Student activities
Activity 2 Permeability and porosity
The results from this experiment should lead students to conclusions about the
suitability of certain substances for holding and transporting water. These results
and a conclusion will be presented in a scientific report.
The material that makes up the surface and the
Questions:
ground of an area determine whether it is suitable
•
Which material had the highest % pore space?
for holding and transporting water. In these
•
Why would this material have the best porosity?
experiments students will investigate the properties
•
Which of these materials would make the most
effective aquifer?
of permeability and porosity.
Students should formulate a hypothesis for each
•
to porosity?
experiment, and construct tables for recording results.
At the end of the experiments students should be
able to conclude what the best materials for an
aquifer are, and present their findings in a scientific
report.
Experiment 1 - Porosity
Aim: calculate the pore space of various materials.
Equipment:
•
500 ml Beaker
•Marker
•Water
•
Graduated cylinder
• Gravel, sand, clay, crushed limestone
Method:
1. Mark a beaker about half way up the side.
2. Fill the beaker with water to this mark and
measure the volume using a graduated cylinder.
This measurement will be the total volume.
Experiment 2 – Permeability
Aim: to measure the speed that water can move
through various materials.
Equipment:
•
the gravel until the water reaches the top of the
gravel.
5. Note the volume of water added to the gravel. This
•
Gravel, sand, clay, crushed limestone
•
Graduated cylinder
•Water
•Timer
Method:
1. Fold a piece of circular filter paper into quarters,
open it so it is a cone, and place it in a funnel.
2. Fill the cone with gravel to about 1 cm from the top.
3. Place the stem of the funnel in a bottle or
graduated cylinder.
4. Pour water into the gravel in the funnel and note
how many seconds it takes to fill the glass bottle
or graduated cylinder.
5. This gives you a comparative permeability rate,
which can be changed to a rate of ml per second.
6. Repeat with sand, crushed limestone and clay and if
you have time you could do combinations of materials.
measurement is the pore space.
6. To determine the total percentage of pore space
in the gravel, divide the pore space volume by
Questions:
•
•
materials.
For an aquifer is it better to have a slow or fast
permeability rate?
7. Repeat with sand, crushed limestone and clay,
and if time permits try combinations of these
Which of the materials had the slowest
permeability rate?
the total volume times 100 (% Pore Space=Pore
Space/Total Volume x 100).
Filter paper
•Funnel
3. Dry the bottle and fill it to the mark with gravel.
4. Using a graduated cylinder, slowly pour water into
Did a combination of materials make a difference
•
Using your results for both of these experiments
is there one material or a combination of materials
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that would make an ideal aquifer.
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