Carbondale, Illinois: Urban Heat Islands Pilot Study
*Mobile Version* A project by Greater Egypt Regional Planning and Development Commission with assistance from the City of Carbondale.
What is an Urban Heat Island?
- Urban areas are hotter than neighboring rural and forested landscapes
- Impervious surfaces such as pavement and rooftops absorb heat, especially dark colored surfaces
- Urban areas have less tree canopy to provide shade and evapotranspiration
- Increased heat generated from vehicle and HVAC exhaust
- Effects of Urban Heat Islands (UHIs) will increase with Climate Change
- Urban Heat Islands often lead to:
- Higher energy bills compared to nearby rural areas
- Increased exposure to air pollution
- Higher risk of heat-related illness
- Impaired water quality
- Impervious surfaces that cause UHI effects also often lead to flash flooding issues
- Lower aesthetic value of the city
Navigation Tips
How hot are Carbondale summers?
This map shows NASA Landsat 8 mean surface temperature for the months of July and August over the last five years (2018-2022).
What are some possible heat mitigation actions?
Photos property of Greater Egypt. From left to right: Arlington Wetlands, Jackson County Extension Gardens, Monterey CA., Rend Lake.
Green Infrastructure such as restored wetlands and nature preserves close to city centers, bike trails shaded by street trees, and rain gardens are all possible projects that could be implemented in Carbondale to combat UHIs and urban flooding. Simple structures such as shaded benches and bus stops can also make a big difference to cool people outside in the city.
The information provided by this pilot project can be used in future grant applications. There are many funding programs that can be used for projects to combat climate change including through the Environmental Protection Agency, the Federal Highway Administration, and the U.S. Department of Agriculture.
Methods
Heat Score
For the Heat Score, the 5-year July & August average temp from the previous map was summarized for each hexagon and scored according to the table below:
A melted flower pot with dead plants sits on a front porch south of Carbondale, July 2022
Zone Score
The hexagon grid was given a zone score according to the table below based on the majority zone area for that grid cell. The zone layer was provided by the City of Carbondale. Areas that would have high densities of people using outdoor spaces, such as shopping districts and housing units, scored higher. Neighborhoods known to have dense tree canopies, such as those zoned low, density residential, did not receive points as those areas have no or little UHI effects.
Landcover Score
Landcover was scored on the majority type for each hexagon. If parking lot was the majority, it was given a score of two. This is because parking lots are generally a large, dark colored, asphalt and coal tar surface, which are very inhospitable to walk across. Any other majority impervious surface was scored with a one.
No Data areas were outside of the Metropolitan Planning Organization (MPO) where landcover data has not been created. However, it consists of forested and rural areas.
Equity Score
Hexagons within a disadvantaged census tract were given a score of one, all other tracts received a zero. These designations are from the Climate and Economic Justice Screening Tool, a part of the Biden Administration's Justice 40 Initiative. The following map shows disadvantaged tracts for Jackson and Williamson Counties, but only the study area was scored.
J40
Walking/Rolling Score
People walking, using mobility devices, bicycling, and skating are exposed to the environment and more at risk from UHI effects than people who commute in vehicles. Physical activity during high heat can be difficult and dangerous to your health. Areas that contain sidewalks received a score of one. Areas with bicycle lanes and shared use paths also received an extra point. Areas without such facilities were scored zero.
A resident poses next to an empty planter box while walking downtown in Carbondale, July 2023.
Results
The final priority index is displayed below, with higher scores corresponding to a higher priority for mitigation of Urban Heat Island effects based on the criteria described in the methods. Scores were not weighted. The final priority index was made specifically for the City of Carbondale, and the scoring process was a combined effort from stakeholders. There is no standardized way to measure UHIs and this study may not reflect all possible methods.
Please note this is just a dataset for policy makers to make informed decisions and does not guarantee that any actions will be implemented. Some areas of high priority may be on private or state property and outside of the City's or County's ability to make changes to the landscape.
UHI Priority Index
Comment Form
If you have any comments related to this project, please use the google form below. This is optional but we encourage community input!
Carbondale Urban Heat Island Pilot Project Comment Form
Next Steps
This project was funded through a planning grant and does not allow for construction activities. Data and maps from this analysis will be used for future grant applications. Public comments will be taken into consideration during decision making.
Special Thanks to our partners for their input and assistance with this project:
- City of Carbondale
- Carbondale Sustainability Commission
- SIU Geography and Environmental Resources - Dr. Ruopu Li
- Jackson County Health Department
- Green Earth, Inc.
- Mary O'Hara
