- Title:
-
Prediction of firefighting resources for suppression operations in Victoria’s parks and forests
- Date:
- December 2003
- Authors:
- Gregory J. McCarthy, Kevin G. Tolhurst and Michael Wouters
Overview
Estimating resourcing levels for park and forest firefighting is a perennial challenge for wildland fire managers. Low numbers of resources during first attack often achieve significant results if fires are caught in the build-up phase. Conversely, during campaign fires, large numbers of resources occasionally appear to under-achieve, with little obvious result in terms of length of fireline constructed despite significant resource inputs.Previous predictions of fireline construction rates in Victoria relied mainly on the experience of Incident Planners and more formally on information derived from studies in USA and Canada. Some information has been based on local trials and demonstrations but most of these were decades old and of variable reliability.
The 1980’s national bushfire research project—Project Aquarius—provided some information on hand trail construction rates but there has subsequently been some speculation on how these may relate to actual fireline situations.
This project was therefore directed towards collecting information on firefighting resource allocation and fireline construction rates achieved in recent actual fire events, with the aim of producing models based on real, and current operational data.
Data on fireline conditions and fireline construction rates were collected from 103 fire events spanning the 1997–98 to 2000–01 fire seasons in Victoria. Models of fireline construction rates for hand trail, small bulldozers and large bulldozers were developed based on this data. Some information was also collected in regard to holding rates of ‘wet lines’ using both ground-based tankers and firebombers. Preliminary data on critical resource combinations for containment of various lengths of fireline was also collected.
Hand trail construction rates, based on actual fireline data, appeared to be considerably lower than those obtained in the past from demonstration-type situations (e.g. Project Aquarius). The main factors influencing the variation in these construction rates were found to be elevated fuel and terrain class, with average rates (90–120 m/crew/hour) declining quickly when the six-person crew was faced with substantial elevated fuels and/or steep, broken terrain (down to 30–60 m/crew/hour).
