Chapter 5 : Rivers

Question 1

How is a waterfall formed?


Answer 1

1 : Soft rocks is eroded first, leaving the hard rock to erode slowly.
2: The water continues to erode the soft rock, leaving a ledge and making the pool of water below deeper and wider.
3: Over time, the hard rock is eroded and the ledge falls into the pit of water.
4: The steps are repeated

Question 2

What is an oxbow lake?

Answer 2

An oxbow lake is a U-shaped lake near the river. It is a meander that was cut off from the river.

Question 3

How is an oxbow lake formed?

Answer 3

An oxbow lake is formed when erosion causes a meander to get narrower and narrower. The river takes and shortcut and eventually, the meander is cut off from the river.

Question 4

What is a meander?

Answer 4

A meander is a bend or curve in a river.

Question 5

Name 4 keywords from erosion

Answer 5

Solution, hydraulic action, attrition, abrasion

Question 5

What are the river processes?

Answer 5

Erosion, transportation and deposition

Question 5

Name 4 keywords from transportation

Answer 5

Traction, suspension, solution, saltation

Question 6

What takes place in the upper course of the river’s long profile?

Answer 6

Erosion

Question 7

What takes place in the lower course of the river’s long profile?

Answer 7

Deposition

Question 8

What takes place in the middle course of the river’s long profile?

Answer 8

Both erosion and deposition

Question 9

What does erosion mean?

Answer 9

Erosion means to wear away

Question 10

What is the difference between traction and saltation?

Answer 10

Traction is larger rocks and stones roll along the river bed. Saltation is when smaller stones bounce along the river bed.

Question 11

Explain abrasion.

Answer 11

Abrasion is when rocks and stones hit and scrape against the river bed, wearing it away.

Question 12

Explain attrition.

Answer 12

Attrition is when rocks and stones hit and scrape against each other, wearing each other away.

Question 13

Explain solution (in erosion)

Answer 13

Water dissolves soluble materials from the beds and banks.

Question 14

Explain bedload.

Answer 14

Bedload is when heavier materials are carried along the river bottom.

Question 15

Explain suspension.

Answer 15

Suspension is when small particles of rocks and sand are carried along, causing the water to appear muddy.

Question 16

What is a confluence?

Answer 16

The point where two rivers meet.

Question 17

What is the start of a river called?

Answer 17

The source

Question 18

What is the mouth of a river?

Answer 18

The mouth of the river is where the river joins the sea

Question 20

List the steps on how rainwater reaches the river

Question 21

What is the flat land beside the river which may flood?

Answer 21

Floodplain

Question 22

What is a tributary?

Answer 22

Tributaries are smaller rivers that join the main one.

Question 23

The dividing line between one river basin and the next is the

Answer 23

watershed

Question 24

What is hydraulic action?

Answer 24

Hydraulic action is when the pressure from the water forms cracks in the river’s banks.