How can future WU fire disasters be prevented?
The opportunity for preventing WU disasters is evident in the WU fire disaster sequence. If the “Highly ignitable structures,” the third condition of the Disaster Sequence (Fig. 22), becomes “Ignition Resistant Structures & Community – Few Ignitions.,” the “Disaster Sequence” is prevented. The following list provides the general attributes of an ignition resistant HIZ, the fundamental building block of ignition resistant communities that would interrupt the disaster sequence, and prevent large scale community conflagrations. An ignition resistant HIZ (reference Fig. 16): 1) Does not support high intensity fire; high intensity burning does not develop within the HIZ and ceases within Zone 2 of the HIZ if spreading inward from wildland vegetation. 2) Can have low intensity fire but cannot have any flame contact or long duration radiation sources of radiation (sheds, woodpiles, etc.) exposing the primary structure to burning objects within the HIZ. 3) Does not have any ignitable/burning material within 1.5 m of the primary structure and its flammable attachments. 4) Is only exposed to burning embers from the wildfire and burning community fuels; these become the only ignition source. 5) Does not have flammable debris on the structure and its flammable attachments. 6) Does not have unscreened openings to the structure’s interior, or burning embers accumulating against exterior flammable inside corners or in gaps of flammable exterior materials, or flammable wood roofs. These attributes, applied to the structure and its surrounding zones of the HIZ, develop individual ignition resistant structures. Groups of ignition resistant HIZ’s function synergistically to produce ignition resistant communities. This is essential in most built environments because, more often than not, HIZs overlap. Consequently, ignition resistance for each structure depends on ignition resistance of neighboring structures. This interdependence presents additional social challenges. Achieving wildfire-resilient communities will require programs that motivate, educate and engage residents/owners in action implement ignition resistance for each and every structure. An ignition resistant community: 1) Understands and supports a structure ignition approach for wildfire risk reduction at all levels; the elected and administrative officials make strategic decisions and investments commensurate with an ignition resistance approach. 2) Has residents and property owners who collaborate and share responsibility for actions toward achieving ignition resistance. 3) Has inter-governmental/agency/departmental capacity and collaborations to facilitate community wildfire risk reduction, operationally and financially. 4) Has achieved individual overlapping, ignition resistant HIZs that collectively create community ignition-resistance.
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