Wildfires

Question 1

Describe the distribution of wildfires?

Answer 1

Require a combination of dry vegetation and lightning strikes > semi-arid climate is susceptible to droughts (Mediterranean and Savanna biomes).USA; Australia; Canada; Southern Europe (S. France, Italy, Greece, Turkey, Mediterranean Islands)

Question 2

What are the three types of wildfires?

Answer 2

Ground fire (ground beneath surface peat and tree roots)
Surface fire (leaf litter and low lying vegetation)
Crown fire (tree canopy)

Question 3

Give an example of human ignition sourced

Answer 3

accidental or arson (90% of US wildfires)

Question 4

Give an example of natural ignition sourced

Answer 4

: lightning without much rain - electrical storms; volcanic eruptions

Question 5

How does vegetation type affect wildfire?

Answer 5

thick dense vegetation allows for fires to spread quickly and easily; flammable oils (eucalyptus and pine) buen more intensely.

Question 6

How does fuel characteristics affect wildfires?

Answer 6

finer dry vegetation causes fires to spread faster but thicker vegetation burns more intensely/longer.

Question 7

How does climate/recent weather affect wildfire?

Answer 7

sufficient rainfall for plant growth but sufficient dry spell to dry out fuel.

Question 8

How does winds affect wildfires?

Answer 8

dry windy weather > provides oxygen to help burn and drive the fire by spreading embers. Eg. Santa Ana and Diablo winds in California.

Question 9

How does El nino/La nina affect wildfires?

Answer 9

In California el nino (warm phase) provides warmer wetter weather to grow vegetation and la nino (cold phase) provides drier weather to dry out vegetation.

Question 10

How does Climate change affect wildfires?

Answer 10

temperature increases cause an increase in the number of wildfires and length of wildfire seasons.

Question 11

How does topography affect wildfires?

Answer 11

fires spread faster on hills as heat rises.

Question 12

Outline three short term responses to the wildfires.

Answer 12

Firefighting - water; chemicals or retardants
Diverting flames away from settlements - beating flames; bulldozing areas of vegetation to prevent flames jumping
Evacuation

Question 13

Prevention of wildfires

Answer 13

education (Home safety and preventing people from starting fires)

Question 14

Preparedness of wildfires

Answer 14

emergency plans etc. Warning systems for potential risk factors (broadcast weather warnings when wildfire conditions; using thermal infrared satellite imagery to evacuate).

Question 15

Mitigation of wildfires

Answer 15

controlled burning of flammable material; create fire breaks

Question 16

Adaptation of wildfires

Answer 16

use non-flammable/non-toxic when burnt building materials; urban planning (increase gap between buildings); insurance.

Question 17

Prediction of wildfires

Answer 17

use computer simulations to predict fire behaviour e.g. fire propagation models.