Please enable JavaScript.

Coggle requires JavaScript to display documents.

hazards - Coggle Diagram

- - - - once vegetation has dried out, the fire depends largely on the wind
      - largest fires occur in dry windy weather with low humidity
      - winds drives the fire further which ignites more vegetation - easily spread
  - - - with natural fires, lightning is the most common source of the fire
      - most often, they are a result of human intervention - especially in areas of human settlement
        
        usually started by discarded cigarettes, falling power lines, children playing with matches, campfires or controlled burning (agricultural)
        
        sometimes there has been evidence that devastating fires have been a result of arson
        
        danger of fires have increased in areas of the us and australia as a result of allowing tourists in wild areas
    - - fuel has to be dry and of sufficient quantity
      - dry climates can increase the frequency of fires - during droughts, vegetation has the opportunity to accumulate and dry out
      - climate also affects the type of vegetation that is grown
  - - - sustains and carries flames
      - combustable materials - vegetation (trees, shrubs, grass etc.)
    - - starts and sustains combustion
      - air supply increased by windy conditions
    - - help to spark the wildfire
      - brings fuel to the ideal temperature for the fire to ignite
      - these include lightning, cigarettes, matches, campfires etc.
  - - - loss of life
      - short and long-term health problems
      - loss of non-insurable possessions
    - - loss of crops, timber and livestock
      - release of toxic gas and particulates
      - destroyed habitats
      - damage to soil structure and nutrient content
    - - loss of property
      - damaged businesses
    - - evacuation
        
        many people are forced to relocate their lives due to the extensive damage
        
        many are not allowed to go back for a long period of time
      - increased flood risk
        
        loss of vegetation leads to less interception - when it rains there will be an increase in overland flow and therefore flooding
  - - - modelling - studying computer simulations of fire behaviour to prepare for any fire fighting methods
        
        allows comprehension and prediction of fire behaviour
      - education - make people in at risk areas aware of the impacts of wildfires and what to do in the situation
      - warning systems
        
        establishing outlook towers and air patrols
        
        tourist areas should have warning signs and notice boards making people aware that they are in an at risk area
      - community action - community helps people create fire safety strategies
      - being well insured - especially in wealthier countries, property such as housing is insured against fire damage to lessen economic impacts
    - - managing vegetation - controlled burning which will reduce the amount of dry vegetation (fuel)
      - managing built environment - increasing the gap between houses and vegetation so the fire cannot jump as easily
        
        using more fire resistant materials - e.g. stone and brick rather than wood, spark arrestors on chimneys (device that prevents emission of flammable debris)
  - - - series of bushfires in the victoria region in australia - the country's worst bushfire disaster
      - 40°c heatwave in the months leading up to the bushfires - provided dry fuel (vegetation) which lead to widespread fires
      - configuration of pressure system meant that hot air was directed towards the area
      - 7th feb - hot north-westerly winds of over 100km/h hit causing low humidity
      - fires started in different places and had different sources
        
        this included lightning strikes, sparks from falling cables, sparks from power machinery/tools and even arson
    - - 173 fatalities
      - 3,500 properties lost - 2,000 homes and 1,500 farm buildings
      - 7,000 people displaced
      - 450,000 ha of land lost
      - loss of livestock (12,000 head including cattle and sheep)
      - large areas of national parks and the wildlife there were burnt
        
        RSPCA determined that around 1 million animals were killed
      - over 60,000 residents had electrical disruptions
      - looting broke out in empty properties
      - estimated to cost A$4.4 billion
        
        total cost of insurance claims came to A$1.2 billion
    - - long-term
        
        october 2009 - new fire system to replace the one in place before the fire
        
        everyday during fire season, bureau of meteorology would forecast an outlook for the Fire Danger Index - considers predicted weather including temps, humidity, wind speed and dryness of vegetation
        
        on high risk days, people would be advised to evacuate
        
        new-building regulations fast tracked by the government
        
        experts urged the government to ban housing in the highest risk areas
      - short term
        
        firefighters creating breaks in the fire to stop spread
        
        local evacuations
        
        fire warnings released via the media
        
        short term fire bans
- - - - shallow focus (0-70km) - cause the most severe damage, count for 75% of earthquake energy released
      - intermediate focus (70-300km)
      - deep focus (300-700km)
    - - at conservative plate margins, the boundary is shown in a fault line - e.g. san andreas fault, california
  - - - ground shaking
      - building collapse
      - ground rupture - major risk for large engineered structures like dams
    - - soil liquefaction - highly saturated soils lose structure and start to behave like a fluid
        
        can lead to buildings sinking
      - landslies/avalanches - slope failure
      - tsunamis - giant sea waves generated by the uplift of the seabed (shallow focus underwater earthquakes)
      - fires - broken gas pipes and collapsed electricity transmission systems can cause fires
      - effects on people and the environment
        
        collapsing buildings
        
        roads destroyed - means aid cannot get in
        
        communication lines
        
        destruction of services like water and sanitation
        
        flooding
        
        outbreak of disease
        
        food shortages
        
        disruption to local economy - businesses destroyed and tourist revenue damages
  - - - aid - providing medical centres, food and water, accessible sanitation, temporary shelter
      - search and rescue
      - issued warnings
      - body recovery
    - - rebuilding and repairing property and damaged roads
      - improving building regulations - possibly inputting earthquake proof buildings (swaying, steel frames, shock absorbers etc.)
      - restoring utilities - i.e. water, sanitation, electricity, gas
      - resettling displaced people
      - installing monitoring systems
  - - - identify at risk regions - plate boundaries
      - attempts to predict events through monitoring groundwater levels, unusual animal behaviour and release of radon gas
      - fault lines monitored
        
        sometimes can predict where the next earthquake may occur - existence of a 'seismic gap' along the san andreas fault
    - - preparing individuals for unexpected earthquakes
      - in the usa, FEMA programme set to meet certain aims:
        
        promote understanding of earthquakes and effects
        
        to better identify earthquake risk
        
        to improve building design and construction techniques
        
        encourage use of earthquake-safe policies and planning practices
    - - building a tsunami wall to protect coastal areas from the waves - e.g. Tohoku
      - regions at high risk to tsunamis have warning systems to warn population before it reaches land
  - - - nature
        
        magnitude 7 on richter scale
        
        fault line runs directly through port-au-prince (capital) - puerto rico trench
        
        haiti - poorest country in the western hemisphere
        
        many aftershocks occurred after the main event
      - impacts
        
        social
        
        death toll reached over 310,000
        
        over 2 million made homeless
        
        major damage to communication lines
        
        education system collapsed - 1,300 schools destroyed and the university buildings damaged
        
        looting broke out and in some areas sporadic violence
        
        collapse of water supply and sanitation lead to the outbreak of disease - 8,000 people died in a cholera outbreak
        
        economic
        
        all hospitals in port-au-prince completely destroyed
        
        vital infrastructure severely damaged - major roads blocked by debris
        
        250,000 residences and 30,000 commercial properties destroyed/needed to be demolished
        
        overall cost was around $8 billion
        
        environmental
        
        sea levels in some local areas changed - parts of the land sinking into the sea
        
        roads had fault lines and cracks
      - responses
        
        short term
        
        us government deployed 3,500 soldiers to help
        
        uk search and rescue team sent to help using dogs
        
        morgues were overwhelmed and mass graves had to be set up
        
        delays in receiving aid lead to an outbreak of looting and violence
        
        long term
        
        recovery took over 3 years
        
        in 2014, over 170,000 still in 'displacement camps'
        
        23% children not in primary school by 2014
        
        the eu gave $330 million
        
        6 months after the event, 98% of rubble still remained
        
        number of people in relief camps reached 1.6 million
        
        $1.1 billion raised by over 20 major charities - however only 2% of the money was released
        
        usa took control of aid distribution while doctors without borders assisted with medical care
    - - nature
        
        7.9 earthquake
        
        60km nw from kathmandu - nepal's capital city
        
        convergent (destructive) boundary - indian and eurasian plates
      - impacts
        
        social
        
        over 8,600 dead and 19,000 injured
        
        people chose to sleep outside to avoid the impacts of aftershocks
        
        entire villages flattened and hundreds of people made homeless
        
        17 people killed by an avalanche on everest base camp
        
        economic
        
        economic losses between 9-50% of the GDP
        
        environmental
        
        harvests reduced and/or lost that season
        
        landslides occurred on steep valleys
      - responses
        
        short term
        
        india and china provided $1 billion in international aid
        
        over 100 search and rescue responders provided by the uk
        
        'crisis mapping' GIS tool used to coordinate the response
        
        aid workers from the red cross came to help with water, sanitation, food supplies etc.
        
        temporary shelter provided - 'tent city' in kathmandu
        
        long term
        
        $3 million grant from the asian development bank for immediate relief efforts
        
        up to $200 million for first phase of rehabilitation
        
        total of £73 million donated by the uk - both public and government
- - - - tropics - between the tropics of cancer and capricorn
    - - +27°c sea temps
      - ocean depth of 70km - moisture provides latent heat (rising air causes moisture to be released by condensation which drives the whole system
      - at least 5° north or south of the equator
        
        this is so the coriolis force can bring winds to maximum rotation
        
        coriolis force is weak at the equator which prevents circular air flow
      - convergence of air occurring at a low level - near the centre of the low-pressure zone
      - rapid outflow of air in the upper atmospheric circulation
    - - usually around 30-50km wide
      - an area of calm - light winds and no rain
      - contains descending air
      - wind speeds are around 160km/h
  - - - northern hemisphere - air goes right
      - southern hemisphere - air goes left
  - - - occur between 5° and 20° north/south of the equator (this is because coriolis effect cannot take place at the equator)
      - tend to move west after formation
      - hurricanes - caribbean sea/gulf of mexico (11%),, western side of central america (17%)
      - cyclones - arabian sea/bay of bengal (8%)
      - typhoons - southeast asia (major area of such storms 1/3 of all major storms occur here)
      - off the southeast coast of africa and madagascar (11%)
      - willy-willies (NW) - north east and north west of australia
    - - measured on the saffir-simpson scale
        
        5 point scale based on central pressure, wind speed, storm surge and damage potential
        
        e.g. five scale event may have these characteristics:
        
        central pressure: 920mb or below
        
        wind speed: +250km/h
        
        storm surge: +5.5m
        
        damage potential: complete roof failure, damage to lower floors of all structures, evacuation of residential buildings on low ground
      - average lifespan: 7-14 days
      - once reaching land, storm starts to weaken - as there is no longer moist air to draw upon
      - around 80-100 storms develop annually - about 80% of these become tropical revolving storms
  - - - physical
        
        intensity of the storm; 1-5 (saffir-simpson scale)
        
        speed of movement
        
        distance from the sea
        
        physical geography of the area
      - human
        
        community preparedness
        
        links to frequency of events (the more frequent the more prepared??)
        
        development of the area at risk
        
        warnings and community response
    - - winds:
        
        strong winds (150-250km/h) can cause structural damage to buildings
        
        roads and bridges can collapse
        
        bring down electricity lines
        
        damage agricultural areas
        
        debris is thrown around and pose threat to people's lives
      - heavy rainfall:
        
        can exceed 200-300mm and can cause excessive flooding
        
        can cause landslides and mudflows
        
        high relief near coastal area can cause rainfall to increase to 500mm/day
      - storm surges:
        
        rise in sea level as a result of tropical storms
        
        wind-driven waves pile up and ocean heaves upwards as a result of the low atmospheric pressure
        
        can have a devastating effect on low-lying coastal areas,, especially in river deltas where flooding can reach far inland
        
        storm surges is the main cause of death in such events
        
        can cause severe long-term damage to agricultural areas (soil contaminated by the sea water)
    - - people injured or killed by debris
      - drowning
      - destroyed/damaged buildings
      - electric supplies cut off as a result of destroyed power lines
      - flooding causes sewage to be released
      - water supplies contaminated
    - - people left homeless
      - lack of clean water and sanitation - can further lead to the outbreak of diseases
      - road and rail networks blocked by debris - aid takes longer/cannot reach the people who need it the most
      - unemployment as a result of the destroyed businesses
      - shortage of food if agricultural areas are damaged/crops destroyed
    - - businesses destroyed/severely damaged
      - looting can occur if people do not have access to things like food or water
      - destruction of infrastructure can make trade links difficult (long-term)
  - - - evacuation prior to the storm event
      - search and rescue
      - temporary shelter - also provides medical care, food and water
      - food and water provided
      - recovery of dead bodies
      - digital maps updated by satellite images to support rescue teams
      - aid provided by governments and NGOs - e.g. the red cross, oxfam
    - - reparing and rebuilding property/infrastructure
      - rehousing people
      - improving forecasting and warning systems
      - provide grants and aid to people to help rebuild houses
      - improve building regulations - better withstanding future storms
      - offering incentives such as tax breaks to help economic recovery
- - - - high population density - many people migrated to the city of tacloban to look for employment
      - overcrowded residential areas - shanty towns full of poorly built houses, unlikely to withstand the effects of a storm
        
        these are built on low-lying land close to the sea - makes people vulnerable to storm surges and flooding
      - others live on steep hills
        
        vulnerable to heavy rainfall and landslides
      - PAGASA, the Philippines' meteorological agency issued warnings two days before it was set to hit - led to the evacuation of 750,000 people
    - - environmental
        
        low-lying areas completely washed away
        
        flooding and landslides
        
        destroyed 33 million coconut trees - main source of living
        
        hit the philippines, vietnam and china
        
        around 71,000 hectares of farmland affected
        
        thousands of trees were uplifted - released co2 and animals lost habitats
        
        flooding caused an oil spill which destroyed mangrove ecosystems
      - social
        
        6,000 fatalities
        
        +1,000 people missing
        
        bodies still being discovered in 2014 - death toll almost reached 10,000
        
        2 million people left homeless and 6 million displaced - 20,000 fleeing to manila
        
        communication cut off as power systems destroyed
        
        the flooding and landslides blocked roads which made it difficult for aid to be given, so it all had to arrive by air
        
        more than 14 million people affected in total
        
        outbreaks of disease in the temporary shelter
        
        widespread looting took place in the city of tacloban
      - economic
        
        widespread building and infrastructure damage
        
        ‘I do not believe there is a single structure that is not destroyed or severely damaged' - american army officer
        
        destroyed 1.1 million houses
        
        overall damage totalled to about $5.8 billion
        
        6 million workers lost their source of income
        
        tacloban airport completely destroyed
        
        30,000 fishing boats destroyed - businesses took a huge hit
        
        rice, corn and sugar-producing areas were severely damaged - impacted international trade as well as local farmers' income
        
        90% of tacloban destroyed
      - political
        
        many local governments collapsed due to the fact that many officials died in the storm - tacloban government only had 70 workers
        
        the philippines declared a 'state of national calamity'
        
        president aquino under pressure to distribute aid (food, water, shelter) quicker
    - - strongest recorded tropical storm
      - determined to be a category 5 storm (super-typhoon) on the 6th of november - wind speeds reached 230km/h
      - reached tacloban on the 7th of november 2013 - wind speeds up to 315 km/h
      - heavy rainfall - reached up to 300mm which fell in under 12 hours
      - huge storm surges which measured up to 6m - was the main cause of death and damage for the event
    - - immediate responses
        
        800,000 people evacuated after tv warning from the president
        
        many took refuge in a stadium in tacloban - however it was flooded and many people died
        
        government provided essential equipment and medical supplies
        
        curfew introduced 2 days after typhoon to lessen looting
        
        main airport reopened after 3 days - allowed for overseas aid to reach people
        
        1 million food packs and 250,000 litres of water distributed within 2 weeks
        
        $1.5 billion in foreign aid pledged - 33 countries promised to help
        
        HOWEVER - many did not receive the aid that they needed due to the blockage of roads and the destruction of the airport
        
        the uk deployed 2 navy ships containing 200,000 tonnes of aid
        
        power restored in some regions after a week
      - long-term responses
        
        build back better was the government's main long-term response
        
        intended to improve and upgrade damaged buildings
        
        set up a no-build zone along the coast of eastern visayas
        
        new storm surge warning developed
        
        mangroves replanted to absorb future storm surges
  - - - first developed on the 23rd of august (over the bahamas) and declared katrina the next day
      - developed in the atlantic ocean
      - upgraded to category 4 on the 28th and became clear it was to pass mississippi and louisiana
      - became category 5 hurricane - sustained wind speeds of up to 280km/h, eventually reached about 345km/h
      - 5th most intense atlantic basin hurricane on record
    - - risk assessments already conducted - national geographic ran an article less than 12 months before the storm
      - new orleans lies on the gulf coast of the usa - area that is expected to experience many tropical storms during certain times of the year
      - since 1924, 33 hurricanes reaching category 5 - katrina was the first to hit new orleans
      - original flood control systems resulted in soil shrinkage - over 50% of the land was below sea level
      - levee systems built to protect the city not built to modern standards - replacement work only 60-90% finished
      - most of the population managed to leave in private cars or school buses - those left behind took refuge in Louisiana Superdome
        
        around 150,000 remained - mostly by choice
    - - immediate
        
        prior to the storm
        
        advanced warnings on the 26th august
        
        president bush declared state of national emergency (27th august)
        
        basic food and water supplies delivered to support 150,000 for 3 days
        
        mayor of new orleans called for evacuation the day before the hurricane hit land
        
        government help rapidly assigned
        
        us senate assigned $10.5 billion in aid (first week of sept)
        
        another $51.8 billion assigned from federal funds
        
        the public donated $1.8 billion to the red cross
      - long term
        
        220 miles of flood defences reinstalled and levees strengthened
        
        congress supplied $16.7 billion to rebuild
        
        DOC invested $1.3 million to improve public broadcasting services
        
        red cross helped 6,000 people with medical aid and over 800,000 with psychological aid
    - - social
        
        over 1 million people displaced
        
        one month after the storm, refugees were registered in 50 states
        
        5 million people left without power - took 2 months for everyone to be reconnected
        
        1,242 fatalities - far below initial estimates
        
        few people died in the aftermath as the usa had already had infrastructure put in place to provide sanitation, clean water and medical care
        
        looters hit abandoned homes and shops in new orleans
      - environmental
        
        flood defenses breached by storm surge and 80% of new orleans was deluged by flood water
      - economic
        
        110,000/180,000 houses in new orleans flooded and 55,000 too badly damaged to repair
        
        power and water supplies disrupted
        
        french quarter of new orleans severely damaged - huge devastations for tourism revenue
        
        oil installations in gulf area damaged
        
        damage estimated to be around $200 billion
        
        many businesses affected
      - political
        
        president bush heavily critised about the speed of response in new orleans
        
        critised about how long it took him to visit the area after the storm hit
        
        new orleans is a city with a predominantly african american population - there were allegations that if it were a white area affected, the response would be much quicker