Lesson 7: Water Everywhere


Reading and Questions
Humans use their natural environments to meet many of their needs. One of the most critical resources that humans need to survive is water, not only for drinking but also for agricultural use, washing, industrial use, and transportation. It can also be a source of power, by using flowing water to either turn paddles for various kinds of machinery or generate electricity.

Geography of the World
provides many examples of the ways in which humans alter their environment to make use of sources of water. (Page numbers are included so that you can see the photographs and examples in the book as you read through the paragraphs below.) While some areas of the Earth have plentiful rainfall and sources of water - like the Mekong delta - that allow for successful farming and fishing without elaborate systems of irrigation (p. 188), other areas - such as Spain and Portugal (p. 100) or Morocco and Tunisia (pp. 210, 212) - receive little rainfall and/or are far away from rivers and require extensive irrigation.

In many parts of the world, water from rivers and lakes or from reservoirs created by dams is used to irrigate crops. In Ukraine and Moldova, the Dnieper and Dniester Rivers allow for irrigation in drier areas (p. 121), just as Yangtze River provides water for irrigation in China (p. 132). In Sudan, the Nile River is used to water crops, and a government-run irrigation program has increased the amount of crops that farmers can grow (p. 217). The Niger River in western Africa supplies water not only for irrigation but also for hydroelectric power (p. 205). Irrigation can even allow farmers to grow food in the deserts of Saudi Arabia (photo on p. 156). On the Great Plains of the United States, water is drawn from underground reservoirs (p. 34). In Kenya, water from dams and lakes allows for irrigation (p. 242). Qanats, traditional underground irrigation systems, are used in Iran (illustration on p. 155).

Read the first two paragraphs and the gray box on page 73 in The Geography Book to learn more about dams and reservoirs, two ways that humans alter their physical environment. (If you have the supplies handy, you can also try the "Building a Better Dam" activity on pages 73-74.)

However, irrigation is not always without cost. The Amu Darya River in central Asia is part of the largest irrigation canal in the world, providing water to allow farming for large areas of land (Geography of the World, p. 164). But since 1960, the practice of drawing water from the Amu Darya River has bought about the shrinking of the freshwater Aral Sea, causing major changes to that environment (image on p. 160).

After visiting the pages cited above, answer the following questions based on what you learned.
  1. How can irrigation allow humans to live in areas that they might not otherwise be able to live?
    Irrigation can allow humans to divert water from places where it is plentiful to places where it is scarce, allowing people to live in places that they might not otherwise be able to inhabit.
  2. Describe one of the images of irrigation from Geography of the World that you found interesting and explain what you thought was interesting about it.
    Answers will vary. Ask your child to show you the image that he selected for this question and talk about it with you.
  3. What might be the pros and cons of continuing to use large amounts of water from the Amu Darya River for irrigation? Consider the impact on the people and the environment along the river and near the Aral Sea.
    Irrigation in this region allows people to grow crops in areas that would otherwise be too dry, but the use of water from the Amu Darya river for irrigation has caused the Aral Sea, which is fed by the Amu Darya, to shrink. While the irrigation has helped farmers, it has had a negative impact on fishing villages and, as the Aral Sea has shrunk, useless land has been created around its edges where dust storms are now common. Opinions about the pros and cons of this irrigation may vary.
In this Reading and Questions section, your child will read about water use around the world in The Geography of the World and The Geography Book and then answer questions about what she has learned.

Activity 1: Know Your Watershed

Materials: Geography of the World by DK Publishing
The land that you live on is part of a watershed. Water that falls on the land in your community drains into a common waterway, which may be a stream, lake, river, aquifer, wetland, or ocean. The choices that individuals, families, businesses, and community groups make can have an impact on the watershed.
Web Link
Web Link
Student Activity Page
Your child will use the EPA's website to identify her watershed and learn about some ways that individual actions can have an impact on the watershed. You may want to work with your child to navigate the website and identify the appropriate watershed. You may also want to talk to your child about how homeschooled kids can help protect their watersheds.