Tackling urban heat across Australia

A new national observatory has been set up at UNSW to report and measure the heat vulnerability and cooling potential of Australia’s urban centres.

The National Heat Vulnerability Observatory (NaHVO) is a partnership between the NSW Department of Planning and Environment and UNSW’s High Performance Architecture team, led by Associate Professor Lan Ding from UNSW’s School of Built Environment. The project’s advisory committee includes representatives from government, industry and academia.

“Urban heat is a major challenge for the future of Australian cities. Understanding its impact and developing appropriate intervention strategies is a critical and urgent task,” Ding said.

Rising temperatures particularly affect cities due to the urban heat island effect — the increased temperature of high-density urban areas compared with surrounding suburban or rural areas.

“This causes increased deaths and emergency admissions from heatwaves, increased energy and water consumption, and equity issues for vulnerable populations,” Ding said. “We need evidence-driven strategies to support smarter cities that improve the quality of life for communities across regional and metropolitan Australia.”

The absence of standardised approaches to data collection, analysis and evaluation makes it difficult to measure the effect of mitigation and adaptation interventions, Ding said. Additionally, an analysis done for one location is not generally transferable to others due to differences in local topography, climate, built form and land use.

“By developing rigorous national datasets, we can better understand performance measures and, in turn, develop a sophisticated methodology and benchmarks for heat vulnerability,” Ding said. “It’s important to plan for resilient and smart places and communities to combat climate change and its serious impacts.”

The project builds on the success of the Microclimate and Urban Heat Island Decision-Support Tool, developed by the UNSW High Performance Architecture team in partnership with government, industry and academic partners.

The role of the tool was to facilitate evidence-based strategies to adapt to climate conditions, in particular urban heat, and minimise humans’ environmental impact, Ding said.

“The tool integrates scientific modelling with various urban heat mitigation techniques — such as building coatings, cool roofs and pavements, urban form and density, canopy cover and green space — to provide analyses of their impact, from building level to urban scale.”

Also informing the observatory’s work are various case studies UNSW has undertaken both in Australia and overseas, such as the award-winning ‘Cooling South Melbourne’ project.

South Melbourne was identified as a heat vulnerability hotspot due to its land use, demographics and ambient temperature. The City of Port Phillip was interested in understanding how it could reduce heat and create a comfortable and livable precinct for residents, workers and visitors.

“The report calculated future climate projections and delivered nine cooling intervention scenarios, based on increasing public and private urban greenery, changes to street, footpath and roof materials, water misting and combinations of these,” Ding said.

“It highlights the maximum possible cooling potential for South Melbourne under both current climate conditions in 2020 and future conditions in 2050.”

The project received an Award for Excellence at the City of Port Phillip’s annual Design and Development Award Ceremony in 2022, demonstrating outstanding community benefit.

“These smart methodologies address the demand for heat mitigation techniques at a local level with the ability to be scaled nationally. The future of our cities depends on it,” Ding said.

Image credit: iStock.com/Marccophoto