GCSE Geography (Edexcel) REVISION

Changing UK Landscapes – Part 1

1. Coastal Processes 2. Glossary of key words3. Revision Quiz (to complete and hand in within 1 week)4. Coastal Landforms 5. Glossary of key words6. Revision Quiz (to complete and hand in within 1 week)7. Human Activities on Coasts 8. Glossary of key words9. Revision Quiz (to complete and hand in within 1 week)

Coastal processesProcesses called erosion, mass movement and weathering break down and remove material from the coast. The material is moved along the coastline by the sea and deposited when there is energy loss.

WavesWhen the wind blows over the sea, it creates waves. The size and energy of the wave depends on certain factors:

the fetch - how far the wave has travelled the strength of the wind how long the wind has been blowing for

Wave types

There are two different types of waves - constructive and destructive. They can affect the coastline in different ways. When a wave reaches the shore, the water that rushes up the beach is known as the L. Jennings

Name: ……………………………………………

swash. The water that flows back towards the sea is known as the backwash. The energy of the swash and backwash determine the type of wave.

Destructive waves

The characteristics of a destructive wave are:

weak swash and strong backwash occurs in stormy conditions, with strong winds the strong backwash removes sediment from the beach the waves are steep and close together tall waves with short wavelength they arrive quickly and have a high frequency – a lot of them come in a short period of

time

Constructive waves

The characteristics of a constructive wave are:

small waves, with low wave height and long wavelength occurs in calm conditions, without much wind strong swash and weak backwash the strong swash brings sediments to build up the beach the backwash is not strong enough to remove the sediment the waves are low and further apart

WeatheringExposed rocks along the coastline can be broken down by the processes of weathering.

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Freeze-thaw weathering

Freeze-thaw weathering occurs when rocks are porous (contain holes) or permeable (allow water to pass through it).

1. Water enters cracks in the rock.2. When temperatures drop, the water freezes and expands causing the crack to widen.3. The ice melts and water makes its way deeper into the cracks.4. The process repeats itself until the rock splits entirely.

Biological weathering

1. Plant roots can get into small cracks in the rock.2. As the roots grow, the cracks become larger.3. This causes small pieces of rock to break away.

Chemical weathering

Rainwater and seawater can be a weak acid. If a coastline is made up of rocks such as limestone or chalk, over time they can become dissolved by the acid in the water.

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Chemically-weathered limestone

Mass movementAnother way material can be moved on the coastline is through mass movement. Mass movement is the downhill movement of sediment that moves because of gravity. There are four different types of mass movement.

Rockfall

Bits of rock fall off the cliff face, usually due to freeze-thaw weathering.

Mudflow

Saturated soil (soil filled with water) flows down a slope.

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Landslide

Large blocks of rock slide downhill.

Rotational slip

ErosionErosion is the wearing away of rock along the coastline. Destructive waves are responsible for erosion on the coastline. There are four types of erosion:

Hydraulic action - this is the sheer power of the waves as they smash against the cliff. Air becomes trapped in the cracks in the rock and causes the rock to break apart.

Abrasion - this is when pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth.

Attrition - this is when rocks that the sea is carrying knock against each other. They break apart to become smaller and more rounded.

Solution - this is when sea water dissolves certain types of rocks. In the UK, chalk and limestone cliffs are prone to this type of erosion.

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TransportationSediment is carried by the waves along the coastline. The movement of the material is known as longshore drift. Waves approach the coast at an angle because of the direction of prevailing wind. The swash will carry the material towards the beach at an angle. The backwash then flows back to the sea, down the slope of the beach. The process repeats itself along the coast in the zigzag movement.

Beach material can be moved in four different ways. These are:

Solution - when minerals in rocks like chalk and limestone are dissolved in sea water and then carried in solution. The load is not visible.

Suspension - small particles such as silts and clays are suspended in the flow of the water.

Saltation – where small pieces of shingle or large sand grains are bounced along the sea bed.

Traction – where pebbles and larger material are rolled along the sea bed.

DepositionWhen the sea loses energy, it drops the material it has been carrying. This is known as deposition. Deposition can occur on coastlines that have constructive waves.

Factors leading to deposition include:L. Jennings

waves starting to slow down and lose energy shallow water sheltered areas, eg bays little or no wind

Glossary1. backwash

The movement of water down the beach.2. constructive wave

Waves which help build up material on the beach. They tend to have a low frequency and strong swash.

3. depositionWhen material is deposited or left behind, eg when a river loses its energy and is unable to carry its load any further.

4. destructive waveWaves which remove material from the beach. The swash is weaker than the backwash.

5. fetchHow far a wave has travelled.

6. longshore driftThe movement of material along a coastline due to the angled approach of waves.

7. mass movementA large-scale downward movement of rocks and material.

8. sedimentSmall fragments of rock and soil that form layers.

9. swashThe water flowing towards a beach when a wave breaks.

Coastal landformsErosional landforms include headlands, bays, caves, arches, stacks, stumps and wave-cut platforms. There are also depositional landforms such as beaches, spits and bars.

Erosional landformsThe process of erosion can create different landforms along the coastline.

Headlands and bays

Cliffs along the coastline do not erode at the same pace. When a stretch of coastline is formed from different types of rock, headlands and bays can form.

Bands of soft rock such as clay and sand are weaker and therefore they can be eroded quickly. This process forms bays. A bay is an inlet of the sea where the land curves inwards, usually with a beach. Hard rock such as chalk is more resistant to the processes of erosion. When the softer rock is eroded inwards, the hard rock sticks out into the sea, forming a headland.

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Erosional features such as wave-cut platforms and cliffs can be found on headlands, since they are more open to the waves. Bays are more sheltered with constructive waves which deposit sediment to form a beach.

Cliffs and wave-cut platforms

Cliffs are shaped through erosion and weathering. Soft rock erodes quickly and forms gentle sloping cliffs, whereas hard rock is more resistant and forms steep cliffs. A wave-cut platform is a wide gently-sloping rocky surface found at the foot of a cliff.

A wave-cut platform is formed when the following occurs:

1. The sea attacks the base of the cliff between the high and low water mark.2. A wave-cut notch is formed by erosional processes such as abrasion and hydraulic action

- this is a dent in the cliff usually at the level of high tide.3. As the notch increases in size, the cliff becomes unstable and collapses, leading to the

retreat of the cliff face.4. The backwash carries away the eroded material, leaving a wave-cut platform.5. The process repeats. The cliff continues to retreat.

Caves, arches, stacks and stumps

Caves, arches, stacks and stumps are erosional features that are commonly found on a headland.L. Jennings

1. Cracks are formed in the headland through the erosional processes of hydraulic action and abrasion.

2. As the waves continue to grind away at the crack, it begins to open up to form a cave.3. The cave becomes larger and eventually breaks through the headland to form an arch.4. The base of the arch continually becomes wider through further erosion, until its roof

becomes too heavy and collapses into the sea. This leaves a stack (an isolated column of rock).

5. The stack is undercut at the base until it collapses to form a stump.

Depositional landformsWhen water loses its energy, any sediment it is carrying is deposited. The build-up of deposited sediment can form different features along the coast.

Beaches

Beaches are made up from eroded material that has been transported from elsewhere and then deposited by the sea. For this to occur, waves must have limited energy, so beaches often form in sheltered areas like bays. Constructive waves build up beaches as they have a strong swash and a weak backwash.

Sandy beaches are usually found in bays where the water is shallow and the waves have less energy. Pebble beaches often form where cliffs are being eroded, and where there are higher-energy waves.

A cross-profile of a beach is called the beach profile. The beach profile has lots of ridges called berms. They show the lines of the high tide and the storm tides. A sandy beach typically has a gentle sloping profile, whereas a shingle beach can be much steeper. The size of the material is larger at the top of the beach, due to the high-energy storm waves carrying large sediment. The smallest material is found nearest the water as the waves break here and break down the rock through attrition.

Spits

A spit is an extended stretch of sand or shingle jutting out into the sea from the land. Spits occur when there is a change in the shape of the landscape or there is a river mouth.L. Jennings

This is how spits are formed:

1. Sediment is carried by longshore drift.2. When there is a change in the shape of the coastline, deposition occurs. A long thin ridge

of material is deposited. This is the spit.3. A hooked end can form if there is a change in wind direction.4. Waves cannot get past a spit, therefore the water behind a spit is very sheltered. Silts

are deposited here to form salt marshes or mud flats.

Bars

Sometimes a spit can grow across a bay to join two headlands together. This landform is known as a bar. Bars can trap shallow lakes behind the bar - these are known as lagoons. Lagoons do not last forever and may be filled up with sediment.

Case study: coastal landforms - Dorset coastline

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Dorset is located in the south of England. Its coastline has examples of many erosional and depositional landforms. For example:

Swanage is an example of a headland and bay Old Harry Rocks is an example of caves, stacks and stumps at Chesil Beach there is a bar

Swanage Bay

The area around Swanage is made up of bands of hard and soft rock. The soft rock is made of clay and sands, and the hard rock is chalk and limestone. The bands of soft rock erode more quickly than those of the more resistant hard rock leaving a section of land jutting out into the sea, called a headland. The areas where the soft rock has eroded away, next to the headland, are called bays. This process created Swanage Bay, Studland Bay and two headlands, including Durlston Head.

Coastlines where the geology alternates between bands of hard and soft rock which are perpendicular to the shore are called discordant coastlines.

A concordant coastline has the same type of rock along its length. The alternating bands of hard and soft rock run parallel to the coast. Lulworth Cove is situated on the south coast of England, on a concordant coastline.

The entrance to the cove is narrow where the waves have cut through weaknesses in the resistant limestone. Then the cove widens where the softer clays have been more easily eroded. At the back of the cove is a band of more resistant chalk, so erosion is slower here.

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Lulworth Cove, DorsetOld Harry Rocks

Old Harry Rocks are located on the headland between Swanage and Studland Bay. The headland is made out of chalk, a hard rock. The headland juts out into the sea, so it is more vulnerable to high-energy waves. This caused the formation of Old Harry, a stack. Over time Old Harry will collapse to form a stump.

Chesil Beach

Chesil Beach is an example of a bar. Sediment has been deposited over time to form a spit. The spit has continued to join to the Isle of Portland. Behind the spit there is The Fleet, a lagoon.

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Glossary1. attrition

The wearing down of the load as the rocks and pebbles hit the sea bed and each other, breaking into smaller and more rounded pieces.

2. backwashThe movement of water down the beach.

3. barA spit that has grown across a bay.

4. bayA low-lying inlet of land on the coast.

5. constructive waveWaves which help build up material on the beach. They tend to have a low frequency and strong swash.

6. depositionWhen material is deposited or left behind, eg when a river loses its energy and is unable to carry its load any further.

7. erosionThe wearing away of pieces of rock, soil or other solid materials.

8. headlandA high area of land that extends out into the sea.

9. perpendicularIf the angle between two lines is a right angle, the lines are said to be perpendicular.

10. siltFertile sand-sized particles found in the lower course of a river. Also known as alluvium.

11. spitA stretch of beach at one end of a coastline caused by waves depositing material.

12. swashThe water flowing towards a beach when a wave breaks.

13. wave-cut notchAn area of erosion at the base of a cliff formed by the waves.

14. wave-cut platformL. Jennings

A flat area in front of a cliff, just below the low tide mark. These were formed when the waves eroded the cliff, but left a flat platform behind.

15. weatheringThe breaking down of rocks in situ by the action of weather, plants, animals and chemical processes.

Human activities on coastsHard engineering management involves using artificial structures, whereas soft engineering management is a more sustainable and natural approach to manage coastal erosion.

Hard engineeringErosion is a natural process which shapes cliffs. Over time, erosion can cause cliff collapse - therefore the coastline needs to be managed. Hard engineering involves building artificial structures which try to control natural processes. Each engineering strategy has its advantages and disadvantages.

Sea walls

A sea wallConcrete walls that are placed at the foot of a cliff to prevent erosion. They are curved to reflect the energy back into the sea.

Advantages

Effective at protecting the base of the cliff. Sea walls usually have promenades so people can walk along them.

Disadvantages

Waves are still powerful and can break down and erode the sea wall. Expensive - approximately £2,000 per metre.

Rock armour/rip rap

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Rock armour on a beachLarge boulders placed at the foot of a cliff. They break the waves and absorb their energy.

Advantages

Cheaper than a sea wall and easy to maintain. Can be used for fishing.

Disadvantages

They look different to the local geology, as the rock has been imported from other areas. The rocks are expensive to transport.

Gabions

GabionsRocks are held in mesh cages and placed in areas affected by erosion.

Advantages

Cheap - approximately £100 per metre. Absorb wave energy.

Disadvantages

Not very strong. Look unnatural.

Groynes

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Wooden groynes on a beach in SussexWooden or rock structures built out at right angles into the sea.

Advantages

Builds a beach - which encourages tourism. They trap sediment being carried by longshore drift.

Disadvantages

By trapping sediment it starves beaches further down the coastline, increasing rates of erosion elsewhere.

They look unattractive.

Soft engineeringSoft engineering does not involve building artificial structures, but takes a more sustainable and natural approach to managing the coast. Each strategy has its advantages and disadvantages for use.

Beach nourishment

Bulldozers moving sand during beach nourishmentSand is pumped onto an existing beach to build it up.

Advantages

Blends in with the existing beach. Larger beaches appeal to tourists.

Disadvantages

Needs to be constantly replaced.L. Jennings

The sand has to be brought in from elsewhere.

Reprofiling

A bulldozer moves sand up the beachThe sediment is redistributed from the lower part of the beach to the upper part of the beach.

Advantages

Cheap and simple. Reduces the energy of the waves.

Disadvantages

Only works when wave energy is low. Needs to be repeated continuously.

Dune nourishment

Marram grassMarram grass planted on sand dunes stabilises the dunes and helps to trap sand to build them up.

Advantages

Relatively cheap. Maintains a natural-looking coastline.

Disadvantages

Can be damaged by storm waves. Areas have to be zoned off from the public, which is unpopular.

Offshore reefs

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Offshore reefs located at Sea Palling, NorfolkOld tyres and cement can be placed in the intertidal zone, parallel to the coast, to create off-shore reefs. This encourages waves to break offshore. This reduces the energy of the wave which reaches the shoreline and therefore causes less erosion.

Advantages

The natural marine ecosystem is only partly disrupted. Dunes are allowed to stabilise onshore. Rocks create a new intertidal habitat for marine wildlife.

Disadvantages

May cause a navigation hazard. Can create an eyesore at low tide. Can disrupt the recreational use of the beach, for example the use of jet skis.

Managed retreatManaged retreat is the controlled flooding of low-lying coastal areas. If an area is at high risk of erosion, managed retreat could be an option. It usually occurs where the land is of low value, for example farm land.

Abbotts Hall Farm salt marshes - an example of managed retreatAdvantages

This is a cheap option compared to paying for sea defences.

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Creates a salt marsh which can provide habitats for wildlife and a natural defence against erosion and flooding.

Salt marshes are diverse ecosystems supporting many species.

Disadvantages

Land is lost as it is reclaimed by the sea. Landowners need to be compensated - this can cost between £5,000 - £10,000 per

hectare.

Case study: coastal management - Holderness coastlineThe Holderness coastline is located on the east coast of England. It is the fastest eroding coastline in Europe.

Reasons for management

The coastline is rapidly eroding at an average of 1.8 metres a year. There are several reasons why the coast at Holderness is eroding so quickly:

Rock type - the cliffs are made from less-resistant boulder clay (made from sands and clays) which slumps when wet.

Naturally narrow beaches - these beaches give less protection to the coast as it doesn't reduce the power of the waves.

Man-made structures - groynes have been installed to stop long-shore drift. This narrows unprotected beaches elsewhere even more.

Powerful waves - waves at Holderness travel long distances over the North Sea (so have a long fetch) which means they will increase in energy.

Management strategies

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Bridlington is protected by a 4.7 km long sea wall. Hornsea is protected by a sea wall, groynes and rock armour. Coastal management at Withersea has tried to make the beach wider by using groynes,

and also a seawall to protect the coast. Mappleton is protected by rock groynes. Spurn Head is protected with groynes and rock armour.

Conflicts

There has been an increase in erosion at Great Cowden because of the groynes used in Mappleton. This has led to farms being destroyed by the erosion and the loss of 100 chalets at the Golden Sands Holiday Park.

Some people disagree with where the sea defences are located, especially if it means the land in their community is not protected.

Some sea defences negatively impact tourism and reduce the amount of money coming in to the area.

Glossary fetch

How far a wave has travelled. groyne

Wooden or rock structures built out at right angles into the sea. hard engineering

The use of man-made structures to control the coast. managed retreat

The controlled flooding of low-lying coastal areas. marram grass

A long type of grass found growing on coastal sand dunes. soft engineering

The use of natural, sustainable solutions to control the coast

Geography - Coastal processes (Edexcel)1What causes waves? L. Jennings

Name: ……………………………………………

Magnetic pull of the EarthGravityWind

2What are the characteristics of a destructive wave?

Weak swash and strong backwashStrong swash and weak backwashWeak swash and weak backwash

3What are the characteristics of a constructive wave?

Weak swash and strong backwashStrong swash and weak backwashWeak swash and weak backwash

4Which type of weathering involves expanding of water?

Freeze-thaw weatheringBiological weatheringChemical weathering

5Large blocks of rock sliding downhill is which type of mass movement?

LandslideMudflowRockfall

6Saturated soil slumping down a curved surface is which type of mass movement?

RockfallRotational slipMudflow

7Which type of erosion is the sheer power of the waves hitting the cliffs?

AbrasionHydraulic actionSolution

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8Pebbles grinding along a rock platform is known as which type of erosion?

AbrasionHydraulic actionSolution

9Which of these describes saltation transportation?

Particles carried within the waterPebbles rolling along the sea bedThe bouncing movement of pebbles along the seabed

10Why does the sea deposit sediment?

It runs out of coastlineIt loses energyThere is a change in rock type

Geography - Coastal landforms (Edexcel)1Bands of hard and soft rock can lead to which landform?

SpitHeadlands and baysWave-cut platforms

2What is a wave-cut platform?

A gently sloping rocky surface found at the foot of a cliffA platform that has been built up from deposited sedimentA small crack that has eroded from a cliff

3Which are the main processes of erosion that form a cave?

Attrition and abrasionAbrasion and longshore driftHydraulic action and abrasion

4Which type of waves form beaches?

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Constructive wavesDestructive wavesBoth constructive and destructive waves

5What is a berm?

A cross profile of a beachA notch found in a cliffRidges on the beach left as a mark of the tide

6What is one of the processes involved in the formation of spits?

Hydraulic actionLongshore driftAttrition

7What is the water behind a bar called?

A lakeA lagoonA pool

8Old Harry Rocks is an example of which landform?

BarHeadlands and baysStack

9What is the name of the lagoon at Chesil Beach?

The FleetThe StreetThe Strand

10What type of rock is Old Harry made from?

ClayLimestone

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ChalkGeography - Human activities on coasts (Edexcel)1What is hard engineering management?

Building artificial structures to control erosionA natural approach to control erosionUsing technology to monitor erosion rates

2What is soft engineering management?

Building artificial structures to control erosionA natural approach to control erosionUsing technology to monitor erosion rates

3Which hard engineering technique reflects wave energy back to sea?

Sea wallGroynesGabions

4What are wooden barriers built out to sea known as?

Sea wallGroynesGabions

5What is an advantage of rock armour?

It looks naturalIt is easy to maintainIt provides a walkway for people

6Which management strategy redistributes sand on the beach?

Beach nourishmentDune nourishmentReprofiling

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7What is a disadvantage of dune nourishment?

It is expensiveIt only works when wave energy is lowIt can be damaged by storm waves

8What is an advantage of beach nourishment?

It blends in with the natural beachIt is simple to maintainIt can be used for fishing

9Why does Holderness have a high rate of coastal erosion?

It has large beaches with lots of sedimentIts rock type along the coastThere are constructive waves in the area

10Which sea defence is present at Mappleton?

Rock groynesRock armourSea wall

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