Virtual Lab Porosityandpermeability

Name______Date ______

Lab # ______

Virtual Lab – PorosityandPermeability

Purpose: To investigate how different types of soil holdwater.

Question: How does soil type affect the movement ofgroundwater?

Background Information:

Groundwater is water that moves through soil and rocks below Earth's surface. When groundwater moves through soil, the structure of the soil affects its movement. Groundwater moves through the spaces between soil particles. These spaces are called pores. Not all soils have the same amount of pore space. The amount of pore space, or porosity depends on the number and size of pores in soil. If the pores in soil are all connected, allowing water to pass through them. This means that soil is permeable. The ease withwhich water moves through the soil is calledpermeability.

A soil with high porosity and many small pores can hold a lot of water, but it takes longer for the waterto enter all the pores. This means that when a soil has higher porosity it has lower permeability.

A soil's porosity and permeability are important to many people. Farmers must be aware of soil conditions so they can determine the best way to grow crops. Builders also consider these conditions in the area they plan to build. Environmentalistsareconcernedwithporosityandpermeabilitywhenthereisariskthatapollutantmightbe introduced into the groundwatersupply.

Pre-Lab :

Describe the difference between a well sorted sediment sample and a poorly sorted sediment sample. ______

Part 1

Procedure:

1. Color in the pore spaces between the particles blue to see which has the highest porosity.
2. Label the diagrams below either Sorted or Unsorted

1. Which has the most open space?Sorted or Unsorted sediments? Circle one
2. Which would hold the most water? ______Why? ______
3. What is the relationship between sorting and porosity? ______
4. What would this look like on a graph?

Part 2: Get a chrome book and log on.

1.Go to you release the water, answer the questions below.

2.Which tube do you think will flow the fastest? ______Explain why ______

______

3.Which tube do you think will flow the slowest? ______Explain why ______

______

• Release the water and watch, repeat to see which tube is the fastest / slowest.

4.Where your predictions correct? ______Why or why not? ______

5.Complete the column below

Table1

6.Compare the amount of water stored in the three sorted samples to the amount of water in the unsorted sample. ______

7.What is the relationship betweenbead/sediment size relate to Infiltration time? ______

8.What would this look like on a graph?

9.Describe the difference between the infiltration rate of a well sorted sediment sample and an unsorted sorted sediment sample. ______

Part 2

1.Go to

2.Before you release the water, use page 6 & 7 of the ESRT to fill in the grain size on the table below and answer questions 3 and 4.

3.Predict which column will empty the slowest______why? ______

4.Predict which column will empty the fastest______why? ______

Table 2

5.Where your predictions correct? ______Why or why not? ______

6.What is the relationship between the grain sizeand rate of permeability of water? ______

7.What would this look like on a graph? Be sure to label axis.

8.Basedonthisinvestigation,whichtypeofsoilisthemostpermeable?Whichistheleastpermeable?Howdo you know? Support your statement withevidence. ______