Hawai'i Space Grant College, Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, 1997

Porosity 
Purpose 

To measure the amount of water stored in the pore space of a soil sample. 

Key Words

 

soil 

particle 

pore space 

porosity 

saturation 

groundwater 
 
 

Materials

 

dry soil sample or sand 

two 500 ml beakers 

water 

Background
Soils are made of particles of different types and sizes. The space between particles is called pore space. Pore space determines the amount of water that a given volume of soil can hold. Porosity is the percentage of the total volume of soil that consists of pore space. This is an important measurement in areas where drinking water is provided by groundwater reserves.

 Procedure

1.
Fill one beaker, up to the 500 ml mark, with dry soil or sand. Place it on a table or flat workspace.

 

2.
Fill the other beaker, up to the 500 ml mark, with water.

 

3.
Slowly pour the water from the second beaker into the soil sample. Stop pouring when the water level reaches the top of the soil. The soil has reached saturation and cannot hold any more water.

 

4.
How much water is left in the second beaker?

 

5.
How much water is now held in the pore spaces of the soil sample?

 

6.
Use your answer from question 5 to compute the porosity (the percentage of pore space) of the soil sample.

 

Return to Gradation Activity Index.


Return to Hands-On Activities home page.

This activity has been copied, with permission, from the University of Hawaii's School of Ocean & Earth Science & Technology server to ours, to allow faster access from our Web site. We encourage you to explore the original site.

Return to Reach Out! Home Page
To Reach Out! volunteer organization at the University of Michigan