SECTION 4: RISK ASSESSMENT
4.5.12 WILDFIRE HAZARD BACKGROUND
A wildfire is an uncontained fire that spreads through the environment. Wildfires have the ability to consume large areas, including infrastructure, property, and resources. When massive fires, or conflagrations, develop near populated areas, evacuations possibly ensue. Not only do the flames impact the environment, but the massive volumes of smoke spread by certain atmospheric conditions also impact the health of nearby populations. There are three general types of fire spread that are recognized. • Ground fires – burn organic matter in the soil beneath surface litter and are sustained by glowing combustion. • Surface fires – spread with a flaming front and burn leaf litter, fallen branches and other fuels located at ground level. • Crown fires – burn through the top layer of foliage on a tree, known as the canopy or crown fires. Crown fires, the most intense type of fire and often the most difficult to contain, need strong winds, steep slopes and a heavy fuel load to continue burning. Generally, wildfires are started by humans, either through arson or carelessness. Fire intensity is controlled by both short-term weather conditions and longer-term vegetation conditions. During intense fires, understory vegetation, such as leaves, small branches, and other organic materials that accumulate on the ground, can become additional fuel for the fire. The most explosive conditions occur when dry, gusty winds blow across dry vegetation. Weather plays a major role in the birth, growth and death of a wildfire. In support of forecasting for fire weather, the National Weather Service (NWS) provides interactive maps that highlight regions of the U.S. that may be at higher risk for wildfire due to current and future weather conditions. This service aids federal and state land management agencies with the prevention, suppression, and management of forest and rangeland fires. As shown in Figure 4.28, the NWS Wildland Fire Outlook for March 28 th , 2024 shows the state of North Carolina at “little or no risk” for fire potential based on current weather conditions.
Wake County, NC Multi-Jurisdictional Hazard Mitigation Plan
WSP June 2024 Page 229
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