This thesis examines techniques that provide a method of computer visualisation of bushfire spread. Existing techniques studied include, Kourtz & O???Regan, Green???s Contact, Heat Accumulation, Percolation modelling and Huygens??? Principle by Anderson et.al., French, Roberts, Richards. Many of these techniques are extended as part of a comprehensive study into how they perform in a two dimensional reference frame (ie over flat terrain only). New techniques are defined for Percolation Modelling and Huygens??? Principle. Each technique is examined in a series of test cases which include computer simulations with no wind, constant wind, variable wind, variable vegetation (including patchy fuel and two fuels) and where fuel burns out. These test cases provide: (a) an incremental approach to understanding the operation of each technique; (b) a basis for comparison; and (c) verification of correctness of the technique in two dimensions. Several of the techniques are shown, by these test cases, to be equivalent. For instance, the Kourtz & O???Regan technique using a square template is equivalent to the Contact Technique, Site percolation is similar to the Heat Accumulation technique and Template percolation is similar to the Contact Technique. Overall the Huygens??? Principle techniques provide the most accurate simulations of bushfire spread.

This thesis examines techniques that provide a method of computer visualisation of bushfire spread. Existing techniques studied include, Kourtz & O???Regan, Green???s Contact, Heat Accumulation, Percolation modelling and Huygens??? Principle by Anderson et.al., French, Roberts, Richards. Many of these techniques are extended as part of a comprehensive study into how they perform in a two dimensional reference frame (ie over flat terrain only). New techniques are defined for Percolation Modelling and Huygens??? Principle. Each technique is examined in a series of test cases which include computer simulations with no wind, constant wind, variable wind, variable vegetation (including patchy fuel and two fuels) and where fuel burns out. These test cases provide: (a) an incremental approach to understanding the operation of each technique; (b) a basis for comparison; and (c) verification of correctness of the technique in two dimensions. Several of the techniques are shown, by these test cases, to be equivalent. For instance, the Kourtz & O???Regan technique using a square template is equivalent to the Contact Technique, Site percolation is similar to the Heat Accumulation technique and Template percolation is similar to the Contact Technique. Overall the Huygens??? Principle techniques provide the most accurate simulations of bushfire spread.

This thesis contends that the image of fire is a multivalent and theologically valuable image for application in British Christian communities. My research offers an original contribution by contextualising the image of fire for Christian practice in Britain, and combining critical observation of several contemporary fire rites with theological analysis. In addition, I conduct original case studies of three Scottish fire rituals: the Stonehaven Fireball Ceremony, the Beltane Fire Festival, and Up-Helly-Aa in Lerwick, Shetland. The potential contribution of fire imagery to Christian practice has been overlooked by modern theological scholarship, social anthropologists, and Christian practitioners. Since the multivalence of the image has not been fully recognised, fire imagery has often been reduced to a binary of ‘positive' and ‘negative' associations. Through my study of non-faith fire rituals and existing Christian fire practices, I explore the interplay between multivalence, multiplicity, and liminality in fire imagery. I demonstrate that deeper theological engagement with the image of fire can enhance participation, transformation, and reflection in transitional ritual experience. I argue that engaging with the multivalence of the image of fire could allow faith communities to move beyond dominant interpretive frameworks and apply the image within their own specific context. First, I orientate the discussion by examining the multivalence of biblical fire imagery and establishing the character of fire within the British social imagination. Second, I use critical observation of community fire practices in non-faith contexts to build a new contextual framework for the analysis of fire imagery. Finally, I apply my findings to a contextual analysis of existing Christian fire practices in Britain. Throughout, I argue that sensory and imaginative interaction with the image of fire provides a way to communicate and interact with theological ideas; experience personal and communal change; and mediate experience of the sacred.