What are wildfires? Using the videos. Create your own description of what a wildfire actually is:

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Kristopher Francis
5 years ago
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1 What are wildfires? Using the videos Create your own description of what a wildfire actually is: A wildfire is a raging inferno. It is an unplanned land fire, that rapidly spreads out of control. They are sometimes known as bushfires in Australia and brushfires in the USA.

2 Global distribution of wildfires

t. Fires need heat, fuel (e.g. dried out vegetation) and oxygen to continue to burn.

4 Wildfires occur on every continent except Antarctica. They happen in hot areas where there are extended periods of drought. Fires need heat, fuel (e.g. dried out vegetation) and oxygen to continue to burn. High temperatures can preheat fuels in the fire's path so that they burn more readily. Strong winds can also fan the flames, pushing them towards new fuel sources as well as transferring burning embers and sparks which can start spot-fires.

5 Santa Ana winds fanning wildfires in California Drought and wind combined. Gusts up to 140km/h!

6 How can the Santa Ana winds aid the rapid spread of wildfires in California?

7 Climate graph for Sydney, Australia What does this graph show? What does it tell us about the threat of wildfires?

8 Causes Natural or Human Look at the statements and organise them into: 1. Natural causes 2. Human Causes Lightning is the single biggest natural cause of wildfires. Most fires started by lightning are small and burn out quickly but if the conditions are right then fires started by lightning can spread very rapidly. About 8 million lightning strikes hit the earth every day! Broken bottles can act as a magnifying glass. The pieces of glass magnify the suns rays onto one small area, which can set fire to dry vegetation/leaves or litter Slash and burn is a method farmers use to clear land to grow crops. Sometimes these fires can get out of control and spread Other causes include sparks from train wheels or machinery, military training, household chimneys and barbeques. Accidents such as children playing with matches, campfires that have not been put out properly and discarded cigarettes Spontaneous heating is where material becomes heated to the point at which it catches fire without a spark. This is common where lots of leaves and branches have fallen to the ground and not been cleared away - the flow of air is restricted and often leads to fire. Arson an act of deliberately starting fires. In some areas it can account for up to 30% of wildfires and was a major cause of the Australian wildfires in 2009 Volcanic eruptions give out red hot lava and ash which can start wildfires

9 Causes of wildfires in New South Wales, Australia ( )

10 Which of the coastal areas is more at risk from wildfires? Explain your answer, using the figure and your own knowledge. (5 marks)

11 Peer assessment: Level 1 (Basic) 1-3 marks: Limited elaboration from the figure. Limited development of ideas. Simple statements. E.g. there are many tourists/campsites/holiday village/picnic sites. More roads/railways/footpaths or people can easily access area and start fires or vice versa for area A. Wind is off the land or wind is dry or vice-versa for area A. Many trees or much fuel for the fire or vice versa for area A. High summer temperatures or vice versa for area A. Level 2 (Clear) 4-5 marks: Clear explanation of risks with development of ideas. E.g. there are many tourists/campsites/holiday village/picnic sites which increase the chances of wildfires as people start campfires which ignite dry vegetation and get out of control or discard cigarettes which ignite vegetation. More roads/railways/footpaths so people can easily access area and start fires (as above) or sparks from engines/rail tracks can start fires. Wind is off the land and will be dry as no moisture is picked up as it does not cross any sea areas. Many trees to fuel the fire which will be dry due to the high summer temperatures or vice versa for area A.

12 Do you think that natural or human causes of wildfires are more significant? Human causes of wildfires will be much more important in? Densely populated areas

When I think of wildfires, I think of

When I think of wildfires, I think of Santa Ana Winds The Santa Ana winds are strong, extremely dry offshore winds that affect coastal Southern California and northern Baja California in autumn and winter.