Unit 1 Flashcards
What is a natural hazard?
a natural hazard is a natural process which could cause death, injury or disruption to humans, or destroy property and possessions.
What is a natural disaster?
a natural disaster is a natural hazard that has actually happened
What are geological hazards?
geological hazards are caused by land and tectonic processes
what are meteorological hazards?
meteorological hazards are caused by weather and climate
example of geological hazards
volcanoes, earthquakes, landslides, avalanches
example of meteorological hazards
tropical storms, other extreme weather such as; heatwaves, cold spells
what is hazard risk
hazard risk is the probability of people being affected by a hazard in a particular area
what are the factors that affect hazard risk?
- vulnerability
- capacity to cope
- nature of natural hazard
what does vulnerability mean as a factor that affects hazard risk?
the more people in an area exposed to natural hazards, the greater the probability they will be affected by a natural hazard.
what does capacity to cope mean as a factor that affects hazard risk?
the better the population can cope with an extreme event, the lower the risk of them being severely affected.
examples of vulnerability
Bangladesh has a high population density on a flood plain, therefore very vulnerable to flooding.
Naples, Italy is at the base of a volcano.
example of capacity to cope
HICs are better able to cope with flooding because they can afford to build flood defences and evacuate people.
nature of natural hazards
- type
- frequency - natural hazards that occur more often may carry a higher risk.
- magnitude - more severe natural hazards tend to have the greatest affects.
why does the type of natural hazard affect the risk?
the risk from some hazards is greater than others.
e.g. Tropical storms can be predicted and monitored, giving people time to evacuate.
Earthquakes happen very suddenly, with no warning, so it’s much harder to protect people.
What does primary effect mean
the primary affect of natural disasters are the immediate impacts caused by the hazard itself
what does secondary effect mean
the secondary effects happen later on, often as a result of the primary effects.
example of primary effects.
- buildings and roads are destroyed by earthquakes, volcanic eruptions or tropical storms.
- people are injured or killed
- crops and water supplies can be damaged or contaminated
- electricity cables, gas pipes, and communication networks can be damaged, cutting off supplies.
example of secondary effects.
- the initial hazard can trigger other hazards e.g. earthquakes can trigger tsunamis.
- aid and emergency vehicles can’t get through because of blocked roads or bridges ( can cause more deaths)
- a shortage of clean water + lack of proper sanitation makes it easier for disease to spread.
- food shortages can occur if crops are damaged
- country’s economy can be weakened
example of immediate responses
- evacuate people (before hazard occurs if possible)
- treat the injured and rescue anyone cut off by damage to roads or bridges.
- recover dead bodies to prevent disease spreading.
- provide temporary supplies of electricity and gas if regular supplies have been damaged.
- provide food, drink and shelter to people without homes.
- foreign governments or charities may send aid workers, supplies or financial donations.
example of long term responses
- repair homes or rehouse people who lost their homes.
- repair or rebuild buildings, roads, railways and bridges.
- reconnect broken electricity, water, gas and communication connections.
- improve forecasting, monitoring and evacuation plans.
- improve building regulations so buildings can withstand similar hazards in the future.
- boost economic recovery
about tectonic plates
- float on the mantle layer.
- plates are made up out of two types of crust:
- continental crust, thicker (30-50km) and less dense.
- oceanic crust, thinner (5-10km) and more dense. - The plates are moving because of convection currents in the mantle.
- The places where plates meet are called plate margins/ boundaries.
what are the three types of plate margins?
- destructive margins
- constructive margins
- conservative margins