Chapter 17: Groundwater
Jan 01, 2016
Chapter 17: GroundwaterChapter 17: Groundwater
Distribution of Fresh WaterDistribution of Fresh Water
IntroductionIntroduction 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
Water TableWater Table
Interaction of
Groundwater with Surface Water
Interaction of
Groundwater with Surface Water Gaining
stream Losing
stream
Gaining stream
Losing stream
Characteristics of MaterialsCharacteristics 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
Materials & Groundwater Yield
Materials & Groundwater Yield
aquitard
aquitard
aquitard
aquiferaquifer
aquiferaquifer
Movement of GroundwaterMovement of Groundwater
Hydraulic GradientHydraulic Gradient Darcy’s Law: Q = K A (h1-h2)
d Q = discharge (m3 / s) K = hydraulic conductivity A = cross-sectional area of aquifer
Darcy’s Law: Q = K A (h1-h2) d
Q = discharge (m3 / s) K = hydraulic conductivity A = cross-sectional area of aquifer
Hydraulic gradient = slope of water table
SpringsSprings
Hot Springs & GeysersHot Springs & Geysers
WellsWells
Artesian WellsArtesian Wells
Problems Associated with Groundwater WithdrawalProblems 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
SubsidenceSubsidence
Septic ContaminationSeptic Contamination
Geologic Work of Groundwater
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
Caverns & SpeleothemsCaverns & Speleothems
Karst TopographyKarst Topography
SinkholesSinkholes