Combined effects of the visual-thermal environment on restorative benefits in hot outdoor public spaces: A case study in Shenzhen, China

In the context of global warming and rapid urbanisation, improving visual-thermal environments in public spaces is key to enhancing well-being in high-density cities. This study utilizes deep learning techniques and field measurements to quantify visual and thermal environment factors. It examines the contribution of influencing factors in different green view spaces and reveals how to modulate multisensory experience through visual factors under specific thermal environments to promote recovery benefits. The result shows that thermal factors play a significant role, with solar radiation being the most important factor affecting restoration in low green view index spaces (GVI < 30 %). Furthermore, the study revealed that high orderliness could alleviate thermal discomfort (solar radiation > 600W/m²) and promote overall restoration. Additionally, under calm or light air conditions (wind speed < 1.5 m/s), enhancing landscape depth can facilitate restoration in spaces with high GVI. Our research allows for a deeper understanding of the potential value of the combined effects of visual-thermal environments in enhancing residents' health under intensified heat exposure. It also provides important implications for how limited greening resources can be used effectively to maximise their restorative benefits in high-density cities.