Rivers

Question 1

What does a river long profile show

Answer 1

The long profile shows how a river’s gradient changes as it flows from its source to its mouth

Question 2

Define source

Answer 2

Where a river begins

Question 3

Define drainage basin

Answer 3

The area from which water drains into the river

Question 4

Define watersheds

Answer 4

An imaginary line that separates 2 drainage basin

Question 5

Define confluence

Answer 5

The point where 2 rivers join together

Question 6

Define tributaries

Answer 6

Smaller rivers which join the main river

Question 7

Define flood plain

Answer 7

Land that floods when a river overflows

Question 8

Define mouth

Answer 8

Where the river flows into the sea or lake

Question 9

Define river bed

Answer 9

The bottom of a river channel

Question 10

Define river bank

Answer 10

The side of a river channel

Question 11

Define channel

Answer 11

What the river flows in

Question 12

Whats the upper course of the river

Answer 12

The steepest part of land in the river, small but flows quickly, energy levels are high and the river cuts away at its bed. As it does it quickly deepens its valley through down cutting which creates a steep sided v shaped valley.

Question 13

Whats the middle course of the river

Answer 13

River starts to flow slowly because it starts to transport lots of sediments as rivers look muddy. As the river moves down its valley a number of changes occur. The river gets wider as more tributaries join together

Question 14

What are the 4 changes that occur in the middle course

Answer 14

1. The valley sides become less steep, giving the shape of a open V
2. The river begins to erode sideways into its bank. This opens out the valley floor and a flood plain starts to develop
3. Erosion and deposition occur
4. The edges of the floodplain are marked by bluffs

Question 15

What is the lower course of a river

Answer 15

When the valleys V shape is so wide that the valley sides have been disappeared. The river approaches its mouth. The river now winds its way slowly across a large flood plain. Deposition is now dominant process

Question 16

Define erosion

Answer 16

Gradual removal of rock from a rivers bank and bed

Question 17

Define abrasion

Answer 17

Rocks carried along by the river wear down the river bed and banks.

Question 18

Define hydraulic action

Answer 18

The force of the river against the banks can cause air to be trapped in the cracks. The pressure builds, weakening the bed and banks and gradually wearing them away

Question 19

Define solution

Answer 19

Soluble particles and minerals are dissolved inti the river

Question 20

Define attrition

Answer 20

Rocks being transported by the river smash together and break into smaller rounder and smoother pieces

Question 21

Define gradient

Answer 21

A steep gradient results in the river water being pulled by gravity, cutting down and eroding the channel

Question 22

Define rock resistance

Answer 22

Erosion rate increases more erodible the rock is

Question 23

Define solution (deposition)

Answer 23

Minerals are dissolved in the water and carried along in solution

Question 24

Define suspension

Answer 24

Fine light material is carried along in the water

Question 25

Define saltation

Answer 25

Small pebbles and stones are bounced along the river bed

Question 26

Define traction

Answer 26

Large boulders and rocks are rolled along the river bed

Question 27

Define capacity

Answer 27

Maximum amount of things a river can carry= overall weight of the load

Question 28

Define competence

Answer 28

Largest sized individual particles a river can carry = the largest rock it could movel

Question 29

Define artificial levees

Answer 29

Where people build up the height of a bank ( piled earth or coated in concrete) to limit the change of a river flooding

Question 30

Define estuaries

Answer 30

The tidal part of a river where fresh water from the river merges with the salt water from the sea