Physical Landscapes in the UK Flashcards
(80 cards)
1
Q
What are the two largest rivers in the UK?
A
- River Severn (354km), Bristol
- River Thames (356km), London
2
Q
Where are upland areas located in the UK, and what are its characteristics?
A
Upland areas are located in Scotland, Lake district and the Pennines
-they are often rugged with steep relief with weathered rocks
3
Q
Where are lowland areas located in the UK, and what are its characteristics?
A
Lowland areas are found in the South and East of the UK
-best for farming as the soil is fertile and relief is gentle
4
Q
What is the crest of a wave?
A
The top of a wave
5
Q
What is the wave height?
A
The vertical distance from trough to crest
6
Q
What is the trough of a wave?
A
The bottom of a wave
7
Q
What is the wave length?
A
The horizontal distance between two crests
8
Q
What is the wave frequency?
A
The number of waves breaking per minute
9
Q
What are characteristics of a constructive wave?
A
- not very tall, calm
- longer wavelength
- low frequency (7-10 per minute)
- strong swash and weak backwash
- deposit material onto coastlines (deposition)
10
Q
What are characteristics of a destructive wave?
A
- taller and more frequent
- shorter wavelength
- high frequency (10-15 per minute)
- strong backwash and weak swash
- drag material away (erosion)
11
Q
What is chemical weathering?
A
chemical composition of rock changes, carbonic acid rain hits rocks, and dissolves the parts made from calcium carbonate
12
Q
What is mechanical weathering?
A
mainly freeze-thaw weathering, in colder conditions when water fills a crack in a rock and freezes. This causes the water to expand, causing the crack to get wider, causing significant erosion
13
Q
What is mass movements, and what causes it?
A
Mass movements describe the large movement of soil and rock down the slope of a hill or cliff, caused by weathering, erosion or gravity
14
Q
What are rockfalls, slides and slumps?
A
Rockfalls = cliff materials break and crumble down the cliff
Slides = material moves down a slope in a straight line
Slumps = material moves down a slope at a curve
15
Q
What is erosion?
A
Wearing away of rock by natural forces like wind or waves
16
Q
What are the 4 types of erosion that affects coasts?
A
- Hydraulic action = force of waves hit against a cliff-face causing rocks to break off
- Attrition = where different bits of material carried by waves hit against each other causing them to break, getting smaller and rounder
- Solution = where weak acids dissolve soluble rocks like chalk/limestone
- Abrasion = pieces of material are picked up by the waves and scrape against the sea bed, wearing away sea bed (sandpaper)
17
Q
Explain the 4 stages of how wave-cut platforms form?
A
- destructive waves erode the base of the cliffs, (hydraulic action and abrasion), forming a wave-cut notch
- the rock becomes less stable above it, until it collapses
- the debris is washed away by the waves, which continue to erode the cliff forming a new wave-cut notch
- more debris falls and cliff retreats, whats left behind is called a wave-cut platform,
= a flat gently sloping ledge of rock that extends out into the sea from the base of the cliff
18
Q
What is the difference between a concordant coastline and discordant coastline?
A
A discordant coastline occurs when different types of rock run perpendicular (at right angles) to the coast.
A concordant coastline occurs when layers of rock run parallel to the coastline.
19
Q
How are bays and headlands formed?
A
In discordant coastlines, the soft rock gets eroded more quickly, creating a bay (indentation), the hard rock which erodes more slowly is a headland.
20
Q
What 4 landforms are created when headlands are eroded?
A
- Caves = cracks get wider due to hydraulic action, abrasion and attrition
- Arches = eroded from one side through the other, eg Durdle Door in Dorset
- Stacks = top of an arch collapses, a column is left behind
- Stump = stack is undercut, collapsing into a stump
21
Q
Explain how longshore drift works?
A
Transports material along the coats
Prevailing wind approaches the coast at an angle (direction of swash). Gravity acts on backwash at a 90 degree angle, causing sediment to move along a beach
22
Q
What are the 4 ways that water can transport sediment?
A
- Solution
- Suspension
- Saltation
- Traction
23
Q
What is solution?
A
Soluble rock are dissolved by water (limestone or chalk) and transported
24
Q
What is suspension?
A
Slit (sand, clay etc) are held in water but not dissolved, transported as lighter sediments
25
What is saltation?
Small sand and gravel particles bounce along the river bed, traveling in the direction of flow (near the source)
26
What is traction?
Large rocks are dragged along the sea bed by the current, near the source
27
What is deposition?
Sea dropping sediment at the coastline, from constructive waves
28
How are shingle beaches formed?
When pebbles and shingle are deposited on the coast, they are big and hard to wash back into the ocean so they build up, making short and steep beaches
29
What are sand dunes and how are they formed?
Hills of sand created at the back of the beach, wind blows deposited sand, objects like wood or rubbish block the wind. These allow plants and vegetation to grow leading to more sand building up.
30
What are the two types of sand dunes?
Embryo dunes = newer sand dunes
Mature dunes = older sand dunes
31
What are spits and how are they formed?
Piles of sand create sheltered zones on the coast, when the coast changes direction at an estuary, long shore drift continues but the river doesn't let it completely join to the coast on the other side (because the river has the energy to move the sediment)
They are long fingers of sand sticking out, often with a marshland.
32
What are bars and how are they formed?
A bar is created when a spit grows across a bay, lagoons (saltwater pools) are often created behind a bar but they may be filled up with sediment.
33
What is hard engineering coastal defences, and give examples?
Hard engineering - protects coastlines using man-made constructions from sea's erosion and destructive waves
eg. Sea walls, rock amour, gabions and groynes
34
Give advantages and disadvantages of sea walls and explain how they work.
Sea walls are materials that blocks waves, to reflect wave's power back out to the sea.
ADV = They also prevent flooding and coastal erosion
DIS = They are expensive and can be broken by waves
35
Give advantages and disadvantages of rock amour , and explain how they work.
Rock amour is simply a pile of rock that absorbs some pressure/energy of waves
ADV = Very cheap to protect coasts
DIS = Enormous waves can remove the rocks and not aesthetically pleasing
36
Give advantages and disadvantages of gabions , and explain how they work.
Gabions are wire cages of rocks, absorbing pressure/energy of waves
ADV = Leading to less erosion and very cheap
DIS = Wires can corrode over time and look unnatural
37
Give advantages and disadvantages of groynes, and explain how they work.
Groynes are fences that stick out at 90 degrees to the coast, stop the process of longshore drift by trapping material against the fence
ADV = Creates wider beaches (better for protecting coat from erosion/floods), cheap and attracts tourists
DIS = Starves beaches further down, leading to erosion elsewhere, can look unattractive
38
What is soft engineering coastal defences, and give examples?
Soft engineering - artificially use the sea and processes to protect coastal areas from flooding/erosion
eg. Beach nourishment, dune regeneration and beach reprofiling
39
Give advantages and disadvantages of beach nourishment, and explain how they work.
Beach nourishment involves adding more sand to a beach
ADV = Blends in with existing beach, making it larger and appealing to tourists
DIS = Needs to be constantly replaced and brought in elsewhere
40
Give advantages and disadvantages of dune regeneration, and explain how they work.
Dune regeneration focuses on maintaining/improving sand dunes by nourishing plants
ADV = Helps them resist wind and absorb destructive waves' energy, relatively cheap and looks natural
DIS = Can be easily damages by storm waves and areas have to be zones off from public
41
Give advantages and disadvantages of beach reprofiling, and explain how they work.
Beach reprofiling involves changing the makeup of sediment and sand to protect coastlines
ADV = Creating a wider beach to slow waves and reduce the energy when it hits the shore, its cheap and simple
DIS = It only works when wave energy is low, needs to be repeated continuously and moving sand/shingle can damage wildlife
42
Where is Dorset Coast located and what coastline is it?
South coast of England, Discordant coastline
43
What are the erosional landforms at Dorset?
1. Durdle door (arch) from limestone headland
2. Lulworth Cove (bay)
3. Old Harry rocks (stacks + stumps)
44
What are the depositional landforms at Dorset?
1. Chesil beach, long bar from longshore drift
2. Sand dunes
45
What are some management strategies at Dorset?
Sea walls
Groynes
Beach nourishment
Dune stability
46
What is managed retreat?
Accepting defeat, removing coastal defences so land is flooded to become swamps or marshland
47
What are advantages and disadvantages of managed retreat?
ADV = protects land behind it, costs no money, swamps are biodiverse, moves the coastline
DIS = land is lost to the sea, houses could be lost, needing compensation
48
What happens to the valley and channel as you go down a river?
Valley gets wider and flatter
Channel gets wider and deeper
49
Describe the upper course of a river.
Erosion dominates deposition, so valley is steep sided and shaped like a V, the channel that water flows is narrow and not deep
50
Describe the middle course of a river.
Erosion nor deposition is dominant so valley has a gentle slope and the channel is wider and deeper
51
Describe the lower course of a river.
Deposition dominates over erosion so valley is wide and flat and channel is wide and deep
52
What does vertical and lateral erosion do?
Vertical erosion makes the valley deeper, dominates at upper course
Lateral erosion makes the river valley wider, dominates at middle and lower course
53
Where is the River Tees located?
North east England, from the Pennine Hills to the North sea
54
What is the name of the famous waterfall on River Tees and how tall is it?
High Force Waterfall, 21m
55
What erosional landforms are found in the upper course and what depositional landform is found in the lower course?
Upper course = V-shaped valleys, interlocking spurs, waterfalls, gorges
Lower course = Floodplains, levees, estuaries
56
Why do rivers lose velocity and drop material?
1. Increased amount of sediment in channel
2. River becomes shallower
3. River's mouth is reached
4. Reduced volume in water
57
How are waterfalls and gorges formed?
When a river flows over hard rock that overlays softer rock, a waterfall can form. Gorgeous are formed when waterfalls retreat overtime.
1. Soft rock erodes, creating a notch and a river rapid
2. Hard rock is undercut forming an overhang, height of drop increases as water pounds soft rock at base (waterfall)
3. Overhanging harder rock collapses, crumbling at the base creating a plunge pool
4. Hydraulic action undercuts behind the waterfall forming a gorge
58
How are interlocking spurs formed?
In the upper course, valleys are steep and v shaped, the river doesn't have a lot of energy so they follow the winding path through the valley, forming interlocking spurs
59
How are meanders formed?
Erosion and deposition in parts of the river with deep and shallow riverbeds creates meanders. When a river bends, the current is fastest at outside of the bend, eroding the side of the river. Current is weaker where the water is shallowest, opposite the river cliff so more sediment is deposited there, creating a slip off slope.
60
How are ox-bow lakes formed?
As erosion continues the river bends get nearer to each other creating a swans neck meander. During a flood, high energy water will breach the meanders neck, making the river flow in a straighter and faster course. Overtime sediment is deposited in the meander bends being cut off from the river, forming an ox-bow lake.
61
What are flood plains?
Wide area of flat land that surrounds rivers in their lower course, these areas can flood.
Created by a meander migrating close to the mouth of the river mouth. During floods, water loses speed and deposits sediment. increasing the height of the flood plain.
62
How are levees created?
When a flood happens, water overflows over banks of a river, the larger sediment gets deposited first. Levees are natural piles of sediment created at the sides of the river, as river bed builds up
63
What are estuaries?
Where the river mouth meets the sea.
64
What happens at high tide estuaries?
- river bank overflows
- water is moving slowly and the sediment gets deposited
- these sediments build up to form large mudflats overtime
- sea retreats and the mudflats are exposed to the air
65
What causes floods?
When the amount of water in a river is greater than the river's capacity. Increasing river level is caused by increasing river discharge.
66
What is river discharge?
The volume of water flowing in a river per second, measured in cumsecs.
67
What factors increase river discharge, leading to floods?
1. Land use, impermeable material for roads mean more surface run off, trees can intercept/absorb water
2. Geology, run off is higher in areas that are mainly made up of impermeable materials
3. Precipitation, heavy rainfall causes high run off as there's no time to infiltrate the soil
4. Relief, rainfall with each the river channel quicker in a steep-sided valley
68
What do hydro graphs show?
Show rainfall and the discharge in a river at a certain point
69
Define the following terms.
Peak rainfall =
Lag time =
Rising limb =
Peak discharge =
Falling limb =
Peak rainfall = maximum rainfall in the time period
Lag time = the interval between peak rainfall and peak discharge
Rising limb = when discharge is rising
Peak discharge = highest level of discharge
Falling limb = when discharge is falling
70
What is hard engineering flooding defences, and give examples?
Hard engineering - aim to reduce the effects of flooding by building man-made constructions that control a river's flow
eg. channel straightening, embankments, dams/reservoirs and flood relief channels
71
Give advantages and disadvantages of channel straightening, and explain how they work.
Channel straightening means bends and meanders are removed by constructing straight channels to connect the meanders,
ADV = reduces the risk of floods by keeping water flowing through an area quickly
DIS = downstream areas are more at risk of flooding and erosion as water flows faster
72
Give advantages and disadvantages of embankments, and explain how they work.
Embankments are walls thats build either side of the river channel to raise the height of the banks
ADV = reduces flooding by increasing capacity of the river
DIS = expensive, can burst and look unnatural
73
Give advantages and disadvantages of flood relief channels, and explain how they work.
Flood relief channels are secondary channels build alongside rivers to divert water away from particular areas if there's too much rainfall
ADV = less river discharge, does not affect river ecosystem
DIS = expensive and the relief channel may also flood if water rises too much
73
Give advantages and disadvantages of dams and reservoirs, and explain how they work.
Dams are a large concrete wall built across a river in the upper course, behind a dam is a reservoir (a man-made lake)
ADV = reduce floods by filling up water (for drinking or hydroelectric power)
DIS = expensive with habitats/towns destroyed
74
What is soft engineering flooding defences, and give examples?
Soft engineering flooding defences aim to reduce the effects of flooding using our knowledge of nature and natural courses of rivers
eg. flood warnings, flood plain zoning, planting trees, river restoration and preparation
75
Give advantages and disadvantages of flood warning and explain how they work.
Flood warning are sent out by the government when river levels are high
ADV = allow people to put sandbags to protect homes or leave
DIS = not everyone watches the news, and we cannot prevent floods entirely
76
Give advantages and disadvantages of flood plain zoning, and explain how they work.
Flood plain zoning is allowing only certain land uses on the floodplain reduces the risk of flooding to houses and more important buildings
ADV = less damage is caused as more expensive buildings are further away
DIS = not always possible to change existing land uses
77
Give advantages and disadvantages of planting trees, and explain how they work.
Planting trees in river basins will increase proportion of rain that's intercepted by trees, increasing lag time
ADV = wildlife can create homes
DIS = less space is available for building homes/faming
78
Give advantages and disadvantages of river restoration, and explain how they work.
River restoration returns a river to its natural state, allowing it to swell its banks and flood the flood plain naturally
ADV = passive approach like managed retreat
DIS = doesn't stop flooding
79
Give advantages and disadvantages of preparation, and explain how they work.
Preparation is building flood-proof infrastructure, or building houses on stilts
ADV = reduces financial and personal impacts of flooding
DIS = expensive for all houses
