Transcript eeos120_3nov09_gontz-1.ppt

From the Mountain to the Sea:
Rivers and Erosion
Join me as we watch the travel log of our friends
Water and Sand
Dr Allen Gontz
Coastal Geologist & Geophysicist
EEOS
EEOS 120, Fall 2009
3 Nov 2009
Today’s Journey
 Rivers
– Types
– Characteristics
 Deltas
– Form
– Function
 What Role Does Erosion Play?
Stream Hydrograph
Image courtesy of U.S. Environmental Protection Agency
Stream
Regions
Images removed due to copyright restrictions.
Aggradation v Degradaton
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See image at http://www.ingeba.org/lurralde/lurranet/lur30/30soria/30soria1.gif
Transport v. Supply
Figure by UMB OpenCourseWare.
Meander Evolution
Images removed due to copyright restrictions.
River
Sinuosity
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Braided River
Systems
Braided River, Jasper NP
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Photo by Hillebrand, Steve
Braided River Flood Plain
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Braided Flow
Image courtesy of NASA
Bar
Types
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Meander Evolution
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Braided
Morphology
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Straight Channel Flow
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Meandering Rivers
Systems
Meandering
Morphology
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Meandering Channel Flow
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The Shape of a River
Straight
Meander
Evolution
Sinuous
Meandering
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Meander Flood Plain
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Oxbow
Formation
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Mississippi Meanders
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Mississippi Meanders
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Meander
Types
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Stream
Classification
Stream
Character
Stream Cross Sections
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Channel Types
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Stream Morphology & Slope
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Control of Slope
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Rosgen Classification
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Erosion
and
Sediment Transport
Sediment Transport
Image courtesy of USGS
Stream Bank Processes
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Flood Plain Cross Section
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Flood Plain
Evolution
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Hjulstrom Diagram
Image courtesy of Karrock, under the Creative Commons Attribution-Share Alike 3.0
Sediment
Transport
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Grain
Size
Delta
Systems
Deltas
 Definition:
– An alluvial/fluvial deposit, usually triangular
in shape, at the mouth of rivers, streams or
tidal inlets
– Location were rivers discharge into large
bodies of standing water (lakes or oceans)
– Change in velocity facilitates the river
dropping its sediment load and allowing for
the rapid aggradation of a sediment deposit
Processes Controlling Delta
Morphology
Mississippi River Delta the classic birds foot
Images removed due to copyright restrictions.
Images removed due to copyright restrictions.
Channelized
Section
Lower
Mississippi
River Delta;
Current
Terminal
Lobe
The Nile the classic
wavedominated
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The Fly the classic
tide-dominated
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Delta Development
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Delta Evolution the Mississippi River Delta
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Delta Evolution the Mississippi River Delta
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The Mississippi & the USACE
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Old River Flow Control
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