GIS based modelling for fuel reduction using controlled burn in Australia : case study : Logan City, Queensland

Abstract: Bushfire problem is a long-lasting problem which is a big threat and environmental problem in Australia. Planning to control bushfire is very important for Australian Environment. One of the most effective methods to fight bushfire disasters is planning for controlled burns in order to reduce the risk of unwanted bushfire events. Controlled burns management and planning has been always considered as important by town planners. In this study the aim is to produce a tool for prioritizing burn blocks based on diffract criteria in order to help planners have a sound scientific basis for choosing the most important blocks to have controlled burn on. In this study the following research tasks have been considered 1. Investigate criteria related to prescribed burn management and their usability to design a model for analysing long term geospatial suitability of bushfire prescribed burns. 2. Finding out suitable model for scoring blocks designated as fuel reduction bushfire prescribed burns blocks in long term 3. Testing model in a pilot area Several criteria for building up a multi-criteria analysis with GIS model were studied and the corresponding importance weight for them were debated. Research methodology used in this section was investigating literature and methods for determining weights and possibly, using experts’ ideas by interviews or small surveys or running focus groups in a stakeholder organization to find out the most relevant and the most important criteria. Finally eleven most important criteria were chosen and compared to each other by interviewees to find out their importance weight. The model developed considers all the criteria which is usable to plan and prioritize burn blocks selected in the criteria analysis phase. This model works as a basis for having a sound and robust decision on which blocks are most suitable to be burnt in long term point of view. GIS database used in this model were acquired from the pilot area’s relevant authorities. Model was developed based on the ESRI’s ArcGIS analysis tools as well as ArcGIS Spatial Analyst extension. In this model Analytical Hierarchical Process Methodology was used for combining criteria importance and develop a unified value-based solution to the study’s Multi Criteria Analysis problem based on two main themes of ‘Implementation’ and ‘Safety’. Model was tested on Logan City Area in south of Queensland, Australia. The case study is an administration area within Australia that all the criteria data has been prepared and acquired from. Results: As combining the final results by overlaying can cause some bias as some blocks show a good match for safety theme but not a good match for implementation and vice versa, two main themes results were combined using an optimization methodology based on probabilistic principles for generating final prioritized blocks. The usability test of the result generated by this model was done by Logan City Council managers and Parks Department bushfire experts. The suitability of the blocks was very close to what experts had in their minds and this model results were validated completely satisfactory by them. All of the blocks ranked by the model were according to what they had a practical perception from the field visit and field knowledge. In overall and in general, the tool created by this study, will help decision makers has a good basis for deciding about long term priorities to plan for controlled burn activities. Decision makers could use this model to have a long term outlook for the budget and resources needed to be allocated to fuel reduction controlled burn practices. This will facilitate short term planning as well.