Urban spaces are experiencing warmer microclimates as the combined result of climate change and the Urban Heat Island (UHI) effect. While climate change projections indicate a likely increase of 2°C in Australia by 2070, an additional heat load of 10°C exists in the built environment. The question is how and to what extent contemporary public spaces can become more resilient to such high temperatures?
This PhD research investigates the social impacts of heat stress in Australian cities. Two intertwined concepts of Spatial Thermal Resilience (indicating physical ability to maintain thermal environment close to humans' thermal comfort) and Activity Thermal Resilience (indicating ability to maintain normal activities in the thermal discomfort conditions) are proposed and tested in three case studies in Darling Quarter (Sydney), Federation Square (Melbourne) and Hajek Plaza (Adelaide). Data collection includes thermal photography, climate measurement and direct observation (air temperatures range: 16-42°C; surface temperatures range: 10°C- 65°C). The data is analysed via correlational and regression analysis and findings are triangulated via a closed questionnaire survey.
Results indicate that necessary, optional and social activities in public spaces with soft landscapes (facilitated by urban greenery and controllable surface water) and smart shadow coverage have higher STR values. Optional activities (including preferred and adjustable activities) start to decline after the apparent temperature reaches the threshold of 28-32°C. However, necessary activities (including vital and habitual) and social activities (including simultaneous, managed and cultural) have a higher neutral thermal threshold of 36°C. Research findings contribute to urban design knowledge by providing STR and ATR as quality indicators for public space and a set of guidelines to facilitate more heat-resilient urban spaces.