Weather Hazards!

Weather Hazards!

Global atmospheric circulation - movement of air around the earth to try and and balance the temperature. 

Main lines of lattitude -

Arctic circle

Tropic of Cancer

Tropic of Capricorn

Antarctic circle

Insolation - Incoming solar radiation

Winds blow from high to low pressure zones

Desserts are never located on the equator

Earth axis tilted at 23.5 degrees

Cyclone - low pressure system

Anti Cyclone - high pressure system 

Low pressure = bad weather

High pressure = good weather

Distribution of tropical storms - 

Known as Hurricane in Carribean sea and USA

Known as Typhoons in east Asia

Known as Cyclones in south Asia

(seas must be at least 27 degrees! hot!!)

When a tropical storm reaches land it weakens - mainly costal damage (storm surges)

Tropical storms move away from the equator

Primary - 

With winds over 200km/h there is 

widespread damage to trees, crops and insecure buildings which can explode as pressure changes - flying debris. 

Instense rainfall can cause flooding

Costal damage from storm surge

Secondary - 

Damage to property, loss of life, homelessness

looting

damaged roads and railways, comms lines, costal damage, looting

Satelllites - use infared images

National Hurricane Centre, California - makes predictions of where hurricanes may hit land, issues hurricane watch and hurricane warnings. 

Ships record water temperatures

Aircraft - flying close to storms gather info on intensity

Radar - tracks info on route and rainfall

Levees and flood walls - protects against storm surge

Houses walls and roofs can be strenghtened 

New housing built further away from risk ares

Houses with flooding risk built on stilts

Improving sanitation

Prediction 

Planning - authorites in area, have equipment ready, evacuation routes. 

Defences - Window borders, defence shelters

Education - Well educated, schools to have emergency equipment. 

Hurrincane Katrina - New Orleans

• 23rd August, 2005 
• New Orleans was below sea level - flooding was a major issue
• 80% of New Orleans was flooded
• 10,000 made homeless
• 3 million without electricity
• Damaged properties - high winds
• flooding - storm surges
• 2 bridges/ roads collapsed
• 23% didn't return to New Orleans 5 years after Hurricane.
• Repair costs - $200 billion
• Defences: 
• Sea walls - Not effective!
• Few buildings had boerderd windows
• Levees
• Tape on windows
• 18,000 people evacuating New Orleans per hour!! before the storm

Weather Hazards in the Uk

Weather - day to day conditions of the atmosphere.

Climate - avarage weather over a longer period of time.

Hazards in the United Kingdom: 

Drought and heat - Rivers and resovours can dry up and become low, affecting water supply and wildlife. Heat waves effect the elderly.

Thunderstorms - Follow a period of hot weather, torrential rain fall, flash floods

Prolonged rainfall - long periods of rain, river floods. Common in winter/ spring. Snowmelt makes matters worse! 

Somerset level floods!

South west of UK 

To the east of somerset is Deven

To the south of somerset is Dorset

Prone to flooding - flat land and many rivers, wetland and costal plain

prolonged rainfall - winter  2013-14

wetest January since 1910

areas of low pressure swept accross Atlantic

350mm of rainfall fell in January and Febuary

High tides and storm surges from rivers up the Bristol channel

Rivers HAD NOT been dredged for at least 20 years!! - WHAT!?

Social - 600 houses flooded, 16 farms eveacuated, Villages cut off, some evacuated to temp accomodation, power supplies cut off, road closures. 

Economic - £10 million repair, agricultural land under water for 3-4 weeks, 1000+ livestock evacuated, Railway lines closed, local businesses lost trade 

Environmental - Floodwaters contaminated with sewage, debris had to be cleared, water had to be reoxygenated before being pumped back into rivers.

Imidiate responses - Rescue boats deployed,

extra police patrol,

flood action plan £20mil,

Royal Marines help,

Uk gov gave £30 mil,

villagers used boats to get to school e.t.c 

Long term responses - 

8km of rivers were dredged

Road levels raised

flood defences in communirties

River banks raised and strengthened

Pumps borrowed from Netherlands.

Evidence: 

2015/16 - very wet, severe storms in Yorkshire and the North

2010 - heavy snow, temperatures of -18 degrees

2003 - heatwave, Kent, 2000 died, temperatures of 38.5 degrees

2008 - floods, Somerset

2009 - heavy snow - heavy floods, cambria lake

IPCC (Intergovournmental panel on climate change) in 2011 agreed extreme world weather becomes more common as global warming heats the planet.

Due to the changing jet streams weather patterns may be getting stuck explaining the long periods of weather. 

Climate change...

Long term change in weather. 

The period of timeline that spans from now until 2.6million years ago is known as the quaternary period