The shrinking of Asia's Aral Sea has led to a number of problems for people in the region. This lesson asks students to consider what happens when a sea shrinks and to compare pictures of the Aral Sea at different times. They will conclude by pretending to be residents of the Aral Sea region, drawing "before" and "after" pictures of how changes to the sea have affected their lives.

Geography, earth science, environmental studies

Standard 14: "How human actions modify the physical environment"
Standard 15: "How physical systems affect human systems"

Two hours (not including observing the evaporation experiment for one week)

• Computer with Internet access
• Wall map of the world
• Measuring cups
• Measuring spoons
• Salt
• Shallow bowls (preferably colored ones so students can observe salt after water evaporates)

Students will

• conduct an experiment to see whether salt evaporates with water;
• hypothesize what might happen to people, animals, and plants living near a shrinking sea;
• compare satellite images of the Aral Sea from 1973 and 1999;
• do the Aral Sea family activity, matching problems in the Aral Sea region with people's statements about these problems;
• discuss changes that are occurring in the Aral Sea region; and
• draw pictures depicting the lives of people in the Aral Sea region before and after the sea began to shrink.

Begin the lesson by conducting a simple evaporation experiment. Have students place two tablespoons (30 ml) of salt into a measuring cup and then add warm water until the water level is at one cup (240 ml). They should stir until the salt is completely dissolved. Have them pour the mixture into a shallow bowl, and ask them to imagine that they have created an inland sea. [Note: Real seas do not have nearly this much salt in relation to water, but the exaggeration in this experiment will help students see the results more clearly.]

Have students place their "seas" near a window, if possible, and look at the water level every day for one week. Ask them to record the changes to the water's appearance.

Ask students what their experiments show might occur if the water level in a real sea were to gradually drop. They should understand that the salt doesn't evaporate with the water. Some of the salt is deposited on the ground around the perimeter of the evaporated sea, some settles on the bottom, and much remains in the water.

Ask students to explain what they think might happen to people, animals, and plants that depend on a sea that is shrinking. How would a reduction of the water level affect people's ability to drink, bathe, and irrigate their farms? How would people, animals, and plants like the saltier water?

Introduce students to the Aral Sea by pointing out its location on a world map (between Kazakhstan and Uzbekistan in the former Soviet Union). Explain that the Aral Sea has shrunk by more than 60 percent in over 30 years because water flowing into the sea has been diverted for cotton farming. As residents there have discovered, when salt water is removed from its original area (through evaporation or diversion), it leaves salty deposits and the water itself becomes more salty.

Have students look at satellite images of the Aral Sea. Ask them to view the images for 1973 and 1999, making sure they view from the six-mile range (the small box on the lower left will say "24 mi"). Ask them to compare what they see in the two images and answer these questions:

• Looking at the 1973 photo, imagine that this part of the sea looks like a dog (with ears at the top and an upraised paw). What has happened to the "dog's" head in the 1999 photo? Why would this have happened?
• What other things do you notice in the 1999 image to suggest that the sea has become smaller?

Have students complete the Aral Sea activity and read the briefing information to learn more about how the Aral Sea has changed and how it affects the people who live near it. They should record their answers to the matching activity on their own paper. Before they go through this activity, point out that increased salinity is just one of the problems the Aral Sea is facing; they will see this as they do the activity.

Discuss students' answers to the matching activity on the Aral Sea activity. Then review what students have learned by discussing the following questions:

• Why has the water become more and more salty?
• Why are more people getting sick?
• How is the climate changing?
• What has happened to the fishing industry, and why?

Ask students to pretend that they are older and have lived near the Aral Sea for at least 30 years. Have them draw two pictures—one depicting their lives before water was diverted from the sea, and the other showing what their lives are like today.

Have students look at their drawings and consider the things they have learned in this lesson. Ask them to write paragraphs answering the question "What are some of the reasons that it's a good idea to take care of seas, lakes, and rivers?"

Ask students to imagine that a body of water near them, such as a lake or river, is shrinking. Have them script and stage a play portraying what people in their community might say and do about this situation. Their characters can include schoolchildren, parents, local politicians, local businesspeople, animals (or people who work to protect animals), and other individuals who might be affected by this situation.

Earthshots: Aral Sea
The Water Cycle at Work