More trees mean healthier neighborhoods, and a new map is helping the city of Chicago identify neighborhoods that could benefit from increased investment in street trees.
Health geographer and data scientist Marynia Kolak and a team of fellow University of Chicago researchers recently partnered with Chicago’s Department of Public Health to develop a new advanced mapping tool—one that combines tree data with other metrics related to health outcomes, including air quality, surface temperature and traffic volume.
That information will help shape the city’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.
Working as part of UChicago’s Healthy Regions + Policy Lab (HeRoP), Kolak and her colleagues found a relationship between these health factors and the amount of canopy cover—the extent to which tree crowns cover a neighborhood. More trees were associated with a range of positive outcomes, including better air quality and lower summer surface temperatures.
“The intersection of pollution and ‘greenness,’” can be complicated to navigate, said Kolak, assistant director for health informatics at UChicago’s Center for Spatial Data Science. Trees, however, are “a point of resonance and agreement.”
In addition to physical health benefits, trees are also associated with a role in boosting mental health. Many scholars have conducted research in this area, including Assoc. Prof. Marc Berman of the Department of Psychology.
But in Chicago, Kolak said, there are often fewer trees in historically redlined and segregated neighborhoods, as well as areas that experienced higher levels of past industrial activity. Those same areas tend to have higher levels of particulate air pollution and higher summer temperatures, which can negatively impact human health.
More pollution can correspond to a wide range of health disparities for people living in those neighborhoods, including higher rates of asthma. By overlaying these different categories of information, new insights can emerge that help officials address these challenges.
The city of 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. The tool will be used to identify areas that could benefit from increased canopy cover over the long term, as measured by three-dimensional LiDAR data.
While there are plans to eventually make the city’s version of the tool available to the public, the HeRoP lab also created a free and open-source version to allow everyone to explore Chicago’s environment, allowing people to zoom in on their own neighborhoods to understand how they compare to nearby areas. Neighborhoods near the lake tend to be the coolest, while those near the interstate highways tend to be hotter and more congested with traffic. Dylan Halpern, a senior software engineer at HeRoP, co-led the development of the open-source tool with Kolak.