Fresh or Salty?
Figure 1. The water cycle.Copyright U.S. Geological Survey http://ga.water.usgs.gov/edu/watercycle.html
More than 70% of the Earth's surface is covered with water and still more water exists in the atmosphere and in underground aquifers. In this lesson, students learn about water bodies on the planet Earth and their various uses and qualities. They learn about several ways that engineers are working to maintain and conserve water sources. They also think about their role in water conservation.
Water is an important resource that all forms of life require for survival. Engineers study the water cycle and the various water bodies that make up the water cycle in order to continually ensure clean water is available. In the U.S., it is easy to take for granted the clean water coming out of our taps, but engineers are the ones who have designed the infrastructure to make sure this clean water is so readily available. They design water treatment plants and distribution systems that bring this resource to our homes. To build a water treatment plant, engineers must thoroughly understand the properties of nearby water bodies, including whether they are a good continual source for water. They also create new technologies and projects, such as tidal turbines and desalination plants to use oceans and their tides for water sources and to create electricity.
After this lesson, students should be able to:
- List the major bodies of water on Earth.
- Describe the Earth's water resources available for humans to use.
- Sketch a personalized water cycle that includes their community's major water resources/bodies and drinking water sources, as well as human treatment.
- Explain several ways that engineers are working to maintain and conserve water sources.