Rivers - PowerPoint Presentation

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Rivers

Chapter 7Slide2

Rivers………

Start on high,

Flow down low,

Creating features

As they flow!Slide3

River TermsSlide4
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Three stages of a riverSlide8
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Youth Stage = Upper Course

Mature Stage = Middle Course

Old age Stage = Lower Course

Three stages of a riverSlide10

The Work of RiversSlide11

Stage

Upper Course

Middle

Course

Lower Course

Slope

Main

processes

Valley shape

Main featuresSlide12
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Stage

Upper Course

Middle

Course

Lower Course

Slope

Main

processes

Valley shape

Main featuresSlide14

Processes of Erosion

How a river erodesSlide15
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The Work of Rivers

Processes of erosion:

Hydraulic Action

The force of the moving water causes erosion of the river bed and the banks of the river. The greater the speed and amount of water the greater the force.Slide17

The Work of Rivers

Processes of erosion:

2.

Abrasion

The rivers load is bounced and dragged along the river bed causing it to scrape and deepen the course of the river.Slide18

The Work of Rivers

Processes of erosion:

3.

Attrition

The rivers load is constantly colliding in the moving river water causing the load to break down into smaller pieces.Slide19

The Work of Rivers

Processes of erosion:

4.

Cavitation

As a river flows over the uneven river bed air bubbles travel up to the top of the river, pop and send ripples out towards the river banks. These ripples gently erode the rivers banks.Slide20

The Work of Rivers

Processes of erosion:

5.

Solution

Chemicals in the rivers water and rocks along the river course change the river chemically which reacts with and erodes various rocks along the way.Slide21
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Transport

How a river moves its loadSlide23
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FeaturesSlide25

F.E.E.D

F:

Feature

(Name, erosion or deposition, stage it is found)

E:

Explain

with at least one or two processes explained

E: Three

examples

, one Irish

D: Clear 1/2/3

diagram

/s to show how the feature is formed.

Describing a featureSlide26

Youth Stage = Waterfalls

Mature Stage = Meanders and Oxbow Lakes

Old age Stage = Deltas

Three features we will studySlide27

Features of the Youth Stage

V – Shaped Valleys

Interlocking Spurs

WaterfallsSlide28

A typical upper course V-Shaped valley with interlocking spurs, steep valley sides and active slope processes.

The diagram below shows the formation of interlocking spurs.

Interlocking spurs

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1

2

3

4Slide31

Feature of Erosion

Name

Found

Processes involved

Waterfall

Youth Stage

Hydraulic Action

AbrasionSlide32

Waterfalls are features of erosion usually found in the upper course (youth stage) of a river.

They are found in areas where a river is flowing over bands of hard and soft rock. The hard rock is slower to break down but the river can erode the soft rock much quicker. A band of hard rock lies on an area of soft rock. The river erodes the soft rock by the processes of

hydraulic action

(the force of the moving water) and

abrasion

(the scraping of the rivers load against the banks and bed). This causes a small notch to be formed into the soft rock which is eroded further into a drop over which the water falls. As the water falls over the drop there is a greater rate of hydraulic action and the rivers load also scrapes and deepens a hole in the bottom of the waterfall. This hole is called a Plunge Pool. The hard rock is slowly eroded and hangs over the edge called a Overhang. This is eventually worn down by the river and is carried away as the rivers load.

f

e

WaterfallsSlide33

Examples of waterfalls include:1

2

3

Diagram of a waterfall being formed

e

dSlide34

Angel Falls,

Venezeula

Victoria Falls, Zimbabwe

Torc

Waterfall, Killarney, Kerry

ExamplesSlide35

1A2Slide36

1A5Slide37

Waterfall

f

oe/

sor

(e) px2

Aoh

/

sr

srw

neisr

rfovd

pp@bow

ucipp

weuSlide38

Waterfall

foe/

sor

=

Feature of erosion….stage of river

(e) px2=

Erosion, Process are

hydrualic

action and abrasion

Aoh

/

sr

srw

=

Areas of hard/soft rock, soft rock weaker

Neisr

=

Notch eroded in soft rock

Rfovd

=

River falls over vertical drop

pp@bow

=

Plunge pool at base of waterfall

Ucipp

=

Undercut collapses into plunge pool

Weu

=

Waterfall erodes upstreamSlide39

Can you put the labels below into the correct place on he

diagram?Slide40
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Feature of Erosion and Deposition

Name

Found

Processes involved

Meanders and Ox Bow Lakes

Mature and Old Age Stage

Erosion and

DepositonSlide42
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Ox Bow lake on MississippiSlide44
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F.E.E.D

F:

Feature

(Name, erosion or deposition, stage it is found)

E:

Explain

with at least one or two processes explained

E: Three

examples

, one Irish

D: Clear 1/2/3

diagram

/s to show how the feature is formed.

Describing a featureSlide46
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1a2Slide49

1a5Slide50

F.E.E.D

F:

Feature

(Name, erosion or deposition, stage it is found)

E:

Explain

with at least one or two processes explained

E: Three

examples

, one Irish

D: Clear 1/2/3

diagram

/s to show how the feature is formed.

Describing a featureSlide51

D

eltasSlide52
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Pg

37Slide55

Examples of deltas include:The River Nile, EgyptThe Mississippi River in Louisiana, USAThe River Shannon in Limerick, IrelandSlide56
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Humans and RiversSlide59

New Orleans, Louisiana, USA

29

th

August 2005Slide60
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New Orleans VideoSlide62
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Read

Page 38-39

Name the river and the city of this case study?

The city is between two physical areas…what are they?

How is the city protected from flooding?

What did the President do to the amount of money available for protection of the land?

When did the disaster strike?

What was the name of the hurricane?

How many poor people could not leave the area?

How many people drowned in this disaster?Slide65

HEP: Hydro Electric Power

Electricity made by the power of moving waterSlide66
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