Resilience Scanner

Data-Driven Tree Mapping Tool for Urban Forestry Prioritization

Solution Overview

A data-driven tree mapping tool guides Chicago's urban forestry strategy by integrating multiple environmental, health, and social vulnerability datasets to identify priority areas for tree planting.[1][3][4] The Chicago Department of Public Health developed this community tree tool with support from the Bloomberg Philanthropies Partnership for Healthy Cities, bringing together data on tree canopy, air quality, land surface temperatures, economic hardship, and other factors.[4] This approach enables the city to work with local nonprofits and community groups to identify priority communities and locations to plant trees.[4]

Technical Components

The mapping tool overlays data on tree canopy with air quality, land surface temperatures, economic hardship, and other social vulnerability and environmental factors.[4] The Morton Arboretum's Chicago Region Trees Initiative combined canopy cover, surface temperature, air quality, flood risk, health, and social vulnerability data into interactive map layers to identify where trees are needed most urgently.[3][7] Tree canopy data comes from a LiDAR-based analysis that can identify trees with less than a four-square-foot canopy.[3] Temperature data were derived from a satellite image that was taken in September of 2021.[3] The system will be used to identify areas that could benefit from increased canopy cover over the long term, as measured by three-dimensional LiDAR data.[1] Individual trees are visible as dots on the map, allowing users to see differences between similar developments in different parts of Chicago.[1] Data from the CDC Places dataset was used to map adult asthma rates across the region, showing the percentage of people 18 years and older who are affected by asthma.[3] The vulnerable populations data set identifies census block groups that are the most vulnerable by distinguishing those with low incomes, non-English-speaking, and a high proportion of minority populations.[3] To create the tool, the UChicago research team harmonized multiple datasets into a standardized format for evidence-based decision making.[1]

Implementation Details

Mayor Lori E. Lightfoot announced on Arbor Day a new tree equity initiative, Our Roots Chicago, which will plant 75,000 trees over the next five years under the $46 million Chicago Recovery Plan investment expanding Chicago's tree canopy across the city.[4] The mapping tool will help shape Chicago's plan to spend $46 million planting approximately 75,000 new trees over the next five years, focusing in part on census tracts with relatively lower numbers of trees.[1] The goal to plant 75,000 trees represents a doubling in tree planting over the previous year.[4] The initiative is a partnership between the City of Chicago, including the Department of Streets and Sanitation and the Chicago Department of Public Health, and non-profit partners, including Morton Arboretum and Openlands.[2] HeRoP partnered with Bloomberg Philanthropies, Vital Strategies, and the Chicago Department of Public Health to create the Tree Equity solution.[9] Bloomberg Associates, a pro bono municipal consulting service, has also supported the development and rollout of the tree equity strategy.[4] Chicago's Department of Public Health partnered with University of Chicago researchers including health geographer and data scientist Marynia Kolak to develop an advanced mapping tool that combines tree data with metrics related to health outcomes, including air quality, surface temperature and traffic volume.[1] Dylan Halpern, a senior software engineer at HeRoP, co-led the development of the open-source tool with Kolak.[1]

The identification of tree planting locations is also supported by a diverse 70-member community-based working group who share a commitment to helping the City expand Chicago's tree canopy and reduce tree removals.[4] Our Roots Chicago created a 115-member tree equity working group to help identify priority community areas and set long-term goals for expanding the tree canopy.[5] The Community Tree Ambassador program launched in May, which trains community residents on how to identify potential tree locations on City parkways.[4][6] Tree ambassadors are able to survey and submit potential tree planting sites from their mobile devices, providing an efficient way to have more trees planted in a shorter period of time.[4] The ambassadors are also able to geolocate trees to monitor their progress and performance in priority community areas.[4] Grow Greater Englewood was allocated $50,000 over two years as part of the Our Roots Chicago tree ambassador program, which they used to host two training events with about 30 people and request about 70 trees.[5] Volunteers from the Southwest Collective requested more than 700 trees after being part of the Our Roots Chicago tree ambassador program for about a year, covering areas from Garfield Ridge to Archer Heights.[5]

In 2023, the second year of Our Roots Chicago, the city planted 23,000 parkway trees, with about 8,600 planted in neighborhoods with the highest need.[5] More than 41,000 trees have been planted in the past two years through Our Roots Chicago, according to data from the city.[5] The city is on track to meet its goal of planting 75,000 parkway trees by 2026, according to spokesperson Mimi Simon.[5] On the Southwest Side, the city planted about 500 trees in Brighton Park, 200 in Archer Heights and 90 in Gage Park in 2023 as part of Our Roots Chicago's 22 priority spots.[5] Chicago recently passed a budget that allocated a total of $188 million in climate and environmental commitments—the most ever spent on the environment in Chicago.[1]

Benefits and Impacts

Working as part of UChicago's Healthy Regions + Policy Lab, Kolak and her colleagues found a relationship between health factors and the amount of canopy cover, with more trees associated with a range of positive outcomes, including better air quality and lower summer surface temperatures.[1] Chicago's urban forest provides ecosystem services valued at $785.7 million annually in 2020, including $740 million in carbon storage, $15.1 million in air pollutant removal, $11.9 million in avoided runoff, $11.2 million in building energy savings, and $7.5 million in carbon sequestration.[11] The urban forest sequesters 39,000 tons of carbon annually and stores 3.9 million tons of carbon.[11] Chicago's urban forest removes 1,300 tons of air pollutants annually and avoids 100 million cubic feet of stormwater runoff.[11] The initiative aims to expand Chicago's tree canopy and its benefits to all 77 community areas.[2] The approach also aims to strengthen the urban forestry sector and create green jobs.[2]

Climate Adaptation Relevance

This effort tackles tree coverage in communities that fall below Chicago's 16% average thus reducing serious climate change impacts such as urban heat island effects and frequent flooding.[4] Our Roots Chicago will equitably convey ecosystem benefits to communities disproportionately impacted by the climate crisis by prioritizing planting in historically marginalized and underserved communities on the South and West sides, where the city's current tree canopy demonstrates a shortage of trees.[4] Currently, the city's average canopy coverage is only 16% which is below the ideal average for cities, and it is even lower in historically under-resourced and underserved community census tracts, often varying from 4% to 10%.[4] The Chicago region has 23% canopy cover, far below the national average.[3]

Business Analysis

The $46 million Our Roots Chicago initiative represents a significant municipal investment in climate adaptation infrastructure, funded through the Chicago Recovery Plan.[4] The Chicago Region Trees Initiative combined all variables to identify areas that have the highest need for improved tree canopy and its related benefits, enabling CRTI to tailor programs, events, and training programs to improve the urban forest where it is needed the most.[3] The Chicago Region Trees Initiative is integrating climate change-related goals into a regional tree master plan and updating its recommended planting list to encourage climate-adapted species.[8] Leslie Brandt, climate change specialist with the Northern Institute of Applied Climate Science and the U.S. Forest Service, partnered with the Chicago Region Trees Initiative to assess the vulnerability of the region's trees to climate change and other factors, and then consider strategies for adaptation.[8] The assessment showed that some of the least vulnerable trees in the Chicago region are non-native invasive species, while many of the species native to the area are vulnerable to changing conditions.[8] The Chicago Region Trees Initiative is seeking grant funding to create real-world demonstrations of adaptation that resulted from the workshops.[8] As the city of Chicago undertakes tree planting initiatives, it plans to do so in partnership with local communities, learning about concerns at a neighborhood level.[1]

Sources