Rivers
Flooding
Cullowhee Creek
Atchafalaya
Slopes & Slides
100
What kind of river has the largest clast size?
Mountain Stream
100
What causes floods?
Intense rainfall Prolonged rainfall Major snowmelts
100
What kind of stream is Cullowhee Creek?
A Channelized steam because of it's man-made parts. It's really a combination of a mountain stream and a meandering stream.
100
What is the main problem that the Atchafalaya poses?
It wants to capture the Mississippi!
100
What are the factors in landslides?
Weight and slope of material (driving force) Strength of sliding surface (resisting force) Shape of the sliding surface (affects both)
200
What is lobe switching?
Changing Active Lobes
200
How does pavement affect flooding?
Doesn't absorb water like the ground, etc.
200
What indicates Cullowhee creek is a meandering river?
Obvious point bars and cut bank, has a wide flood plain.
200
Why is the Mississippi always trying to change it's course?
Because it is always trying to find the shortest route to the Gulf with the steepest gradient.
200
What is the difference between a rock fall and a rock slide?
Rock falls happen at steep rock walls, usually made of granite (which has lots of cohesion), and "catch air" due to gravity. Whereas rock slides move on a downslope, usually along a discrete failure surface
300
Why does a river have a concave up profile?
Because as the stream starts at the head water is has the highest elevation, and ends at the ocean. Roughness/clast size goes down, sediment goes up and discharge goes up.
300
What is the equation to recurrence intervals?
R = n+1 (number of years of research)/m (number of floods)
300
How was Cullowhee Creek made?
By bull-dozers
300
How have the artifical levees affected the natural process of flooding?
As the river bed builds and rises, so do the levees. However, since there is no flooding the layer of mud that overflows from river is no longer there to build up the flood plain.
300
What is the three main causes of landslides? (TERMS)
Morphologic Human Geologic
400
What is an oxbow lake?
Meander channels that are cut off
400
What is the 100 year flood?
A flood that typical happens once during an 100 year period. There is a 1% chance of a 100 year flood occurring in any given year.
400
Why doesn't Cullowhee Creek flood?
Because of the channelization. The channel is much deeper than the actual amount of water.
400
How did channelization increase flooding?
When engineers channelized the river they caused more water to go down a shorter distance, which caused the river to flood more and more often
400
What guarantees a landslide is evident? 1. A steep slope 2. When the force of friction weakens 3. When the force of gravity down the slop is greater than the friction and cohesion 4. When gravity is stronger than the cohesion of the slope material.
3!!!!!!!!
500
What is a delta?
It forms where sediment from streams enter cal water. Balance of erosion of the drainage basin.
500
What is the recurrence interval of a flood that has occurred 2 over 9 years of research?
2
500
What effect would the manmade structure have on the diversity of plant and animal life?
Goal was to increase diversity of plant life and animal life as if the stream was still meandering.
500
When was New Orleans founded?
1718
500
Explain what geologic, morphologic, and human causes of landslides are.
Geologic - (RESISTING FORCE) Weak materials, fractures, contrast in material Morphologic - (DRIVING FORCE) Tectonic Uplift, erosion of toeslope, vegetation removal, and earthquakes Human - Deforestation, Irrigation, mining, under slope, etc.
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