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Rivers. Location Profiles Processes Landforms. Main UK Rivers. Thames. 10. Spey. 1. Clyde. 4. 2. Shannon. 1. 7. Tees. 3. 5. Ouse. 9. 5. 4. Tay. 2. Severn. 8. 7. Trent. 6. 6. Forth. 9. 3. 8. 10. 2. 5. River Profile. Source. Mouth + Delta.

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Presentation Transcript
slide1

Rivers

Location

Profiles

Processes

Landforms

slide2

Main UK Rivers

Thames

10

Spey

1

Clyde

4

2

Shannon

1

7

Tees

3

5

Ouse

9

5

4

Tay

2

Severn

8

7

Trent

6

6

Forth

9

3

8

10

slide3

2

5

slide4

River Profile

Source

Mouth + Delta

Classic River Profile

Upper Course

Middle Course

Lower Course

Steep ground

Moderate ground

Gentle ground

Fast flow

Moderate flow

Gentle flow

Erosion

Transportation

Deposition

V-shaped valley

Waterfall

Small meander

Small floodplain

Large meander

Large floodplain

Oxbow lake

slide5

River Processes - Transportation

Now Watch The Flash Presentation

On River Transportation

slide6

Process

Description

Saltation

Force of water drags or rolls rocks along river bed.

Traction

Dissolved material is carried along in the water.

Suspension

Pebbles are picked up and bounced along the river bed by flowing water.

Solution

Very light clays are held up in the water as it flows.

River Processes - Transportation

slide7

River Processes - Erosion

Abrasion/Corrasion

Hydraulic Action

Corrosion

Attrition

Force of water hitting off river banks causes them to wear down.

Stones carried by river hit into river bed and bank, eroding & scraping them.

Stones collide into each other knocking edges off – get smaller and rounder.

Rocks dissolve in water e.g. limestone

slide8

Landforms Of The Upper Course

V-shaped Valleys

Waterfalls

slide9

V-shaped Valley

River Gradient

River Speed

Erosion

slide10

1 As the river flows it erodes downwards initially, due to the great energy it has. This happens mainly because of the process of corrasion (explain in detail for in exam!)

slide11

2 The river therefore forms a deep and steep sided channel. Over time freeze thaw (again explain) weathering acts upon the riverbank. This loosens the rock and soil.

slide12

3 As the rock & soil from the river bank breaks up, it is transported to the river by to gravity and the wash effect of rain on the soil.

slide13

4 The eroded material that falls into

the river is then transported

downstream by the river and is

deposited on its bed or on a river beach.

slide14

2

1

3

4

1

2

3

4

River erodes downwards due to fast flowing water carrying stones.

A deep/steep sided channel forms & weathering loosens soil on the banks

Rock & soil from river bank breaks up, falls into river due to gravity & rain

Eroded material transported downstream and deposited on river bed.

slide15

Waterfall

River Gradient

River Speed

Erosion

slide16

Waterfall

Now Watch The Two Flash Presentations

On Waterfall Development

slide17

Waterfall

Now Watch The Second Flash Presentation

On Waterfall/Gorge Development

slide18

A =

Hard Rock

Swirling Rock

Soft Rock

Unsupported Rock

Plunge Pool

Undercutting

A

D

C

B

Waterfall- Diagram

C =

F =

D =

B =

E =

E

F

slide19

Waterfall

gorge ~ soft ~ abrasion ~ collapses ~ cliff ~ deeper ~ plunge ~ hard

A waterfall is formed when a river flows over a layer of ______ rock, which is lying over a layer of soft rock. The _____ rock erodes more quickly. The hard rock sticks out forming a _____ in the river, which is a waterfall. The soft rock at the bottom of the waterfall/cliff is then eroded further to form a ____________ pool. This pool becomes bigger and ____________ as water swirls broken rock around. The hard rock is left unsupported and so eventually ______________. Over a long period of time the waterfall retreats backwards forming a narrow and steep sided valley called a _______. You will gain marks for describing either how the erosion occurs e.g. Hydraulic Action & __________.

hard

soft

cliff

plunge

deeper

collapses

gorge

abrasion

slide20

Meander

Oxbow Lake

Floodplain

Landforms Of The Middle & Lower Course

slide22

Meanders

Inner Bend Outer Bend

Slow Flow Fast Flow

Low Energy High Energy

Small Rocks Large Rocks

Deposition Erosion

Shallow Water Deep Water

River Beach River Cliff

slide23

Bank will

collapse

Small

river

cliff

( river beach )

Deposition of

Sand and shingle

Deepest part

of the river

Meander - River bend

Fastest current

slowest current

Outer bank

Is undercut

slide24

Meanders - Sequence Exercise

Use your cross section diagram and the words in the same order as below to write 2 paragraphs explaining how meanders form.

Paragraph 1

Outer bend ~ fast flow ~ high energy ~ large rocks ~ erosion ~ deep water ~

river cliff.

Paragraph 2

Inner bend ~ slow flow ~ low energy ~ small rocks ~ deposition ~ shallow water

~ river beach

slide25

Formation of a Meander

Alluvium river cliffs greatest speed deposition

erosion loss of energy meanders

The course of a river usually has many bends in it. These are

called___________. The _____________of water is on the

outside of the bend where _________takes place and the

channel is worn away to make___________The water flows

more slowly round the inside of the bend. This causes

__________________ and _________________ when the river

overflows its banks it deposits material called ______________ on the valley floor.

meanders

greatest speed

erosion

river cliffs

loss of energy

deposition

alluvium

slide26

Deposition

Erosion

Meander

Floodplain

Alluvium

Shallow Water

Deep Water

slide27

Blue - River

Green Valley Floor

Brown Valley Sides

slide29

2

5

slide31

Outer Bend

An oxbow lake starts to form when large meanders develop close together (A). As their outer bends erode more, there is only a small piece of land remaining between them, called a neck (B).

Large Meanders

Neck

Oxbow Lakes

slide32

Straighter Channel

Eventually the river erodes through the neck of the meander and makes a new straighter river channel (C). The river now flows down this channel and deposits material blocking up the old channel.

Deposition

Old Channel

slide33

This leaves an oxbow lake in the old river channel and without a supply of water the lake can dry up (D). The lake may reform when there is heavy rain or flooding.

Oxbow Lake

slide34

Flat Land

Floodplain

slide35

Floodplain

Flat Land

Meander Sketch

slide36

A

A

F

F

Floodplain

E

B

C

D

A =

B =

C =

D =

E =

F =

Bluff Line

Layers Of Alluvium

River Bed Level Rises With Increased Deposition

Small Particles Deposited Away From River

Larger Particles Deposited Close To River

Levee

slide37

Floodplain

A floodplain is a flat area of land either side of a river, which floods regularly. The widest examples are found in the middle and lower course.

The river valley gets wider as meanders continue to grow, eroding back the sides of the valley.

The flat valley that forms is called a floodplain and develops as alluvium (mud/silt) sediment is deposited after a flood.

The smallest particles are found at the edge of the floodplain and the largest particles nearest to the river. The largest particles by the river bank form a mini ridge called a levee, which runs parallel with the river.