Wildfires

Question 1

What are wildfires?

Answer 1

• a wildfire or a bush fire is any rural fire which is uncontrolled and spreading

Question 2

Where do we see wildfires?

Answer 2

• areas which have a large amount of people living there
• most continents, lots in South America
• near the equator
• none out at sea
• areas which have lots of forests
• none in dessert areas (as there is no vegetation)

Question 3

Why can wildfires be found practically anywhere?

Answer 3

• they don’t require specific characteristics e.g. plate boundaries or above a certain temperature

Question 4

What are the 3 things you need for a wildfire (triangle)?

Answer 4

A HEAT source, OXGYEN supply, FUEL to burn

Question 5

What are some examples of heat sources?

Answer 5

• battery in electronics
• lightening
• smoke
• BBQ/camp fires
• volcanic activity
• exhausts from cars

Question 6

What are types of fuel?

Answer 6

• grass
• wood
• houses
• diesel/petrol
• trees
• dry vegetation
• fertiliser
• roots

Question 7

What are the heat transfer processes to creating wildfires?

Answer 7

• radiation is the transfer of fire to an adjacent object by causing it to combust without touching it. Convection is similar to radiation but in an upward direction. Finally, conduction occurs when flames are in direct contact with another fuel source

Question 8

What are the 3 things that affect wildfire behaviour?

Answer 8

1) fuel
2) topography
3) weather

Question 9

How does weather affect wildfire behaviour?

Answer 9

• as you cant control it
• the sun (heat) dries out land quickly
• wind provides more oxygen and takes the moisture out of the ground/plants

Question 10

How does the topography of the land affect wildfire behaviour?

Answer 10

• fire moves more quickly up hill than on flat land
• hot things rise
• we should build houses/infrastructure at the bottom of valleys

Question 11

How does fuel affect wildfire behaviour?

Answer 11

• highly flammable
• can be built with
• remove any ladder fuels (helping fire to not rise up as quickly)

Question 12

Why does removing ladder fuels from your property reduce your risk of wildfires?

Answer 12

Helps fire not to travel higher than the ground as they will then spread quicker, so removing things e.g. a ladder or plant, can reduce your risk

Question 13

Why is it misleading to say that wildfires are natural phenomenons?

Answer 13

• as most wildfire are caused by human activity. For example, debris burning has caused 3940 fires within a 90 year period. Arson= 9517 within this time period

Question 14

How do seasons lead to conditions being favourable for wildfires?

Answer 14

In the summer its hotter and this heat leads to vegetation drying out, taking all water/moisture out of soil/plants which leads to more wildfires. Windy time periods also help them to spread quicker.

Question 15

In what way could rural land use worsen or prevent wildfires?

Answer 15

Worsen: having eucalyptus crops, as they use the nutrients released from the ash as well as making use of additional light provided by surrounding vegetation
Prevent: succulent plants e.g. cacti, as they store their own water and are harder to burn

Question 16

Suggest why wildfire occurrence in certain areas may appear to be cyclical?

Answer 16

As warmer water moves eastward and turns the colder water hot which then leads to wildfires as this water gets evaporated and the heat in the atmosphere dries out the land. Because of this shift they are only cyclical occurrence