Theme 1 - Landscapes and Physical Processes Flashcards
1
Q
What is an upland area + example?
A
A landscape that is hilly or mountainous, eg Snowdonia, LLanberis Pass
2
Q
What is a lowland area + example?
A
An area of land that is lower than the land around it, eg Gwent Levels
3
Q
An example of a river area?
A
River Severn, Gloucester
4
Q
An example of a coastal landscape?
A
Stair Hole, Dorset
5
Q
What 4 factors make a landscape distinctive?
A
- Geology
- People and culture
- Vegetation
- Land-use
6
Q
What is visitor pressure?
A
The increased impact on the landscape, resources and services of an increased number of people due to tourism.
7
Q
What is a honeypot site?
A
A place of special interest that attracts tourists.
8
Q
What is carrying capacity?
A
The maximum population size that an environment can sustain.
9
Q
What is meant by ‘environmental challenges’?
A
Problems caused by human use of the natural landscape or resources.
10
Q
What is a national park?
A
An area which is protected because of its beautiful countryside, wildlife and cultural heritage.
11
Q
What is an AONB?
A
Area Of Outstanding Beauty - a part of the countryside that is designated for conservation due to its natural beauty. Visited by high numbers of people who might damage the landscape so management usually has to be put in place.
12
Q
What 3 factors cause river landforms to change?
A
- Fluvial erosion
- Transportation
- Deposition
13
Q
What is ‘fluvial’?
A
Referring to a river and its landforms.
14
Q
What is erosion?
A
The wearing away of land.
15
Q
What is transportation?
A
The movement of material through flow of water.
16
Q
What is depostion?
A
The dropping of the material carried by the river.
17
Q
What is bedload?
A
The material carried by the river being bounced or rolled along its bed.
18
Q
What is a meander?
A
A bend in the river formed by lateral erosion.
19
Q
What are the 3 erosional processes of a river channel?
A
Abrasion, hydraulic action and solution.
20
Q
What is abrasion?
A
Stones and material carried by the river hitting the river bed and banks, wearing them away.
21
Q
What is hydraulic action?
A
The sheer force of water hitting the river bed and banks, compressing air in gaps of the soil and rock which causes material to be washed away.
22
Q
What is solution?
A
The slightly acidic river water dissolves chalk and limestone rocks which are made from calcium carbonate.
23
Q
What are the 2 procosses eroding the river bedload?
A
Attrition and Abrasion
24
Q
What is attrition?
A
Stones carried by the river collide together and are broken down, becoming rounder and smaller.
25
What is abrasion?
Stones and natural material carried by the river hitting the river bed and banks become eroded themselves to become smaller are rounded
26
What 4 processes help rivers move their materials?
Solution, suspension, saltation and traction.
27
What is meant by suspension?
Fine material is help up and carried within the rivers flow.
28
What is meant by saltation?
Small pebbles and stones are bounced along the river bed. The load is alternatively lifted and then dropped in line with a local rise and fall in the velocity of the water.
29
What is meant by traction?
Large boulders and rocks are rolled along the river bed.
30
What are the 3 reasons behind deposition in a river?
- Where there has been less been a lack of rainfall, so there is less water moving in the river channel
- On the inside of a meander because the majority of the water is on the outside of the bend. Therefore, the water on the inside of the bend is moving slowly and cannot transport the load.
- At the mouth of the river, where the river water flows against the direction of the sea.
31
What are the 5 landforms rivers can shape?
V-shaped valleys, waterfalls, gorges, floodplains and meanders.
32
What is a v-shaped valley?
A narrow valley with steep sloping sides found in the rivers upper course.
33
What is a waterfall?
Water falling from a higher level to a lower level due to a change in rock structure or as a result of glacial erosion.
34
What is a gorge?
A steep-sided narrow valley formed by a retreating waterfall.
35
What is a floodplain?
A flat piece of land on either side of a river forming the valley floor.
36
What is a meander?
A bend in the river formed by lateral erosion.
37
What is vertical erosion?
Erosion of the river channel that results in it deepening rather than widening.
38
What are interlocking spurs?
Hard, resistant rocks that a river cannot easily erode and therefore the river goes around them.
39
What is a plunge pool?
A deepened part of the river bed at the base of the waterfall caused by the impact of the falling water.
40
Which 2 ways can waterfalls form?
Apart of glacial erosion or differential erosion.
41
How are waterfalls formed from glacial erosion?
Where waterfalls have formed due to the erosive power of the iceage. Glaciers carved steep valleys into the landscape, often handing above one another. Once the glacier melted, water drains from the smaller valleys and falls into the larger ones.
42
How are waterfalls formed from differential erosion?
Where waterfalls are formed due to a change in rock structure, which leads to river bed being eroded at different rates.
- As the river bed crosses onto soft rock from hard rock it is eroded (hydraulic action and abrasion) at a faster rate and a step is created.
- As the water falls, hydraulic action continues to erode the rock underneath the hard rock as it splashes against it.
- As the soft rock is further eroded, the overhang becomes too heavy and the rock collapses, causing the position of waterfall to retreat upstream.
- A plunge pool is created underneath the waterfall due to the sheer force of the water hitting the river bed and the abrasion caused by the rocks from the overhang being moved by the water.
43
What is a slip-off slope?
A bank of gently sloping deposited material found on the inside bend of a meander.
44
What are the characteristics of a meander?
Erosion on the side with the fastest flow
On the opposite bank deposition occurs, causing the formation of a slip off slope
Erosion can cause river 'cliffs'
Shallower water on side of depostion
Deeper water on side of erosion
45
What happens when a river floods?
- The floodplain becomes covered with water
- As the water is shallower on the land than it is in the river, material (silt, alluvium)
- This makes the soil fertile
46
What part of a river are wide floodplains found?
Middle and lower regions of a river.
47
3 types of weathering and examples?
- Physical (freeze-thaw action + salt crystal growth)
- Biological (plant roots + burrowing animals)
- Chemical (carbonation)
48
3 reasons for cliff retreation?
weathering, rockfalls and landslides
49
What is freeze thaw action?
The breakdown of rocks due to water entering cracks and repeatedly freezing and thawing.
50
What is carbonation?
Where chemicals in rainwater such as carbonic acid react with chemicals in rocks such as limestone.
51
What is mass movement?
When soil, rocks or stones move down a slope.
52
What are the 3 procceses that erode the cliff?
Hydraulic action - air trapped in cracks is compressed, breaking up rock
Abrasion - waves hurl sand and pebbles, wearing land away.
Solution - salt water dissolves rocks made of calcium carbonate.
53
What are the proccesses that erode beach material?
Abrasion - waves hurl sand and pebbles against the cliff, wearing land away.
Attrition - pebbles are rolled back and fourth, they collide with each other which makes them smaller and rounder, eventually turning them into sand.
54
Describe the process of longshore drift?
The wave is pushed by prevailing winds diagonally up the beach, causing a large swash. (90*)
Backwash moves straight down the beach due to the pull of gravity. This moves all the sediment along.
Process continues down the beach.
55
What is a headland?
An area of land that juts into the sea and is formed due to harder, more resistant rock being eroded more slowly.
56
What is a bay?
Formed between headlands due to softer, less resistant rock which erodes more quickly. Beaches often form in more sheltered bays.
57
How is a wave cut platform created?
- Hydraulic action and abrasion cut a wave-cut notch into the base of the cliff, which makes the cliff vulnerable to collapse.
- continued erosion at high tide makes the cliff unstable and will collapse.
- the material from the cliff will be moved by the sea, and abrasion will smooth over the platform left behind.
- if the cliff is made from well-jointed rocks, then the wave-cut notch will often occur along the bedding planes as these are weak points and will erode much more quickly.
58
What is a bedding plane?
Clearly visible layers of rock in a a cliff face.
59
How are stacks and stumps formed?
- form in headlands, with rock relatively resistant to erosion such as limestone.
- arches from when 2 caves meet through the headland
- weathering continues to erode top of cave, so the arch becomes higher.
- wave cut notches form and widen the arch
- arch roof will collapse, leaving a stack, which over time will topple and form a stump.
60
What 2 features are formed when the swash is stronger than the backwash?
Beaches and spits (a sand or shingle beach that is joined to the land but projects outwards into the sea into the direction of the prevailing wind)
61
What are rock pools?
Rock pools are small hollows in rocks found at the coastline such as a wave-cut platform
At high tide the pools are covered by the sea, and at low tide, some sea water remains in the hollows, creating a rockpool.
The rockpools are enlarged by the process of abrasion at high tide as small rocks within the pool whirl around due to the movement of the waves and gradually increase the size of the hollow.
62
What factors affect the rates of landform change?
Geology, climate and human activity
63
What is a cavern?
A large underground cave which has been created due to enlargement of joints of carboniforous limestone
64
What is a sinkhole?
A hole in the ground caused by the collapse of the surface layer, often found in carboniferous limestone where caverns are present.
65
What is a concordant coastline?
Rocks are formed parallel to the sea so that erosion rates along the coastline are present
66
What is a discordant coastline?
Rocks are formed at right angles to the sea and so erosion rates vary along the coastline depending on rock type.
67
How will coasts affect the shape of the landscape?
The prevailing wind effects the angle at which the waves break on the coastline, and therefore the direction of erosion and transportation. The waves break on to the beach at this angle, pushing material up and across the beach. Therefore, the wind direction determines where depositional features form.
68
How will rivers affect the shape of the landscape?
The more water that is flowing in the a river, the higher the erosion rates will be. The highest erosion rates in UK rivers are found during the winter months when there is more rainfall.
69
How will extreme weather events affect the shape of the landscape?
The more destructive the storm, the more powerful waves it can create.
This is because increased wind speed and fetch.
As a result, the most powerful storms hit the UK from the south-west, due to large distances of open water from the Atlantic Ocean.
70
What is a drainage basin?
An area of land drained by a river and its tributaries.
71
What is the flow?
The movement of water
72
What is meant by interception?
When rainfall does not reach the ground as it is blocked by something.
73
What is meant by infilteration?
The movement of water into the soil.
74
What is throughflow?
The flow of water through the soil.
75
What is overland flow?
The flow of water across the ground surface
76
What is groundwater flow?
The flow of water through rocks
77
What is transpiration?
Water given off by plants
78
What is stem flow?
Movement of water that has been intercepted down the stem or trunk of a plant.
79
What is percolation?
The movement of water from the soil into the bedrock.
80
What can affect the speed water flows through a drainage basin?
- type and quantity of rainfall
- type and quantity of vegetation cover
- size and shape of the drainage basin
- the steepness of slopes
- geology and soil type within the basin
81
How does the climate affect rivers flooding?
- Seasonal rainfall (saturated ground, increases overland flow)
- A storm event (flash floods)
82
How does vegetation affect rivers flooding?
- Different vegetation intercept different amount of rainfall
- Removal of vegetation (deforestation) can cause increased infiltration in a smaller amount of time
83
How does geology affect rivers flooding?
- Porous rocks has large spaces, reduces flood risk as it increases groundwater flow.
- Impermeable rocks have few spaces, increasing flood risk as creates higher overland flow.
- Rocks can be well-jointed, allowing water to pass through lines of weakness, eg carboniferous limestone.
84
How does urbanisation affect rivers flooding?
Urbanisation leads to the ground being covered in impermable surfaces like tarmac, causes flooding as it increases overland flow.
Also, some settlements are built on floodplains, where flooding is most likely to occur.
85
What is a hydrograph?
A line graph used to display the discharge of a river over a period of time.
86
What is meant by lagtime?
The time between the peak rainfall and peak discharge in the river.
87
What is meant by a rising limb?
The part of a hydrograph where the discharge of a river is increasing after a rainfall event.
88
How does urbanisation impact a hydrograph?
- Decreases lag time
- steep rising limb
- high peak
89
How do porous rocks impact a hydrograph?
- increases lag time
- gentle rising limb
- lower peak
90
How does impermeable rocks impact a hydrograph?
- decreases lag time
- steep rising limb
- high peak
91
How do broad-leaved trees impact a hydrograph?
- increases lag time
- gentle rising limb
- lower peak
92
3 types of management for flooding in the UK?
Soft engineering, hard engineering and land use zoning.
93
What is are hard engineering strategies?
- Involve constructing defences to control natural processes
- They are often expensive, large scale and relatively effective
94
Examples of hard engineering strategies?
Dams, artificial levees and embankments, artificial river channels (channelisation), gabions, dredging the river channel, creating a flood relief channel.
95
What is soft engineering?
- Working with the environment rather than against it
| - Often cheaper, have less impact on the environment, less effective when river has actually flooded.
96
Examples of soft engineering?
Restricting building on floodplains, afforestation, ecological flooding, warning systems
97
What is land use zoning?
- Planning what the land use is used for within a river basin so that less valuable land is closer to the river, like grazing land and playing fields.
- Housing and key services are usually put on higher ground away from the river to lesson the chance of them being flooded
- Not always easy to carry out, as cities and towns have already been built without land use zoning in mind
