gcse rivers river landforms formation

8/13/2019 GCSE Rivers River Landforms Formation

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Which River is associated with

these cities? New York

London

Glasgow

Liverpool

Newcastle

Cairo

Paris

New Orleans

Bristol

Hudson

Thames

Clyde

Mersey

Tyne

Nile

Seine

Mississippi

Severn


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The Drainage Basin

Sketch the

diagram and use

pg 4-5 in KeyGeography to help

you add the

following labels:

Mouth

Source Watershed

Confluence

Tributaries

Main channel


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The Drainage Basin


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Drainage Basins


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The long profile of a river

The upper course has a

steep gradient

The lower course has a

more gentle gradient


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Long profile of a river

A. Upper

Vertical erosion

Deep channel V

shaped valley

Narrow

Interlocking spurs

Fast flowing rapids

Waterfalls

Gorges

B. Middle

Lateral erosion

Shallower channel

Wider channel

Slower flow

Floodplain

Meanders

River cliff

C. Lower

Deposition

Very shallow

Very wide

Very slow carrying

small particles

Ox-bow lakes

Braiding

Estuaries

Deltas


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The different stages of a river.
http://earthasart.gsfc.nasa.gov/images/ganges_hires.jpghttp://www.flickr.com/photos/coda/186599041http://fusion.sas.upenn.edu/caterpillar/viewimage.cfm?id=1128&lecture=25&slide=2


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How do rivers shape the land?

Erosion

TransportationDeposition


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How a river carries its load

(Transportation)

View animation
http://www.juicygeography.co.uk/animations.htmhttp://www.juicygeography.co.uk/animations.htm


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The Upper Course


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Learning objectives:To be able toidentifyand distinguish some of

the main features of theupper courseof a riverand to be able to explainwhyand howcertainprocesses occur.

Keywords:

Fluvial processes

Fluvial landforms

Waterfall

GorgeV-shaped valley

Load: The material that is carried by a river.

Bedload: The heavier material carried, rolled or bounced along the river bed.


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Famous Waterfalls

Niagara fallsStraddles theUSA/Canadian border.56 m

Niagara River

Victoria fallsAfrica- Zambia,Zimbabwe. 103 m

Zambezi River.

Angel fallsThe worlds highestwater fall. 979 m

Venezuela

Carrao River,


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In the upper course, the river is high above sea level. This gives the river a lot of potential

energy. The river is trying to cut down to its base level or downwards so it mainly does this

through vertical erosion. This creates the classic feature known as a V-shaped valley - seen

below.

The main characteristics of aV - shaped valley and its river:

The valley is narrow with a

narrow, shallow river

channel

The valley has steep sides

The channel has a steep

gradient with features such

as pot holes, rapids and

waterfalls

The water is mainly slow

flowing as most of the riversenergy is used to overcome

the friction of the river bed &

obstructions

The load is mainly large,

angular and rough

View animation
http://www.cleo.net.uk/resources/displayframe.php?src=308/consultants_resources%2F_files%2Fintespur2.swfhttp://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes%20GCSE%20Blog%20Resources/Images/Rivers/v-shapedvalleys.gifhttp://www.cleo.net.uk/resources/displayframe.php?src=308/consultants_resources%2F_files%2Fintespur2.swfhttp://www.cleo.net.uk/resources/displayframe.php?src=308/consultants_resources%2F_files%2Fintespur2.swfhttp://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes%20GCSE%20Blog%20Resources/Images/Rivers/v-shapedvalleys.jpg


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http://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes%20GCSE%20Blog%20Resources/Images/Rivers/v-shapedvalleys.jpg


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W f ll f i
http://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes%20GCSE%20Blog%20Resources/Images/Rivers/V-shapedvalley.jpghttp://www.slideshare.net/AHamill/the-formation-of-waterfallhttp://www.slideshare.net/AHamill/the-formation-of-waterfallhttp://www.slideshare.net/AHamill/the-formation-of-waterfallhttp://www.slideshare.net/AHamill/the-formation-of-waterfall


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Waterfall FORMATION:-The river flows over a band of

hard rock above a layer of softer

rock.

-The soft rock erodes more

quickly so the hard rock is

undercut and overhangs until it

eventually collapses.

-A deep plunge pool is formed

and the river erodes backwards

as the water and rocks swirl

around.

-Gradually, over time, thisprocess continues and the

waterfall retreats upstream

forming a gorge.

Waterfall formation
http://www.slideshare.net/AHamill/the-formation-of-waterfallhttp://www.slideshare.net/AHamill/the-formation-of-waterfallhttp://www.slideshare.net/AHamill/the-formation-of-waterfallhttp://www.slideshare.net/AHamill/the-formation-of-waterfall


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Waterfalls have:

A steep dropin the river

A plunge poolat the base

A hard

resistant cap ofrock at the topwhich overhangs

Softer rocks

below the hard rockwhich are undercut


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Gorge Formation

Gorge ofRecession:

A steep sidedvalley created bywaterfall retreat
http://www.cleo.net.uk/resources/displayframe.php?src=307/consultants_resources/_files/gorge.swfhttp://www.cleo.net.uk/resources/displayframe.php?src=307/consultants_resources/_files/gorge.swfhttp://www.cleo.net.uk/resources/displayframe.php?src=307/consultants_resources/_files/gorge.swfhttp://www.cleo.net.uk/resources/displayframe.php?src=307/consultants_resources/_files/gorge.swf


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Erosion happens in the upper course in four ways.

1. Hydraulic ActionIn a fast flowing river, water is forced into the cracks in the bank. Over time the

pressure builds up and breaks the bank up. This particularly happens when the riveris in flood.2. Corrasion / AbrasionThe river carries material like pebbles, boulders, sand and silt. These can rub alongthe bed and banks and wear them away.3. AttritionThis happens when the load (pebbles, boulders etc) carried by the river collide andrub against each other. The particles become smoother and smaller4. Corrosion / SolutionRiver water is sometimes slightly acidic. This can erode rocks such as limestoneand chalk.

This video clip of the River Conwy in Wales gives a

good illustration of some of the processes and

landforms happening along the course of the river.

Now sketch and label the erosion diagram from page 66

in Geog.GCSE
http://www.bbc.co.uk/learningzone/clips/waterfalls-and-gorges-erosion-and-deposition/3239.htmlhttp://www.bbc.co.uk/learningzone/clips/waterfalls-and-gorges-erosion-and-deposition/3239.html


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Sketch a copy of the outline of this river channel and stick

your labels in the appropriate places.


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Describe the Fluvial landforms and fluvial processes ofthe upper course of a river. (8 marks)

Featurescreated byrivers

The processesby which ariver erodes,transports anddeposits.

Fluviallandforms

Fluvialprocesses

Trigger words The upper course of a river is

very active. This means that

there is a lot of movement and

many features are created.


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The Middle Course


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Going Round theBend..?

Learning objective:To be able toidentifyand distinguishsome of the main features of themiddle courseof a riverand to be able explain whyand howcertain processes occur.

Keywords:

Meander

Transportation

Deposition


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Mississippi

River

Tigre River-An

Amazon tributary

River Kanuti-

Alaska

RiverSevern- UK

RiverThames-

London

What do theserivers have in

common?

Erosion happens in the upper course in four ways
http://www.stacey.peak-media.co.uk/Year7/7-7Rivers/7-7Meanders/341.jpghttp://www.scienceclarified.com/landforms/images/ueol_03_img0106.jpghttp://www.cox-internet.com/coop/photomn.gif


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Erosion happens in the upper course in four ways.

1. Hydraulic PowerThis is the force of theriver against the bed and

banks. When the river is inflood, the force wouldremove material.2. Corrasion / AbrasionThe river carries materiallike pebbles, boulders, sandand silt. These can rub alongthe bed and banks and wearthem away.3. AttritionThe load carried by theriver collides and rubs

against each other.Particles become smoothand become smaller4. CorrosionRiver water is sometimesslightly acidic. This canerode rocks such as

limestone and chalk.

So, whathappens to allthe pieces ofrock that areeroded?

The eroded pieces of rock are transported down the river
http://www.free-pictures-photos.com/stones/stones-02.jpg


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The eroded pieces of rock are transported down the river.This is a fluvial process. ( Movement that the river causes)

SaltationA:Smaller pebbles arebounced along `the riverbed. They are picked up andthen dropped.

SuspensionC: Finer sand and silt arecarried in the flow, makingthe river look brown.

SolutionB: Minerals are dissolved inthe water and carried inthe flow. They cannot beseen.

Solution

SaltationSuspensionTraction

TractionD: The largest rocks andboulders are rolled alongthe river bed.

Suspension

Saltation

Traction

Solution

1 2 3

4

It drops more of its load than it did upstream This is called deposition It


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Meanders

It drops more of its load than it did upstream. This is called deposition. It

also begins to build up its bed instead of tearing it down .

Slip off slope: Gentle slopeforming the inner bank of ameander. It is formed bythe deposition of fine silt,or alluvium, by slow-flowing

water

River Cliff-Steep slopeforming the outer bank of ameander. It is formed bythe undercutting of the

river current, which at itsfastest when it sweepsaround the outside of themeander.
http://www.cleo.net.uk/content/_files/meander4.swfhttp://www.cleo.net.uk/content/_files/meander4.swfhttp://www.cleo.net.uk/content/_files/meander4.swfhttp://www.cleo.net.uk/content/_files/meander4.swf


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The Formation of Ox Bow Lakes

In the lower course the meanders

become even larger. Erosion onthe outside of bends anddeposition on the slip off slopescontinue to take place.

The erosion causes the meanderneck to narrow until eventually itbreaks through. This often takesplace when the river has moreenergy as in times of flood.

The river now follows a straightpath. After the meander has beencut through the river seals off thebend by deposition and an ox-bow

lake is formed. In time, especiallyin dry areas the ox-bow lake maydry up to form a meander scar.

OXBOW LAKES
http://www.school-portal.co.uk/GroupDownloadFile.asp?file=21606


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(1) On the inside of the loop, the

water travels more slowly leading

to deposition of silt.

(2) On the outside edges the

water is faster, which erodes

the banks making the

meander even wider.

(3) Over time the loop of the

meander widens until the neck

vanishes altogether. Then themeander is removed from the

river's current and the horseshoe

shaped oxbow lake is formed


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Using a diagram to support youranswer, explain how a meander is

formed. (4 marks)Erosion

Deposition

River Cliff

Slip off SlopeA meander isformed because


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MEANDER MIGRATION

Notice onthe diagram below

The meanders have got wider due to

sideways erosion on the outside bends

The meanders have moved

downstreamA line of river cliffs has formed along

the edge of the valley floor

As the meanders get wider so does

the valley floor or flood plain.


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The Lower Course

The river is now nearing the sea

and deposition becomes thedominant process.


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The main features of the river channel and river valley are:

It is wide and deep with a moreefficient shaped channel

It is lined with sand and mud so thisresults in less friction

There maybe islands of silt calledeyots in the river and the river can splitinto a number of channels - river

braiding The river carries a large load of

alluvium

There is a wide, flat flood plain eitherside of the river

There are features such as meanders,ox bow lakes and deltas

The flood plain is made up of a thicklayer of alluvium

A line of river cliffs are found at theedge of the flood plain called bluffs


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The End of the Road

The End of The Road

Learning Objective:

To be able toidentifyanddistinguish some of the mainfeatures of theLowerCourseof a river and to beable explain whyand how

certain processes occur.

Keywords:

LeveeDelta

Estuary


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Levee formation(ii) LEVEESThese are natural

embankments of silt along theriver banks. They are formedalong rivers that:flow slowly carry a large loadflood every so often

The diagram shows that when theriver floods material is depositedleading to levees building up.
http://www.geo.wvu.edu/~donovan/geol101/animations/17.swfhttp://www.geo.wvu.edu/~donovan/geol101/animations/17.swf


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Eventually ... in'old age' the riverempties its load ofwater and

'material' into thesea.

This is calleddeposition

(1) Deltas are formed at the end of rivers (river mouth) as itflows into the sea.(2) Rivers carry a lot of sediment (mud), the river flows into a

calm sea slowing the river down.(3) This makes the river drop its sediment.(4) This deposited sediment builds up over years creating adelta.(5) The river is forced to split up. The smaller rivers made bydeltas are called distributaries.


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Deltas

Some rivers reach the sea indeltas, which form where rivermouths become choked withsediment, causing the main riverchannel to split into hundreds ofsmaller channels or distributaries.Deltas only form under certain

conditions The river must be transporting a

large amount of sediment

The sea must have a small tidalrange and weak currents

The sea must be shallow at theriver mouth

Famous deltas consist of theMississippi delta, The Ganges andBrahmaputra delta (Bangladesh)and the Nile delta.


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An estuary is where a river

meets the sea or ocean. Nonew land is formed here, or

if it is, it is submerged.


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Task:

Produce a power point presentation or a word document whichdescribes and explains what is happening in the lower course

of the river. You must include pictures and diagrams. Examples

e.g. The Ganges Delta would also be useful.

Your work should cover: Levees (natural, not man-made)

Flood plains (including river cliffs/bluffs)

Deltas

Estuaries

Please make sure you include the following key words somewhere in your

work:

* Load * Flood * Deposit/deposition

* Alluvium * Silt * Flow

* Sediment


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Sort the following into the correct category: Upper, Middle

or Lower course. (There should be 8 in each section).

1. Dominant process is erosion

2. Lateral (sideways) erosion

3. Meanders start to develop

4. Steep gradient

5. Waterfalls and rapids

6. Wide and deep channel

7. Smooth Channel

8. Large boulders in channel

9. Widening valley floor

10. Eroded material carried downstream11. Lots of suspended load

12. Narrow and shallow channel

13. Ox-bow lakes

14. Clear water

15. River cliffs

16. Medium gradient

17. Vertical (downwards) erosion

18. Alluvium

19. Flood plain

20. Lots of deposition

21. Slip off slopes

22. Meander migration23. V-shaped valleys and interlocking

spurs

24. Meander scars


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Draw and fill in the following table:

Upper Course Middle Course Lower Course


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Upper Course Middle Course Lower Course

Dominant process iserosion Medium gradient Wide and deep channel

V-shaped valleys and

interlocking spurs

Lateral (sideways)

erosion

Smooth channel

Narrow and shallow

channel

Meanders start to

develop

Ox-bow lakes

Steep gradient River cliffs Deltas

Waterfalls & rapids Widening valley floor Alluvium

Large boulders in

channel

Eroded material carried

downstream

Flood plain

Clear water Slip off slopes Lots of deposition

Vertical (downwards)

erosion

Meander migration Lots of suspended load

Features Check list:


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Features Check list:

Feature Diagram Detailed

Description

Example

V-Shaped ValleyInterlocking

Spurs

Waterfall

Gorge

Meander

Ox-bow Lake

Flood plain

Levee

DeltaEstuary

P h kli t


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Processes checklist

Process Diagram Explanation

Erosion:

Hydraulic Action

Attrition

Abrasion/Corrasion

Solution/Corrosion

Vertical erosionLateral erosion

Transportation:

Traction

Saltation

Suspension

Solution

Deposition

Meander migration

gcse rivers river landforms formation

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