Understanding Urban Heat Islands
Students will be introduced to the main reasons an urban heat island occurs. Students will explain how communities can use certain heat island reduction strategies to reduce the impact of an urban heat island effect.
Prior to class:
Prepare an overhead transparency of the Temperatures with Infrared Thermometer Data Chart located in Teachers Resources.
At the beginning of class:
Select two students to students go outside with the infrared thermometer to obtain temperatures with an infrared thermometer of asphalt in sun, asphalt in shade, concrete sidewalk, grass in the sun, and grass in a shaded area under a tree. Have students record the data on the overhead transparency of the Temperatures with Infrared Thermometer Data Chart.
Important information:
Data taken on a cloudy day without the sun present may produce mixed results in the data taken with the infrared thermometer.
- Begin class by asking students why it feels hot when they get out of a car on a hot sunny day at the mall. Next, ask them why it feels much cooler by a tree.
- Introduce the concept of urban heat islands by showing the EPA video clip, Urban Heat Island Effect - Mitigation. Prior to showing the video clip, ask students to focus on the following questions:
a) What is an urban heat island effect?
b) What causes an urban heat island effect?
c) How can cities reduce an urban heat island effect?
- Show the video clip. After showing the video clip, discuss the above questions.
- Handout Urban Heat Islands to students. Explain the graph of the urban heat-island profile. Emphasize to students that trees absorb the same amount of heat as to other surfaces found in cities, but release it over a longer period of time through the process of evapotranspiration.
- Handout the Understanding Urban Heat Islands worksheet. Instruct students to read the Urban Heat Islands handout in order to complete the Understanding Urban Heat Islands worksheet.
- As a class, review responses to the Understanding Urban Heat Islands worksheet. Be sure to discuss the last question. Emphasize that using a combination of heat island reduction strategies will most effectively reduce a city's temperature.
- Show students the infrared thermometer. Explain how it uses a laser to measure the amount of infrared energy emitted by an object to determine its temperature.
- Display the completed Temperatures with Infrared Thermometer Data Chart. Review the temperatures of the different outdoor materials.
Materials Needed:
Infrared Thermometer
Assessment
Urban Heat Islands (PDF / MS Word)
Understanding Urban Heat Islands (PDF / MS Word)
Video
Urban Heat Island Effect – Mitigation (Quicktime video) (2 minutes)
Assessment Information:
Understanding Urban Heat Islands Assessment (PDF / MS Word)
Supplemental Homework Readings for Student
Heat Island Reduction Activities (PDF)
Green Roofs - Reducing Urban Heat Islands: Compendium of Strategies (PDF)
Teacher Resources
Temperatures with Infrared Thermometer Data Chart (PDF / MS Word)