Topic 4: The UK's Evolving Physical Landscape

Question 1

UK Physical Landscape

Answer 1

Made up of Lowlands and Uplands with important rivers such as the Tyne, Severn & Thames.

Lowlands are South & East, Uplands North & West.

Question 2

Rocks

Answer 2

Three types each formed differently:

1. Igneous: molten rock (magma) cools and hardens. Hard eg Granite.
2. Sedimentary: compacted layers of sediment. Two main types:

(A)Carboniferous Limestone & chalk formed from shells and skeletons of sea creatures. Limestone quite hard but chalk is soft.

(B)Clays & shale formed from mud and clay minerals, very soft.

3. Metamorphic: made when other rocks are changed by heat & pressure. New rock becomes harder and more compact, eg shale becomes slate.

Question 3

Tectonic Activity

Answer 3

Three main processes:

Active volcanoes - magma.
Plate collisions - formed uplands & metamorphic rocks.
Plate movements - UK was in tropics and partly underwater.

Question 4

Characteristics of rock types

Answer 4

Granite. Very hard and impermeable. Forms up land landscapes.

Slate and Schist. Very hard and impermeable but layered so can be split into thin slabs. Forms up land landscapes and waterlogged acidic soils.

Chalk and clay. Chalk is harder than clay, it forms hills in lowland areas and cliffs at the coast. Chalk is permeable, clay is very soft and easily eroded.It forms wide flat valleys in the lowlands, it is impermeable so water flows over it creating lots of streams and rivers.

Carboniferous limestone. Softer and permeable. Weathering creates features such as Caverns and gorges. Creates dry valleys.

Question 5

Physical processes alter the landscape.

Answer 5

Weathering. 
Erosion. 
Post glacial river processes. 
Slope processes. 
Climate.

Question 6

Human changes to the landscape.

Answer 6

Agriculture.
Forestry.
Settlement.

Question 7

Coastal weathering and erosion.

Answer 7

Mechanical.
The breakdown of rock without changing its chemical composition, main type that affects coasts is salts weathering.
Chemical.
The breakdown of rock by changing its chemical composition, main type is carbonation weathering.
Biological.
The breakdown of rock by living things such as plant roots growing into cracks and pushing them apart.

Question 8

Mass movement.

Answer 8

The shifting of rocks and loose material down a slope such as a cliff. It happens when the force of gravity acting on a slope is greater than the force supporting it.

Mass movement causes coasts to retreat rapidly and is more likely to happen when the material is full of water as it acts as a lubricant and makes it heavier.

Question 9

Three types of Mass movement.

Answer 9

Slides.
Material shifts in a straight line.

Slumps.
Material ships with a rotation.

Rockfalls.
Material breaks up and falls down the slope.

Question 10

Three types of coastal erosion.

Answer 10

Hydraulic power.
Waves crashing against the rock and compress the air in the cracks putting pressure on the rock and making bits break off.

Abrasion.
Eroded particles in the water scrape against the rock removing small pieces.

Attrition.
Eroded particles in the water smash into each other and break into smaller pieces their edges get rounded off.

Question 11

Coastal landforms caused by erosion.

Answer 11

Concordant or discordant.
Concordant coastline bands of hard and soft rock are parallel to the coast.

Discordant coastline bands of hard and soft rock or at right angles to the coast.

Question 12

The U.K.’s climate has an impact on coastal erosion.

Answer 12

Temperature. Mild temperature increases the rate of salt weathering because water evaporates more quickly.

Storms are very frequent in the winter, strong winds create high energy destructive waves which increased erosion, intense rainfall can cause cliffs to become saturated leading to mass movement.

The prevailing winds are mostly warm south-westerlies bringing storms from the Atlantic, the south coast is exposed to these winds.

Cold northerly winds are common the east coast.

Question 13

Destructive waves.

Answer 13

Waves that carry out erosional processes are called destructive waves.

High, steep and high-frequency (10 to 14 per minute).

Backwash (movement of water back down beach) more powerful than swash(movement of water up the beach). Material is removed from the coast.

Question 14

Coastal landforms caused by erosion.

Answer 14

Wave cut platforms. Erosion at foot of the cliff causes a wave cut notch. Rock above becomes non stable and collapses. Repeated collapses results in cliff retreat and the formation of a wave cut platform.

Headlands and bays. Formed where there are alternating bands of resistance and less resistant rock along a discordant coastline.
Bays have a gentle slope, headlands have steep sides.

Caves, arches and stacks. Headlands formed of resistant rocks that have weaknesses such as cracks. Cracks made bigger by hydraulic power and abrasion, become caves, eventually become an arch. Eventually top of arch collapses to create a stack.

Question 15

Coastal landforms caused by deposition.

Answer 15

Material transported along coast by Longshore drift. Waves follow the direction of the prevailing wind.

Constructive waves deposit more material than they erode.

Low, long and lower frequency (6 to 8 waves per minutes).

Swash more powerful than backwash, material deposited to form beaches.

Splits and bars.

Spits formed at sharp bends in coastline such as river mouth. Longshore drift transports material past the bend and deposits in the sea. Strong winds and waves can curve end of the spit forming a recurved end, sheltered area behind the spit is protected from waves and overtime plants can grow here e.g. mudflats or salt marsh.

A bar is formed when a spit joins two headlands together cutting off the bay from the sea forming a lagoon.

Question 16

Climate change is increasing the risk of coastal flooding.

Answer 16

Rising sea levels: threat to low-lying coastal areas, higher tides flood coastal areas more frequently and remove more material from beaches, expose more of the coastline to the erosion with beaches becoming narrower than the sea moving further inland.

Storm frequency: more frequent storms give the sea more erosional power with more energy to transport material. High energy waves can move more material for greater distances, storm surges more frequent and can reach further inland.

Question 17

Coastal management.

Answer 17

Hard and soft engineering.

Hard engineering is man-made structures built to control the flow of the sea and reduce flooding and erosion e.g. Sea walls and groynes.

Soft engineering is using knowledge of the sea processes to reduce the effects of flooding and erosion e.g. beach replenishment, slope stabilisation and strategic realignment.

Question 18

River landscapes. A Rivers long profile and cross profile vary over its course.

Answer 18

Upper course is very steep with a V shaped Valley and a narrow shallow channel.

Middle course is medium with a gently sloping valley, has a wider and deeper channel.

Lower course has a gentle gradient with a very wide almost flat valley and deep channel.

Question 19

Vertical and lateral erosion.

Answer 19

Vertical erosion deepens the river valley and channel making it V shaped. Dominant in the upper course with high turbulence causes rough angular particles to be scraped along the river bed causing intense downward erosion.

Lateral erosion widens the river valley and channel during the formation of meanders, it is dominant in the middle and lower courses.

Question 20

River processes.

4 processes of erosion

Answer 20

Hydraulic action, the force of water breaks particles away from the river channel.

Abrasion,eroded rocks scrape against the channel wearing it away.

Attrition, rocks smash into each other and break into smaller pieces with their edges getting rounded and particles decrease in size.

Solution, with a water dissolves some types of rock e.g. chalk and limestone.

Question 21

Transportation is the movement of eroded material.

4 processes of transportation.

Answer 21

Traction, large particles are pushed along the river bed by the force of water.

Saltation, pebble sized particles are bounced along the river bed by the force of water.

Suspension, small particles like silt are carried along by the water.

Solution, soluble materials are dissolved in the water and carried along.

Question 22

Deposition is when a river drops eroded material.

Answer 22

Happens when a river slows down and lose its velocity.

The volume of water in the river falls.
The amount of eroded material in the water increases.
The water is shallower e.g. on the inside of a bend.
The river reaches its mouth.

Question 23

Waterfalls and gorges. Both found in the upper course of the river.

Answer 23

Waterfalls form where a river flows over hard rock followed by an area of softer rock. The softer rock is eroded by hydraulic action and abrasion and creating a step in the river. Over time the step erodes further and a steep drop is created.

The hard rock is eventually undercut becomes unstable and collapses. The collapsed rock erodes the softer rock further and creates a plunge pool.

Overtime this process continues and the waterfall retreats back up the channel leaving behind a steep sided gorge.

Question 24

Interlocking spurs.

Answer 24

In the upper course most of the erosion is vertically downwards creating steep sided V shaped Valleys. The river is not powerful enough to erode sideways so must go round the hillsides in their path, these hillsides interlock with each other as the river winds round them.

Question 25

Meanders are formed by erosion and deposition.

Answer 25

Rivers develop meanders in the middle and lower courses where there are both shallow and deep sections in the channel.

The current is faster on the outside of the bend where the channel is deeper. So more erosion (abrasion and hydraulic) happens on the outside of the bend, forming river cliffs.

The current is slower on the inside of the bend where the channel is shallower. So eroded material is deposited on the inside of the bend, forming slip off slopes.

Question 26

Oxbow lakes are formed from the meanders.

Answer 26

Erosion causes the outside bends of the river to get closer over time. The small bit of land left between the bends is called the neck. The river breaks through the neck usually during a flood. The river flows along the shortest course with deposition eventually cutting off the meander to form an oxbow lake.

Question 27

River landforms: deposition.

Floodplains, levees and daughters. All found in the lower course of a river.

Answer 27

Floodplains are in the wider valley floor on either side of the river which occasionally gets flooded. When a river floods onto the floodplain, the water slows down and deposits material, building up the floodplain.

Meanders move across the floodplain making it wider as well as moving downstream flattening out the valley floor. The deposition that happens on the slip off slopes also builds up the floodplain.

Levees are natural embankments on the edges of a river channel. During a flood the heaviest material is deposited closest to the river channel, over time this material builds up creating levees.
Deltas are low-lying areas where a river meets the sea or a lake. The river slows down when it meets the sea or a lake causing material to be deposited, this material builds up and the channel gets blocked. This forces the channel to split up into lots of small rivers called distributaries, eventually the material creates a Delta.