Formation Of River Landforms

Question 1

Where are waterfalls formed in a river?

Answer 1

Where the river is steep.

Question 2

Explain the formation of a waterfall. (5)

Answer 2

1. River erosion wears away soft rock to form a step, by abrasion and hydraulic action.
2. The falling water erodes a deep lake called a plunge pool.
3. The swirling water undercuts the resistant rock above.
4. The resistant rock collapses.
5. The waterfall retreats, forming a gorge.

Question 3

Give an example of a waterfall.

Answer 3

Yosemite Falls

Question 4

When do meanders form in a river?

Answer 4

As the gradient of the river evens out.

Question 5

Explain the formation of a meander. (4)

Answer 5

1. The river flows over bumps and round hills which causes it to bend in places.
2. The water flows fastest on the outside of the bend, meaning it has more energy and erosion of the bank occurs.
3. Slow moving water on the inside of the bend deposits sand and mud, due to the lack of energy.
4. Over time, erosion and deposition form a large bend in the river called a meander.

Question 6

Give an example of a river with a meander.

Answer 6

Mississippi River.

Question 7

Explain how a floodplain forms.

Answer 7

1. As a river meanders back and forth it flattens the land around it by eroding it and depositing sediment on it, creating a flat floodplain in its valley.
2. During a flood, a river bursts its banks and covers this surrounding land and deposits a thin layer of fertile alluvium on to it.

Question 8

What is spread over the floodplain each time a river floods?

Answer 8

A thin layer of silt/alluvium.

Question 9

Explain the formation of a levee.

Answer 9

A levee is formed over time by larger material which is deposited along the banks of a river because the river does not have enough energy to carry them.

Question 10

Define a levee.

Answer 10

A levee is a natural embankment of deposited material, sometimes strengthened to protect the surrounding area from floods.

Question 11

Define a floodplain.

Answer 11

The flat area of land on either side of a river that will be covered with water if the river bursts its banks.

Question 12

Explain what the water from a river does as it floods onto the floodplain, and how what it does is beneficial.

Answer 12

The water slows down, loses energy and deposits a sediment called alluvium, which is fertile (good for growing crops).

Question 13

What is the bluff?

Answer 13

The remains of higher land, where the rest has been eroded