The Role of Extreme Value analysis in construction practice and planning for bushfire prone environments.

Speaker: Grahame Douglas

Affiliation: University of Western Sydney

Time: Monday 26/10/2015 from 14:00 to 15:00

Venue: Access Grid UWS. Presented from Penrith (Y239), accessible from Parramatta (EB.1.32) and Campbelltown (26.1.50).

Abstract: While wildland fires (bushfires) are an anticipated event with each fire season, it is important that the extent of likely annual fire weather conditions and those of more extreme conditions are identified as part of the preparation of communities to those fire events. In preparing defendable space arrangements (often referred to as asset protection zones) for both existing homes and when planning for future urban expansion, the characteristics of fire weather conditions is critical. Historically extreme value analysis has been used for floods, storms and wind, however, such analysis has not been routinely undertaken for fire weather. This may be because historically fire weather is a composite of differing parameters which at their extreme, individually may not be related to wildland fire. Fire danger rating and index systems generate non-dimensional parameters and in Australia, this has generally focussed on forest fire danger indices or grassland fire danger indices.
While it is difficult to ascertain individual extremes related to traditional parameters like wind speed, temperature and relative humidity, the use of the extreme value distributions are a suitable process for fire danger indices in Australia. This can then be applied to deterministic fire behaviour assessments whether through the identification of rate of spread, flame height (or length), intensity or suppression effort.
This paper offers new insights in the use of a three extreme value assessment techniques for both MacArthur and Project Vesta models so as to determine comparable defendable space for buildings under both existing and planned urban developments in NSW, Australia. Treatment options for existing homes can be more effectively determined and quantified under such an approach so as to better balance resident and fire fighter safety as well as recognising environmental assets.

Biography: Grahame previously worked with the NSW Rural Fire Service in the area of community safety for 15 years and was responsible for developing the legislative provisions and policy relating to bush fire risk management planning, development control for bushfire prone areas, environmental impact of hazard reduction activities and currently participates in a number of sub-committees working on the review of AS3959 Construction in Bushfire Prone Areas. He has recently been appointed to the University of Western Sydney and is completing his PhD in bushfire weather and climate change research.