Wildland Firefighting Practice Exam

When a fire burning in brush enters grass, how do firefighters expect the rate of spread to change?

1. It will slow down

2. It will double

3. It will remain unchanged

4. It will be extinguished

The correct answer is: It will double

When a fire transitions from burning in brush to grass, firefighters anticipate that the rate of spread will increase. This is because grass typically has a lower moisture content and is finer compared to brush, which means it ignites more easily and burns more rapidly. As the fire encounters grass, the available fuel allows it to spread faster than it did in the brush, leading to a potential doubling in rate of spread. While other options might suggest different outcomes, they do not take into account the characteristics of grass as a fuel source. For instance, the notion that the fire will slow down overlooks the fact that grass can act as a conduit for flames, facilitating quicker movement. Similarly, suggesting that the fire will remain unchanged fails to recognize the dynamics of fuel types and their impact on ignition and spread patterns. Lastly, the idea that the fire will be extinguished does not align with the behavior of fire in varying fuel conditions; rather, it emphasizes the need for adjusted firefighting tactics when different fuels are involved.