BUSHFIRE INDUCED WINDS INTERACTION

Bushfire Induced Winds Interaction And Its Implications On Buildings



Bushfire Induced Winds Interaction And Its Implications On Buildings

Introduction

It has been estimated that arson, in all its forms, costs Australia approximately US$1. 6 billion per annum. Arson has significant impacts associated with injury, loss of life, psychological trauma, property and environmental damage. Future projections for the growth of the populations of Australian cities vary, but there is agreement that significant levels of growth are expected. Indeed, in Western Australia (WA), the Government's planning vision for the future, Network City, estimates that 375 000 new homes will be required by 2031 and 60 per cent will be built in existing urban areas. The remaining 40 per cent will be developed on 'greenfield' sites, many of which are likely to be at the urban-bush fringe. Given the destruction experienced during the 2009 Victorian bushfire season, unless appropriately managed, significant population 'build up' in the peri-urban fringes of our major cities may result in an increasingly larger number of people being placed at risk.

A review of the literature indicates that there are up to 60 000 vegetation fires per year across Australia, which represents 40-50 per cent of all fires attended. Although only 6 per cent are 'natural fires' over 90 per cent are the result of people's actions. Between 25 per cent and 50 per cent of bushfires are deliberately lit, but rates can increase to 80 per cent in some places. Deliberate ignitions; incendiary (maliciously lit fires) and suspicious fires account for 50 per cent of known fire causes. Furthermore, 40 per cent of all fires have no designated cause assigned by the responding fire agency- and it is suggested that some of these are also potentially deliberate.

Deliberately lit bushfires in Australia represent a high proportion of all bushfires and significantly, offender-based responses currently dominate the field of bushfire arson prevention. However, it is noted that such approaches are derived from incomplete and limited insights from a tiny minority (less than 1 per cent) of arsonists who have been apprehended. Crucially, this cohort of offenders is also likely to represent largely ineffective arsonists, in terms of their failure at avoiding detection and apprehension (Maclean, 2001).

Furthermore, much of this offender-focused research was conducted in the United Kingdom and United States, further limiting the relevance of this approach to Australian contexts. Indeed, Christensen has argued 'while behavioral programmes are important, proactive situational programmes that prevent and mitigate bushfire arson through decreasing rewards, increasing risks and removing excuses for deliberate fire-setters are also critical, particularly when very few deliberate fire-setters are actually caught'. Modern thinking in criminology increasingly recognizes the importance of the spatial and situational dynamics of crime, however, such approaches have only recently been considered by those active in the bushfire arson prevention field. This article argues that while offender-based strategies to reduce bushfire arson are necessary and important, the utility of theories from environmental criminology can provide an alternative set of prevention tools, which can be used alongside offender-based strategies ...