1. Chapter 17: Groundwater

2. Distribution of Fresh Water

3. Introduction Groundwater: water within the zone of saturation Zone of Saturation: zone where all pore spaces are filled with water Water Table: upper limit of zone of saturation Zone of Aeration: area above water table that includes capillary fringe, and belt of soil moisture Capillary Fringe: groundwater is held by surface tension only Belt of Soil Moisture: zone above the water table where water is held by molecular attraction Groundwater: water within the zone of saturation Zone of Saturation: zone where all pore spaces are filled with water Water Table: upper limit of zone of saturation Zone of Aeration: area above water table that includes capillary fringe, and belt of soil moisture Capillary Fringe: groundwater is held by surface tension only Belt of Soil Moisture: zone above the water table where water is held by molecular attraction

4. Water Table

5. Interaction of Groundwater with Surface Water Gaining stream Losing stream Gaining stream Losing stream

6. Characteristics of Materials Porosity: % of total volume of rock or sediment what consists of void spaces Permeability: ability to transmit a fluid Aquifer: layers that transmit groundwater freely Aquitard: layers that prevent groundwater movement Porosity: % of total volume of rock or sediment what consists of void spaces Permeability: ability to transmit a fluid Aquifer: layers that transmit groundwater freely Aquitard: layers that prevent groundwater movement

7. Materials & Groundwater Yield aquitard aquifer

8. Movement of Groundwater

9. Hydraulic Gradient Darcy’s Law: Q = K A (h 1 -h 2 ) d Q = discharge (m 3 / s) K = hydraulic conductivity A = cross- sectional area of aquifer Darcy’s Law: Q = K A (h 1 -h 2 ) d Q = discharge (m 3 / s) K = hydraulic conductivity A = cross- sectional area of aquifer Hydraulic gradient = slope of water table

10. Springs

11. Hot Springs & Geysers

12. Wells

13. Artesian Wells

14. Problems Associated with Groundwater Withdrawal Subsidence Saltwater Contamination Other Contamination Septic tanks Agricultural chemicals Acid mine run-off Materials from landfills Subsidence Saltwater Contamination Other Contamination Septic tanks Agricultural chemicals Acid mine run-off Materials from landfills

15. Subsidence

16. Septic Contamination

17. Geologic Work of Groundwater Caverns Speleothems: dripstone features found in caverns Stalactites: on ceiling, reaching toward floor Stalagmites: on floor, reaching toward ceiling Karst Topography Sinkholes (AKA Sinks): depressions formed from subsidence due to underground cavers Caverns Speleothems: dripstone features found in caverns Stalactites: on ceiling, reaching toward floor Stalagmites: on floor, reaching toward ceiling Karst Topography Sinkholes (AKA Sinks): depressions formed from subsidence due to underground cavers

18. Caverns & Speleothems

19. Karst Topography

20. Sinkholes