Materials List: globe; resource literature on lakes, rivers, seas, glaciers, oceans; Bubble Map BLM; ziti pasta; food coloring; rubbing alcohol; large plastic bag; newspaper; science learning log; Internet access; chart or white board; classroom art supplies
Note: This activity will take more than one day to complete. There is some pre-preparation required to dye pasta for this activity.
To activate prior knowledge, examine a globe with students. See if students can locate where they live on the globe. Instruct students to point to lakes, rivers, seas, glaciers, and oceans. Explain these are called surface waters. Ask students if they know which bodies of water are salt water and which are fresh water. Ask if they have ever tasted salt water. Was it good? Have students discuss the differences between lakes and oceans. Divide students into five small groups. Assign each group a body of water to research. Using the Bubble Map BLM or student created bubble maps, have students list the characteristics of each body of water. Next have groups present information and compare the similarities and differences in the bodies of water. Facilitate a discussion of several bodies of water found in Louisiana and classify them by type. State waterways can be found at http://enlou.com/places/water.htm. Have students record in their science learning log (view literacy strategy descriptions) the location and description of several bodies of water found around their home, school, town, or state. Finally have students participate in a TPR (Total Physical Response) graphing activity. Prior to the activity, create three category cards labeled “most,” “some,” and “very little”. Place these cards in three different parts of the room. Explain to the students that they are to predict how much of the water they see represented on the globe can be used by plants, animals, or people using the given categories. As each child makes his/her choice, they are to walk to the category card that shows their prediction. Count the students in each category and transfer this information to a chart or white board. Complete the following activity before discussing the results and reality of the students’ predictions.
To illustrate the proportions of usable water, take uncooked ziti (pasta) and prepare it ahead of time by dyeing it in alcohol and food coloring. To dye pasta, put approximately 1 tsp. of alcohol and 15 drops of food coloring in a large plastic bag and mix well. Next add the pasta and let it sit for several minutes. Pour pasta onto newspaper to dry. Color ninety-seven pieces blue, one piece red, and two pieces green. Then spread the ziti on a table. Explain that there are 100 ziti pieces representing all (100 percent) of the water of the world. Explain that two green ziti represent water that is stored as ice in glaciers and the poles. The one red ziti represents fresh water that is available for plants, animals, and people. The blue ziti represents the ocean water or salt water of the Earth. Have students discuss what this activity revealed to them when compared to their predictions in the prior graphing activity. Students should be able to explain why most of the water on Earth cannot be used as drinking water.
Have students suggest ways to conserve water. Make a chart of the actions suggested by students and record for a week what conservation actions they practiced. Encourage students to think about such things as turning the water off while brushing teeth or rinsing dishes in a sink full of water rather than under running water. Create a class bar graph of the designated actions and record daily how many students practiced the conservation actions.
The students can create ad slogans for water conservation that encourage positive actions. Students can create illustrations to go with the slogans and place them in various places around the school to increase an awareness of conservation and encourage students to be proactive in the conservation of natural resources.