Wildfire Hazards

Question 1

What is a wildfire?

Answer 1

A large, uncontrolled fire that quick;y spreads through vegetation.

Question 2

How does vegetation type influence wildfire progression?

Answer 2

• Dense, close together vegetation allows fires to spread more easily.
• Trees and thick vegetation allows leads to more intense wildfires; grasslands do not burn as intensely.
• Vegetation with flammable oils e.g. eucalyptus, leads to more intense wildfires.

Question 3

How does fuel characteristics influence wildfire progression?

Answer 3

• Vegetation needs to be dry for it to catch on fire.
• Finer vegetation allows for fires to spread quicker, while thicker vegetation allows for fires to burn for longer and more intensely.

Question 4

How does overall climate influence wildfires?

Answer 4

• Wildfires can occur globally.
• Often occur in climates with some rainfall for plant growth, but with considerable dry spells and droughts to dry out fuel.
• Areas with wind allow for fires to spread quicker.
• Many climatic events can cause wildfires to be more intense and extend wildfire seasons- e.g. California’s La Nina (cold phase) causes warmer, wetter seasons to extend vegetation growth, and El Nino (warm phase) causes dryer seasons to increase the prevalence of wildfires.

Question 5

How have recent changes in climate influenced wildfires?

Answer 5

• Recent temperature increases have caused an increase in the frequency of wildfires and an increase the length of wildfire seasons.
• Forest fires in Western USA are occuring x5 as often, burning x6 the amount of land, and are lasting x5 as longer in comparison to wildifres in the 1970’s.