TnirstiiVs  Ground  Water
                              Movement  Activity
Ground water must be able to move through underground materials at rates fast enough to supply useful
amounts of water to wells or springs in order for those materials to be classified as an aquifer. For water to
move in an aquifer, some of the pores and fractures must be connected to each other. Water moves through
different materials at different rates, faster through gravel, slower through sand, and even slower through
clay. Gravels and sands are possible aquifers; clays usually are not aquifers. The following activity demon-
strates how different sizes of rock materials that make up an aquifer affect water movement.

A O5JECTIVES: Students will:
1. Identify several sources of rock materials that make up an aquifer.
2. Discuss how water moves through gravel, sand, and clay.

• At least 10 students.
• Large area to conduct activity

This activity can be conducted in the classroom, gymnasium, or outside the school building. If conducted in the
classroom, move all furniture to allow for sufficient room for the movement of students. This is a three-part
demonstration that may create some excitement.

Select two or three students to be molecules of water. The remaining students will be rock materials.
1. Activity One: Water movement through gravel. The students represent gravel by holding arms out-
stretched, leaving a 15- to 30- centimeter (cm) space between their outstretched arms. Locate these stu-
dents in the center of the activity area. The students representing water molecules are to start on one side of
their "gravel" classmates and move through them, exiting on the other side. The water molecules will move
easily through the gravel.

2. Activity Two: Water movement through sand. The students represent sand by extending arms, bending
them at the elbows and touching their waists with their fingers. Locate these students in the center of the
activity area, spacing them approximately 15cm apart. Once again, have the water molecules slowly make
their way through their "sand" classmates. The water molecules will experience some difficulty, but should
still reach the other side.
3. Activity Three: Water movement through clay. Students become clay particles by placing their arms
straight down the sides of their bodies and standing approximately 10cm apart. Locate these students in the
center of the activity area. It will be a formidable task for water molecules to move through the clay. The
water molecules may not be able to move through the clay at all.
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