physical landscapes in the uk Flashcards
1
Q
Name four major upland areas in the UK and their location.
A
upland areas
- Grampian Mountains - part of the highlands with Ben Nevis (highest mountain in the UK), north of UK, north of Scotland
- Snowdonia - glaciated, formed from rock from an old volcano, steep mountains, Snowdon is also there, west of UK, north of Wales
- Lake District - lots of glacial features, national park, popular with tourists, west of UK, north west of England
- Pennines - middle of UK, north of England
2
Q
Name two major lowland areas in the UK and their location.
A
lowland areas
- River Clyde Lower Valley - flood plain, wide, low valley, Glasgow is here, north of UK, south of Scotland
- The Fens - flat, low-lying, marshy, much has been drained for farming, south east of UK and England
3
Q
Name four major river systems in the UK and their location.
A
river systems
- River Clyde Lower Valley - flood plain, wide, low valley, Glasgow is here, north of UK, south of Scotland
- River Severn - 354km, south west of UK, west of England (goes into Wales)
- River Thames - 346km, London, south west of UK and England
- River Trent - 297km, centre of UK and England
4
Q
What is weathering?
A
Weathering is the breakdown of rocks where they are.
5
Q
What is erosion?
A
Erosion is the breakdown of rocks and then being carried away by something, like sea water.
6
Q
Name the two types of weathering.
A
types of weathering
- mechanical
- chemical
7
Q
What is mechanical weathering? Give an example.
A
Mechanical weathering is the breakdown of rocks where they are without changing its chemical composition. An example is freeze-thaw weathering.
8
Q
Describe the process of freeze-thaw weathering and the conditions required for it to occur.
A
freeze-thaw weathering
- temperature must alternate between above and below 0°C (freezing point of water)
1) water gets into the cracks of a rock, like granite
2) when water freezes, it expands by 9%, which puts pressure onto the rock
3) when water thaws, it contracts, which releases the pressure on the rock
4) repeated freezing and thawing widens the crack and causes the rock to break up
9
Q
What is chemical weathering? Give an example.
A
Chemical weathering is the breakdown of rock by changing its chemical composition. An example is carbonation weathering.
10
Q
Describe the process of carbonation weathering and the conditions required for it to occur.
A
carbonation weathering
- requires warm and wet conditions
1) rainwater has carbon dioxide dissolved in it, which makes it a weak carbonic acid
2) carbonic acid reacts with rock that contains calcium carbonate, so these rocks are dissolved by rainwater
11
Q
What is mass movement?
A
Mass movement is the shifting of rocks and loose material down a slope. It happens when the force of gravity is larger than the force supporting it. They cause coasts to retreat rapidly.
12
Q
When is mass movement more likely to happen?
A
Mass movement is more likely to happen when the material is full of water; it acts as a lubricant and also makes the material heavier.
13
Q
Name the three types of mass movement.
A
mass movement
- landslides
- slumps
- rockfalls
14
Q
What are landslides?
A
Landslides are a form of mass movement. It is when the material shifts in a straight line.
15
Q
What are slumps?
A
Slumps are a form of mass movement. It is when the material shifts with a rotation.
16
Q
What are rockfalls?
A
Rockfalls are a form of mass movement. It is when the material breaks up and then falls down the slope. The fallen material is called scree.
17
Q
What are the four processes of erosion?
A
processes of erosion
- hydraulic action
- abrasion
- attrition
- solution
18
Q
What is hydraulic action?
A
Hydraulic action is when waves crash against the rocks and compress the air in the cracks. This puts pressure onto the rock and repeated compression widens the cracks and makes bits of the rock break off.
19
Q
What is abrasion?
A
Abrasion is when eroded particles in the water scrape and rub against the rock, removing small pieces.
20
Q
What is attrition?
A
Attrition is when eroded particles in the water smash into each other and break into smaller fragments. Their edges also get rounded off.
21
Q
What is solution?
A
Solution is when the river dissolves some types of rock, such as chalk and limestone.
22
Q
Which forms of erosion wear away the coast?
A
Waves wear away the coast using hydraulic action, abrasion and attrition.
23
Q
What are destructive waves?
A
destructive waves
- waves that carry out erosional processes
- higher frequency (10-14 waves per minute)
- high and steep
- backwash is more powerful than their swash, so material is removed from the coast
- long fetch
24
Q
What are constructive waves?
A
constructive waves
- waves that carry out depositional processes
- lower frequency (6-8 waves per minute)
- low and long
- swash is more powerful than their backwash, so material is deposited onto the coast
- short fetch
25
What is the fetch?
The fetch is the distance traveled by the wind over water.
26
What is swash?
Swash is the movement of water up the beach.
27
What is backwash?
Backwash is the movement of water down the beach.
28
Describe the formation of wave-cut platforms.
wave-cut platforms
1) waves cause the most erosion at the foot of a cliff
2) this forms a wave-cut notch
3) this is enlarged as erosion continues
4) the rock above the notch becomes unstable and collapses
5) the collapsed material is washed away and a new wave-cut notch starts to form
6) repeated collapsing causes the cliff to retreat
7) a wave-cut platform is the platform that is left behind as the cliff retreats
29
What is soft rock?
Soft rock, or rock with a lot of joints, have low resistance to erosion.
30
What is hard rock?
Hard rock, or rock with a solid structure, have a high resistance to erosion.
31
What are headlands and bays? How are they formed?
headlands and bays
- headlands are made of hard rock
- bays are made of soft rock
1) alternating hard and soft rock
2) the soft rock (eg. clay) is eroded quickly and forms a bay, which has a gentle slope (beach-like)
3) the hard rock (eg. chalk) is eroded slowly and juts out either side of the bay, forming headlands, which have steep sides (cliff-like)
32
Describe the formation of caves, arches, stacks and stumps.
caves, arches, stacks, stumps
1) headlands are made of resistant rock that has weakness like cracks
2) waves crash into the headlands and enlarge the cracks by erosion, mainly hydraulic action and abrasion
3) repeated erosion and enlargement causes a cave to form
4) continued erosion deepens the cave until it breaks through the headland, causing an arch
5) erosion continues to wear away the rock supporting the arch, until it collapses
6) this forms a stack - an isolated column of rock - which further erosion causes it to shorten and from a stump
33
Name three different coastal landforms caused by erosion.
landforms by erosion
- wave-cut notches and platforms
- headlands and bays
- caves, arches, stacks and stumps
34
What is longshore drift?
Longshore drift is the transportation of material along a beach.
35
Describe the process of longshore drift.
longshore drift
1) waves follow the direction of prevailing (most common) wind
2) waves hit the coast at an oblique angle (not 90)
3) the swash carries the material up the beach in the same direction as the waves (which is the same direction as the prevailing wind)
4) the backwash carries the material down the beach at right angles due to the force of gravity
5) the material zigzags along the coast
36
What is traction?
Traction is when large particles, like boulders, are pushed along the sea bed by the force of the water.
37
What is suspension?
Suspension is when small particles, like silt and clay, are carried along in the water by the force of the water.
38
What is saltation?
Saltation is when pebble-sized particles are bounced along the sea bed by the force of the water.
39
What is solution?
Solution is when soluble materials dissolve in the water and are carried along by the force of the water.
40
Name five processes of coastal transportation.
coastal transportation
- longshore drift
- traction
- suspension
- saltation
- solution
41
What is deposition?
Deposition is when material being carried by seawater is dropped on the coast due to the decrease in speed, so that it isn't fast enough to carry the sediment.
42
When is the coast built up? How can the amount of material built up be increased?
The coast is built up when the amount of deposition is greater than the amount of erosion. This happens due to constructive waves.
the amount of material deposited is increased when
- lots of erosion elsewhere on the coast, so there's lots of material available
- lots of transportation of material into the area
43
Where are beaches found?
Beaches are found on coasts between the high water mark (the highest point on land the sea level gets to) and the low water mark (the lowest point on land the sea level gets to) where constructive waves deposit sand and shingle.
44
Name four characteristics of sand beaches.
sand beaches
- flat
- wide
- particles are small
- long, gentle slope due to weak backwash that can move the particles down the beach
45
Name four characteristics of shingle beaches.
shingle beaches
- steep
- narrow
- particles are large
- steep slope due to weak backwash that can't move the particles down the beach
46
Name three things that deposited sediment can form.
deposited sediment can form
- spits
- bars
- sand dunes
47
Where are spits formed? How are they formed?
spits
- they form at sharp bends in the coastline
- longshore drift transports sand and shingle past the bend and deposits it in the sea
- strong winds and waves can curve the end of the spit, forming a recurved end
- the sheltered area behind a spit is protected from the waves, and lots of material is deposited here, so plants grow there
- the sheltered area becomes a mud flat or salt marsh
48
How are bars formed?
bars
- formed when a spit joins two headlands together
- the bar cuts off the bay between the headlands from the sea
- a lagoon forms behind the bar
49
How are sand dunes formed?
sand dunes
- formed when sand deposited by longshore drift is moved up the beach by the wind
- obstacles, like driftwood, cause wind speed to decrease so sand is deposited
- the sand is colonised by plants and grasses, and they stabilise the sand and encourage more sand to grow there, forming small dunes called embryo dunes
- the oldest dunes migrate inland as newer embryo dunes are formed
- these mature dunes can reach heights of up to 10m
50
How are caves, arches, stacks and stumps shown on a map?
caves, arches, stacks, stumps on maps
- caves and arches on maps can't be seen on a map because of the rock above them
- stacks and stumps on maps look like small blobs in the sea
51
How are cliffs and wave-cut platforms shown on a map?
cliffs and wave-cut platforms on maps
- cliffs and other steep slopes are little black lines
- wave-cut platforms are bumpy edges along the coast
52
How are sandy and shingle beaches shown on a map?
beaches on a map
- sand beaches are shown as a pale yellow region
- shingle beaches are shown as white or yellow regions with black speckles
53
How are spits shown on a map?
spits on a map
| - a beach (region of pale yellow) carries out into the sea, but one side is still attached to the land
54
What is hard engineering?
Hard engineering is man-made structures built to control the flow of the sea and rivers and reduce flooding and erosion.
55
What is soft engineering?
Soft engineering is schemes set up using knowledge of the sea and rivers and its processes to reduce the effects of flooding and erosion.
56
Name four examples of hard engineering for beaches.
hard engineering
- sea wall
- gabions
- rock armour
- groynes
57
What is a sea wall? Name two benefits and two costs.
sea wall
- a wall made of a hard material, like concrete, that reflects the waves back into the sea
benefits - prevents erosion of the coast
- acts as a barrier to prevent flooding
costs - creates a strong backwash erodes under the wall
- very expensive to build and maintain
58
What is a gabion? Name two benefits and two costs.
gabion
- a wall of wired cages filled with rocks, usually built at the foot of cliffs
benefits - absorb wave energy, so reduce erosion
- cheap and easy to build
costs - ugly
- the wire cages can corrode over time
59
What is rock armour? Name three benefits and a cost.
rock armour
- boulders that are piled up along the coast
- can also be called rip-rap
benefits - absorb wave energy, so reduce erosion
- reduce flooding
- fairly cheap
cost - boulders can be moved around by strong waves, so they need to be replaced
60
What are groynes? Name three benefits and one cost.
groynes
- wooden or stone defenses built at right angles to the coast to trap material transported by longshore drift
benefits - create wider beaches, which slow the waves
- greater protection from erosion and flooding
- fairly cheap
cost - they starve beaches of sand further down the coast, making them narrower, which doesn't protect the coast as well, so greater erosion and floods
61
Name two examples of soft engineering for beaches.
soft engineering
- beach nourishment and reprofiling
- dune regeneration
62
What is beach nourishment and reprofiling? Name one benefit and three costs.
beach nourishment and reprofiling
- sand and shingle is taken from elsewhere, such as the sea bed, or from lower down the beach
- this is added to the upper part of the beach
benefit - creates wider beaches, which slows the waves, giving greater protection from flooding and erosion
costs - taking material from the sea bed can kill organisms, like sponges and corals
- very expensive
- must be repeated
63
What is dune regeneration? Name two benefits and two costs.
dune regeneration
- creating or restoring sand dunes by either nourishment or planting vegetation to stabilise the sand
benefits - stabilisation is cheap
- provides barrier between land and sea, reducing erosion and flooding
costs - protection is limited to a small area
- nourishment is very expensive
64
What is managed retreat, or coastal realignment? Name benefits and costs.
managed retreat / coastal realignment
- removing current defenses and allowing the sea to flood land
- overtime, the land becomes marshland, which protects the land behind that from flooding and erosion
benefits - cheap and easy
- doesn't need maintaining
- marshland creates new habitats
costs - the land is lost to sea, so choosing the area to flood can cause conflict, especially with farmers (usually farmland is flooded)
- saltwater has negative effects on existing ecosystems
65
What is the course of a river? Name the three courses.
The course of a river is the path it takes as it flows downhill.
- the upper course
- the middle course
- the lower course
66
What is the long profile of a river?
The long profile of a river shows how the gradient changes over the courses.
67
What is a channel, in terms of a river?
A river channel is the width of the river.
68
What is a valley, in terms of a river?
A river valley is the width between the area around the river eroded by it.
69
What two things do rivers do?
rivers carry out...
- erosion
- deposition
70
Name seven characteristics of the upper course of the river.
upper course
- closest to the source of the river
- steep gradient
- V-shaped valley
- steep sides
- narrow channel
- shallow channel
- higher speed
- lots of erosion
71
Name five characteristics of the middle course of the river.
middle course
- medium gradient
- gently sloping valley sides
- wider channel
- deeper channel
- medium speed
72
Name seven characteristics of the lower course of the river.
lower course
- closest to the mouth of the river, when it feeds into a larger water source
- gentle gradient
- very wide, almost flat valley
- very wide channel
- very deep channel
- low speed
- lots of deposition
73
What is vertical erosion? Where is it dominant and why?
Vertical erosion deepens the river valley and channel, making it V-shaped. It's dominant in the upper course. high turbulence there causes rough, angular particles to be scraped across the river bed (abrasion), causing most downwards erosion.
74
What is lateral erosion? Where is it dominant and why?
Lateral erosion widens the river valley and channel during the formation of meanders. It mostly occurs in the middle and lower courses.
75
Give four reasons why the river deposits material.
why deposition occurs (loss in speed)
- volume of water in the river falls
- amount of eroded material in the water increases
- the water is shallower
- the river reaches its mouth
76
Describe the formation of waterfalls and gorges.
waterfalls and gorges
1) a river flows over an area of hard rock followed by soft rock
2) the softer rock is eroded by hydraulic action and abrasion more than the hard rock, creating a lower platform (like a step) where the soft rock is
3) as water goes over the step, it continues to erode until a steep drop is created; a waterfall
4) the hard rock is undercut by erosion, becomes unsupported and collapses
5) the collapses rocks swirl at the foot of the waterfall
6) here, the soft rock beneath is vertically eroded by abrasion, creating a deep plunge pool
7) more undercutting and more collapses causes the waterfall to retreat, leaving a steep-sided gorge
77
Describe the formation of interlocking spurs.
interlocking spurs
1) in the upper course, most erosion is vertical, creating steep sided, V-shaped valleys
2) the rivers aren't powerful enough to erode laterally, so they move around the high hillsides
3) the hillsides that interlock as the river winds around them are interlocking spurs
78
Describe the formation of meanders.
meanders
1) the current is faster on the outside of the bend as the river channel is deeper, so there's less friction
2) therefore, more erosion occurs on the outside of the bend, forming river cliffs
3) the current is slower on the inside of the bend as the river channel is shallower, so there's more friction
4) therefore, eroded material is deposited on the inside of the bend, forming slip-off slopes
5) over time, these processes continue so that the bend in the river is much sharper
79
Describe the formation of oxbow lakes.
oxbow lakes
1) when a meander is formed, the meander neck can get very thin as more erosion occurs due to either side of the neck being the outside of the river
2) the river breaks through this thin piece of land (neck) during a flood usually
3) the river continues to flow along the shortest course
4) deposition cuts off the meander from the shorter, straighter course
5) the oxbow lake is formed; the cut off meander
- this can dry up, leaving a scar in the landscape
- this can form a small pond
80
What are flood plains?
The flood plain is the wide valley floor on either side of a river which occasionally gets flooded.
81
What happens when the river floods onto flood plains?
rivers flooding onto flood plains
1) the water slows down and deposits the eroded material it is transporting
2) this builds up the flood plain and makes it higher
3) meanders migrate across the flood plain, making it wider
4) meanders also migrate downstream, flattening out the valley floor
5) the deposition that occurs on slip-off slopes of meanders also builds up the flood plain
82
Describe the formation of levees.
levees
- natural embankments (raised bits) along the edges of a river channel
1) during a flood, eroded material is deposited over the whole flood plain
2) the heaviest material is deposited closest to the river channel as it's first dropped when the river slows down
3) over time, the deposited material builds up, creating levees along the edges of the channel
83
What are river estuaries? Give three characteristics found here.
River estuaries are found at the mouth of a river, where it meets the sea.
- land is close to sea level
- river valley is at its widest
- the water is tidal (rises and falls)
84
Describe the formation of mudflats.
mudflats
1) the river at estuaries floods over banks of the river carrying silt and sand onto the valley floor
2) as the tide reaches its highest point, the water moves very slowly so the sediment is deposited
3) over time, more mud builds up, creating large areas of mudflats
4) at low tide, the wide, muddy banks are exposed
85
Name five river landforms formed by erosion.
river landforms by erosion
- waterfalls
- gorges
- interlocking spurs
- meanders (erosion + deposition)
- oxbow lakes (erosion + deposition)
86
Name five river landforms formed by deposition.
river landforms by deposition
- flood plains
- levees
- estuaries
- meanders (erosion + deposition)
- oxbow lakes (erosion + deposition)
87
How can the upper and lower course be shown on a map?
maps
upper course - lots of contour lines (high to low land)
- thin blue line for river
- a cliff (black, blocky lines)
lower course - less contour lines (flat land)
- wide blue line for river
- meanders and oxbow lakes
88
What is river discharge? Give the units.
River discharge is the volume of water that flows in a river per second, measured in cumecs (m^3/s).
89
What is peak discharge?
Peak discharge is the highest discharge in a period of time.
90
What is lag time? Why does this happen?
Lag time is the delay between peak rainfall and peak discharge. This usually happens because most rainwater doesn't land directly into the river channel, so there's a delay as it gets to the water. It gets there by runoff or soaking into the ground (infiltration) and flowing underground.
91
What is rising limb?
Rising limb is the increase in river discharge as rainwater flows into the river.
92
What is falling limb?
Falling limb is the decrease in river discharge as the river returns to normal level.
93
What graph shows river discharge?
Hydrographs show river discharge.
| cumecs on y axis, time on x axis
94
What is relief?
Relief is the change in height of the land.
95
Describe four physical factors that increase discharge from the river.
increasing discharge
- prolonged rainfall - soil becomes saturated so further rainfall can't infiltrate, increasing surface runoff
- heavy rainfall - arrives too rapidly for infiltration, so a lot of runoff, increasing discharge
- geology - clay soils and some rocks, like granite and shale, are impermeable, so runoff is increased
- relief - steep-sided valley means water will reach the river channel faster, discharge increases
96
Describe a human factor that increases discharge from the river.
increasing discharge
- land use - buildings are oftem made from impermeable materials, like concrete, and are surrounded by roads of tarmac (impermeable), increasing runoff
- trees take up water and store it, so cutting down trees increases the volume of water that reaches the channel, increasing discharge
97
Name four examples of hard engineering for rivers.
hard engineering
- dams and reservoirs
- channel straightening
- embankments
- flood relief channels
98
What are dams and reservoirs? Name three benefits and three costs.
dams and reservoirs
- huge walls built across the rivers, usually at the upper course
- an artificial lake formed behind a dam
benefit - reservoirs store water, which reduces the risk of flooding
- the water in reservoirs can be used as drinking water
- water can be used to generate hydroelectric power
cost - very expensive to build
- reservoirs can flood settlements
- eroded material is deposited in the reservoir and not along the river's natural course so farmland downstream can become less fertile
99
What is channel straightening? Name a benefit and two costs.
channel straightening
- straightening the river's course
- cut out meanders by building artificial straight channels (oxbow lakes)
benefit - water moves quickly out of an area because it doesn't have to travel as far, reducing flood risk
costs - flooding may happen downstream as water is carried there faster
- more erosion downstream as water is faster there
100
What are embankments? Name a benefit and two costs.
embankments
- raised walls built along the river banks
benefit - river can hold more water, so flood less
costs - quite expensive
- risk of severe flooding if water rises above embankment or if they break
101
What are flood relief channels? Name two benefits and two costs.
flood relief channels
- channels built to divert the water around important areas, or take it elsewhere if the water gets too high
benefits - river discharge is reduced
- gates on flood relief channels means the release of water can be controlled
costs - increased discharge where the relief channel rejoins the river or joins another river
- if water level gets too high for relief channels, they could also flood
102
Name five examples of soft engineering for rivers.
soft engineering
- flood warnings
- preparation
- flood plain zoning
- planting trees
- river restoration
103
What are flood warnings? Name a benefit and two costs.
flood warnings
- Environmental Agency warns people about possible flooding through TV, radio, newspapers and internet
benefit - impact of flooding is reduced
costs - don't stop the flood
- may not have access to warnings
104
What is preparation? Name two benefits and two costs.
preparation
- buildings modified to reduce potential damage
- people make plans and stock items
benefits - impact of flooding is reduced
- people are less likely to worry
costs - doesn't guarantee safety (false sense of security)
- expensive to modify homes and businesses
105
What is flood plain zoning? Name two benefits and two costs.
flood plain zoning
- restrictions stop building on parts of a flood plain that are likely to be affected
benefits - risk of flooding is reduced as impermeable surfaces aren't created
- impact of flooding is reduced
costs - expansion of urban area is limited
- no help for areas that are already in the zone
106
What is planting trees? Name three benefits and a cost.
planting trees
- in the river valley, increases interception of rainwater and increases lag time
benefits - discharge reduced
- vegetation reduces soil erosion
- provides habitats
cost - less land available for farming
107
What is river restoration? Name three benefits and a cost.
river restoration
- making the river more natural (like removing man made levees so flood plain can flood more naturally)
benefits - less risk of flooding downstream as discharge is decreased
- little maintenance needed
- better habitats
cost - local flood risk can increase
