Nature Of Wildfires

Question 1

What is a wildfire (2)

Answer 1

Uncontrolled rural fire
Destroy forests, grasslands and other areas of vegetation

Question 2

Types of fires (3)

Answer 2

Ground
Surface
Crown

Question 3

What is a ground fire (4)

Answer 3

Slow smouldering fire
Burns organic matter in the soil, such peat
Spreads slowly at fairly low temperatures for long periods of time
There may be no flame

Question 4

What is a surface fire (5)

Answer 4

Burning of leaf litter and low-lying vegetation
The most common type of fire
Can be low or high intensity
Cools quickly
Relatively easy to control

Question 5

What is ladder effect

Answer 5

Process where fires may spread from the ground to the tree canopy

Question 6

Conditions needed for fire (3)

Answer 6

A ready supply of fuel – dry vegetation
An ignition source – can be natural or human
Favourable climatic or weather condition

Question 7

What effects the behaviour of wildfires (4)

Answer 7

Type of vegetation (fuel)
Local climatic conditions
Local terrain or topography – relief and landscape = travel faster uphill and the steeper the slope the faster they travel

Question 8

What normally happens not El Niño (3++)

Answer 8

In the south Pacific trade winds blow from east to west
Piles warm surface water up against southeast Asia and eastern Australia
As the warm water leaves the east cold water = air rises in the west where the ocean is warmer =creating low pressure + rain
Air sinks in the cooler east = high pressure + drought conditions in the east

Question 9

What is El Niño (4)

Answer 9

Cyclical climate event:
Occur on an average every six to eight years
Westerly trade winds weaken so less warm water is transferred westwards which reduces the pressure difference between west and east
The temperature of the eastern Pacific Ocean rises creating warmer than average weather in South America
Rainfall follows the warmer weather towards South America and away from southeast Asia and eastern Australia = causing drier conditions = risk of wildfires

Question 10

In general El Niño is what (3)

Answer 10

Affects global climate
Results in a general rise in temperatures
Some regions experiencing wetter weather and some experiencing drier conditions

Question 11

What is a crown fire (4)

Answer 11

Moves rapidly through the canopy (top layer of vegetation)
Has a dramatic effect on forested areas
The hottest type of fire
Very difficult to contain