drainage basins and the river valley

Question 1

what is a drainage basin?

Answer 1

The area of land drained by a river

Question 2

what type of system is a drainage basin?

Answer 2

a drainage basin is an open system

Question 3

what is an open system?

Answer 3

an open system has inputs, flows, stores and outputs

Question 4

what is the input of of a drainage system?

Answer 4

precipitation

Question 5

name as many flows of the drainage basin as you can?

Answer 5

• surface run off
• channel flow
• infiltration
• through flow
• groundwater flow
• percolation

Question 6

name as many stores of a drainage basin as possible?

Answer 6

• channel storage
• groundwater storage
• interception storage
• surface storage

Question 7

name 3 outputs of the drainage basin?

Answer 7

• evaporation
• transpiration
• river flow into the sea

Question 8

what is the boundary called that separates drainage basins?

Answer 8

a watershed

Question 9

how does the watershed work?

Answer 9

the watershed is a high ridge of land, the water will run down both sides of the ridge into different drainage basins

Question 10

what is a tributary?

Answer 10

a smaller river or stream that joins a main river

Question 11

what is a source?

Answer 11

the source is where the river starts, usually in an upland area

Question 12

what is a confluence?

Answer 12

a confluence is the point where two rivers join

Question 13

what is a mouth?

Answer 13

a mouth is where the river flows into a river or lake

Question 14

what is mechanical weathering?

Answer 14

is the breakdown of rock without changing its chemical composition

Question 15

what is chemical weathering?

Answer 15

chemical weathering is the breakdown of rock by changing its chemical composition

Question 16

what is biological weathering?

Answer 16

biological weathering is the break down of rock by living things, such as plant roots

Question 17

what type of weathering is freeze thaw weathering?

Answer 17

mechanical weathering

Question 18

how does freeze thaw weathering work?

Answer 18

the temperature drops to below freezing point, water gets into cracks in the rock, the water freezes and expands which puts pressure on the rock,when the ice thaws the pressure is released and the crack widens

Question 19

what type of weathering is carbonation weathering?

Answer 19

chemical weathering

Question 20

how does carbonation weathering work?

Answer 20

rainwater has carbon dioxide in it; therefore making it a weak carbonic acid, carbonic acid reacts with rocks that contain calcium carbonate (for example limestone) and the rocks are dissolved by the rainwater

Question 21

what is the river’s course?

Answer 21

the path of a river as it flows downhill

Question 22

what is the upper course of a river?

Answer 22

the part of the river closest to the source

Question 23

what is the lower course of a river?

Answer 23

the part of the river closest to the mouth

Question 24

what do rivers flow in?

Answer 24

channels and valleys

Question 25

what causes the shape of the valley and channels to change?

Answer 25

erosion and deposition

Question 26

what is deposition?

Answer 26

the material being carried being deposited

Question 27

which course of the river has a steep gradient?

Answer 27

the upper course

Question 28

which course of the river has a medium gradient?

Answer 28

the middle course

Question 29

which course of the river has a gentle gradient?

Answer 29

the lower course

Question 30

what is the shape of the valley like in the upper course?

Answer 30

the valley is V shaped with steep sides and a narrow, shallow channel

Question 31

what is the shape of the valley like in the middle course?

Answer 31

gently sloping valley sides with a wider, deeper channel

Question 32

what is the valley like in the lower course of the river?

Answer 32

it is a very wide, almost flat valley, with a wide deep channel