Summary: This set of activities allows the students to investigate how shade affects the temperature of a body of water while using a temperature and light probe or sensor.
Preparation: The focus of this activity is for students to be aware that the amount of vegetation surrounding a body of water can change the temperature of the water.
Teachers should visit the body of water before taking students to it, and note the best places for observation. It is helpful to preassign students to their group locations. Check with the owners or authorities (e.g., park service) to arrange good times to bring the students.
Look carefully for any hazards, such as poison ivy, steep cliffs, broken glass, etc. Review medical records of the students, obtain proper permission slips, and always carry a first aid kit appropriate to the needs of the students. Students should be dressed appropriately with clothes that can be soiled or get wet. Have the students wear shirts and pants that cover their arms and legs (protects from poison ivy and bug bites) and shoes that cover the toes.
Discuss with the students in advance that they are invited guests into the homes of many different types of insects, birds, animals, and fish. They should be careful to not disturb the ecosystem.
Materials:
temperature probe
light probe
meter stick
optional: tent stakes
optional: colored tape or string
Classroom Management: This activity is designed to allow the students "hands on" work in teams. The size of the teams will depend on the number of available probes. Each member of the team should have a specific task to complete.
Activity Steps:
Conditions That Effect the Temperature of Body of Water
Explain to the students that shade from the vegetation surrounding streams, called riparian vegetation, is an important part in keeping bodies of water cool. Areas with adequate shade keep cooler than those exposed to sunlight and support different types of wildlife. Overhanging grasses, shrubs, and trees and even debris in the water provides shade that keeps the water cool.
Prior to going to the site, ask the students to discuss within their group other conditions surrounding a body of water that would influence the temperature of the water. Have the students share their ideas with the class. Possible conditions include:
depth of the water
width of the body of water
seasonal conditions
speed of the water
time of day
amount of sunlight
Have the students look for these conditions when they visit the site.
Describing the Site
Ask the students to complete an inventory of their site and to pay special attention to those conditions that might change the temperature of the water.
Mapping the Site
Have the students use a meter stick to measure one square meter at their test site and, if possible, mark the area with tent posts and colored ribbon. Encourage the students to select an area that is partially in the shade and partially in the light.
Using an electronic or paper notebook, the students should spend time sketching their site. It is important that the students have a sense of scale while drawing their sketch. Make a meter stick or even string marked with specific distances available to each group. They should mark distances between major features found on their sketch including those that might affect temperature.
Recording Light and Temperature Readings
Although the students may be familiar with the Celsius temperature scale, they may not be familiar with the term Lux. Explain that this is the unit for the light intensity (brightness) as it spreads from a source.
Demonstrate the use and setup of the both the light and temperature probes to the students. You may wish the students to practice before releasing them to their selected sites.
Based on variations of shade found in their square, students should select five test locations. Have the students mark these locations on their map and predict which location will be the coolest and which will be the warmest.
Ask the students to test the water with the temperature and light probe at five different locations within their square. Have them record the temperature and light readings at each location on an electronic or paper notebook.
Have the students compare their predictions to the actual readings and speculate the reasons for any differences.
Displaying Data on an x-y Line Graph
Have the students enter data from each location within their square into a spreadsheet. Ask the students to order the data starting with highest temperature to lowest temperature readings in the first column and enter the corresponding light data in the second column. The first row of each column should contain a header with the type of data and the units.
If you would like to see how to use a enter data into the spreadsheet, check out these Technical Hints.
Ask the students to highlight the temperature and light data and select Make a Chart from one of the menus. Have them select x-y line graph from the options. The graph will automatically open. Have the students investigate the options to title their graph.
If you would like to see how to create an X-Y line graph, check out these Technical Hints.
Interpreting the Data on an x-y Line Graph
In a prior activity, the students were asked to explain the relationship between light and temperature. Again ask the students to answer the following questions:
According to your spreadsheet, did the temperature at each location increase when the light increased?
Does the graph show you the same relationship? Explain.
In this activity, they should realize that the relationship is a direct relationship. In other words, as the light increases, the temperature increases. If their data does not represent a direct relationship, ask the students to reconsider the other possible factors that can affect the temperature of the water and to identify those factors that existed at their site.
Have the students write a paragraph about the relationship between light and temperature in their body of water. Encourage them to explain any factors that affected temperature at their site.
Extensions:
Allow the students to repeat the tests at the same locations at different times of the day or during different seasonal conditions. Have them compare the values on the same graph.
Environmental
Light, Temperature and Depth (1
class - field trip) 
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