The UK's Evolving Physcial Landscape Flashcards
1
Q
What are the three types of rocks?
A
Igneous
Sedimentary
Metamorphic
2
Q
How are igneous rocks formes?
A
Formed when molten rock from the mantle cools down and hardens.
3
Q
How are sedimentary rocks formed?
A
When layers of sediment are compacted together until they become solid rock.
4
Q
How are metamorphic rocks formed?
A
Metamorphic rocks are formed when other rocks are changed by heat and pressure. The new rocks become harder more compact.
5
Q
What are the three main ways that past tectonic process have shaped the UK landscape?
A
Active volcanoes
Plate collisions
Plate movements
6
Q
Characteristics of Granite
A
Very resistant and forms upland landscapes.
Has a lot pf joints which aren’t evenly spread
7
Q
Characteristics of slate and schist
A
Slate forms in layers creating weak planes in the rock, it is generally hard and resistant.
Schist has bigger crystals than slate
Slate and schist often form rugged upland landscapes
8
Q
Characteristics of Carboniferous Limestone
A
Permeable
9
Q
Characteristics of Chalk and Clay
A
Chalk is harder than clay, it is permeable
Clay is very soft and easily eroded
10
Q
What are the physical processes altering the landscape?
A
Weathering
Erosion
Post-glacial river processes
Slope processes
11
Q
Weathering
A
Breakdown of rock into smaller pieces. It can be mechanical, chemical or biological
12
Q
Erosion
A
Wearing away of rocks.
13
Q
Post glacial river process
A
Melting ice at the end of glacial periods made the rivers much bigger than normal with more power to erode the landscape
14
Q
Slope process
A
Includes mass movement
15
Q
Give an example of a upland landscape
A
Snowdonia
16
Q
Give an example of lowland landscape
A
The downs and the weald
17
Q
Name how humans have changed the landscape through agriculture?
A
Agriculture
Forestry
Settlement
18
Q
How has agriculture changed the landscape?
A
People have cleared the land of forest to make space for farming.
19
Q
How has forestry changed the landscape?
A
Some places, deciduous woodland has been replanted to make the area more a natural state
20
Q
How has settlements changed the landscape?
A
Lots of factors have influenced where settlements have developed. For example, early settlements needed a water supply, somewhere that could easily be defended or that sheltered from wind and rain.
21
Q
Mechanical Weathering
A
The breakdown of rock without changing its chemical composition.
22
Q
Explain the main type of mechanical weathering that affects coast - salt weathering
A
The seawater gets into the rock
When the water evaporates, salt crystals form. As the salt crystals form they expand, which puts pressure on the rock.
Repeated evaporation of saltwater and slat crystals widens the rock and causes the rock to break up.
23
Q
Chemical weathering
A
Is the breakdown of rock by changing its chemical composition
24
Q
Carbonation weathering is a type of chemical weathering that happens in warm and wet environments. Explain what Carbonation weathering is?
A
Seawater and rainwater have carbon dioxide dissolved in them, which makes them weak carbonic acids.
Carbonic acids reacts with rock that contains calcium carbonate, so the rocks are dissolved by the rainwater
25
Biological weathering
Breakdown of rock by living things
26
Mass movement
The shifting of rocks and loose materials down a slope
27
What are three types of mass movement?
Slides - materials shift in a straight line
Slumps - materials shifts with a rotation
Rockfalls - material breaks up and falls down slope
28
Waves wear away the coast using three processes of erosion
Hydraulic Power
Abrasion
Attrition
29
Hydraulic power
waves crash against rocks and compress the air in the cracks, putting pressure on rocks. Repeated compression widens the crack and makes the bits of rock break up
30
Abrasion
Eroded particles in water scrape and rub against rock, removing small pieces.
31
Attrition
Eroded particles in the water smash into each other and break into smaller fragments.
32
Discordant coastlines
Rock layers perpendicular to coast
Headlands and bay
More common
Coastal erosion and deposition landforms
33
Concordant coastlines
Rock layers are parallel to the coastlines
Unusual
Usually just coastal erosion landforms
34
Hard rocks
Such as igneous, granite take longer to erode. If they are parallel to the coast they can form a barrier to protect softer rocks
35
Soft rocks
Soft rocks consist of less resistant rocks such as clays, which are more easily eroded
36
Joints and faults are cracks and weaknesses in the rock. Describe joints and faults.
Joints - small cracks found in many rocks
| Faults - larger cracks caused by past tectonic movements, where rocks have moved
37
Destructive waves
Are waves that carry out erosional processes.
They are high, steep and have a high frequency.
Backwash is more powerful than their swash. Meaning material is removed from the coast.
38
Waves erode cliffs to from wave cut platforms. What is wave cut platforms?
It is the platform thats left behind as the cliff retreats.
39
Explain how waves form wave cut platforms.
1) waves cause most erosion at the foot of a cliff
2) forms a wave cut notch, which enlarges as erosion continues
3) the rock above the wave cut notch becomes unstable and eventually falls off
4) collapsed material is washed away and a new wave cut notch is formed
5) repeated collapsing results im cliff retreating
6) a wave cut platform is the platform left behind as the cliff retreats1
40
Where do headlands and bay form?
Form along discordant coastlines
41
How do headlands and bay form?
Form where alternating brands of resistant and less resistant
rock along a coast.
The less resistant rock is eroded quickly and forms a bay
The resistant rock is eroded more slowly and its left jutting out forming a headland
42
What are headlands made up off?
Made of resistant rocks that have weaknesses like cracks
43
What causes a cave to form?
Repeated erosion and enlargement of the cracks
44
Hows an arch formed?
Continued erosion deepens the cave until it breaks through the headland
45
Hows a stack formed?
When an isolated rock is separated from the headland
46
What is transportation?
It is the movement of material
47
Material is transported along coasts by a process called longshore drift. Explain longshore drift.
Waves follow the direction of the wind. Usually hit it at an oblique angle. The swash carries materials up the beach in the same direction as the waves. The backwash carries materials down the beach at right angles, back towards the sea. Zigzags along the coast
48
Constructive waves deposit material. Explain this.
Deposition is when material being carried by seawater is dropped on the coast. Occurs when water carrying sediment slows down so that it isn't fast enough to carry so much sediment. Waves that deposit more than erode are called constructive waves. Constructive waves are low, long and have low frequency. Swash is powerful. Backwash is weak. Constructive waves deposit material such as sand and shingle alomg the coast
49
How is a spit formed?
Spits 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
50
How is a bar formed?
A bar is formed when a spit joins two headlands together.
| The bar cuts off the bay between the headlands from the sea.
51
How does agriculture have an effect on coastal landscape?
Agriculture land has a low economic value which means its often left unprotected. Has a direct effect on the coastal landscape because the sea can erode the cliffs and shape the land
52
How does development have an effect on coastal landscape?
Coastal areas are often popular places for people to live near and work so they often have lots of development eg infrastructure. Coasts with more settlements are often more protected than other areas because people want to protect their homes and business. Positive effect on coastline as the land is better protected against erosion.
53
How does industry have an effect on coastal landscape?
Coastal quarries expose large areas of rock, making them more vulnerable to chemical weathering and erosion
54
How does coastal management have an effect on coastal landscape?
Coastal defences can reduce erosion. Prevents the landscaping from changing
55
What is making flooding more likely?
Rising sea levels
| Storm Frequency
56
Rising sea level
Pose a threat to low lying and coastal areas.
Increase in sea levels could cause higher tides that would flood coastal areas more frequently. Higher tides could also remove larger amounts of material from beaches causing more erosion.
57
Storm frequency
Climate change is causing storms to become more frequent. Storms give the sea more erosional power - areas of hard rock will be more vulnerable to erosion and softer rocks will erode quicker.
58
Outline how coastal flooding poses a threat to people.
Could become impossible to inhabit
Damage to equipment and building e.g fishing boats can be destroyed.
Flooding and erosion put people off to visiting. Fewer tourists means business relying on tourism may close.
Infrastructure may damage
59
Outline how coastal flooding poses a threat to environment.
Ecosystem will be affected because seawater has a high salt content. Meaning flooding can damage or kill organisms in an ecosystem. Also effects agriculture land by reducing soil fertility.
60
Hard engineering
Man made structures built to control the flow of the sea and reduce flooding and erosion
61
Soft engineering
Schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion
62
Name the benefits/ costs and what a sea wall is.
Benefits - prevents erosion of coast. Prevents flooding
Costs - very expensive to build and maintain
What is it - a wall made out of a hard material like concrete that reflects waves back to the sea.
63
Name the benefits/ costs and what a groyne is.
Benefits - creates wider beaches which slows the waves. This gives greater protection from flooding and erosion. They are fairly cheap.
Costs - they starve beaches further down the coast making them narrower. Narrower beaches dont protect the coast as well, leading to greater erosion and floods.
64
Name the benefits/ costs and what beach replishment is.
Benefits - creates wider beaches which slows waves. Gives greater protection from flooding and erosion.
Costs - its very expensive defence, it has to be repeats.
What is it - sand and shingle from elsewhere or from lower down the beach are added to the upper part of beaches.
65
Name the benefits/ costs and what a slope stabilisation is.
Benefits - prevents mass movements by increasing the strength of the slope
Costs - very expensive and sometimes very expensive to install
What is it - slopes are reinforced by inserting concrete nails into the ground and covering the slope with metal netting
66
Name the benefits/ costs and what a strategic realignment is.
Benefits - overtime the land will becomes marshland - creating new habitats. Flooding and erosions are reduced behind the marshland.
Costs - people may disagree what land is allowed to flooded on
What is it - removing an existing defence and allowing the land behind kt to flood
67
Management strategies need to be sustainable.
Make sure erosions and flooding are controlled without causing more problems elsewhere. Strategies need to be cheap to avoid conflicts about the spending of public money.
68
What does long profile show?
Shows you how the gradient changes over the different courses
69
What is a course?
Path of a river as it flows downhill
70
What is cross profile?
Shows you what a cross section of river looks like
71
Vertical erosion
Deepens the river valley making it V shaped. Dominant in upper course of the river. High turbulence causes the rough, angular particles to be scraped along the river bed, causing intense downwards erosion.
72
Lateral Erosion
Widens the river valley during the formation of meanders. Dominant in middle and lower courses
73
Upper course
The source of the Eden is about 600m above sea level in an area of hard, resistant rock.
74
Middle course
Basin are made from sandstone, a less resistant rock easily eroded by river
75
Lower course
The valley is very wide and flat
76
Weathering helps shape river valleys. What is freeze thaw weathering?
Happens when temperature alternates above and alternates below 0 degrees. Water gets into the rock. When the water freezes it expands which puts pressure on the rocks. When the water thaws it contracts, which releases the pressure on the rock. Repeated freezing and thawing widens the cracks and causes the rock to break up.
77
What are the four processes of erosion?
Hydraulic action
Abrasion
Attrition
Solution
78
Hydraulic action
Force of the water break rock particles away from the river channel
79
Abrasion
Eroded rocks picked up by the river scrapes and rubs against the channel, wearing it away.
80
Attrition
Eroded rocks picked up by the river smash into each other and break into smaller fragments. The further the material travels, the more eroded it gets.
81
Solutiom
River water dissolves some types of rock
82
Transportation has four processes what are they?
Traction
Saltation
Suspension
Solution
83
Traction
Large particles are pushed along a river bed by the force of the water.
84
Saltation
Pebble sized particles are bounced along the river bed by the force of the water
85
Suspension
Small particles like slit and clay are carried along by the water
86
Solution
Soluble materials dissolve in the water are are carried along.
87
What is deposition?
When river drops eroded material.
88
Why does the river slow down and deposit material?
Volume of water in the river falls
Amount of eroded materials in the water increases
The water is shallower
River reaches its mouth
89
River landscapes and sediment load are influenced by physical factors. What are the physical factors?
Climate
Geology
Slope processes
90
How does climate influence river landscape and sediment load?
Rivers in wetter climates have higher discharge because there's more more water entering the floods
Higher discharge increases the rate of erosion, if a river has a higher volume of water, it has more power to erode the rivet banks and beds.
Weather will increase freeze thaw weathering
91
How does geology influence river landscapes and sediment loads?
Rivers flowing through areas of hard rock have a slower erosions rate because hard rocks are more resistant.
Areas with softer rocks will experience more erosion - adds more material to the rivers sediment load
92
How does slope processes influence river landscapes and sediment load?
Vertical erosion makes valley sides steeper, increasing the movement of material down the slopes
Mass movement can add large amounts of materials to river loads
Soil creep is when soil particles move down a slope because of gravity.
93
What does hydrographs show?
Change in river discharge
94
Peak discharge
Highest discharge in the period of time you're looking at
95
Lag time
Delay between peak rainfall and peak discharge
96
Rising limb
The increase in river discharge as rainwater flows into the river
97
Falling limb
Decrease in river discharge as the river returns to its normal level
98
Storm hydrographs are affected by different factors. What are the different factors?
```
Geology - physical factor
Soil type - physical factor
Slope - physical factor
Drainage basin type - physical factor
Antecedent conditions - physical factor
Urbanisation - human factor
Deforestation - human factor
```
99
Physical factors increasing the risk of flooding in River Eden
Wettest parts of the UK, often experiencing periods of heavy rainfalls. Areas around it are made of hard, impermeable rocks. Meaning water cannot soak into the ground and runs off into river channels.
100
Human avtivities increasing the risk of flooding in River Eden
Natural woodland have been cleared from many upland areas increasing surface run off when it rains, means more water end up in the river more quickly.
101
What are the reasons why the risk of flooding is increasing in the UK?
Increased frequency of the storm - more period of wet rain means the ground is saturated, making flooding more likely.
Land use change - population grows more pressure to expand urban areas. Leads to increase in impermeable surfaces which cause rapid surface run off
102
Flooding threatens people and environment, explain how.
Flooding destroys homes and possessions etc
Floodwater contaminated with sewage and rubbish can pollute rivers, damaging wildlife habitats. Farmland can be ruined by silt and sediment deposited after a flood. River banks are eroded
103
Hard engineering river management schemes
Flood walls - artificial barriers built along the river wall. Designed to allow the river to hold more water
Embarkments - high banks built along or near rivers. Stop the river flowing into built up areas during a flood, protecting buildings and infrastructure
Flood barriers - floodgates built on river estuaries to stop flooding from storm surges or very high tides
104
Soft engineering management schemes
Flood plain retention - maintaining rivers flood plain. Helps slow floodwaters down and maintain the flood plains ability to store water. Cheap
River restoration - involves making the river more natural. Less risk of flooding downstream because discharge is reduced.
105
How are waterfalls formed?
Form where a river flows over and area of hard rock followed by an area of softer rock.
Softer rock is eroded more than harder rock, creating a step.
Water goes over the step it erodes more and more of the softer rock.
Steep drop is eventually created, which is called a waterfall
106
How are meanders formed?
Current is faster on the outside of the bend because the river channel is deeper (less friction to slow water down). So more erosion takes place on the outside of the bend, forming river cliffs.
Current is slower on the inside of bend because the river channel is shallower. So eroded material is deposited on the inside of the bend, forming slip off slopes
107
Ox bow lakes are formed through meanders. Explain how ox bow lakes are formed?
Erosion causes outside bends to get closer
Until theres only a small bit of land left between the bends
River breaks through this land, usually during a flood
And the river flows along the shortest course
Deposition eventually cuts off the meander
Forming an ox bow lake
108
Flood plains
Flood plains is the wide valley floor on either side of a river which occasionally gets flooded. (flat areas of land that flood)
109
Leveees
Natural embarkments along the edges of a river channel.
During a flood, eroded material is deposited over the whole flood plain.
Heaviest material is deposited closest to the river channel, because it gets dropped first when the rover slows down.
Over time deposited material builds up, creating levees along the edges of the channel
110
What is a delta and how are they formed.
Deltas are low lying areas where river meets sea or lake.
Rivers are forced to slow down when they meet the sea or lake, causing them to deposit the material that they're carrying. And eventually material builds up so much that low lying areas of land called deltas are formed
