Topic 1 - The Changing Landscapes of the UK Flashcards
1
Q
2 examples of metamorphic rock.
A
Schists and Slate
2
Q
2 examples of igneous rock.
A
Baslat and Granite
3
Q
2 examples of sedimentary rock
A
Chalk and Limestone
4
Q
State the types of rock found in upland and low land regions.
A
Upland - igneous and metamorphic
Lowland - sedimentary
5
Q
State a type of mechnaical weathering.
A
Freeze thaw
6
Q
Explain freeze thaw weathering.
A
Water freezes and expands this causes stress within the rock.
when water melts it sits deeper and a higher volume of water comes in.
7
Q
How are grykes formed?
A
Grykes are formed by freeze-thaw weathering and acid rain on the top of limestone pavements.
8
Q
How are clints formed?
A
Clints are formed by the widening and deepening of grykes.
9
Q
What is a clitter slope?
A
A clitter slope includes material that has come away from a tor after the tor has been eroded.
They line the bottom of the slope.
10
Q
Describe the formation of a tor?
A
Tors are formed when soft rock is eroded by freeze thaw weathering leaving the hard rock exposed.
11
Q
What is a joint?
A
A joint is a brittle fracture surface due to tensile stress in the rock.
12
Q
How is an escarpment formed?
A
Erosion creates an escarpment by wearing away rock on one side more than the other due to difference in type of sedimentary rock.
13
Q
Why would a stream be found at the bottom of the scarp slope?
A
Water flows through the chalk rock which is permeable when it meets the clay it is forced above ground where it forms a stream.
14
Q
What is a dip slope?
A
A gentle gradient usually found at the back of a scarp slope.
15
Q
How are bars formed?
A
When a spit grows across a bay and joins two headlands together. Leaving a pool of water behind it called a lagoon.
16
Q
3 types of weathering.
A
Biological, Chemical and Mechanical.
17
Q
How can rising sea level lead to an increase in erosoion?
A
The sea will erode cliffs from a higher point. The sea will erode further inland. It will be able to overcome sea defences.
18
Q
Two examples of coastal soft-engineering techniques.
A
Beach nourishment.
Sand dune regeneration.
19
Q
What is beach nourishment?
A
Sand or shingle added to a beach to make it higher and wider.
20
Q
What is sand dune regeneration?
A
Grasses, bushes and trees are planted to stabilise dunes.
21
Q
Define hard engineering.
A
Hard Engineering involves building artificial structures, to try to control natural processes.
22
Q
Define soft-engineering.
A
Allows natural processes to work and land to change in a more environmentally stable way.
23
Q
How is a spit formed?
A
LSD carries sediment in a straight line after the coastline has changed direction.
24
Q
What is a spit?
A
A depositional landform that includes a strip of sand stretching form the mainland out into the sea.
25
What is terminal groyne syndrome?
At the end of groynes erosion is more active due to the natural barrier of a beach being removed.
26
How do sea walls often end up deconstructing a beach?
Force the sea to break early so not all energy is dissipated. Resulting in a strong backwash which will deconstruct the beach.
27
3 examples of hard-engineering techniques in beaches?
Groynes.
Sea walls.
Rip-rap.
28
What are groynes?
Wooden/rock structures built along the beach at right-angles, that trap sediment and broaden the beach.
29
What are sea walls?
Concrete walls, built at the top of a beach and curved to reflect waves back out to sea.
30
What is rip-rap?
Large boulders piled at the top of the beach or foot of the cliff, which dissipate energy of the waves by forcing them to break.
31
What is a bar?
A spit that grows across a bay joining two headlands together. They can trap shallow lakes behind the bar, called a lagoon.
32
What is dredging?
When sand and gravel is removed to build up another beach or dock, leaving the area it is taken from exposed.
33
What does hold the line mean in terms of shoreline management plans?
Maintain the existing shoreline by building defences.
34
What does management realignment mean?
Allow shoreline to change naturally but manage and direct the process.
35
What does advance the line mean?
Build new defences on the seaward side.
36
What is suspension?
When fine material such as clay are carried by the river.
37
What is traction?
Large boulders and pebbles are rolled along the riverbed.
38
What is solution?
Dissolved materials are carried by the river.
39
What is saltation?
Small pebbles bouncing along the riverbed.
40
What is the source of the river?
The beginning of the river.
41
What is a confluence?
When two rivers meet.
42
What is a watershed?
An area of high land between two drainage basins.
43
What is the mouth of the river?
Where a river flows into a lake or the sea.
44
What is a tributary?
A small river or stream that flows into a larger river.
45
What is a drainage basin?
An area drained by a river and its tributaries.
46
What is mass movement?
Downhill movement of sediment due to gravity, weak rocks, steep slopes and heavy rainfall.
47
What is soil creep?
Individual particles of soil moving slowly down a slope.
48
What is sliding?
Where material moves rapidly down slope in one go.
49
What is flows?
Where masses of soil or rock, mixed with water, flow like a liquid downhill.
50
Explain the process of mass movement that happens in the upper course of rivers.
Weathering processes loosens rocks and boulders over time. This material moves down the steep valley sides.
51
Define the term long river profile.
Shows the change in gradient along the course of a river.
52
Define the term weathering.
The breakdown of rocks due to exposure to the atmosphere.
53
Landforms in upper section of a river.
Waterfalls, Gorges and Interlocking spurs.
54
Landforms in lower sections.
Flood plains and river meanders.
55
What is deposistion?
When the river loses energy and drops off any material it has been carrying.
56
What leads to deposition taking place?
Shallow water.
End of rivers journey.
Volume of water decreases.
57
What does a rivers load look like in the upper course?
Large, as it hasn't been broken down by erosion yet.
58
What does a rivers load like in the lower course?
Fine sediment, as erosion has broken down the rocks.
59
What does the gradient of the land look like in the upper course of a river?
Steep.
60
What does the gradient of the land look like in the lower course of a river?
Flat.
61
Describe the shape of the river in it's upper course.
As the river flows downhill there is lots of vertical erosion leading to steep sides. The channel is shallow and narrow because there is not a lot of water in the channel.
62
Describe the flow of a river in it's middle course.
As the river flows into the middle course, it gains more water and therefore more energy. Lateral erosion starts to widen the river.
63
Describe the flow of a river in it's lower course.
In the lower course there is a lot less erosion, with only some lateral erosion. The channel is at its widest and deepest.
64
What happens when a river goes around a meander?
Most water pushed to the outside. This causes increased speed and therefore, increased erosion creating a river cliff.
Water on the inner bend has less energy causing material to be deposited forming a slip-off slope.
65
What does discharge mean?
The volume of water in a river passing through a point in a given time.
66
How are oxbow lakes formed?
Erosion narrows the neck of the meander. And as the process continues the meander move closer together. When there is high discharge the river cuts across the neck to take a straighter and shorter route. Deposition means that the original meander will be cut off.
67
What is a floodplain?
An area of low-lying land next to a river that is prone to flooding.
68
How are floodplains formed?
They are formed from both erosion and deposition.
Erosion removes any interlocking spurs creating a wide flat area of land next to the river.
In the case or a flood, material is deposited and the height of the floodplain increases.
69
Why does the river deposit material in the case of a flood?
The river loses its speed and energy to transport material when it overflows its banks.
70
Why do levees occur in the lower course of rivers?
Because there is an increase in the water flowing downstream so flooding is more likely to occur.
71
How do levees form?
When a river floods, material is deposited on the banks of the river. After many floods, sediment builds up to increase the height of the river.
72
How do levees protect against flooding?
The greater height of the river, means that the river can carry more water (have a greater discharge).
73
What is an estuary?
It is when the open mouth of the river meets the sea.
74
How are the mudflats formed in an estuary?
When the sea retreats the volume of water in the estuary is also reduced. The river loses energy and deposits slit to form mudflats.
75
Why are mudflats important?
They are an important habitat for wildlife.
76
What are 2 human causes for flooding?
Deforestation and Urbanisation
77
How does deforestation cause flooding?
When deforestation takes place, the top layer of soil can be dislodged – this is also known as soil erosion. When the top layer of soil is unstable, it is unable to retain any of the water that falls on it, resulting in increased surface run-off, which, in turn, increases the risk of flooding.
78
How does urbanisation cause flooding?
Impermeable surfaces such as concrete and tarmac. Causes water to run off immediately to drains and river channels.
79
What are 5 physical causes of flooding?
Intense rainfall - soil becomes saturated
Duration of rainfall - soil becomes saturated
Snow melt - large volume of snow in winter, releases large volumes of snow melt
Rock permeability
Relief - water reaches channel faster when slopes are steeper.
80
What are advantages of embankments (levees)?
Blend in with environment.
Stop flooding.
81
What are disadvantages of embankments (levees)?
Flood water may go over top and then get trapped.
They can burst under pressure.
82
What is channelisation?
Straightening the river so high volumes of water can travel through an area quickly.
83
What is an advantage of channelisation?
Allows higher volume of water to flow through channel.
84
What are some disadvantages of channelisation?
Water taken downstream may put other places at risk.
Doesn't look natural.
85
What are flood relief channels?
Extra channels built next to rivers or leading from them.
86
What is an advantage of flood relief channels?
Can accommodate high flows without bursting banks.
87
What are disadvantages of flood relief channels?
Unsightly and expensive.
88
What are some advantages of dams and reservoirs? (4)
Long lasting.
Produce HEP.
Local water supply.
Attract tourists.
89
What are some disadvantages of dam and reservoirs?
Expensive.
Displaces people.
Habitats are flooded and leading to rotting vegetation, meaning more GHG's released into atmosphere.
90
What are washlands?
Area on floodplains that are allowed to flood.
91
What are some advantages of washlands?
Slow floodwaters down.
Safe for water to go.
Sediment restored in floodplain, making it more capable of storing water.
92
What is a disadvantage of washlands?
Limits the use of land.
93
What is river restoration?
Restoring a rivers original course by taking away embankments.
94
What are some advantages of river restoration?
More attractive.
Natural habitat for wildlife.
95
What are some disadvantages of river restoration?
Flood banks still needed.
You have to change the land use surrounding the river.
96
What is flood-plain zoning?
Governments allocate areas of land to different uses depending on flood risk.
97
What is an advantage of flood-plain zoning?
Prevents building homes and businesses in high risk zones.
High-risk area's can be used for recreational purposes as flooding will be less costly.
98
What is a disadvantage of flood-plain zoning?
Floodplains are attractive places to build on.
99
What are 3 characteristics of sedimentary rocks?
Formed in layers.
Contains fossils.
Easily eroded.
100
What are 2 characteristics of igneous rocks?
Formed of crystals.
Hard and resistant to erosion.
101
How are metamorphic rocks formed?
Heat and pressure.
102
How is the UK split geologically?
North-western UK is mainly harder igneous and metamorphic rocks. (upland landscapes)
South-eastern UK is mainly softer sedimentary rocks. (lowland landscapes)
103
What is chemical weathering?
Rocks reacting with slightly acidic water.
104
What is biological weathering?
Burrowing animals and tree roots widening cracks in rocks.
105
What is Long shore drift?
The process by which sediment is transported up the beach at the same angle as the swash.
Then is transported back to sea at right angles to the coastline due to gravity.
106
What are concordant coasts?
Made up of the same rock type.
107
What are discordant coasts?
The rocky type alternates. Forming headlands and bays.
108
What are joints?
Small cracks in rocks.
109
What are faults?
Large weaknesses in rocks.
110
What is a constructive wave?
Low energy waves, that occur in calm conditions.
Material is deposited, building up the coast.
111
What is a destructive wave?
High energy waves, where the backwash is stronger than the swash, eroding the coast.
112
What is a fetch?
The stretch of ocean water over which the wind blows.
113
How do the prevailing winds in the UK impact coastal erosion?
The prevailing winds, in the UK, are south-westerly. This brings warm, moist air from the Atlantic Ocean and, therefore, frequent precipitation. This adds to weathering and mass mass movement.
Long fetch
114
How do cold temperatures in winter lead to increased coastal erosion?
Leads to freeze-thaw weathering.
115
How do storms lead to coastal erosion?
Heavy rainfall can saturate cliffs and cause slumping.
It subjects coasts to stronger winds and destructive waves.
116
Define erosion.
The wearing away and removal of a material by a moving force.
117
Define prevailing wind.
Direction from which wind usually blows.
118
Define velocity.
How fast the water is flowing.
119
What is weathering?
The breakdown and decay of rock by natural processes.
120
How are interlocking spurs formed?
In the upper course there is more vertical erosion. The river cuts down into the valley. If there are areas of hard rock which are harder to erode, the river will bend around it. Creating interlocking spurs.
121
When does a waterfall form?
It forms when there are horizontal bands of resistant rock (hard rock) positioned over exposed, less resistant rock (soft rock).
122
How are gorges formed?
Due to the retreat of waterfalls because of abrasion and hydraulic action.
123
What is a gorge?
A deep narrow passage that usually has a river flowing through it.
