The potential for wildfire exposure is a growing hazard as temperatures rise, wildland fuels accumulate, and people continue to build structures in areas of elevated wildfire risk. Wildfire Risk Extreme provides an up-to-date, scientific model that accurately captures wildfire risk under severe conditions, for every location in the United States.
Wildfire Risk Extreme was designed as a companion product to Precisely's existing Wildfire Risk. Wildfire Risk Extreme includes temperature, relative humidity, and maximum wind speeds under fire conditions that occur only 1 percent of the time. Additionally, the direction of predominant winds in an area provides insight provides insight into where communities may be vulnerable. This new product offers a nationwide wildfire hazard and risk assessment tool that incorporates the predicted severity (hazard) and predicted frequency (risk) or wildfire at a given location.
Many wildfire-related datasets are delivered in a format that divides the landscape into square grids. A square has very little relation to how a fire burns and the variation from square to square can be difficult to interpret. Wildfire Risk Extreme takes a different approach: All the datasets Wildfire Risk Extreme uses to create a final analysis – many of which come in a grid format – are integrated into polygons that reflect the landscape and how wildfires would actually burn within that landscape. Wildfire Risk Extreme divides the data into firesheds that are based on the topography (hills and valleys) of the landscape. These firesheds correlate to vegetation or wildland fuels and determine how a fire might burn and behave. This means that firesheds are more likely to divide geography into landscape-based units that exhibit similarities in vegetation, slope, and resultant fire behavior. The Wildland and Intermix modules in Wildfire Risk Extreme use the concept of firesheds to aggregate the landscape.
Wildfire Risk Extreme also accounts for the fact that firesheds are impacted by wildfire effects from outside of their boundaries. A fireshed may be mostly covered by a meadow but surrounded by volatile timber or chaparral (a California reference). If a structure exists in the meadow, it is not only subject from the grass fuel in the fireshed, but also to fire embers in the surrounding firesheds' vegetation. To account for this, Wildfire Risk Extreme incorporates adjacent fireshed values into the threat profile for every fireshed, providing a more realistic definition of the fire environment.
Wildfire Risk Extreme uses the concept of dividing the landscape into relative amounts of built environment (structures, roads, and other infrastructure) versus pure wildland fuels. The rationale for this distinction is that wildland fires behave differently when burning in pure wildland areas than when burning through fuel that is interrupted by structures and roads. Similarly, suppression of wildland fires is conducted differently – and with varying degrees of success – in remote areas compared to densely populated areas. Wildfire Risk Extreme captures these differences by categorizing the landscape into four separate wildfire risk types, each of which modeled with its own set of inputs and methodology:
