Resilience to heat in public space: a case study of Adelaide, South Australia

Abstract

During summer heatwaves, heat load exacerbates in urban heat islands (especially in hot climates) and threatens public life in cities. This paper examines the links between urban microclimates, outdoor thermal discomfort and public life through an exploratory case study. Heat resilience is highlighted as the ability of the space to support its normal activities when experiencing out-of-comfort temperatures. It also reports on the correlations between heat sensitive outdoor activities and urban greenery in three disparate case studies in Adelaide. Results indicate that necessary and optional activities start to decline after the apparent temperature reaches the threshold of 28 °C–32 °C, while activities in public spaces with more urban greenery show higher resilience to heat stress. Research findings propose heat resilience as a quality indicator in public space and support the application of urban greenery to make urban settings more resilient to heat stress.

Keywords:

• summer heatwave
• heat resilience
• outdoor thermal discomfort
• heat stress
• outdoor activities

Acknowledgements

This paper draws on the work of the authors at the University of South Australia. It is a part of an ongoing research project on Urban Microclimates of Australian Cities, supported by the CRC for Low Carbon Living and the cities of Adelaide, Sydney and Melbourne. The research is approved by UniSA's Human Research Ethics Committee (PR 31464). The authors appreciate the generous and constructive assistance of the editorial board of Journal of Environmental Planning and Management and the anonymous reviewers in finalising this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Sensible heat refers to the energy, which directly changes the temperature of a substance, whereas latent heat refers to the energy, which changes the state of a substance without causing any temperature differences, such as water evaporation.

2. Net radiation absorption is a function of surface temperature differences between the target object (in this case, the human body) and the surrounding mean radiant temperature (MRT) and thermal conductivity of insulations (in this case, clothing) (Bradshaw 2010).

3. EXTECH RHT20: temperature resolution 0.1 °C; temperature accuracy ±1 °C; relative humidity resolution 0.1 %RH; relative humidity accuracy ±3%.

4. Kestrel 4000: temperature resolution 0.1 °C; temperature accuracy ±0.5 °C; relative humidity resolution 0.1 % RH; relative humidity accuracy ±3%; wind speed resolution 0.1 m/s; wind speed accuracy 3%.