Wind speed Reduction Factors (WRF): utilities for WRF assessment and communication | Natural Hazards Research Australia

Wind speed Reduction Factors (WRF): utilities for WRF assessment and communication

Research theme

Learning from disasters

Project type

Commissioned research

Project status


This project is part of the Black Summer research program funded by the Commonwealth Government through the 10-year extension of funding into natural hazard research in Australia.

Project details

Wind is a key driver of fire behaviour and can be highly variable and difficult to predict, particularly within the lowest 1-2km of the atmosphere where it interacts in complex ways with topography and vegetation. Operational fire spread modelling quantifies the impact of vegetation or fuel type on wind speed using Wind speed Reduction Factors (WRFs).

The purpose of the project was to undertake an evaluation of WRFs used in Australia (including during Black Summer) to quantify the reduction of open space wind speed by Australian fuel types.

The review found that the use of approximated static WRFs has caused minor to significant error accumulation in the fire spread model outputs produced by fire simulation applications, including PHOENIX Rapidfire. To reduce error in fire spread modelling, the review concluded that the development of dynamic WRF modelling capabilities should be a priority. These dynamic WRFs should respond to key wind, fuel, fire and topography parameters that change over time and space.

Read the final report here. 

Date Type Title
25 January 2023 Hazard note edition Hazard Note 1: Understanding the Black Summer bushfires through research