Hazards Flashcards
What is a hazard?
- An event that threatens the well-being of people and their property
What are the four categories of hazards?
- Biological
- Tectonic
- Atmospheric
- Geomorphic
What is risk?
- The possibility of suffering harm or loss
What ia natural disaster?
- A hazard produced by enviornmental processes, e.g. storms, floods, earthquakes and volcanic eruptions.
What are the seven conditions needed to produce a tropical cyclone?
- Surface temperature 26C
- Warm water to depth of 70m
- Disturabnce in lower atmospheric circulation
- Large enough coriolis force to produce certain patterns of wind
- Unstable air with high humidity
- Rapid outflow of air at high level and inflow of air at low level
How does a tropical storm form?
- Start when strong clusters of thunderstorms dift over warm ocean waters
- The very warm air fromt he strom and the ocean surface combine and begin rising creating low pressure at the surface
- Trade winds blowing in opposite directions cause the strom to start spinning and rising warm air causes pressure to decrease hgih altitudes
- Air rises faster and faster to fill this low pressure, in turn drawing more air off the sea and sucking cooler, drier air downwards
- As the stotm moves over the ocean it picks up more moist, warm air. Wind speeds increase as more air is sucked into the low pressure centre.
Where are tropical storms found?
- Between 10 to 30 degrees Northa nd South of equator
What are storm surges?
- Combination of low pressure near the centre and strong onshore winds, which results in large increases in sea levels.
When are tropical storms classified as hurricanes?
- When their wind speeds are greater than 118 km/hr
When do tropical storms dissipate rapidly?
- When they moe over cold water or over a large mass of land as they derive their energy from warm water and latent heat of condensation.
What are the three distinct elements of a hurricane?
- Eye - region usually 30-60km in diamtere found in center of hurrican where skies are clear
- Eye wall - wall of cloud an thunderstomrs surround eye
- Spiral rainbands - bands of thunderstorms that spiral around the hurricane
What are synoptic weather charts?
- Used to show a pressure map of depression or tropical storm
What is the saffir-simpson scale?
- A scale made up of five categories distinguished by wind that is sustained and measured by its present intensity
How does naming hurricane helps?
- improves communication, especially exhcaning detailed storm information between weather stations coastal bases and ships.
What is mitigation?
- The action of reducing the severity of a hazard event
What are some methods of mitigation of a hazard?
- Aircrafts
- Satellites
- Radars
- Buoys and floats
How are aircrafts used to mitigate a tropical storm?
- Used to measure a cross section of a hurricane by ejectin onboard radards and dropwindsodes from the plane’s belly
How are satellites used to mitigate a tropical storm?
- Used to view large weather systems
- Display cloud formation
- An imager acts like a camera and gathers infromation on cloud movement and patterns
How are radars used to mitigate a tropical storm?
- Measure reflected sound waves
- Reads precipiation intensity and movement and wind wind data
How are buoys and floats used to mitigate a tropical storm?
- Transmit data about air, wind temprature, wave height and wind direction and speed
How do meterolists help to mitigate hazard events?
- Meterologists use specialised computer forcecast models to track and predict progress of hruricane
- Warm people in predicated path
- Asseses the level of damage that will impact an area
What can be done to prepare before a hazard event?
- Educate people on what to do when hurricane approaches, can be done thorugh lealets or broadcasting
- Low coast loans to residents so that they can strength properties with storm shutters
- Hurrican shelters set up
- Build levees to reduce the impact of storm surges on the coastline
- Build better roads so evacuation is more effective and rescue can reach quicker to affected areas
- Sea walls to protect densly populated areas
- Raise banks of rivers
What can be done in the short term to mitigate the consequences foa hurricane?
- Relief camps to provide food, water and shetler
- Emergency serves and army take action
- Use lifting gear to clear away rubble
- Restoring basic services
- Providing medical help and counselling victims
What is appraisal?
- Examination of what happended after teh event with many questions asked and answered
What can be done in a longer term to mitigate the conseuences of a hurricane?
- Government providing funding and guidance
- FEMA refer to long term recovery as the “need to re-estavblish a healthy, functioning community that will sustain itself over time”
- Government building a long term community recovery program
- Banks set up laons with low intrest rates so people can rebuild their homes or businesses
- Government finances small businesses to start up again
- Securing aid from other countries and NGOs
When did Katrina happen?
- 25th August 2005
When did Nargis happen?
- 27th April 2008
What is the GNI of the US?
- $48,586
What is the GNI of Burma?
- £1900
What were the social effects of Katrina?
- 1,833 people died
- 1 million people moved away from central Gulf coast
- Population decline of Lousina was 4.87%
- Severe physiological stress - 45,000 children suffered mental health problems by 2007
What were the social effects of Nargis?
- 138,000 people died
- Labutta lost 80,000 people
What were the economic effects of Katrina?
- Impact >$180 million
- Oil spills - 26 million litres
- Petrol and energy prices soared
What were the economic effects of Nargis?
- Impact = $10 billion
- Major lost in harvest
- Loss of income
What were the enviornmental impacts of Katrina?
- 8.5m storm surges
- 80% of New Orleans flooded
- Levees only designedfor category 3 hurricanes.
- Mississippi flooded 6-12 miles inland
- 217sq miles of land lost to water
What were the enviornmental effects of Nargis?
- 7.6m storm surges
- Huge amount of rice and crop fields flooded, especially in Irrawaddy Delta
- Impacted 65% of Burma’s paddies
- Flooded inland estimated 40-50km
- 95% of buildings collapsed on the delta
- 1,163 temples lost
What were the responses to Katrina?
- Bush signed $10.5 billion relief package
- Eu helped
- Blankets, medial, water, 50,00 food rations
- $854 million foreign aid, only $40 million spent to help
- National disgrace becasue of slow response
What were the responses to Nargis?
- Poor response by miltary and government refused foreing aid
- Asked UN for help 7 days after the disaster
- Only let South East Asia Nations to deliver aid
- 3 weeks until international aid workes allowed in.
