Study of Rivers Definitions

Question 1

drainage basin

Answer 1

the area of land drained by a river

Question 2

catchment area

Answer 2

the area within the drainage basin

Question 3

watershed

Answer 3

the edge of highland surrounding a drainage basin that marks the boundary between two drainage basins

Question 4

source

Answer 4

the beginning or start of a river

Question 5

confluence

Answer 5

the point at which two rivers or streams join

Question 6

tributary

Answer 6

a stream or smaller river which joins a larger stream or river

Question 7

mouth

Answer 7

the point where the river comes to the end, usually when entering a sea

Question 8

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

abrasion

Answer 9

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

Question 10

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

solution (erosion)

Answer 11

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

Question 12

the 4 types of erosion

Answer 12

hydraulic action, abrasion, attrition, solution

Question 13

the 4 types of transportation

Answer 13

traction, saltation, suspension, solution

Question 14

traction

Answer 14

large, heavy pebbles are rolled along the river bed. this is most common near the source of a river, as here the load is larger

Question 15

saltation

Answer 15

pebbles are bounced along the river bed, most commonly near the source

Question 16

suspension

Answer 16

lighter sediment is suspended (carried) within the water, most commonly near the mouth of a river

Question 17

solution (transportation)

Answer 17

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

Question 18

erosion

Answer 18

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

Question 19

transportation

Answer 19

the process in which the river picks up sediment and carries it downstream

Question 20

deposition

Answer 20

the process in which whenever the river loses energy, it drops any of the material it has been carrying

Question 21

3 factors leading to deposition

Answer 21

• shallow water
• at the end of the river’s journey (at the river’s mouth)
• when the volume of the water decreases