your picture

http://www.curriculumbits.com/

prodimages/details/geography/geo0008.html

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And this was Gustav that did less damage than feared!

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Hard Times for ‘The Big Easy’(a nick name for New Orleans)

Just eight months after the Asian tsunami, the world is again humbled by the power of nature. This event, however, makes us ask new questions ……. about

human nature and American society.

VV ’05

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The Location of New Orleans

New Orleans is in the state of Louisiana. It is located on the delta of the Mississippi River about 170km from its mouth on the Gulf of Mexico

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Mississippi River

Gulf of Mexico

Mississippi Delta

Lake Pontchartrin

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Mississippi River

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New Orleans : some facts

• A city of 470,000 people (67% Afro American)• Founded by the French in 1718• Expanded by the Spaniards • Bought by the USA for $15 million in 1803• A lively port and industrial city• Home of jazz and cajun and creole cooking• Hosts an annual mardi gras carnival• Attracts hundreds of thousands of tourists

every year

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But in the aftermath of Hurricane Katrina which swept by on 29 August 2005, the levées broke and the city was

flooded………

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Two days before, the people of New Orleans had watched and waited as Hurricane Katrina approached…….

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People who had transport fled the city

Shop keepers boarded up their windows

Volunteers helped to fill sandbags

And those without the means to drive out had to stay behind

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Downtown New Orleans at the height of the storm on 29 August

The eye of the hurricane passed to the east of the city

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After the storm…..

It seemed New Orleans had got off more lightly than expected…

until the levées broke and water flooded into the city…………

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Within 24 hours 80% of the city was under water

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Affluent housing sinking beneath the rising tide

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Public transport is out of action

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Many people drown – Government estimates warn of several thousand dead

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One hundred thousand people

who were not able to leave the city….

…are trapped in their homes.

Most of these had simply been too poor to flee

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The water is polluted with sewage and oil

….but people are forced into it in order to survive

Food and drinking water becomes scarce within hours and is only flown in two days later

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Hospitals evacuate patients by boat

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As the story unfolds on TV screens across the globe, the American

government seems slow to respond to the scale of the disaster

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The police struggle to contain a rising tide of lawlessness

A slow evacuation begins

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Some emergency relief begins to arrive in the

city

But with no means of evacuation,

conditions continue to

deteriorate for most of those still trapped in the city

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23,000 people take refuge in the New Orleans Superbowl without running water and adequate sanitation. Reports

likened conditions to ‘a Third World refugee camp’

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Four days after the storm US President George Bush flies over the city to view the catastrophe first hand …….

“The enormity of the task requires more resources”

“In America we do not abandon our fellow citizens in their hour of need”

“Where our response is not working we will make it right. Where our response is working, we will duplicate it”

“The main priority is to restore and maintain law and order and assist in recovery and evacuation.”

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More helicopters are drafted in to

help with the evacuation of the

city

Convoys of buses evacuate people from the

Convention centre in New

Orleans

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The waters are slowly receding…

And the grim task of searching

buildings must begin.

Six days after the storm, the city is almost empty

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“The first few days were a natural disaster, the last four

days were a man-made disaster”   

Phillip Holt, 51New Orleans evacuee

Photograph credits – ‘Der Spiegel’

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A couple of words• Impacts are forceful consequences or

strong effects of something – These impacts may economic (about money)

or human (about people)

• Responses are reactions ,what people do as a result of a situation– The responses may be short term (actions

that taken within days of the event) or long term (taken over months or years afterwards)

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Impacts – human, economic, both or neither?

• 1,500 deaths occurred in the states of Louisiana, Mississippi and Florida • The impacts of Katrina is thought to have cost about $300 billion • Thousands of homes and businesses were destroyed • Thousands of jobs have been lost and millions of dollars in lost tax incomes

to the affected states and USA federal government. • Agricultural production was damaged by tornadoes and flooding. Cotton and

sugar-cane crops were flattened. • Three million people were left without electricity for over a week after the

Hurricane struck. • Tourism centres were badly affected, probably reducing income for several

years. • There have been adverse impacts on the oil and gas industry. A significant

part of the USA oil refining capacity was disrupted after the storm due to flooded refineries and broken pipelines, and several oil rigs in the Gulf were damaged.

• Evacuees have not returned to the affected areas, producing a shortage of workers for businesses that reopened months after the hurricane struck.

• Major highways were disrupted and some major road bridges were destroyed.

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Responses- long term, short term or neither?

• Many of those who left, went to other towns and the migration has become permanent as people have settled in other parts of the USA, for instance when peoples’ houses and businesses were permanently destroyed.

• Around 20,000 people in New Orleans sheltered in the Superdome football stadium when warned the hurricane was about to strike.

• However, the living conditions in the Superdome soon deteriorated. It became hot and stuffy, toilets were broken and there were no washing facilities.

• Eventually a convoy of 475 buses transported many of these people to the Astrodome stadium in nearby Houston, Texas.

• Lawlessness broke out and emergency services could not operate properly.

• Criminal gangs roamed the streets, looting homes and businesses and committing other crimes. Army and police had to try with difficulty to maintain order when living conditions became intolerable and there was competition for food and drink.

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Responses- long term, short term or neither?

• Unfortunately, bodies of people who died in the August 2005 were still being discovered late into 2005.

• One of the first challenges in the aftermath of the flooding was to repair the broken levees. Vast quantities of materials, such as sandbags, were airlifted in by the army and air force and the levees were eventually repaired and strengthened.

• But the water took many months to dry out and much rebuilding had to wait.

• Although the USA is one of the wealthiest developed countries in the world, it highlighted that when a disaster is large enough, even very developed countries struggle to cope with natural disasters, particularly the poorest people.

• But many Americans felt their government could have done a whole lot better – and certainly much more quickly.