Glossary

Building Footprint  

A digital representation of a structure or other human development derived from satellite images. 

Burn Probability 

The probability that a wildfire will burn a specific location over a specified period of time. The SB762 risk map presents annual burn probability. Burn probability is usually expressed as a value between 0 and 1. 

Fire Intensity 

The amount of energy produced at the flaming front of a fire. Fire intensity is frequently expressed as  flame length, where longer flame lengths indicate greater intensity.  

Flame Length 

The length of the flame measured at the front of the fire. Flame length is used as a measurement of  intensity and is estimated from wildfire behavior models.  

Fuel Model

A general description of combustible vegetation that allows for a realistic estimate of wildfire behaviour. Fuel models can be defined in the field and have also been incorporated into nation-wide map with a 30m resolution. Fuel models are useful tools for planning prescribed fuel treatments

 Net Value Change 

A unitless value used to quantify wildfire risk in relative terms. Negative numbers for net value change  indicate a net loss of value, and the more negative a value is, the greater the expected annual damage.  

Other Human Developments 

Essential facilities (ORS 455.447) that support community functions, public communication, energy and  transportation in excess in size 400 square feet. 

Structure 

A permitted building on a lot that is used as a place where one or more people sleep. 

Susceptibility 

The propensity of a structure or other human development to experience damage as a result of burning  at a given level of wildfire intensity.  

Wildfire Intensity 

The rate of energy release of a wildfire at a point on a fire perimeter, typically measured as flame length.  

Wildfire Risk 

The magnitude of expected annual damage to structures and other human developments at  a specific location. 

Wildland-Urban Interface 

The geographic area where structures and other human development meets or intermingles with  wildland or vegetative fuels