Read and answer questions on page 21&22 in Earth Systems.

FLOW OF GROUNDWATER— PERCOLATION/PERMEABILTY You don't miss your water until your well runs dry. -an old country proverb Nearly all materials within the Earth’s surface have spaces between their particles. This characteristic is called porosity. The amount of space between material particles can be a lot or very little and can affect how quickly water travels through. Before you begin this investigation, develop a hypothesis about the rate of water flow through sediments of different sizes. How quickly do you think water will travel through sand? Clay? Gravel? What do you think will happen to the flow of water if you combine sand, clay and gravel? Record your hypotheses in your journal.

Activity Overview: Activity Overview: A synopsis of this lesson is as follows… You will observe the porosity of gravel, sand, clay and a combination of the three. After hypothesizing about the probable flow of water through each material, or combination of materials, you will see that the greater the porosity of a material, the greater its permeability. You should also see that combining different amounts of materials would affect the flow of water, dependent upon the resulting porosity of the mixture. GOALS: GOALS: In this lab activity, you will … Observe the flow of groundwater through sand, gravel, clay and a combination of all three. Compare the results of their investigations to determine the effect of porosity on groundwater flow

Materials Needed (per group) 6 cups, three with a hole three without 100 ml beaker 1/2 cup of sand 1/2 cup of gravel 1/2 cup of clay 300 mL of water Stopwatch or clock with second hand

MAKE A TABLE TO RECORD RESULTS AMOUNT/TIME Materials amount /time average Sand Gravel Clay Mixture

The Activity 1.After you have prepared a hypothesis regarding the flow of water through sand, gravel, clay and a combination of the three, your group should send one person to retrieve the materials needed for this investigation. 2.You should set up their investigation as follows: a.Cup with holes in the bottom should be placed into the cup without holes. A filter should be placed in the bottom of the bottle with cup with holes to prevent sand or clay from falling through to the lower bottle. Do this for each material (sand, clay, gravel) ---be sure clay is crushed b.You should place 1/2 cup of sand into one of the set-ups, 1/2 cup of clay should be placed into the next container and 1/2 cup of gravel should be placed into the third container. c.Students should measure out 100 mL of water and place it into a cup. 3.One student should pour the entire 100 mL of water into one of the containers while another student measures how long it takes for the water to completely travel through the material being tested. 4.Step 3 should be repeated for all materials (sand, clay and gravel). 5.Each group should create a different mixture of sand, gravel and clay to test. Record how much of each material you use. Results of these tests should be shared for class data.

Review and Reflect Answer the following questions prior to a class discussion: 1. What type of material (sand, clay or gravel) allowed water to travel through at the fastest rate? 2. What combination of sand, gravel, and clay allowed water to travel through at the fastest rate? 3. What property of a material most affects the rate of water flow?

Important lessons of this activity: Earth materials with high porosity allow water to travel through them at a faster rate then do materials with a lower porosity. Explain how you proved this statement in your lab. When combined, earth materials can affect the rate of water flow differently dependent upon the amount of porosity provided by the mixture. Mixtures with a large amount of gravel will allow water through more quickly then mixtures with a high percentage of clay. Make a “T” chart using your results and 4 other groups.

GRAVEL-1.18 MINUTES ML 1.03 MINUTES FOR 1 ML SAND-1.10 MINUTES ML 1.5 MINUTES FOR 1 ML CLAY-2 MINUTES ML 2 MINUTES FOR 1 ML