Maps

Using data to target priority areas

Trees improve quality of life. To identify which areas have the most needs, we combined canopy cover, surface temperature, air quality, flood risk, health, and social vulnerability data into maps. See your community’s canopy cover and how it impacts your neighborhood.

Tree Canopy

Trees in the Chicago region are not distributed evenly or equitably. The Chicago region has 23% canopy cover, far below the national average.

This map shows the percentage of canopy for each census tract. Tree canopy data comes from a LiDAR-based analysis that can identify trees with less than a four-square-foot canopy.

Canopy cover
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Surface Temperature

Trees keep our neighborhoods cool.

Urban areas tend to be hotter because concrete and other built surfaces absorb the sun’s energy and release it as heat, raising temperatures to dangerously high levels that make cities less livable and require more energy for cooling.

This map shows the average temperature for each community. There is a direct correlation between canopy cover and excessive heat; areas with more trees tend to be much cooler. Temperature data were derived from a satellite image that was taken in September of 2014.

Surface temperature
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Flood Risk

Trees intercept stormwater and reduce stormwater runoff.

Their leaves hold rainwater, preventing it from entering the sewage system. Trees also remove water from the ground in a process known as evapotranspiration.

This map shows how susceptible each community is to flooding. Higher values indicate more susceptible areas.

Flood risk
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Air Pollutants

Urban areas have a lot of factories and cars that cause air pollution. But trees help keep our air clean and breathable.

Their leaves intercept airborne pollutants and store carbon. Trees that are planted in areas that have poor air quality can improve the health of residents.

This map shows the abundance of small particulate matter (PM2.5) as modeled by the Environmental Protection Agency’s EJScreen tool. Higher numbers indicate areas with more PM2.5.

Air pollutants
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Asthma Rates

People who live in areas with lots of trees tend to have lower rates of asthma—in part because of trees’ ability to improve air quality.

Data from the CDC Places dataset was used to map adult asthma rates across the region. The numbers are the percentage of people 18 years and older who are affected by asthma.

Asthma rates
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