Urban Tree Canopy Viewer – Easing Access to Priority Planting Projects

City of Cincinnati and Hamilton County

The Challenge

Urban planners in Cincinnati and Hamilton County faced a critical need for updated and accessible tree canopy data to inform environmental planning efforts. The last comprehensive canopy study had been nearly a decade old, leaving agencies without current data on tree cover changes and planting opportunities. This inequity meant some communities – often those facing higher pollution and heat – had far less canopy than others. Previously, such data was locked away in technical GIS reports or disparate systems, inaccessible to the public or to planners across different agencies. As a result, efforts to combat air pollution, urban heat, and stormwater runoff through tree planting lacked a unified, public-facing tool to guide decision-making.

The Outcome

The Cincinnati & Hamilton County Tree Canopy Viewer provides an interactive Google Maps-based interface, allowing users to toggle data layers (e.g. 2020 canopy, canopy change, air pollution, and stormwater) and click on neighborhoods or block groups for detailed insights.

Sanborn delivered a comprehensive solution using Google Maps Platform and Google Cloud technologies. At the foundation of the project was cutting-edge data creation: Sanborn’s team collected Quality Level 1 (QL1) leaf-on LiDAR for the entire City of Cincinnati and much of Hamilton County, enabling a highly detailed tree canopy analysis. From this data, the project derived seven distinct land cover layers – including existing tree canopy, possible planting areas, impervious surfaces, and other land cover classes. These datasets allowed the team to perform a change detection analysis to identify where canopy was lost or gained over the decade. The resulting geospatial data were then integrated into the web mapping application.

The Details

The solution brought together multiple datasets into one planning-oriented tool. The map loads census block group polygons color‑coded by metrics such as existing canopy percent, canopy change, and possible planting area. It also overlays environmental data: a layer for Air Pollution (PM2.5) shows fine particulate pollution levels by area, and a Stormwater Retention layer illustrates the relative amount of rainfall intercepted by the current tree canopy in each block group. All of the map’s layers are easily selectable via checkboxes or toggles on the side panel of the app.

Project Milestones

The project has significantly improved public access to detailed urban tree canopy information. Where previously only experts with GIS software could analyze this data, now any resident or official can easily view canopy coverage and trends through the Google Maps-based interface. The City of Cincinnati uses this public-facing inventory as a means to identify priority reforestation areas and track progress in planting initiatives. In short, the data is no longer confined to reports – it’s live and interactive for all.

One Planning-Oriented Tool

The application itself was built as an interactive map using the Google Maps JavaScript API for a familiar and responsive user experience. The frontend map interface is deployed on Google Cloud App Engine for scalability and reliability. Users can switch between standard Map and Satellite basemaps and overlay the specialized canopy layers on top of Google’s base map. Custom map controls and legends were implemented for intuitive toggling of data layers. For example, viewers can turn on the “2020 Tree Canopy” layer or compare it with “2011 Tree Canopy” to visually spot changes. A “Tree Canopy Change” layer highlights percent increase or decrease in canopy cover across the region, drawing attention to areas of significant tree loss or growth.

Streamlined Collaboration and Decision-Making

With the tree canopy viewer, planners and the public can use an address lookup (powered by Google’s geocoding services) to zoom to a specific location or neighborhood, then click on a block group or municipality to see a pop-up with detailed statistics – for example, the exact canopy coverage percentage in 2020, the change since 2011, estimated stormwater runoff reduction, and pollution index for that area. The user interface was designed with clarity in mind: a clean map, intuitive layer controls, and informative legends make the complex data accessible even to non-technical users. By leveraging familiar Google Maps navigation (pan, zoom, search) and overlaying domain-specific data, the application successfully translates raw geospatial data into actionable insights for urban forestry planning.

Key Results

By providing a single, authoritative platform for tree canopy data, the viewer has empowered cross-departmental planning and equity-focused initiatives. City departments (Parks, Environment & Sustainability, Public Works) and county agencies now reference the same maps and metrics when planning projects. This shared tool enhances collaboration – for example, urban foresters, sustainability officers, and stormwater managers can jointly pinpoint neighborhoods that need trees the most. Community groups advocating for green infrastructure also use the viewer to support grant applications and educate the public. The successful ReLeaf program – which distributed 20,000 free trees and helped raise Cincinnati’s canopy by 5% in five years – exemplifies the kind of data-informed effort that the application can support and amplify going forward.