| Local Government | Urban Greening | Strategy Implementation |
Focus
The Thriving Perth Portal team worked with the City of Gosnells to develop a spatial evidence base to help guide where trees can be planted, where they should be prioritised, and how much future canopy can realistically be achieved across City-managed land.
Using detailed spatial analysis that draws on, extends, and applies multiple data layers within the Thriving Perth Portal the work supports practical, transparent decision-making and the on-ground delivery of the City’s Public Tree Strategy 2022–2030.
The first stage of the work mapped and identified the potential plantable spaces for new trees based on different land tenure and uses across the City of Gosnells. To identify realistic planting opportunities, all non-plantable or constrained areas were systematically removed, including:
• Underground gas, water and power infrastructure (with required clearance buffers)
• Overhead powerlines and associated buffers
• Traffic signals, power poles and streetlight poles
• Waterbodies
• Roads, footpaths and paved surfaces
• Sports courts, playing fields and required run-off zones and existing buildings
• Current tree canopy extent
• Projected tree canopy extent of newly planted trees providing a realistic baseline for understanding existing canopy provision and future gains already “in the pipeline”.
🌱 Identifying potential plantable space 🌱
🌱 Suitability of plantable spaces 🌱
Recognising that long-term tree survival depends on more than space alone, each potential planting area was attributed with key site and environmental considerations to inform species selection and planting feasibility, including:
• Verge width and surface cover (grass or bare earth)
• Soil type
• Depth to groundwater
• Flooding and waterlogging risk
• Bushfire prone areas
• Bush Forever and environmentally sensitive areas
🌱 How many trees could fit? 🌱
Agreed average mature tree sizes, based on species commonly used by the City of Gosnells, were applied to estimate realistic planting densities, the number of trees that could be accommodated within each potential plantable space, and the potential future canopy contribution at defined modelling horizons (e.g. 2039).
This work produced a spatial dataset of potential plantable spaces, attributed with site constraints and the estimated number of trees that could be accommodated at each location. Potential tree locations within each plantable space were also modelled.
🎯Tree planting multi-criteria prioritisation framework and hot spot map 🔥
Trees deliver multiple benefits – urban cooling, biodiversity, walkability, equity, and shade – but not all planting locations deliver the same level of benefit. Ad hoc or opportunity-driven planting risks missing areas of greatest need or benefit. To address this, the Thriving Perth Portal team developed a spatially explicit, multi-criteria prioritisation framework aligned with the City of Gosnells’ strategic objectives, to help identify Which playing locations address / support what strategic priorities and thus ensure that urban forest investment is targeted where it delivers the greatest combined outcomes for people, place, and environment.
Using the multitude of spatial layers in the Thriving Perth Portal, each land parcels plantable space was assessed against a set of strategic priorities, developed in consultation with City officers. These included:
• Existing low canopy provision and canopy deficit
• Future predicted canopy provision
• Area-level disadvantage (SEIFA)
• Land surface temperature and heat vulnerability
• Shade over footpaths
• Shade along cycle networks
• NatureLinks and ecological / biodiversity corridors
• Black cockatoo roosting and foraging areas
• Areas of bare earth or degraded verge condition
• Shady places and spaces – walkable catchment areas and routes to schools, public transport, activity centres and parks
• Bus stops without shelters
• Underground power project areas
The resulting 🎯🔥priority hotspot map🔥🎯delivers a clear, visual output showing how many strategic priorities are addressed at each land parcel and highlights locations where multiple priorities intersect and can be addressed simultaneously through targeted tree planting, ensuring investment is directed to areas of greatest combined benefit.
When exploring the data through the interactive web map, plantable spaces can be queried or filtered by individual priorities – or by any combination of priorities – making it easy to identify locations where tree planting will deliver one or multiple strategic outcomes.
This flexible, spatially explicit approach supports transparent and defensible decision-making by clearly demonstrating why certain locations are prioritised within the planting program. This approach directly informed the Urban Forest Strategy implementation plan of planting 2500 trees per year by translating strategic objectives into a spatially explicit, on-ground planting program.