Ground Water Occurrence

1
Ground Water Occurrence
Fracture porosity
Intergranular porosity
2
Ground Water Flow System
3
Unconfined vs Confined Aquifers
4
Key Aquifer Properties

• Capacity to store water
• Volume of pore space
• Confined vs unconfined
• Capacity to transmit water
• Interconnected pore space
• Permeability

5
Porosity
Fracture porosity
Intergranular porosity
6
Ground Water Flow System
7
Seasonal Water Level Fluctuations
8
Climatic Water-Level Fluctuations
9
Cone of Depression
10
Overlapping Cones of Depression
11
Well Efficiency
12
Sources of Water to Wells
Pre-pumping flow system
Water removed from storage Decreased disharge to
stream
Water removed from storage Decreased disharge to
stream Capture of water from stream
13
Aquifer Properties

• Unconfined Aquifer
• Higher storage capacity
• Local pumping effects

• Confined Aquifer
• Lower storage capacity
• Widespread pumping effects

14
Long-Term Aquifer Stability
15
Long-Term Aquifer Declines