Rivers

Question 1

What are the 3 stages of a river?

Answer 1

Upper, middle and lower.

Question 2

Where in the river does the river start to meander?

Answer 2

Middle

Question 3

Which part of the river is the deepest?

Answer 3

Lower

Question 4

Which part of the river has the slowest flow?

Answer 4

Upper

Question 5

What are the 4 types of erosion?

Answer 5

Abrasion, attrition, hydraulic action, solution.

Question 6

What are the four types of transportation?

Answer 6

Suspension, solution, saltation, traction

Question 7

What is solution(erosion)?

Answer 7

When the water dissolves certain types of rocks, eg limestone.

Question 8

What is hydraulic action?

Answer 8

The sheer power of the water as it smashes against the river banks. Air becomes trapped in the cracks of the river bank and bed, and causes the rock to break apart.

Question 9

What is abrasion?

Answer 9

When pebbles grind along the river bank and bed in a sand-papering effect.

Question 10

What is attrition?

Answer 10

When rocks that the river is carrying knock against each other. They break apart to become smaller and more rounded.

Question 11

What is traction?

Answer 11

Large, heavy pebbles are rolled along the river bed.

Question 12

What is Saltation?

Answer 12

Pebbles are bounced along the river bed

Question 13

What is suspension?

Answer 13

Lighter sediment is suspended (carried) within the water

Question 14

What is solution(transportation)?

Answer 14

The transport of dissolved chemicals. This varies along the river depending on the presence of soluble rocks.

Question 15

How are waterfalls formed?

Answer 15

1. Water crosses a bed of more resistant rock
2. Erosion of less resistant rock underneath creates a ledge
3. Ledge hangs/collapses
4. Waterfall takes new position/ repeats

Question 16

What creates a v-shaped valley?

Answer 16

Rivers eroding vertically down.

Question 17

What is velocity? What is it measured in?

Answer 17

The speed of the river. Measured in meters per second.

Question 18

What is the discharge of a river? What is it measured in?

Answer 18

It is the volume of water flowing in a river. It is measured in cubic meters per second

Question 19

On a meander where is the fastest flow and what is it called?

Answer 19

It is on the outside of the bend and it is called a thalweg

Question 20

On a meander, where is the slowest flow?

Answer 20

On the inside of the bend

Question 21

What is the flow on the inside of a bend in a meander called?

Answer 21

Helecoidal flow

Question 22

What process takes place on both sides of the bend in a meander?

Answer 22

Outside: erosion
Inside: deposition

Question 23

What is a floodplain?

Answer 23

Flat area of land that the river spills onto when it bursts its banks

Question 24

What are levees?

Answer 24

A small ridge or raised area of land on the banks of the river. Can be natural or man-made

Question 25

How are levees naturally made?

Answer 25

After a river bursts its banks many times, sediment get deposited onto the banks raising it.

Question 26

How is a river delta formed?

Answer 26

A delta is formed when the river deposits its material faster than the sea can remove it.

Question 27

What are the 3 types of river deltas?

Answer 27

Arcuate or fan-shaped, cuspate and birds foot

Question 28

How does a flood occur?

Answer 28

A flood occurs when the water in a river overtops its banks because the amount of water flowing(discharge) is too great for the capacity of the channel.

Question 29

What are the causes of a flood?

Answer 29

Heavy rain, snow melting, antecedent rainfall, hot dry weather, deforestation, impermeable surfaces, steep slopes, urbanisation, ploughing.

Question 30

What is antecedent rainfall?

Answer 30

Antecedent rainfall is when it is raining after it has just rained so the surface is saturated with water therefore the rain just runs of the surface.

Question 31

What is the difference between soft and hard engineering?

Answer 31

Hard engineering is a coastal management technique used to protect coasts,by absorbing the energy of waves, preventing erosion and flooding. They are highly visible man-made structures used to stop or disrupt natural processes. Soft engineering works with nature to protect the coast rather than trying to stop natural processes.

Question 32

What is a dam? What does it do? Etc.

Answer 32

A dam traps water and releases it in a controlled way controlling flooding. It is a form of hard engineering and is very expensive.

Question 33

What happens in afforestation? What is it?

Answer 33

In afforestation, trees are planted near to the river. This means greater interception of rainwater and lower river discharge. This is a relatively low cost option, which enhances the environmental quality of the drainage basin. It is a form of soft engineering