River processes *

Question 1

What is erosion?

Answer 1

• the process that wears away the river bed and banks, and breaks up the rocks that are carried by the river

Question 2

What is hydraulic action?

(erosion)

Answer 2

• the sheer power of the water smashes against the river banks
• air becomes trapped in the cracks of the river bank and bed
• this causes the rock to break apart

Question 3

What is abrasion?

(erosion)

Answer 3

• when pebbles grind along the river bank and bed

Question 4

What is attrition?

(erosion)

Answer 4

• when rocks that the river is carrying knock against each other
• they break apart to become smaller and more rounded

Question 5

What is solution?

(erosion)

Answer 5

• when the water dissolves certain types of rock, e.g. limestone

Question 6

What is transportation?

Answer 6

• the river picks up sediment and carries it downstream in different ways

Question 7

What is traction?

Answer 7

• large, heavy pebbles are rolled along the river bed

Question 8

What is saltation?

Answer 8

• pebbles are bounced along the river bed

Question 9

What is suspension?

Answer 9

• lighter sediment is suspended within the water

Question 10

What is solution?
(transport)

Answer 10

• the transport of dissolved chemicals

Question 11

What is deposition?

Answer 11

• when the river loses energy, it drops any of the material it has been carrying

Question 12

What factors lead to deposition?

Answer 12

• shallow water
• at the end of the rivers journey, at the rivers mouth
• when the volume of water decreases

Question 13

What is a drainage basin?

Answer 13

• the area of land around the river that is drained by the river and its tributaries

Question 14

What is watershed?

Answer 14

• the area of high land forming the edge of a river basin

Question 15

What is the source?

Answer 15

• where a river begins

Question 16

What is the mouth?

Answer 16

• where a river meets the sea

Question 17

What is a confluence?

Answer 17

the point where two rivers meet

Question 18

What is a tributary?

Answer 18

a small river or stream that joins a larger river

Question 19

What is a channel?

Answer 19

this is where the river flows

Question 20

Describe the upper course of a river

Answer 20

• upland area
• rivers load is larger - hasn’t been broken down by erosion

Question 21

Describe the lower course of a river

Answer 21

• flat land
• rivers load is fine sediment - erosion has broken down the rocks