The nature of wildfires and their natural and human causes; the physical and human factors affecting occurrence and spread; the primary and secondary impacts; and prevention, preparedness, mitigation, response and recovery.

What this dot point is asking

AQA section 3.1.5 wants you to explain the nature of wildfires and their natural and human causes, the physical and human factors that affect their occurrence and spread, the primary and secondary impacts, and the management cycle (prevention, preparedness, mitigation, response, recovery). Wildfires are the most clearly climate-sensitive hazard, so they link directly to climate change.

The nature and causes of wildfires

Ignition has natural causes (chiefly lightning, also occasionally volcanic activity) and human causes (arson, discarded cigarettes, campfires, sparks from machinery and power lines), which now account for the majority of fires. A wildfire is sustained only where there is enough dry fuel and favourable weather.

Physical and human factors affecting spread

Physical factors:

• Fuel (vegetation): type, amount, density and moisture; dry, dense, resinous or oil-rich vegetation (eucalyptus, chaparral) burns fast and hot.
• Climate and weather: prolonged drought and high temperatures dry the fuel; strong wind supplies oxygen and carries embers ahead of the front (spotting); low humidity raises flammability.
• Relief: fire spreads faster uphill, because rising heat preheats the slope above.

Human factors:

• Land use and management: fire suppression that lets fuel accumulate, building in fire-prone bush (the wildland-urban interface), and ignition sources all raise risk and the toll.

These interact: drought plus wind plus steep, resinous fuel produces the most dangerous fires.

Impacts

Primary impacts are deaths and injuries, destroyed homes, infrastructure and crops, and burnt vegetation and wildlife. Secondary impacts include severe air pollution (smoke causing respiratory illness far downwind), soil erosion and flooding/landslides once protective vegetation is lost, economic disruption and displacement, across short and long term. As ever, development and governance shape the human toll.

Managing wildfire hazards

Wildfire management follows the hazard management cycle:

• Prevention: prescribed (controlled) burns to reduce fuel load, firebreaks, public education on ignition, and total fire-ban days.
• Preparedness: warning systems, evacuation plans, defensible space around homes, and community fire plans.
• Response: firefighting on the ground and from the air (water-bombing), and evacuation.
• Recovery and mitigation: rebuilding to fire-resistant codes, ecosystem restoration, and reviewing land-use planning.

Because fires are driven by uncontrollable weather, no single measure is enough; the most effective approach combines fuel management and prevention with preparedness and rapid response. Climate change is lengthening fire seasons and raising risk, so prevention and adaptation matter increasingly.

Try this

Q1. State the three components of the fire triangle. [3 marks]

• Cue. Fuel (vegetation), oxygen and heat (an ignition source).

Q2. Explain why strong winds increase wildfire spread. [3 marks]

• Cue. Wind supplies more oxygen and carries embers ahead of the front (spotting), starting new fires beyond the main blaze.

Q3. Outline one prevention strategy and one response strategy for wildfires. [4 marks]

• Cue. Prevention: prescribed burns or firebreaks to reduce fuel; response: firefighting (including aerial water-bombing) and evacuation.