Rivers

Question 1

What is a source

Answer 1

Where the river begins usually high up in a mountain

Question 2

What is a tributary

Answer 2

Small streams that join to flow into a larger river

Question 3

What is a load

Answer 3

Material transported by a river

Question 4

What is a sediment

Answer 4

Solid material that has been or is being eroded, transported and deposited

Question 5

What is the mouth of a river

Answer 5

Where the river flows into the ocean or sea

Question 6

What are the three sections of a river

Answer 6

Upper, middle and lower course

Question 7

What is the shape of the valley in the upper, middle and lower course of a river

Answer 7

Upper course: v shaped valley

Middle course: a wider v shaped valley

Lower course: a wide open valley with a wide u shape

Question 8

What is the width of the valley in the upper, middle and lower course of a river

Answer 8

Upper course: narrow

Middle course: wider

Lower course: widest

Question 9

What is the speed of the river in the upper, middle and lower course of the river

Answer 9

Upper course: fast

Middle course: slower

Lower course: slowest

Question 10

What is the size of the material transported at the upper, middle and lower course of the river

Answer 10

Upper course: large

Middle course: smaller

Lower course: smallest

Question 11

What is the main action of the river in the upper, middle and lower course of the river

Answer 11

Upper course: erosion

Middle course: erosion and deposition

Lower course: deposition

Question 12

What are the features formed at the upper, middle and lower course of the river

Answer 12

Upper course: Interlocking Spurs, rapids, gorges waterfalls

Middle course: meander, slip of slope and river cliff

Lower course: delta, braided streams and ox bow lakes

Question 13

What is a confluence

Answer 13

Where two tributaries join

Question 14

How do interlocking Spurs form

Answer 14

Tributaries join other tributaries to form a main river. Between the tributaries there are ridges of harder rock which the river is forced to flow around on its downward-winding course, creating interlocking spurs

Question 15

How do gorges form

Answer 15

Streams carve through hard layers of rock, breaking down or eroding it. Sediment from the worn-away rock is then carried downstream. Over time, this erosion will form the steep walls of a gorge.

Question 16

How do rapids form

Answer 16

They form when fast flowing water flows over resistant rock, creating white water form the frothy bubbly water

Question 17

What are the 4 main ways rivers erode

Answer 17

Hydraulic action, Abrasion, Attrition and corrosion

Question 18

What is hydraulic action in rivers

Answer 18

The riverbed and bank break away by shear force of the water getting into small cracks

Question 19

What is abrasion in rivers

Answer 19

Rocks carried by the water wear away the bed and the banks of the river

Question 20

What is attrition in rivers

Answer 20

Wearing down of the load of the load as the rocks and pebbles hit the riverbed and each other, breaking into smaller rounded pieces

Question 21

What is Corrosion in rivers

Answer 21

Water dissolves minerals from the rocks and washes them away

Question 22

What are the four main ways rivers can transport their load

Answer 22

Traction, saltation, suspension and solution

Question 23

What is traction in rivers

Answer 23

Large stones can be rolled or dragged along the riverbed by the force of the river

Question 24

What is saltation in rivers

Answer 24

Small stones which the river cannot lift, bounce off each other and the river bed are are carried forward short distances

Question 25

What is suspension in rivers

Answer 25

If particles are small enough the river can lift and carry them long distances

Question 26

What is solution in rivers

Answer 26

When the river dissolves minerals from the rocks they are carried in the water itself

Question 27

Label the diagram of the waterfall

Answer 27

Hard rock, soft rock, overhang collapses causing steep gorge like valleys, undercutting, plunge pool develops at the base of the waterfall

Question 28

How do meanders form

Answer 28

Meanders form due to greater volume of water carried by the river in lowland areas. This results in lateral erosion causing the river to cut its banks

Question 29

Where does water flow the fastest in meander

Answer 29

In the outer bends

Question 30

Where does water flow the slowest in a Meander

Answer 30

In the inner bends

Question 31

What happens on the outer bends of a meander

Answer 31

Steel sided River cliffs form due to water being flung towards the outer bend and erosion

Question 32

What happens on the inner bends of a meander

Answer 32

Deposition occurs and over time material builds up causing a slip off slope

Question 33

Label the diagram of a meander

Answer 33

Fastest flow, slowest flow, small river cliff, deposition, erosion, slip off slope, undercut by lateral erosion

Question 34

How does an oxbow lake form

Answer 34

1. Outer banks of a meander continue to be eroded until the ends meet 2. This causes another path fro the water to flow. The water now takes the shortest route of least resistance 3. Deposition cuts off the old meander causing and ox bow lake. Sometimes these lakes dry up causing a meander scar

Question 35

What is a braided river

Answer 35

A braided appearance caused by deposition in the middle of its channel.

Question 36

What is a delta

Answer 36

When a river reaches flat land I slows down, loses its energy and deposits sediments in its path, creating a triangular shaped deposit, usually where the river meets the ocean

Question 37

What happens in the upper course of a river

Answer 37

The gradient is steep and the river flows fast. The river has enough energy to carry large rocks along the river bed. The rivers load enables the river to cut vertically in the land, creating a v shaped valley

Question 38

What happens in the middle course of a river

Answer 38

Erosion is still the main action of the river but some deposition also takes place. The gradient of the slope becomes more gentle, the river widens and flows more slowly. The valley becomes wider and flatter and the river starts to curve creating meanders

Question 39

What happens in the lower course of a river

Answer 39

The gradient of the land becomes very gentle, the river slows down and the valley becomes very widethe main features are caused by deposition. A flood plain develops from the river repeatedly flooding its banks, depositing thick, fertile soil.

Question 40

Draw and label a diagram meander

Answer 40

Did you get it right?

Question 41

Draw and label a diagram waterfall

Answer 41

Did you get it right

Question 42

Draw and label a diagram of an oxbow lake

Answer 42

Did you get it right?