Spatial plan research
Climate change risk and vulnerability
ACTPLA commissioned AECOM Australia to do a pilot study into the vulnerability of Canberra's population to projected climate change. AECOM modelled a two degree average temperature rise by approximately 2050, which is considered to be a likely future. Using a method adapted from the CSIRO's pilot study of the Sydney Regional Organisation of Council area, the project assessed the exposure, sensitivity and adaptive capacity of Canberra to the probable threats of extreme heat, bushfire, flash flooding and water scarcity. The project advanced previous research about Canberra as its spatial assessment of vulnerability provided a more finely grained analysis.
While significant data gaps made a comprehensive assessment difficult, it was still possible to draw valid conclusions about the risks posed by climate change.
Key Findings
Bushfire:
The risk of bushfire is expected to increase, due to the expected increase in hotter and drier weather. The number of days rated as high or extreme (under the old system) is expected to increase from 23 to 36 days per year. The overall risk is also likely to be exacerbated by fewer opportunities for hazard reduction burning. Bushfire is one area of risk which has been extensively studied, and the data available to inform decision makers is readily available. The report does suggest areas of analysis which could be enhanced.
Extreme Heat:
Of all natural events, heatwave has historically been the biggest killer. Climate change is very likely to result in higher exposure to extreme heat as the number of hot days (>35°C) and very hot days (>40°C) are projected to increase. One of the key data gaps identified was the prevalence and exent of the urban heat island effect, that is localised city heat 'traps'.
Flooding:
Since the 1970s, flood attenuation has been included as part of the integrated urban form. Open space, such as parks and ovals, is often used to manage and reduce potential flood hazards. The study identified the general ageing status of drainage infrastructure as an issue, as well as the need to incoprorate anticipated climate change impacts into any new studies.
Water supply:
The surface runoff feeding the ACT’s dams decreased from the mid 1990s. Climate projections indicate this trend is likely to continue or even worsen in the future. Water sources in the ACT are rainfall dependent and, as such, are sensitive to any change in rainfall pattern. An understanding of the implementation of water saving initiatives at the suburb level would greatly increase the vulnerability assessment.
Population vulnerability:
The most vulnerable in our society are those who will be most affected by the risks posed by impacts from climate change, that is the very old, very young, the sick, poor and least educated.
In locating groupings of more vulnerable people, such as in old age residential complexes and hospitals, consideration needs to be given to mitigating all risks, including those that may be exascerabated by climate change.
Climate change adaptation and mitigation interventions
This study investigates how changes to Canberra’s urban form can assist in the mitigation of and adaptation to climate change. It was prepared by SGS Economics and Planning as part of the Spatial Plan evaluation.
The study:
1. Modelled the impacts of climate change under a two degree warming scenario in relation to four typical existing urban form case studies (town centre, group centre, local centre and suburban edge)
2. Identified key potential interventions that may assist adaptation to the effects of climate
change and mitigation of climate change at the urban form level
3. Indicated where these interventions would require changes to the Spatial Plan
4. Suggested refinements to the overall principles of the Spatial Plan, and
5. Suggested additional interventions in urban design and planning for the individual centres used in the case studies.
A number of urban design 'options' were developed for case studies of different urban forms. This allowed the expected performance to be expressed on a per person and per dwelling basis. This in turn allowed a comparison with the existing Canberra averages of energy, CO2-e and water consumption, and for broad qualitative assessments of whether the different options being investigated for each case study would be likely to improve or reduce the adaptive capacity of Canberra as a whole.
