Technical glossary

Daily Severity Rating – A numerical measure, based on the Fire Weather Index (FWI), specifically designed for averaging, either for any desired period of time (e.g. week, month, year) at a single fire weather station or spatially over a number of stations. The FWI itself, on the other hand, is not considered suitable for averaging, and should be used as its single daily value only. The DSR averaged over a whole fire season is termed the Seasonal Severity Rating (SSR) which can be used as an objective measure for comparing fire weather severity from one season to the next, or the fire climate of one region with another.

Damage Appraisal – A method of determining financial or other losses resulting from a wildfire. Note Fire Damage(s) and Fire Effects Value Appraisal.

Depth of Burn (DOB) – The reduction in forest floor thickness due to consumption by the fire process; most commonly used in connection with prescribed burning. Recommended SI unit is centimetres (cm).

Detection – Note Fire Detection.

Detection Aircraft – An aircraft deployed for the express purpose of discovering, locating, and reporting wildfires. Note Aerial Detection.

Discovery – Determination that a fire exists at a specific location; in contrast to action related to detection, reporting of the fire is not required.

Division – The segment of the fire perimeter consisting of two or more sectors. Note Division Boss under Fire Overhead.

Drop height – Height of the airtanker at load release, usually given in feet above tree top level.

Drop zone – target area for the release of the airtanker's load.

Dry Lightning Storm – A thunderstorm with negligible precipitation reaching the ground.

Dummy run – a simulated bombing run made on a target by the birddog aircraft to indicate target and run to the airtanker. Note Inspection Run and Lead-in.