2. What happens to the water that is received on Earths surface?
1.) Water storage – stored on land as ice or snow, held on leaves
2.)Infiltration (seep) – water sinks into the ground to become ground water
3.)Runoff – flows over land surfaces into bodies of water
4.) Evapotranspiration – evaporation and transpiration by plants back into the atmosphere

3. Factors Effecting Infiltration
1. Slope steeper slope (gradient) = less infiltration
INFILTRATION
GRADIENT

4. 2. Porosity- The amount of open space in between sediments or rock
The higher the porosity, more infiltration will occur
INFILTRATION
POROSITY

5. Porosity is determined by:
a. Shape - Well rounded particles have greater porosity than angular.
ROUND
ANGULAR
POROSITY
ROUNDNESS

6. b. PACKING- The more closely packed the particles the lower the porosity.
UNPACKED
PACKED

7. - If all particles are the same size they are sorted.
c. SORTING-
- If all particles are the same size they are sorted.
- If the particles are different sizes/mixed they are
unsorted
- The more sorted, the higher the porosity
POROSITY
SORTING

8. Particle Size alone does NOT effect porosity
Particle Size alone does NOT effect porosity!!!!! (Shaping, Packing, Sorting does)

9. Real world application: Clay vs. Sand
Sand has a LOWER porosity than clay even though it has a larger grain size

10. 3. Degree of saturation- if pore spaces are already filled with water, less water will infiltrate
INFILTRATION
SATURATION

11. The more permeable the soil/rock, the greater the infiltration
4. Permeability- ability of a material to allow fluids to
pass through; is measured by how CONNECTED the pores are
Impermeable = means water cannot pass through (Ex: clay layers in ground)
The more permeable the soil/rock, the greater the infiltration
INFILTRATION
PERMEABILITY

12. Porosity is not the same as permeability!

13. Retention increases with a decrease in particle size.
5. Retention- When water “sticks” to the materials that it is passing through.
Retention increases with a
decrease in particle size.
*Fine sand has greater retention than coarse sand
*Smaller grains= less infiltration
RETENTION
PARTICLE
SIZE

14. 6. Vegetation-
Plants retain water and decrease runoff allowing more time for water to infiltrate into the ground
Main relationship: little vegetation = high runoff, less infiltration
INFILTRATION
VEGETATION

15. 7. Anthropogenic Influences – Roads and buildings are impermeable, reducing infiltration.
Urbanization

16. Real world connection: How does the local geology influence a regions likelihood of flash flooding?

17. An look at Ground Water Movement

19. FINE SAND Moderate drainage
PERMEABILITY
GRAVEL  Rapid drainage
 FINE SAND Moderate drainage
 CLAY Slow drainage

22. Other Activities
Complete Porosity/Permeability/Capillarity worksheet