Why is mop up considered more intensive in direct attack strategies?

Mop up is considered more intensive in direct attack strategies primarily because the fire can easily rekindle. When a direct attack is made, firefighters are engaging the fire front head-on, which often leaves residual hot spots and smoldering material in the aftermath. These areas can reignite if not properly managed, especially if conditions change, such as a rise in temperature or a shift in wind direction. The nature of direct attack means that there is a higher likelihood of unburned fuel remaining very close to where the fire was actively fought, making thorough mop up essential to ensure that every potential ignition source is extinguished. This involves ensuring that all residual heat within the soil and surrounding materials is eliminated, which often requires more careful and thorough work compared to other strategies.