Water Cycle

Water Cycle

During this lesson, students played a game to simulate water traveling through the earth’s water cycle! We learned that at its simplest, the water cycle can be summarized as:

1. Water vapor in the atmosphere condenses into clouds
2. Water particles in the clouds grow bigger, and fall to the earth as rain
3. Rainwater lands in either the ocean, rivers, and lakes, or on the ground
4. From the ocean, rivers, and lakes, water evaporates and re-enters the atmosphere
5. On the ground, water infiltrates the earth and joins the groundwater, which eventually flows to the ocean

But during our activity, we discovered that the real water cycle is more complicated. Water can go through mini-cycles back and forth, traveling, for instance, from the atmosphere to the ocean and back to the atmosphere. Water can also become trapped for many years in the ocean, groundwater, or glaciers. It turns out that almost all (more than 96%) of the earth’s water is stored in the oceans; the water we use for drinking and watering crops mostly comes from the tiny fraction that is stored as fresh water in rivers and lakes!

The version of the game we played in class used KLS students to represent water drops, but students can play a similar online game on their own here: http://www.discoverwater.org/blue-traveler/.

In addition to the game, students also put together miniature water cycles.  Each group filled a plastic container with rocks, leaves, and other material from the area around the school, then added a small dish of water.  We left the closed containers in sunny spots, and when we checked on the containers at the end of class, we were able to see evidence of the water cycle in action: evaporation and condensation occurred inside the containers.  Instructions for making these miniature cycles accompany this post, in case students are curious to make longer-term observations.