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48 Cards in this Set
- Front
- Back
What is throughflow? |
Water travelling through the ground, on top of the saturated soil |
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What is the drainage basin or watershed? |
The total area drained by a river or stream |
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What is the Source? |
The upper reaches of the drainage basin |
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What is the mouth? |
The area where the stream joins another water body at the bottom of the drainage basin |
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How is Streamflow measured? |
Discharge: the volume of water flowing past a point in a unit of time m^3 / second Measured using velocity and cross sectional area |
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Where should discharge velocity be measured? |
At approx. 40% depth, where maximum velocity occurs |
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On a hydrograph: 1) What is Peak Flow? 2) What is the Falling Limb? 3) What is the Rising Limb? 4) What is the Lag time? 5) What is the little bump after the rainfall? 6) What is the larger bump later? 7) How does urbanization change this? |
1) The highest point of discharge 2) The decrease in discharge after peak flow 3) The increase in discharge leading up to the peak flow 4) The amount of time between the rainfall and peak flow 5) The water falling directly on the river itself and nearby soil saturating 6) Water coming from the drainage basin 7) The second peak would occur faster, and both peaks would be higher |
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What is a flood plain? How is a flood plain built up? |
Flat portion of a river valley adjactent to a channel, gets covered up by water during a flood. Built up by deposition of sediments from river |
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What is a thalweg? What does a thalweg indicate? |
Line that connects the deepest portions of the stream. Indicates line of maximum velocity |
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What are pools and riffles? |
Deeper sections (pools) and shallow grained deposits (riffles) |
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What is typically the distance between pools? |
5-7x the width of the stream itself. |
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What are the 4 stream patterns? |
1) Parallel 2) Trellised 3) Dendritic 4) Deranged |
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What is the most common stream pattern? Where do they occur? |
Dendritic, occur where local geography controls them to. Randomly slope around everything. |
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Where do Parallel streams occur? |
Areas of steep slope |
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Where do Trellsed streams occur? |
Areas with strong regional structural control i.e. Appallachians |
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Where do deranged streams occur? |
Areas of highly irregular topography, where lakes can form |
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What is a meander? |
Series of curves or loops in the main course of the stream |
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What is the measure of how curvy a stream is? How is it calculated? What are the two categories, and what values correspond to them? |
Sinuosity Ratio = actual length / straight line length SR < 1.5 = straight channel SR > 1.5 = meandering channel |
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What is the most common channel pattern in Southern Ontario? |
Meandering Channel |
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What conditions are predisposed to creating a meandering channel? |
Where unconsolidated sediment is present; easily erodable material. |
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What is a point bar and a cut bank? |
Point Bar - Deposition on the inside of the channel Cut Bank - erosion on the outside of the bend |
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How quickly do meandering channels migrate across floodplains? |
Up to 10 m / year |
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How does grain size change up a point bar? What is this called? |
Diminished up a point bar.
"Fining Upwards" |
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Why does erosion occur on the outer side of the meander and deposition on the inner side? What is this type of flow called? |
Corkscrew flow, because the of the speed difference between the point bar and the cut bank. "Helicoidal Flow" |
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What type of feature does Helicoidal flow produce over time? |
Oxbow Lake |
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What is a braided channel? |
When you have large channels that split apart and rejoin. |
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What seperates braided channels? |
Deposition inbetween called Braid Bars |
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What are 3 characteristics of Braided Channel Systems? |
1) Large fluctuations in discharge 2) Large amounts of bedload - lots of course material 3) Easily erodable banks |
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Where are braided channels often found? Give 2 specific examples. |
Areas of high relief. 1) Glacial Meltwater Systems 2) Mountainous Terrain |
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Are you able to map braided channels? Why or why not. |
No, because they change everyday. |
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Describe Anastomosing channels in terms of: 1) # of channels 2) Stability 3) Areas they form 4) Slow-moving |
1) Multi-channel systems
2) Stable 3) Floodplains with stable banks and sediment gain 4) Slow-moving |
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What are the 3 common channel types? |
1) Meandering 2) Braided 3) Anastomosing |
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What are the 4 different kinds of deposits within a floodplain? |
1) Colluvium - material slumping into the valley from the sides (not been moved by water) 2) Channel Fill Deposits - material deposited in the stream by itself (gravel, silt, sand) 3) Channel Lag - material deposited within that can't be moved 4) Splay - material deposited when a break occurs in a levee |
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What are meander scrolls? |
Alternating ridges and troughs on a floodplain, caused by point bar migration |
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What are vertical accretion deposits? |
1) Deposits that sit on top of lateral accretion deposits 2) Made up of finer materials 3) Deposited as a flood recedes i.e. Levee |
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What is Laminar Flow? What Reynolds number corresponds to it? |
Calm, linear flow, w/out mixing Re < 500 |
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What is turbulent flow? What Reynolds number corresponds to it? |
Water flowing in a nonlinear fashion with variable velocity Re > 2000 |
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What is the formula for the Reynolds number? |
Re = VRp/u V - velocity (m/s) R - hydraulic radius (m) p - density of water (1000 kg/m^3) u - molecular viscosity of water (1) |
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How do you find the hydraulic radius of water? |
R = A / P A - cross sectional area P - Wetted Perimeter |
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What happened in Horse Cave City Kentucky? |
Town built around a base of a cave, where drinking water was taken from. CHrome Plant was built, and began dumping waste into local sinkhole. However, because they were connected, it polluted the drinking water and people got sick. Closed 40 years b/c of pollution |
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What latin word does Pollution come from? What does it mean? |
Pollutus - to soil or defile |
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When is water considered polluted? |
If unusable for a purpose |
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What are the 4 classes of pollution, and what do they correspond to? |
1) Class AA and A - good enough to drink from 2) Class B - good enough to swim in 3) Class C - boating, fishing, fish propogation 4) Class D - fishing |
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What percentage of lakes are considered polluted by the EPA in 2010? When was the peak level of increase? To what extent? What was it caused by? |
40% 1995-1999, 26% increase, caused by industrial |
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Describe the Clean Water Act Ammendment in terms of: 1) Year of origin 2) Requirements for cities 3) Effect of act |
1) 1972 2) Cities required to have water treatment plant 3) Only 1/3 of lakes acceptable for fishing/swimming, now up to 2/3 |
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Who is stricter about Water Pollution; Canada or US? |
US In Canada we can drill for natural gases in the Great Lakes, in US they cannot. |
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What is Point Source Pollution? |
Pollution discharged through a discrete identifiable location. Easy to evaluate and easy to fix. |
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What is Nonpoint Source Pollution? What are two examples? |
Pollution from broad, diffuse sources. Hard to identify and quantify, and fix. I.e. Road Salt, Pesticide. |