What is a natural hazard

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What are natural hazards?

What is a natural hazard?

A natural hazard = a natural event that poses a threat to humans and/or property.

The three deadliest natural hazards are:

Floods

Earthquakes

Droughts

What are the different types of natural hazard?

Natural hazards are classified according to the process that caused them:

Geological = caused by land (landslides, avalanches) and tectonic (volcanoes, earthquakes) processes.

Meteorological = caused by weather and climate (tropical storms, extreme weather, climate change).

Geomorphological = caused by rivers (floods).

Biological (forest fires).

What is ‘hazard risk?’

Hazard risk = the probability that a natural hazard may take place.

What factors affect risk?

Urbanisation:

Over 50% of the world’s population live in cities.

Some of the world’s largest cities and most densely populated areas (Tokyo, Istanbul, Los Angeles) are at risk from earthquakes and tropical cyclones.

The 2010 Haiti earthquake destroyed much of the capital killing 230,000 people.

Poverty:

Poverty forces people to live in high-risk areas in cities such as Lima in Peru or Caracas in Venezuela.

In these high-risk areas, people build on slopes prone to floods and landslides.

Climate change:

In a warmer world, the atmosphere will have more energy leading to more intense storms and hurricanes.

Climate change may cause parts of the world to become wetter, increasing the risk of floods.

Other areas may become drier and so more prone to drought and famines.

Farming:

Rivers flood depositing fertile silt on their floodplains, which is excellent for farming. But when people chose to live there they put themselves at risk.

In low-lying countries, many people live on floodplains, like the River Ganges in Bangladesh.

What are primary and secondary effects?

Primary effects = effects which occur at the time of the hazard (destruction of houses caused by a landslide).

Secondary effects = effects which occur as a result of the primary effects (homelessness).

All natural hazards have both primary and secondary effects.

What are natural hazards?

What is a natural hazard?

A natural hazard = a natural event that poses a threat to humans and/or property.

The three deadliest natural hazards are:

Floods

Earthquakes

Droughts

What are the different types of natural hazard?

Natural hazards are classified according to the process that caused them:

Geological = caused by land (landslides, avalanches) and tectonic (volcanoes, earthquakes) processes.

Meteorological = caused by weather and climate (tropical storms, extreme weather, climate change).

Geomorphological = caused by rivers (floods).

Biological (forest fires).

What is ‘hazard risk?’

Hazard risk = the probability that a natural hazard may take place.

What factors affect risk?

Urbanisation:

Over 50% of the world’s population live in cities.

Some of the world’s largest cities and most densely populated areas (Tokyo, Istanbul, Los Angeles) are at risk from earthquakes and tropical cyclones.

The 2010 Haiti earthquake destroyed much of the capital killing 230,000 people.

Poverty:

Poverty forces people to live in high-risk areas in cities such as Lima in Peru or Caracas in Venezuela.

In these high-risk areas, people build on slopes prone to floods and landslides.

Climate change:

In a warmer world, the atmosphere will have more energy leading to more intense storms and hurricanes.

Climate change may cause parts of the world to become wetter, increasing the risk of floods.

Other areas may become drier and so more prone to drought and famines.

Farming:

Rivers flood depositing fertile silt on their floodplains, which is excellent for farming. But when people chose to live there they put themselves at risk.

In low-lying countries, many people live on floodplains, like the River Ganges in Bangladesh.

What are primary and secondary effects?

Primary effects = effects which occur at the time of the hazard (destruction of houses caused by a landslide).

Secondary effects = effects which occur as a result of the primary effects (homelessness).

All natural hazards have both primary and secondary effects.