Percolation and Sedimentation Rates of Soils
Sedimentation Rate:
The rate and order in which a mixture of various sizes of soil,
rock particles in water settles to the bottom of a pond/stream or river bottom.
Each group should have a SEDIMENTATOR TUBE. In this tube there is a mixture of sand, small pebbles, organic rich matter (such as potting soil) and water.
Take the tube and turn it over once and then leave it on the table for the
next 15-20 minutes. After the time has passed, go back and look at the tube and
answer the questions found on the student answer sheet under Sedimentation
Rate.
Percolation and Absorption Rates of Various Soils
1. Take a Percolation Tube ( 1 X
4 inch clear tube with 3 holes in the bottom of it)
CLICK HERE FOR A PIC
OF THE PERCOLATION TUBE SET UP
2. Place gravel in the tube
first. Fill it up with gravel to the black line (you will see the line inside
the tube). Place the percolation tube in the red bowl. Leave the tube sitting in the bowl, do
not move it around. The bowl will catch the water that percolates through
the soil/gravel.
3. Using the water bottle provided, fill
a graduated cylinder up with 100 mls of water.
4. Now slowly pour the water from the graduated cylinder over the top of the
gravel. Make sure that you pour all of the water into the tube over the gravel.
5. After the water has been allowed to percolate through the gravel (1-2 mins), lift the tube slowly up from the bowl and set it aside. Then pour the water in bowl back into the graduated cylinder. How much water has percolated through?
6. Write down your results under Percolation and Absorption rate on the
student answer sheet
7. Complete this experiment again, only this
time you will use sand. How
much water was allowed to percolate through the sand? Write down the results for sand under the student answer
sheet.
Percolation and Sedimentation Rates of
Soils
STUDENT ANSWER SHEET
SEDIMENTATION
1. What can you see happening in the tube over time? How many layers do
there appear to be?
2. What order did the various type of soil settle in? (sand, dark soil,
pebbles)
3. Which one stayed at the top and remained floating in the water the
longest?
4. If you were to look at a creek bed, what you find in the top layer of the creek bottom? Sand, dark soil or pebbles?
Percolation and
Absorption Rates of Various Soils
1. How much water was allowed to percolate through with the gravel? __________ milliliters
2. How much water was allowed to percolate through with the sand? ______________ milliliters
3. Which soil absorbed and held onto the most water?
4. If you wanted to use a soil that would hold the water long enough for a
plant to be able to use the water, which would you use sand or gravel?
