Rivers Flashcards
1
Q
What is a drainage basin?
A
The area of land that drains the water input(through precipitation) into a main outlet(river) is separated by watersheds
2
Q
What are the features of the upper course of the river?
A
- Interlocking spurs
- V shaped valleys
- Large angular rock
- Steep sides
- Waterfalls
- Shallow river
3
Q
What are the features of the upper course of the river?
A
- Meanders
- Gentler gradients
- Wider, deeper rivers
- Smoother rocks
- Floodplains
- Estuaries/ delta
4
Q
What are the four different methods of transportation?
A
- Traction - rolled
- Saltation - pebbles bounced
- Suspension - fine particles
- Solution -
5
Q
What are the two types of weathering?
A
Mechanical:
- freeze thaw
- biological
Chemical:
- change its chemical composition eg. through carbolic acid
6
Q
What factors affect rate of erosion?
A
- Steeper gradient = more erosion
- Bigger bedload = more erosion
- Softer rock = more erosion
- Cutting own trees = more water in river= more erosion
7
Q
What 3 conditions favour delta formation?
A
- When river slows down(so it loses energy so it deposits load- heavier ones first)
- When gradient decreases so velocity is lower
- When it flows into the sea or lake
8
Q
Why does a delta split off into many tributaries?
A
Because the deposition blocks the main outlet and so it is forced to split off into smaller tributaries?
9
Q
What are the 3 different types of deltas?
A
- Arcuate - spread out and splits off lots
- Bird’s foot - river splits many times
- Cuspate - arrow jutting into sea
