Flashcards in Hazards case studies Deck (66):
Black Saturday (dates, location)
-Australias worst bushfire disaster
Impacts of Black Saturday
-3,500 properties destroyed
-450 ha burnt (forest loss)
-7,000 displaced people from homes
-Losses of agriculture inc. cattle, sheep and horses, loss of standing crops
-large areas of natural parks along with the wildlife (RSPCA estimated over 1 million perished during fires)
-Electricity supplies disrupted
-Looting of empty properties reported
-Cost= $4.4 billion- largest component was insurance
Causes of the wildfires of black Saturday
-Eucalyptus forests cover Victoria which have an oil rich foliage which easily burns
-The summer climate often features periods where the temperates are over 40c with low humidity and the state also suffers from period droughts (produces tinder try vegetation and it will only take a spark to set off a major fire.
-Area is also susceptible to huge winds blowing out of Australias interior which can fan and spread fires
-Power cables into rural areas (they can produce the spark that starts a fire)
-rural depopulation (less rural services meaning it is more difficult to fight the fires when they occur)
Responses to the wildfire of black Saturday
-In Oct 2009 it was announced that a new fire hazard system would replace the one existing before the fires.. A new fire system would replace the one existing before the fire.
-Everyday during the fire system the Bureau of meteoroligy would forecast an outlook for the fire danger index by considering the predicted weather inc. temperature, humidity, wind speeds and dry mass of vegetation. On the highest risk days residents would be advised to leave the potentially affected areas
-New building regulations for bushfire- prone areas were fast tracked by the government. As part of an on-going debate, the government also urged by experts to ban housing in the highest risk areas. (the gov. recieved criticism for allowing rebuilding in Maryville which had been 90% destroyed by the event.
Background to the fires (black saturday)
-Late Jan 2009 an exceptional heatwave affected he south-eastern parts of Australia. The configuration of the pressure systems also meant that the hot tropical air was directed towards that area.
-On 7th Feb, hot, north westerly winds of over 100km hit the state causing a low hurricane
-sources: lightening strikes, sparks from falling power cables, sparks from power tools and machinery (in some cases the fires being deliberately started with arson
Earthquakes- Christchurch summary
-22nd Februrary 2011
-There was no deaths after an earthquake of 7.1 on the 4th September 2010.
-Chrustchurch in the Canterbury region of South Island experienced an aftershock from an earthquake that had happened several months earlier. After short-term emergency action the New Zealand government launched a a plan called blueprint to help the city recover from the catastrophe
-Most deaths were caused by the collapse of 2 office blocks.
What were the impacts of the earthquake in Christchurch?
-The old city centre core was made virtually unstable, with 40% of the buildings damaged beyond repair. Some of them including the Canterbury TV building collapsing completely
-185 people were killed and 6,000 injured
-Economic damage was estimated to be over $20 billion. $10 billion was set aside to completely redevelop the city
-Secondary impacts: landslides, particularly around Lyttelton. Further away a large chunk of the Tasman Glacier calved into the sea
-The Rugby world cup was moving to other locations further affecting the future economic influence of the city.
What was the cost of damage in Christchurch equal to?
20% of New Zealands GDP.
Explain a secondary effect of Christchurch
Liquefaction of soil- producing around 400,000 tonnes of silt. This was a massive natural disaster
What were the short term responses to Christchurch's aftershock?
-Army treated the injured, retrieved the dead and provided food, water and electricity,
-Companies sent generators and tankers of water
-Power and water supplies were restored to most house holds within two weeks
-Sewerage systems were so damaged that households put up emergency latrines
-Community laundries and portable shower units were set up.
What was 'the blueprint'?
-run by New Zealand's central government.
-consists of a number of projects lasting 20 years forming a compact CBD.
Describe the features Blueprint comprises of
-A frame for the CBD made up of two strips of open space, east and south, combined with a corridor along the River avon
-anchor projects including a conference centre, hospitals, libraries, and a redeveloped Cathedral square
-a light rail network, walkways and cycle lanes providing links
-precincts for health, arts and entertainment, retail and the justice and emergency centre.
4 years after the earthquake in Christchurch what were the conditions like?
Still signs of rebuilding:
-cranes on the skyline
-landmarks like the cathedral were slowly decaying because its future was undecided
What were the immediate consequences of the blueprint?
-commercial areas developing outside the CBD
-wealth being transferred
-heritage buildings being demolished
What is a tropical storm?
a localized, very intense low-pressure wind system, forming over tropical oceans and with winds of hurricane force.
What are the characteristics of a tropical storm?
-known as a cyclone (India)
-hurricane (North Atlantic)
-typhoon (south-east Asia)
-they can extent 500km in diameter
What are the average winds caused by a tropical storm?
-in excess of 120km/h
What is the eye wall?
-the bank of cloud that rings the central eye
How are oceans important in affecting the distribution of tropical storms?
1.) Oceans-tropical storms derive their moisture (through the transfer process of evaporation) and energy (in the form of latent heat) from the oceans: there are clear links with the water cycle. This explains why tropical storms form and continue to develop over ocean areas and then peter out on reaching land
How are high temperatures important in affecting the distribution of tropical storms?
-a sea surface temperature in excess of 26 degrees is required for formation of tropical storms
-this is why they are formed in low lattitudes during the summer, when temperatures are at their highest
How is atmospheric instability important in affecting the distribution of tropical storms?
-tropical storms are most likely to form in regions of intense atmospheric instability, where warm air is being forced to rise. The ITCZ where two limbs of the Hadley cell converge to form low pressure on the ground, is perfect for spawning ground for Tropical storms.
How is rotation of the earth important in affecting the distribution of tropical storms?
-a certain amount of 'spin' is needed to initiate the rotating motion of a tropical storm
-the influence of the Earths rotation on surface phenomena is called the Coriolis effect. This increases with distance away from the Equator and expplains why tropical storms do not usually form in the region between 5 degrees n and 5 degrees s (close to the equator)
How does uniform wind direction at all levels affect the distribution of tropical storms?
-winds from different directions at altitude prevent a tropical storm from attaining height and intensity. The vertical development is effectively 'sheared off' by the multi directional winds.
How does a tropical storm form?
-warm moist air rises rapidly in its centre to be replaced by air drawn in at the surface
-a central vortex will develop as more and more air is drawn in and rises.
-the very centre of the storm (the eye) is often characterised by a column of dry, sinking air.
-as the air rises, it rapidly cools. This leads to condensation and the formation of towering cumulonimbus clouds.
-sometimes a number of isolated thunderstorms will coalesce to form a single giant storm
-when condensation occurs latent heat is released which effectively powers the storm
-a tropical storm will continue to grow and develop as it is driven by the prevailing winds across the oceans. Only when it reaches land and the supply of energy and moisture is cut off the storm will start to decay, it it moves back over the ocean it will become reinvigorated
What are the hazards associated with tropical storms?
-coastal and river flooding
How do strong winds caused by a tropical storm cause a hazard?
-average speeds in excess of 120km/h, although gusts of over 250 km/h have been recorded at eye wall
-tearing off roofs, breaking windows and damaging communication networks
-debris forms flying missiles
-damaged power lines often lead to widespread electricity cuts and occasionally fires
-debris on the road can cause transport disruption
How do storm surges caused by a tropical storm cause a hazard?
-this is a surge of high water, typically up to 3m in height, this sweeps inland from sea, flooding low-lying areas.
-it is caused by a combination of the intense low atmospheric pressure of the tropical storm together with the powerful, driving surface winds
-Hurricane Katrina recorded a storm surge of 7.6m.
-loss of life
-flood agricultural land with saltwater and debris
-pollute freshwater supplies and destroy housing and infrastructure.
-enhanced coastal erosion can lead to the undermining of buildings and highways
How can coastal and river flooding caused by a tropical storm cause a hazard?
-the warm humid air associated with a tropical storm can generate potential rainfall, often in excess of 200mm in just a few hours
-this can trigger flash flooding (particularly in urban areas where surface water can overwhelm the drainage system due to impermeable surfaces encouraging overland flow.
-as tropical storms move inland it gradually weakens as its moisture supply is cut off
-however there is still a huge quantity of rain falling over a river basin.
How can landslides caused by a tropical storm cause a hazard?
-estimated that 90% of landslides each year are caused by heavy rainfall and many are triggered by tropical storms
-the intense rainfall increases hydrostatic pressure within a slope, which weakens cohesion and triggers slope failure.
-the additional weight of water exacerbates the problem
-some evidence that load release caused by tropical storm-induced landslides may trigger earthquakes in tectonically stressed areas.
Is Haiti a LIC or HIC?
Why did the Haiti earthquake occur?
-it is located where the Caribbean and North American plates slide past one another in an east-west direction.
-it is on a conservative plate margin
When was the Haiti earthquake?
-12th January 2010
What magnitude was the Haiti Earthquake?-what was the equivalent energy?
-the equivalent energy of an atomic bomb was transmitted outwards, violently shaking the whole country
Where was the epicentre located?
-24km south-west of the capital Port-au Prince
What were the primary effects of the Haiti earthquake?
-Much of port-au-prince was flattened in less than 60 seconds
-over 230, 000 lives were lost
-50% of poorly built concrete buildings collapsed inc. key government buildings e.g police headquarters
-over 180,000 homes damaged
-1.5 million people made homeless
-many left Port au Prince (600,000)-most to live with host families
-nearly 5000 schools were damaged
-liquefaction on looser sediments caused building foundations to subside
-infrastructure was severely damaged-the main port subsided and became unstable, roads were cracked and blocked by building debris
What were the secondary effects of the Haiti earthquake?
-strong aftershocks, inc a 6.1 magnitude earthquake on the 20th January
-with the loss of hundreds of civil servants, the Haiti government was crippled.
-with the devastation of the police force and the main prison, the city became lawless
-by the 1st anniversary of the earthquake, cholera had killed over 1500.
-1.5m still homeless
What were the short term responses of the Haiti earthquake?
1.) Rescue efforts- search teams struggled in the dense urban environment. Local people employed by the UNDP helped to find and rescue survivors out of the debris and clear roads
2.)Infrastructure- in Port-au Prince the US military took control of the airport to speed the distribution of aid
3.)Security-16,000 UN troops and police restored law and order, coordinated by a new UN joint operations tasking centre
4.)Food-in absence of local food markets, the UN world food market provided basic food necessities. Farmers given immediate support
5.)Water-UK disaster emergency committee provided bottled water and purification for over 250,000 people
6.)Health- emergency surgeries to provide life saving operations. DEC provided over 100,000 consultations
7.)Shelter-1.5 homeless ppl accommodated over 1100 camps, mostly in the form of tarpaulins. Most of these people were at critical risk from storms and flooding
What were the long term responses of the Haiti earthquake?
1.) Aid- Haiti relief fund manages an $11.5 billion reconstruction package with controls in place to prevent corruption. Reconstruction is due to be completed by 2020
2.)Food- the farming sector was reformed to encourage greater self-sufficiency and less reliance on food imports
3.)Health-a shift in emphasis to focus on follow-up health care, including mental health
4.)Buildings-hospitals, schools and government buildings rebuilt. Local people were employed as construction workers. Slums were demolished and high risk areas such as unstable hillsides avoided when new settlements were built. New homes more safe.
5.)Economy- economic activities moved away from port-au-prince. UN strategy= reduce the effects of uncontrolled urbanisation.
When was the Tohuku earthquake?
11th of March 2011
What were some of the general effects of the Tohuku earthquake?
-shifted the earths axis at least 10cm
-caused visible waves in the Norwegian fords
What was the magnitude of the Tohuku earthquake?
What caused the Tohuku earthquake?
-a large segment of the North American plate was being dragged down by the subducting Pacific plate, this suddenly slipped upwards between 5 and 10 metres. The resulting Sea water displacement caused a tsunami to spread in all directions at hundreds of kilometres per hour
Describe how the tsunami hit the area
-Japans tsunami warning system kicked in, but people along a 3000km stretch of coastline had just minutes to escape. The first wave hit the North-East cost only 30 minutes after the earthquake
-There were 10 waves, each about 1km apart as they reached the shallower coastal water. they reached 10km in height. They surged 10km inland.
Describe the primary effects of the Tohuku earthquake and Tsunami
-ground shaking caused buildings to collapse, some were set ablaze by broken pipes and petrol pipes
-the tsunami swept inland, mainly along the north-east coast, causing devastation to everything in its pat.
-It flooded an area of almost 500 square kilometres
-when the waters receded, whole cities were in ruins
- In Tokyo, skyscrapers had started 'shaking like trees'. But their earthquake proof design meant damage was limited.
-In Minami-Sanriku half the population of 17,000 died-few buildings were left standing
-over 18, 000 died, Japans tsunami warning system saved many lives
Describe the secondary effects of the Tohuku earthquake
-Half a million left homeless. For weeks 150,000 people lived in temporary shelters
-1 million homes left without running water
-shortages of food, water, petrol and medical supplies
-in the two weeks after the earthquake, there were more than 700 aftershocks
-explosions and radiation leaks at the Fukushima Daiichi nuclear power plant shortly after the earthquake spread fear around the world
-the earthquake severed the power supply to the cooling system, the tsunami then destroyed the back-up generators. Workers struggled to prevent a meltdown.
-fears of nuclear disaster caused panic-selling across global stock markets
What were the immediate responses to the Tohuku earthquake?
-in freezing temperatures survivors huddled in shelters and hoarded supplies as rescue workers searched submerged homes
-helicopter crews picked up survivors from rooftops and flooded farmland
-100,000 soldiers were mobilised to establish order
-offers of aid from other countries such as the USA and China
-Uk sent 63 search and rescue specialists.
-exclusion zone set up around the Fukushima plant. Iodine tablets to prevent radiation sickness distributed
-Government ordered shutdown of of nuclear plants due to the Fukushima explosions
-no reports of looting for violence
What were the long term responses to the Tohuku earthquake?
-Japan coped well with the earthquake but the tsunami defences were inadequate against the extraordinary height of the water
-2013-new upgraded tsunami warning system as many had underestimated their personal risk and assumed the tsunami would be smaller like previously experienced
-Japanese gov set up an advisory body called the reconstruction design council to plan long term growth in the Tohuku region. Special zones for reconstruction were designated with relaxed planning regulations to encourage rapid rebuilding and tax incentives to promote new investment in commerce
-before 2011, nuclear power provided 30% of Japans electicity, they relied from 2011 to 2016 on fossil fuels as anti nuclear groups meant it wasn't until 2016 until reactors were issued licenses to restart
-100, 000 residents still had no returned home five years after
-radioactive rubble and refuse was still awaiting permanent disposal. No Japanese prefecture was prepared to accept it.
-the total damages from the earthquake and tsunami are estimated at US$300 billion, making it them most costly natural disaster in history
Describe the tectonic setting of Eyjaffjallajokull
-located on a spreading ridge on the island of Iceland
-convection currents are driving apart the North American plate and the Eurasian plate along a constructive plate boundary creating the mid-atlantic ridge
-the plates are moving apart at a rate of 1cm-5cm per year
-the last eruption of Eyjafjallajokull was in 1823
Describe the nature of the volcanic hazard
-the major problem was the volcanic ash and ash plume that resulted from the eruption
-the ash plume reached 11,000m into the air, high enough to reach the stratosphere
-the ash was very fine grained-33% of the sample is in the range of 10-50mm
-the fine grained ash poses a problem to airplanes as it can affect many systems when it enters the engines and even turn to a gassy substance because of the heat of the jet engine
-the volcano was covered by an eyjafjallajokull glacier on the 14th April when an eruption partly melted a glacier which set off a major flood which prompted authorities to order 700 people to evacuate
-the volcano emitted lava from a long fissure, spewing 1000 degrees hot lava into the air
Describe the vulnerability of Eyjafjallajokull
-there were plenty of warning signs of an eruption as there were over 3,000 recorded earthquakes, the vast majority of these being less than 2 on the Richter scale
-the vent for the volcano is located close to a much more active volcano-katla, which is much more active
-the Icelandic meteorological office monitors earth movements, water conditions and weather issue warnings
-there was 24/7 watch at the IMO where a meteorologist is on call
-the event was tracked and prepared for, and the ash cloud was tracked by satellites
-The European Union has a GDP of $24,400 meaning it can cope
-the EU also has good transport mechanisms e.g the channel tunnel. It is also largely self-sufficienct in food production
-EU's insurance system meant many could claim back losses
Describe the short and long term effects of Eyjafjallajokull
-within Iceland many people were very lucky as the volcano is on the South Coast and the wind carried the ash South East towards Europe
-The people living down wind of the volcano had to wear goggles and facemarks as the ash cloud was so thick
-500 families and their families and their families had to be evacuated from the area around the volcano and many of the roads around the volcano had to be closed
-the ash contaminated local water supplies and farmers were warned not to let their livestock drink from contaminated streams and water sources, as high concentrations of fluoride from the ash mixed with river water can have deadly effects particularly on sheep
-the main impact was internationally however as winds re-distributed the ash that was pumped high into the atmosphere, causing an 8 day flight ban-airlines were losing about £130 million a day
-LEDC's were badly affected- particularly Kenya
-20% of Kenyas economy is based on vegetables and cut flowers, these are perishable but flight ban meant they returned unsold and destroyed, 1 million flower stalks were unsold in the first 2 days
Describe the responses to Eyjafjallajokull
Immediate responses: Evacuation.
Long term responses: Further research into the effects on ash on aircraft. Reconstruction of roads, local flood defences needed reconstructing.
Was Tyohoon Haiyan in an LEDC or MEDC?
When was Typhoon Haiyan?
Describe the general details of Typhoon Haiyan?
-developed in the Pacific Ocean
-one of the strongest Typhoons ever recorded
-responsible for over 6,300 deaths
-phillipines has a population of 98.4 million
-population density distributed unevenly across the islands
-its average GDP per capita is $2,765
-phillipines is part of the pacific ring of fire
What caused Typhoon Haiyan?
-tropical storm is an intense low pressure weather system
-form where ocean waters are warmer than 27 degrees and the depth is at least 60m
-this fuels rapid evaporation and moves energy from the ocean into the atmosphere
-high pressure, cold, dense air is drawn from the upper atmosphere towards the ocean surface which is now at low pressure
-it mixes with the rising warmer air
-begins to create a swirling movement in the air
-trade winds moving towards the tropics speeds up the mixing of warm and cold air.
-the Coriolis effect then spins these depressions away from the equator towards land
-when the storm hits land the storm loses the heat evaporation energy from the ocean and begins to weaken
-wind speeds strongest on the edge of the storm-calm eye.
What were the impacts of Typhoon Haiyan?
-storm surge (because the sea levels rise due to the low atmospheric pressure and strong wind blowing onshore )
-the storm surge of 7.5 metres hit the coast, the main one being Tacloban city where at least 5,800 people were killed.
-due to the low lying ground the surge was able to extend for over 1km inland.
-in Herneni town, the surge was so powerful that bodies were washed out from graves, causing grief among a very religious community
-In Tacloban (a town of 220,000 people) 90% of buildings were destroyed, trees were uprooted or flattened, debris covered the land, electricity supplies were cut and infrastructure and communications destroyed. 5 million saw their homes destroyed or become inhabitable, the airport was unusable.
-essential infrastructure such as the airport, roads, bridges, electricity supplies and communications were destroyed- hampering rescue efforts
-'state of national calamity' was declared
What were the emergency responses to Typhoon Haiyan?
-the emergency response was coordinated buy the world health organisation and the United Nations, also the Red Cross.
-the DEC launched an international fundraising appeal on 12th November via television, radio, internet and social media. This made millions of pounds in weeks
-the destruction of infrastructure particularly the airports slowed relief efforts as much aid remained halted on entry to the country not to be distributed where it was needed
-In mid-November only 20% of those requiring air in Tacloban had received it
-there were attempts to move thousands of people by military aircraft but miscommunication and panic slowed the evacuation
-there were incidents of looting and assault during these early days- exacerbated by the fact that there were only 100 police reported for duty
-Some United Nations police were pulled out for duty for safety reasons
-Charity agencies unable to get to victims
-Taclobans hospitals ran low on supplies and were shut down either because they were low on staff or for safety reasons
-relief trucks were attacked and items stolen inc 33,000 large bags of rice
-curfew was imposed, president declared martial law in some areas
-democratic gov. criticised for its slow response, media said they were poor organised
-5 days after typhoon people still lacked basic things such as water
What are the long term effects of Typhoon Haiyan
-much of work in Tacloban constructed by residents themselves, in jan 2015 this was still continuing.
-thousands signed up to 'cash for work' schemes-people paid by Red Cross to help rebuild the city.
What is the case study for a multi hazardous environment?
Describe the perception, management and vulnerability to hazards in the Philippines
Wealth-The Philippines is a poor country ($8,200) per person, this means they can't invest as heavily in mitigation aa other countries such as Japan. This also means their general perception is fatalism as they don't have the money to dominate, adapt or leave
Population makeup-very young population. 1/3 below the age of 14. Makes the population very vulnerable so adults have to help rather than save themselves in many cases
PAGASA-national meteorological and hydrological services agency of the Philippines aimed at providing protection against national calamities and to insure the safety, well being and economic security of all the people.
CRITISISM OF PAGASA: criticised for lack of modern equipment, forest inaccuracies and slow voluntary response.
Describe typhoons in the Philippines
-ocean temps warm as they absorb sunlight
-phillipines located in a Hadley cell, it therefore experiences a lot of tropical storm activity
-lacks barriers, nothing lies between the 7,000 islands and the sea
-the mangroves that mitigate the impact of the storm surges and stabilise soil have disappeared by almost half since 1918 due to deforestation
-severe flooding and landslides
-destructive typhoon season costs the nation 2% of its GDP
-Typhoon Haiyan- 6,300 lives lost.
-appropriate land use planning
-The Philippines National Red Cross along with foreign Red Cross organisations, has started programmes at community level-encourages people to collaborate in protecting their lives
-Top down approach administrative system, but a bottom-up approach is required to involve the most vulnerable communities.
-there are on average 4-12 typhoons a year
-82% of the Philippino population is catholic- fatalistic approach
-Fillipinos have flocked to low lying risky areas for cheap crammed housing where there is a clear link to poverty and vulnerability to natural disasters.
Describe Volcanoes in the Philippines
-23 active volcanoes (the most active being Mount Mason)
-the pacific plate is subducting underneath the Philippines plate on the East side of the country
-base of 80 miles
-there have been more than 30 eruptions recorded since 1616
-eruption in 1993 caused 79 deaths
-both a blessing and a curse for the farmers living near its slopes for generations
-volcanic ash can kill vegetation immediately after an eruption , but as it seeps into the soil it can also enrich the soil with minerals that sustain future crops- if the ash is thin it will become a great fertiliser
-vegetable prices have already started to soar
-the history of these volcanoes can bring tourists to the area
-Phillipine trials offer day treks.
Describe Hurricane Katrinas development
-tropical storms and hurricanes begin as a 'wave' on the African side of the Atlantic.
-Katrina developed as a tropical depression, approaching Florida
-It made its first landfall at 6:30 pm
-over the whole of the Caribbean Sea surface temperatures were at least 28 degrees.
-air pressure had dropped as low as 918mb
What were the impacts of Hurricane Katrina?
-New Orleans hit. When the levees protecting the city form its adjacent lakes failed the whole area flooded
-Katrina made its third and final landfall near the Louisiana border with 150mph winds meaning the damage done at this stage was immense
-the largest Storm surge was recorded in the USA at 10m
-services were soon at standstill and by the time flooding had occurred, roads were impassable and the environment was highly toxic
-by the 5th of September 363,000 had fled New Orleans and its immediate area
-some states struggled with the amount of evacuees (Texas being the main one)
Katrina was a category 4 storm.
Storm surges reached over 6 metres in height.
New Orleans was one of the worst affected areas because it is below sea level and protected by levees. The defences were unable to cope with the strength of Katrina.
Despite an evacuation order, many of the poorest people remained in the city.
People sought refuge in the Superdome stadium. Conditions were unhygienic, and there was a shortage of food and water. Looting was commonplace throughout the city. Tension was high and many felt vulnerable and unsafe.
1 million people were made homeless and about 1,200 people drowned in the floods.
Oil facilities were damaged and as a result petrol prices rose in the UK and USA.