Chapter 13 ISO at Wildland and I-Zone Fires Flashcards
Define Blowup
A wildland fire term used to describe the sudden advancement and increase in fire intensity due to wind, prewarmed fuels, or a topographical feature such as a narrow canyon or “chimney”
Define Control line
All constructed or natural barriers and treated fire edges used to control a wildland fire
Define fire line
The part of a control line that is scraped or dug to mineral soil
Define fire storm
A violent convection caused by a large continuous area of intense fire. They are characterized by violent surface in-drafts near the fire perimeter and occasional tornado-like whirls
Define flare up
A sudden, but short-lived, rise in wildland fire intensity that is usually attributed to wind, fuel, or topographical changes
Define Scratch line
A preliminary control line hastily constructed as an emergency measure to check fire spread
Define Torching
The burning of the foliage of a single tree, or small bunch o trees, from the bottom up (sometimes called candling)
Define wet line
Water or water agent sprayed on the ground as a temporary control line for a low-intensity fire or to ignite a burn-out
Define Wildland-urban interface (WUI)
Also referred to as the I-zone; areas where homes and businesses have minimal separation from, or are interspersed with, natural growing wildland areas.
As a wildland fire grows so does its……
Resource demand
What type of wildland fire incidents are handled by the initial ISO
Type 4 and 5
How is “Line” defined in wildland?
a barrier to fire spread
How are threatened buildings classified in the I-zone
Defensible or indefensible
What make the determination between defensible and indefensible?
distance between building and flame lengths of burning vegetation, and combustible exterior materials
What are the 2 attack classifications for wildland fires
direct and indirect
3 factors that affect wildland fire spread are?
Weather, Topography, Fuels
Fire weather factors
Temp, humidity, barometric pressure, wind, pressure fronts
Topography factors
slope, aspect, and physical features like chimneys, saddles, barriers
Fuel factors
moisture content, type, continuity of fuel (sparse, fractured, dense)
Wildland flame length less than 4 feet
can generally be attacked directly using hand lines and tools
Wildland flame length 4 to 8 feet
Fire too intense for a direct attack on the head. Flanking attack with increased gallons per minute may be effective. indirect with wet lines are advisable
Wildland flame length 8 to 11 feet
The fire presents serious control problems, direct fire attacks are dangerous
Wildland flame length 11+ feet
Major fire runs are likely. Defensive measures are required
3 considerations the ISO uses to form a judgement of wildland potential and risks
potential for blowup, signs of flaring, and flame length
