"What if" questions drive future policy

What if an earthquake hit central Adelaide? A major flood on the Yarra River through Melbourne? A bushfire on the slopes of Mount Wellington over Hobart?

‘What if?’ scenario modelling by the CRC is helping government, planning authorities and emergency service agencies think through the costs and consequences of various options on preparing for major disasters on their urban infrastructure and natural environments and how these might change into the future.

The CRC research is based on the premise that to reduce both the risk and cost of natural disasters, we need an integrated approach that considers multiple hazards and a range of mitigation options. The Improved decision support systems for optimal natural hazard mitigation project, led by Prof Holger Maier at the University of Adelaide, has completed a case study for Adelaide, and is soon to finish analysis for Melbourne and the whole of Tasmania. Based on the success of the research, further work began in Western Australia in 2017, funded through the National Disaster Mitigation Program.  

Taking into account future changes in demographics, land use, economics and climate, the modelling analyses areas of risk both now and into the future, tests risk reduction options, identifies mitigation portfolios that provide the best outcomes for a given budget, and considers single or multiple types of risk reduction options, such as land use planning, structural measures and community education. CRC partners, along with local governments have been engaged in the entire process, from direction on the hazards to include and feedback on process, to advice on how the modelling will be used when complete and by whom.  

The modelling for Adelaide incorporates flooding, coastal inundation, earthquake, bushfire and heatwave, as well as land-use allocation. Expected impacts of these hazards have been modelled from 2015 to 2050 with an annual time step under different plausible future scenarios that were developed by end-users, showing the change in risks in different localities.

The integrated nature and comprehensive data available is exciting, says Mike Wouters, a Senior Fire Ecologist at South Australia’s Department of Environment, Water and Natural Resources.

“We have not had access to this type of technology before,” he says.

“We need to be thinking at least a decade ahead, and this research will help us with that.”

The Melbourne and Tasmania case studies are nearing completion, incorporating bushfire, flood, coastal inundation and earthquake risk in Melbourne, and bushfire, coastal inundation and earthquake risk for Tasmania.

The powerful nature of the system is its biggest assets, believes the Country Fire Authorities Deputy Chief Officer Alen Slijepcevic.

“We will need to rely on modelling to help us more and more into the future. We do not have the luxury of waiting 20 or 30 years to assess the impacts of our land management decisions,” Alen says.

Agencies will be able to use the system to help allocate budgets, demonstrating that they are using the best available science to inform decision-making.

This study is the only approach that compares different natural hazards and their mitigation options, while also taking into account long term planning. The ultimate aim is to develop a decision support framework and software system that is sufficiently flexible to be applied to large and small cities around Australia that will help planners from local councils through to state treasury departments answer the vital question on mitigation options that balance cost and impact: ‘what is the best we can be doing?’

This project is an outstanding example of the collaborative process that the CRC is all about, and incorporates findings from other CRC work on recognising non-financial benefits of management and policy for natural hazards, for example, the economic, social and environmental benefits of prescribed burning, the vulnerability of buildings to hazards, such as how they can be made more resilient through cost-effective retrofitting for improved safety, and the benefits and understanding of community resilience efforts like improved warnings, community engagement, education, volunteering and community resilience.