GEOL 4220: Test 1
66 Cards in this Set
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Hydraulic Conductivity
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The property of sediment or rock that indicates how readily water can flow through it.
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Porosity
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The percentage of the rock or soil that is void of material.
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Permeability
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The degree to which a material allows fluids to pass through it via an interconnected network of pores and cracks
-GW is able to flow through aquifers b/c of this
-2 types- primary and secondary
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Darcy's Law
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Saturated flow of water through the whole soil with pores being the path
"movement through soils"
describes the flow of a fluid through porous medium
Q = KA(ΔH/L)
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Head
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Energy expressed as a length
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Darcy flux
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assumes water flows everywhere
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K (Hydraulic Conductivity)
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Properties of the porous media and the fluid.
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Intrinsic Permeability
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ki (lowercase)
quantifies the ability of a rock or sediment to transmit a fluid. (in this case, water)
Rocks that have a high k can transmit water much faster: gravel, clean sand, Karst limestone, fractured basalt
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If Hydraulic conductivity is the same in all directions it is....?
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Isotropic
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Is the World anisotropic or isotropic?
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Anisotropic
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Horizontal hydraulic conductivity
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Kh = (K1d1)/d + (K2d2)+.....
d = total thickness
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Vertical hydraulic conductivity
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Kv= d/(∑((d1/K1)+.....)
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Moisture content is equal to porosity?
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True.
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What controls the size of the capillary fringe?
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Amount of pores and surface tension (usually fine pores)
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Water travels from a _____ head to a _____ head.
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Higher; Lower
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A higher head has _____ pressure than a lower head.
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Lower
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The pressure head is less than zero in the ________ zone.
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Unsaturated
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The pressure head is greater than zero in the ________ zone.
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Saturated
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Westerlies
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Wind blows from west to east.
Driving force of climate.
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Summer Circulation Patterns
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Rising air warmed by land surfaces leads to generation of convective storms, most prevalent during summer afternoons
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Winter Monsoonal patterns vs. Summer monsoonal patterns
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Winter - High pressures moving inland; Summer - Low pressures moving toward the coast
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Convectional storms
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-Warm air rising, cool air falling
-Creates thunderstorms
-Short lasting
- As the air warms, the greater the amount of water the air can hold
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Frontal Storms
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warm front: warm air lifted over cold air
cold front: cold air displacing warm air
Generally last along time
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Orographic storms
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The mechanical lifting of the air because the land gets higher
More precipitation falls on the windward side
Leeward side is warming and drying (rain shadow)
Moist air becomes cool and condensates
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How do we measure precipitation?
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Rain gauge:
Recording
Non-recording (older)
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What is a storm?
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7 hours of no rain means a new storm (can vary depending on the location in the country)
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Hortonian Overland Flow
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Water infiltrates slower with more water in system
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Hot is on the ____
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Left
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Water flows ______
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downhill.
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Influent stream
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Losing water
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Effluent stream
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Gaining water
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Intermitent stream
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Flows seasonally
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Ephemeral stream
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Flows only during a storm
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Does water chemistry change with discharge?
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Yes.
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Low flow
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-Water table is low
-7Q10
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Capillary fringe
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Water that sits above water table (energy churn), provides water for plants
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Capillary forces
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Water held by pores with a stronger force than gravity.
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Are all confined aquifers unconfined at one point?
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Yes.
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Artisian aquifer
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Well is below piezometric surface, well will flow
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Total head
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The amount of water that can stay in a well.
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Perched Water
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Water that lies above the water table on a confining bed/aquitard
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Aquifuge
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A completely impervious bed or formation which neither contains nor transmits water. What you would want to line a land fill.
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Aquitard
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-Material with a relatively low hydraulic conductivity.
-Flow is vertical
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Perennial Stream
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A stream that has a well-defined channel and flows year-round, except during times of extreme drought
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Aquifer
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Contains water and can be used by man, all aquifers have horizontal flow
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Unconfined Aquifer
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An aquifer made of porous rock covered by soil, which water can easily flow into and out of
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Confined Aquifer
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an aquifer that is separated from Earth's surface by materials with low permeability (aquiclude or aquitard)
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Aquiclud
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rocks that lack permeability and will not transmit
water
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Unconsolidated Material
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Geological deposit in which individual elements are desperate and not cemented together. Sand and gravel, for instance.
Can break with fingers
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High energy environments yield _______ grain size.
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Uniform
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Poorly sorted material = _____ porosity.
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Low.
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Secondary Porosity
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Developed after rock formation
Sources: fracturing, faulting, dissolution
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Homogenous porosity
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Same everywhere
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Potentriometric surface
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Water table, top of unconfined aquifer
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Alluvium
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Mineral deposited by flowing water
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Till
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Unsorted, not a high flow property
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Ice-contact deposits
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Stratified drift, big rocks
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Loess
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Deposited by wind, act as an aquitard
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Colluvial Deposits
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loose, incoherent deposits at the foot of a slope or cliff brought by gravity
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Lacustrine sands
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Deposited in still water (clays)
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Ablation till
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Sediment deposited as the ice is melting, or when sediment is clogged at the bottom of glacier and deposited. Loose.
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Lodgment till
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sediment which has been deposited by plastering of glacial debris from a sliding glacier bed.
-Aquiclud (clay size)
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Primary permeability
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Flow through the rock
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Secondary permeability
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Flow through the fractures
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Primary porosity
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void space in rock
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Carbonates
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Surface observations usually misleading
Vertical joints widespread
Openings along bedding planes more important
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