Wildfires

Question 1

Define “wildfire”?

Answer 1

UNCONTROLLED, RURAL fires that clear large areas of land.

Question 2

Define Crown Fire?

Answer 2

Fire that spreads across tree canopies and affects forested areas.

Question 3

Define Surface Fire?

Answer 3

Fire that burns on the undergrowth surface.

Question 4

Define Ground Fire?

Answer 4

The ground burns beneath the surface/ peat.

Question 5

What is the “ladder effect”?

Answer 5

When the fire spreads upwards from the forest floor to the canopy

Question 6

What 4 FACTORS favour forest fires?

Answer 6

VEG TYPE= thick undergrowth, eucalyptus and pine have a large oil content

Fauna Characteristics= fine/dry material

Climate= Hot, dry EL NINO which makes a drying action= increased flammability

Fire Behaviour= convection currents support the ladder effect

Question 7

What THREE things make up the fire/ ignition triangle?

Answer 7

FUEL
HEAT/ IGNITION
OXYGEN

Question 8

What are the main causes of WILDFIRES?

Answer 8

HUMAN

• arson
• cigarettes
• campfires

NATURAL

• El Nino
• Lightning
• Drought
• Volcanic Eruptions

Question 9

What affects the Distribution of Wildfires?

Answer 9

NATURAL CYCLES of rainfall and dryness eg: the boreal forests of Canada in SUMMER

Across Africa= a band of widespread burning takes place N to S for Agricultural purposes in the dry season

S-E ASIA= agricultural burning during late winter/ early spring

Question 10

What 3 FACTORS affect Wildfires?

Answer 10

FUEL
TOPOGRAPHY
WEATHER

Question 11

How does FUEL affect Wildfires?

Answer 11

-amount =”FUEL LOAD”

• a small fuel load leads to a lack of intensity and the fire moves slowly
• SMALL “FLASHY FUELS” -= burn faster

Arrangement
Moisture Content- can suppress or exacerbate fire spreading

Question 12

How does Topography affect Wildfires?

Answer 12

SLOPES

Move faster UPHILL than downhill= heat rises in convection currents

Question 13

How does Weather affect wildfires?

Answer 13

• TEMPERATURE
• WIND= “fire whirls can be created” which in turn cause crown fires
• HEAT= one of the three pillars of the fire triangle

Question 14

ENVIRONMENTAL IMPACTS?

Answer 14

destruction of habitats and ecosystems
death/ injury of animals
short term surge of co2 and burning releases gg emissions
atmosphere pollution due to smoke and water pollution due to ash in water courses

Question 15

ECONOMIC IMPACTS?

Answer 15

cost of rebuliding
financial loss
possibility for new employment

Question 16

POLITICAL IMPACTS

Answer 16

changes laws/ advice regarding the use of forests for recreational activities
cost and effectiveness of strategies to mitigate
preparedness/ mitigation
responses of local/ national gov

Question 17

SOCIAL IMPACTS

Answer 17

damage/ destruction of businesses and structures
displacement of people from their homes
loss of crops and livestock
loss of life and injury