Queensland, known to Australians as the Sunshine State, is home to over five million people and boasts a tropical, warm climate for most of the year. With the climate warming, Queensland is getting hotter each year. Tree shade is scientifically proven to help protect people from the sun’s harmful ultraviolet (UV) radiation, reducing their risk of developing skin cancer.

To help keep people in Queensland active and safe, our landscape architects and digital specialists collaborated with Queensland Health to design the Healthy Places, Healthy People Shade Tree Guidance. The Guidance includes accessing CanopyCast, a digital solution that analyses UV radiation and shade protection.

The Shade Tree Guidance and CanopyCast help state agencies, local councils and developers plan and develop effective shade against UV radiation. Tree shade is particularly important along footpaths to provide people with healthy, safe and active transport options. 

The guideline is a first for Australia and a novel approach to harnessing tree shade for UV protection. Other Australian states, territories and cities across the globe can adapt the guideline’s research and digital solutions.

Digital design

CanopyCast is accessible through an internet browser and can help state agencies, local councils and developers plan for the right type of trees along pathways. UV radiation is a complex concept translated into CanopyCast to demonstrate how trees can protect humans from harmful sun exposure.

The digital solution uses evidence-based research by Professor Nathan Downs from the University of Southern Queensland’s School of Mathematics, Physics and Computing. Professor Downs undertook shade analysis by creating a ‘sky fraction’ value using a 360-degree camera to understand how much UV radiation is blocked by different types of trees. 

Parametric design

The model, combining shade analysis and an algorithm based on Queensland’s real-time UV radiation data, measures the effect of various types of tree forms and planting intervals  to optimise shade and human comfort. 

CanopyCast enables users to view different scenarios by choosing various Queensland locations, the time of day, UV radiation level, amount of time in shade and the type of tree form, spacing and planting intervals needed. 

Illustration of six types of trees
CanopyCast includes six types of shade trees, with varying height, canopy spread and leaf characteristics.
Illustration of a tree at different times of the day
CanopyCast can simulate scenarios of the impact of canopy spread to block ultraviolet (UV) radiation during three timeframes.

Landscape architecture

To create the Guidance, we underwent rigorous engagement with over 30 stakeholders who represented State government agencies and Regional and Local Government Areas to understand the constraints they experience with urban greening. 

We tested our assumptions and collected perspectives on how each organisation would use the Guidance and digital solution. For example, stakeholders consistently told us they would be more likely to use a digital step-by-step document, which informed the format of the Guidance.

The Guidance is an ever-evolving resource to help educate planning decision makers and the public about the health benefits of tree canopy. It encourages them to submit case studies and lessons learned on successful shade tree planting projects and ultimately, how they have used CanopyCast to create more shade in their local area.

Founded by the need to investigate sustainable, preventative health measures, the Guidance and digital solution inform users how to maximise tree shaded pathway networks to reduce UV radiation exposure in our urban environments. Tree planting supports urban cooling and improves thermal comfort, encouraging communities to choose active modes of transport to support their physical and mental wellbeing.

We are excited by user feedback, and with widespread uptake the Healthy Places, Healthy People Shade Tree Guidance and CanopyCast resource will be a game changer in supporting effective shade delivery and reducing UVR exposure and Queenslander’s skin cancer rates.

Jodie Antrobus

Senior Health Promotion Officer, Prevention Strategy Branch, Queensland Health