1. Today’s Objective: How are permeability and porosity related to infiltration?

3. – the amount of open space in a rock
Porosity
– the amount of open space in a rock
Describe the sediments of each
vs.
High Porosity
Low Porosity

4. Porosity Varies with… Amount of Cement Sorting
The more cement between the particles the less pore space.
Well sorted (round) soils have more pore space than unsorted soils.
Fracturing
Bedrock with more fractures or cracks has more pores than bedrock without many cracks.

5. Porosity IS NOT affected by particle size.
48%
Porosity
48%
Porosity
48%
Porosity
Each container has an equal volume of sediment and equal pore space.

7. Permeability – The ability of water to flow through a soil.
Permeability depends on soil composition
(size and sorting)
** What would impermeable mean?**
Large
Particles
Small
Particles
Sorted
Particles
Unsorted
Particles

8. Large Particles
Small Particles
More permeable
Water flows easily from space to space
Less permeable
It’s hard for water to find a path through the soil
Sorted Particles
Unsorted Particles
More permeable
Plenty of open spaces that connect to each other
Less permeable
Small particles fill up the spaces leaving little room for water to move

9. Amt. of water the comes out
The amount, availability, and movement of groundwater depends largely on porosity and permeability.
As water permeates soil, some water molecules get stuck on the sediments and do not flow through. This is known as RETENTION
Amt. of water pored in
100 mL
Amt. of water the comes out
87 mL
Amount Retained
13 mL

11. The ability of water to rise in small openings.
Capillarity –
The ability of water to rise in small openings.
ex. Water being pulled into a paper towel
-wet to this height
-water
-container

12. Properties of Water

13. Capillary Action in Nature

14. More Surface Area