Aim: How does water move through the
ground?
Do now: Thinking back to our lesson on the
water cycle, which term would describe
water moving into the ground?
I. Source of Ground Water
• Precipitation infiltrates the ground to
become part of the groundwater supply.
• The ground can
retain (hold) the
water.
Water will infiltrate the ground if it is…
- Unsaturated: not filled with water.
- Permeable: allows water to flow through.
Water will not infiltrate the ground if it is…
- Saturated: filled with water.
- Impermeable: does not allow water to flow
through.
What happens if water
does not infiltrate?
II. Factors that influence Infiltration and
Run off
1.Slope (steep vs. gentle)
Leave
two
2.Soil Composition (sorted vs. mixed)
lines
of
3.Rate of Precipitation (heavy rain vs. light rain)
space
betwee
4.Vegetation (many vs. few)
n each
With the person sitting next to you, discuss
how you think these four factors influence
the amounts of infiltration and run-off.
Slope
- Steeper slopes cause more run off
- Gentle slopes allow for more infiltration
Soil Composition
Sorted Particles
allow for more
infiltration
Mixed Particles
cause more run off
Rate of Precipitation
Heavy Rain cause
more run off
Light Rain allow for
more infiltration
Vegetation
Many plants cause
more infiltration
*roots create
spaces for water to
infiltrate
Few plants allow
more run off
Closure:
From the back TOP DO NOW
obtain the Infiltration
Worksheet
III. Soils Influence on Groundwater
Movement
• Groundwater's movement through the
soil and rock depends on porosity and
permeability.
Pores
A. Porosity – how much open space there is in
rock/soil.
Sorted Sediment
Has larger pore spaces
and more openings.
Pores
Mixed Sediment
Small sediments fills in
spaces creating smaller
spaces and less
openings.
Given three graduated cylinders; each holding the same volume
of well sorted sediment. Which graduated cylinder hold the
most volume of water?
THEY ALL HOLD THE SAME AMOUNT!
Porosity (empty space) IS NOT affected by particle
size when the sediment is well sorted.
Small
sediment
Medium
sediment
Large
sediment
B. Permeability – water flowing through soil.
- Depends on the size of sediments.
Fine = Slowly
LINK
Coarse = Quickly
C. Capillarity –
– The ability of water to rise in small
openings.
Closure:
From the back BOTTOM DO
NOW BIN obtain the Ground
Water Movement worksheet