1. Groundwater Systems

2. Importance of Groundwater
Earth’s
Water
Only 3% of the Earth’s water is fresh & potable.
Freshwater
Although groundwater is only 0.6% of the Earth’s water it is 14% of the fresh water.
Freshwater – no Glaciers
Excluding glaciers, groundwater is 94% of the available freshwater.
Groundwater usage
Drinking water for > 50% of the population
Accounts for 40% of the Irrigation water
Provides 25% of industry’s needs

3. Using the terms below complete the concept map.
A) saturated zone
B) unsaturated zone
C) partially saturated zone
D) sandstone
E) shale
F) confining unit
G) unconfined aquifer
H) confined aquifer
I) porosity
J) permeability
K) aquifer
M) water table
L) infiltration
Rock/Sediment
With high 1) _______
(storage of water) & high
2) _________ (transmission
of water)
With low 1) _______
& low 2) _________ 3. 4.
For
example
Between 2
confining layers
Near the
surface
For
example 5. 6. 7. 8.
Pores are filled
with water & air
Pores are filled
with water
1 – I
2 – j
3 – K
4 – F
5 – D
6 – G
7 – H
8 – E
9 – B
10 – A
1 pt for each correct answer 9.
10.
Daily Assignment

4. How does water get below the Earth’s surface
Water infiltrates in recharge areas – areas at the Earth’s surface that allows water to move through it

5. Is groundwater an underground river?
Groundwater occurs everywhere
Zone of Saturation – all the pore space is filled with water
But not all the ground is saturated
Zone of Aeration – pores are filled with air and water
Water Table – upper surface of the zone of saturation

6. Where is groundwater stored?
Porosity
Percentage of total volume of rock or sediment that consists of voids (pores)
Function of
Size and shape of the grains
The packing of the grains
Sorting of the grains

8. Permeability Ability of a material to transmit a fluid (water)
The interconnectedness of the pores
Shales have a low permeability
Sandstones have a high permeability

9. Unconfined Aquifer – top of the aquifer is exposed to the atmosphere
Confined Aquifer – an aquifer lying between two aquitards, water is under pressure

10. The water table is a subdued replica of the topography

11. Groundwater movement
Groundwater is not stagnant, it responds to climatic changes
i.e. the water moves up wet periods & moves down during dry periods

12. Energy Drives Water Movement
Groundwater moves from high “energy” to low “energy”
Groundwater has two types of energy
Potential (stored) energy – controlled by elevation & gravity – how far can the water drop
Kinetic (in motion) energy – controlled by pressure and velocity (very small can be ignored)
Total of potential and kinetic energy is hydraulic head
Groundwater is moving, but slowly

13. Artesian Conditions
Artesian is applied to any situation where the groundwater in a well rises above the level where it is initially encountered.
Associated with confined aquifers – due to excess pressure from overlying material