Rivers Flashcards
How is a meander formed
The flow on one side of the river is faster on the outside of a bend so this area is eroded and be uses of this silt is dropped off on the inside bend
What’s is a delta
Deltas are low lying areas where river meets sea or lake
What are the three types of deltas
Arcuate, cuspate and birds-foot
What course are deltas found in
Lower
What are the 4 types of erosion so transport in a river
Traction,saltation,suspension and solution
What is traction
Where large Boulder like rocks are pushed along the river bed
What’s is saltation
Where pebble like rocks bounce along the river bed
Why is suspension
Where very small pebbles float (are carried) along the river bed
What’s solution
It is like suspension but the rocks are much smaller (particles)
What is an oxbow lake
An oxbow lake is a meander that has been cut off over time
How is an oxbow lake formed
As a meander gets bigger the out side bends until it is very big, after this a flood may happen which cuts off the initial flow of the river and creates a new one, then the meander is cut off by left over silt creating an oxbow lake
What is a v shaped valley
A river that erodes downwards that creates literal “v shaped valleys”
How is a v shapes valley formed
The rivers ant powerful enough to erode sideways so they have to erode the high hillsides that stick out into their path on either side,the hillsides interlock with each other creating v shaped valleys
Which course is a v shaped valley in
Upper
What is a meander
A large bend in a river
Tell me the percentages of water across the earth
50%-ground water
40%-atmosphere
20%-lakes and rivers
10%-glaciers and polar ice
What’s ground water
Water stored under ground
What’s surface runoff
Where a surface is steep and water runs off it
What’s interception
Where a tree stops rain from hitting the ground for longer
What’s ground water flow
When the water flows from one ground water to another
What’s infiltration
When water slows seeps into into the ground
What’s surface storage
When water is stored at the surface e.g river
What’s percolation
The movement of water through soil or rock
What’s through flow
The movement of water sideways though soil towards a river
What’s precipitation
Water falling to the earth
What’s channel flow
The downhill movement of water and rivers
What is the difference between weathering and eroding
Weathering is Breaking and eroding is carrying away the rocks
What’s ‘in site’
In its original place
What’s physical weathering
When a rock is broken by heat then filled with water and each time the water freezes the rock expands letting more water in the crack
What is chemical weathering
Where oxygen and Carson dioxide add with rain and erodes a rock
What’s biological weathering
Where a plant/plants grow in a rock weather and erode it away
What are some characteristics of the upper course
- the gradient is steep
- the sediment shape/size is big
- the velocity is high and fast
- the valley cross section is a v
- all three river proses occurs in the upper course but the main process is erosion
What are some characteristics of the middle course
- the gradient is less Steep
- the sediment shape/size is small
- the velocity is medium/slow
- the valley cross section is U
- all three river process occur in the middle course but the main process is transportation
What are some characteristics of the lower course
- The gradient is flat
- the sediment shape is tiny
- the velocity is low/slower
- the valley cross section is { but not sideways lol
- all three river processes occur in the lower course but the main process is deposition
