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11: Ground Water. Hydrogeology : The study of ground-water/earth-material interactions Geology controls ground-water recharge, flow, discharge and availability Ground water acts as a geologic agent: Weathering, dissolution, volcanism, metamorphism, slope stability, earthquakes….
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11: Ground Water Hydrogeology: The study of ground-water/earth-material interactions • Geology controls ground-water recharge, flow, discharge and availability • Ground water acts as a geologic agent: Weathering, dissolution, volcanism, metamorphism, slope stability, earthquakes….
Ground WaterThe Unseen Part of the Water Cycle Aquifer Salt Groundwater
Hydrogeology DefinedWater/Earth Interactions Earth materials • Rock • Sediment (Soil) • Fluids (Water) Geologic processes • Form, • Distribute and • Change Earth materials • Water is a primary agent of many (all?) geologic processes
Hydrogeology DefinedWater/Earth Interactions Interactions go both ways • Groundwater controls geologic processes • Geology controls flow and availability of groundwater
Hydrogeology DefinedWater/Earth Interactions Geology controls groundwater flow • Permeable pathways are controlled by distributions of geological materials
Hydrogeology DefinedWater/Earth Interactions Geology controls groundwater flow • Permeable pathways are controlled by distributions of geological materials • Where groundwater is available as a resource is controlled by geology
Hydrogeology DefinedWater/Earth Interactions Geology controls groundwater flow • Permeable pathways are controlled by distributions of geological materials • Where groundwater is available as a resource is controlled by geology • Contaminant transport in the subsurface is controlled by geology
Hydrogeology DefinedWater/Earth Interactions Groundwater controls geologic processes • Volcanic Processes: • Igneous Rocks: Groundwater controls water content of magmas • Metamorphic Rocks: Groundwater injected by magmas can metamorphose country rocks • Volcanism: Geysers are an example of volcanic activity interacting with groundwater
Hydrogeology DefinedWater/Earth Interactions Groundwater controls geologic processes • Earthquakes: fluids control fracturing and fault movement, lubrication and pressures • Landslides: groundwater controls slope failure • Landforms: Valley development and karst topography
Ground Water Zones • Degree of saturation defines different soil water zones
Soil and Groundwater Zones Unsaturated Zone: Water in pendular saturation Caplillary Fringe: Water is pulled above the water table by capilary suction Water Table: where fluid pressure is equal to atmospheric pressure Saturated Zone: Where all pores are completely filled with water. Phreatic Zone: Saturated zone below the water table
Ground water and the Water cycle • Infiltration • Infiltration capacity • Overland flow • Ground water recharge • GW flow • GW discharge
Hydraulic Conductivity of bedrock is controlled by Size of fracture openings Spacing of fractures Interconnectedness of fractures Bedrock Hydrogeology
1843: Acton v. Blundell“English Rule” The landowner can pump groundwater at any rate even if an adjoining property owner were harmed. 1861: Frazier v. BrownEnglish Rule in Ohio Groundwater is “…occult and concealed…” and legislation of its use is “…practically impossible.” Ohio Groundwater Law
1903:Huber v. Merkel English Rule in Wisconsin A property owner can pump unlimited amounts of groundwater, even with malicious harm to a neighbor. 1974:Wisconsin v. MichelsPipelineConstructors Inc. English Rule Overturned Landowners no longer have “an absolute right to use with impunity all water that can be pumped from the subsoil underneath.” Wisconsin Groundwater Law
1984: Cline v. American Aggregates English Rule overturned in Ohio Justice Holmes: “Scientific knowledge in the field of hydrology has advanced in the past decade…” so it “…can establish the cause and effect relationship of the tapping of underground water to the existing water level.” Today: Lingering effects of English Rule It is very difficult to prove cause and effect to be defensible in court. English Rule Overturned in Ohio