Distinctive landscapes Flashcards
(115 cards)
1
Q
What is a landscape?
A
all of the visible features of an area of land. It can contain both natural features and man-made features.
2
Q
What is relief?
A
the way the landscape changes in height
3
Q
4 points
What are some characteristics of built landscapes?
A
- Urbanisation (e.g. skyscrapers)
- Deforestation
- Aforestation (repeating trees)
- Man made rivers
4
Q
What are some characteristics of natural landscapes?
A
- Glaciers have had a major impact on the landscape, they have carved out the straight ribbon lakes and made the mountains steep-sided
- Tectonic forces created the mountains
- Sedimentary rock (deposited over hundreds of years)
- River carving out meanders, caused by lateral erosion
5
Q
Granite is a (…) rock, whereas chalk is a (…) rock
A
hard - so eroded slowly
soft - so eroded easier/quicker
(limestone ranges from very hard to soft)
6
Q
What is glaciation?
A
The build up of ice on the land during colder periods in time.
7
Q
Where are the upland areas in the UK?
A
They are mostly found in the north and west of the UK.
Wales also upland
8
Q
Where are the lowland areas in the UK?
A
They are mostly found in the south and east of the UK
9
Q
Where are the glaciated landscapes in the UK?
A
They are mostly found in upland areas in the north-west of the UK.
10
Q
Describe the geology of upland areas in the UK
A
- They are generally formed of harder rocks which resist erosion, e.g. slate, granite and some limestones.
- Many are glaciated landscapes e.g. Snowdonia
- The gradient of the land is often steep
11
Q
Describe the climate of upland areas in the UK
A
- The climate tends to be cooler and wetter.
- The harsh climate and thin soils allow rough vegetation to thrive, and some upland areas are used for forestry
12
Q
Describe the human activity in upland areas in the UK
A
- sheep farming
- quarrying
- tourism
- forestry
13
Q
Describe the geology of lowland areas in the UK
A
- They are generally formed from softer rocks, e.g. chalk, clay and some sandstones.
- The landscape is flatter with gently rolling hills
14
Q
Describe the climate of lowland areas in the UK
A
- The climate tends to be warmer and drier
- Vegetation grows easily in the more fertile soils and includes grassy meadows and deciduous forests
15
Q
Describe the human activity in lowland areas in the UK
A
- quarrying
- tourism
- dairy farming
- arable farming (growing crops)
- most urban areas/towns and industries (e.g. factories) are located here
16
Q
Describe the geology of glaciated areas in the UK
A
indigenous rock (granite)
Powerful ice carved out:
- steep, high mountain peaks
- steep slide slopes
- valleys with ribbon lakes
deposited lots of material as it melted
17
Q
Describe the climate of glaciated areas in the UK (mention plants as well)
A
- Colder and wetter
- Shrubs and grassland in lowland areas
- moss and lichen in highland areas
18
Q
Describe the human activity in glaciated areas in the UK
A
- hill farming
- hiking
19
Q
on top of hard or soft
What type of rock is granite? What type is chalk?
A
Granite - (hard) indigenous rock - formed by lava cooling (older)
Chalk - (soft) sedimentary rock - formed by layers of sediment being compressed together over centuries (younger)
20
Q
What are the 5 geomorphic processes?
A
- Weathering
- Mass movement
- Erosion
- Transport
- Deposition
21
Q
What are geomorphic processes?
A
The ways in which the land is shaped
22
Q
What is weathering?
A
The breakdown of rock in situ (in its original place)
23
Q
What is mechanical weathering?
A
The breakdown of rock (in situ) without changing its chemical composition
24
Q
Describe the processes of freeze-thaw (mechanical weathering)
A
- Water enters cracks in rocks.
- Freezes, expands, putting pressure on the rock
- The ice melts and the process repeats
25
What is chemical weathering?
The breakdown of rock (in situ) by changing its chemical composition
26
Describe the processes of chemical weathering
Rainwater reacts with minerals in the rock causing the rock to be broken down
27
What is biological weathering?
The breakdown of rock by living organisms
28
Describe the processes of biological weathering
Plant growth leads to roots expanding in size, putting pressure on the rocks, leading to breakdown of the rock
29
What is mass movement?
A large-scale downward movement of rocks and material
30
When does mass movement occur?
when the force of gravity acting on a slope is greater than the force supporting it
*it causes coasts to retreat rapidly*
31
When is mass movement more likely to occur?
They're more likely to happen when the material is full of water - it acts as a lubricant and makes the material heavier
32
What are the two types of mass movement?
Slides - material shifts in a straight line
Slumps - material shifts with a rotation
33
What factors can trigger mass movement?
* Rainfall
* weathering
* erosion
* human activity
34
What is erosion?
The wearing away of land
35
What are the 4 types of erosion?
* hydraulic action
* abrasion
* attrition
* solution
36
Describe hydraulic action
Waves crash against rock and compress the air in the cracks. This puts pressure on the rock. Repeated compression widens the cracks and makes bits of rock break off
*In rivers, the force of the water breaks rock particles away from the river channel.*
37
Describe abrasion
Waves pick up rocks from the seabed and smash them against cliffs, wearing it away gradually
38
Most erosion happens by (…)
abrasion
39
Describe attrition
Pebbles picked up by the waves, bash into each other, wearing down into smaller, rounded pebbles
40
Describe solution (erosion)
Rocks like limestone slowly dissolve in water
41
The greater the energy, the (…) the erosion
faster/more powerful
and so greater the size/power of the wave
42
Describe how rock different rock types will be affected by erosion?
Hard rock (e.g. granite) is resistant to erosion and may only experience significant erosion during times of glaciation - this is because ice has more erosive power
Soft rocks (e.g. chalk, limestone) are more easily eroded
43
What is transportation?
Movement of material in the sea or rivers
44
What are the four processes of transportation?
* traction
* saltation
* suspension
* solution
45
Describe traction
Large particles like boulders are pushed along the river bed or sea floor by the force of the water
46
Describe saltation?
Pebble sized particles are bounced along the river bed or sea bed by the force of the water
47
Describe suspension
Small particles like silt and clay are carried along by the water
48
Describe solution (transportation)
Soluble materials dissolve in the water and are carried along
49
# 2 needed
If a river speeds up, what processes of transportation will increase
large material can be carried by saltation and traction
50
What may the solution (transportation) be dependent on?
he type of rock over which the river flows - e.g. less solution over granite than say limestone/chalk
51
What is deposition?
Material dropped by the sea or a river when it loses energy
52
Where and when will deposition occur at the coast?
where - at bays, beaches, etc (i.e. sheltered low energy areas of coast)
when - during periods of small waves
53
Where and when will deposition occur in a river?
Where - the inside of a meander and in lower course (as have less energy there)
When - during periods of low flow
54
Name 7 coastal landforms?
* headlands
* bays
* cave
* arch
* stack
* beach
* spit
55
Label a coast
56
How are coastal landforms (cliff, cave, arch, stack and stump) formed at a headland?
1. A fault in the rock is widened to form a crack in the rock
2. **Hydraulic action and abrasion** (+ **solution** if a chalk/limestone _cliff_) widen the crack to form a _cave_
3. **Erosion** continues and the cave gets so big it erodes through the headland to make an _arch_
4. The arch widens until it can no longer support the roof of the arch. The roof is also weakened by **weathering** from above.
5. When an arch collapses, a _stack_ is left
6. The stack will be **eroded** at its base by waves - a wave-cut notch will form and the stack will eventually topple over leaving a _stump_
Note that this is all caused by erosion
57
The processes of longshore drift form a beach due to the geomorphic processes of (…) and (…)
transportation
deposition
58
# 4 processes
How is a beach formed via longshore drift?
1. Prevailing wind direction approaches coast at angle
2. Swash moves sediment up the beach at an angle
3. Backwash movies sediment back down the beach due to gravity
4. Process repeats moving sand along the coast
59
What are spits?
Spits are beaches that stick out into the sea - they're joined to the coast at one end. Spits form at sharp bends in the coastline, e.g. at a river mouth
60
How are spits formed?
* Spits form where there is a sharp change in the direction of the coastline e.g. at a river estuary.
* Longshore drift transports material along the coastline and past the bend. Then deposits it in the sea as the wave's loose energy in the deeper water.
* This process repeats and the spit gets bigger over time.
* Changes in the direction of the wind can cause the spit to become curved at the end (a hook).
* The spit won't grow across the whole river estuary due to the river current flowing out into the sea.
* Behind the spit a saltmarsh is created as the area is protected from the waves and plants start to grow there.
61
State the 7 river landforms
* waterfall
* gorge
* v-shaped valley
* floodplain
* levee
* meander
* ox-bow lake
62
What is a river basin?
An area of land surrounding a river, where any rain falling on the land eventually makes its way into the river.
63
How does the erosion change from the source to mouth of a river?
Erosion changes from vertical erosion (downwards) to lateral erosion (side to side)
64
How does the size and shape of the river valley change form the source to mouth?
The valley changes from being narrow and steep sided to being wide and flat
65
How does the size and shape of the bedload change form the source to mouth?
The bedload changes to become smaller and smoothe
66
How does the type of energy stored in the river change from the source to mouth?
GPE - upper course
Kinetic energy - lower course
*mixture in middle*
67
How are waterfalls and gorges (both found in upper course) formed?
1. River flows over hard + soft rock in the upper course
2. Soft rock **erodes** at a faster rate. **Abrasion + hydraulic action** wear the rock down. **Vertical erosion** dominant
3. Plunge pool begins to form; back wall is steepened
4. Large overhang forms where the rock has been undercut; overhang collapses
5. This process continues and the waterfall retreats upstream
6. A steep-sided valley is left where the waterfall once was
68
How are v-shaped valleys (found in upper course) formed?
* Rivers erode **vertically** in the upper course of the river
* The **processes** of hydraulic action and abrasion help the river cut down into the landscape.
* The valley sides are exposed to freeze-thaw **weathering** and falling rocks steepen the valley sides.
* The steep slopes and **high** rainfall lead to mass movement on the valley sides, further steepening them
69
How are meanders (bends in the river) formed?
* The faster water travels around the outside of the bend, eroding the banks through abrasion and hydraulic action.
* This creates a steep river cliff.
* On the inside of the bend the velocity is much slower and consequently, deposition fo sand and shingle occurs creating a slip-off slope
70
How are ox-bow lakes formed?
1. River breaks through the narrow neck of a meander during a storm event.
2. So river flows in path of least resistance, cutting off the other path and forming an ox-bow lake
71
What is a floodplain?
The floodplain is a wide, flat area of land either side of the river in its lower course. It is covered with water during times of flood
72
What causes the formation of floodplains?
1. Lateral erosion and the formation of meanders have caused the floodplain to get wider
2. Interlocking spurs have been eroded away
3. When a river floods onto the floodplain the water becomes shallow and the river's velocity decreases leading to deposition.
4. River returns to normal level
*interlocking spurs are when the valleys cross over (google it if confused)*
73
What are levees?
Natural embankments (raised structure) along the edges of a river channel
*found at floodplains*
74
How is a levee formed?
They are formed when the river deposits material as it floods:
1. During a flood the river will deposit its heaviest material first (i.e. closest to the banks).
2. Over the years, material builds up to create a levee.
3. The floodplain also gets built up with the fine sediment to create alluvium (fine silt) which makes the floodplain very fertile.
75
Why might have the south and east of England lacked glaciated landscapes?
The South And East of England was warmer and did not receive as much rain
76
Where is the Jurassic Coast?
The south coast of England
*It is called the jurassic coast because fossils of ancient dinosaurs have been found in the area, so the rock was created in the jurassic era.*
77
What type of landform is Dudle Dor?
headland with an arch
78
Describe the landform of Dudle Dor (What is it made of? Geology? Shape?)
Promontory (bit that sticks out) of hard limestone extending from the coast with a pronounced arch
*for an exam question, list the type of landform and geomorphic processes involved in the creation as well*
79
# 3 needed
What geomorphic processes created Dudle Dor?
Weathering (weakening of headland)
Erosion (widening cracks and caves to make the arch)
Transportation and deposition - to form the sandy beach
80
What are constructive waves?
Waves that have a low frequency
81
What are destructive waves?
Waves that have a high frequency
82
Describe the difference between constructive and destructive waves
Destructive waves have a stronger backwash
So they transport sediment away from the beach, constructive waves deposit sediment onto the beach
83
What type of landform is Lulworth Cove?
Bay
84
Describe the landform of Lulworth Cove
Horseshoe shaped bay with two prominent headlands
Parallel layers of hard and soft rock
85
What geomorphic processes created Lulworth Cove?
* Weathering (weakening of the cliff)
* Erosion (waves have broken through the band of more resistant rock)
* Deposition (the waves lose energy when entering the bay and deposit sediment)
* Mass movement - played a role in cliff collapse
86
What type of landform is Chesil beach?
Barrier Beach
87
Describe the landform of Chesil Beach?
A long stretch of sand and shingle (big bits of sediment e.g. pebbles) extending along the coast and out towards an island
88
Describe the geomorphic processes that formed Chesil Beach
* Transportation of the sediment by longshore drift has allowed the beach to extend out from the coast.
* Deposition of sand has built the beach up
89
What are the three types of climate that have affected the geomorphic processes at Jurassic Coast?
* Temperature
* Wind
* Rainfall
90
How has temperature affected the geomorphic processes at the Jurassic Coast?
* The Dorset Coast has warm, dry summers (around 21C in July) and mild and wet winters
* Salt weathering is the dominant form of mechanical weathering, particularly in summer.
* The warm temperature cause sea water to evaporate from rocks quickly, leaving a build-up of salt crystals in tiny cracks in the rock.
* The mild winters mean that freeze-thaw weathering is less common because it's usually not cold enough for ice to form.
*don't need all points - like other cards*
91
How has rainfall affected the geomorphic processes at the Jurassic Coast?
* The Dorset Coast receives relatively low amounts of rainfall annually, but can experience very wet winters, with rainfall heaviest during storm periods.
* Soils and rocks become heavier when they're saturated, which can make them more prone to mass movement.
* In January 2016, intense rainfall combined with high-energy waves during Storm Frank to cause the collapsing of cliffs
92
How has wind affected the geomorphic processes at the Jurassic Coast?
* The Dorset Coast's location means that it's exposed to prevailing winds from the south-west.
* These prevailing winds can bring storms to the UK from the Atlantic Ocean. Storms bring high energy, destructive waves which increase erosion of the cliffs.
* Hydraulic action and abrasion both increase during a storm and erode the base of the cliffs. This makes the cliffs unstable, making mass movement more likely to happen.
93
How has geology affected the geomorphic processes at the Jurassic Coast?
* The coastline is made from bands of hard and soft rock. These rocks have been eroded at different rates, which has created the area's coastal landforms, e.g. at Lulworth Cove.
* Soft rock like sandstone and clay are easily eroded by hydraulic action and abrasion.
* The harder chalk and limestone cliffs are weathered and eroded more slowly, meaning that they stick out into the sea as exposed headlands. Chalk and limestone are vulnerable to erosion by solution, where the sea water (contains acid) chemically reacts with the rock, causing it to dissolve.
* Weathering tends to happen gradually and cause small changes. Erosion can happen more suddenly on a much larger scale. A single storm can cause large amounts of erosion along a big stretch of the coast.
94
What is hard and what is soft engineering?
**Hard**: Works against natural processes, such as erosion, to protect the coastline - more expensive, needs more maintenance
**Soft**: Works with nature to protect the coastline - less expensive
95
Identify 6 SMPs (Shoreline Management Plans) and identify whether they are hard or soft engineering
* Rock Armour (H)
* Groynes (H)
* Sea Wall (H)
* Beach Nourishment (S)
* Offshore Reef (H)
* Managed Retreat (S)
96
Describe how rock armour works and some of its features
Acts as a physical barrier to the waves
* makes access to beach hard
* Often used in conjunction with groynes
* Suitable where space is constricted
97
Describe how groynes work and some of their features
Groynes work by trapping sediments that is being moved along the coastline between barriers
* Often used in conjunction with other techniques e.g. rock armour
* Build up beach
* Cheap
* Needs repairing and maintenance constantly
* Ineffective in storms
98
Describe how sea walls work and some of their features
Physical barrier to sea, used most successfully when used in conjunction with other SMPs as a ‘last line of defence’
* Very effective
* But expensive
99
Describe how beach nourishment works and some of its features
Replenishes the beach with sand to act as a barrier against the waves reducing erosion as waves lose energy more quickly
* Creates beach due to deposition
* All of sediment can be transported away within weeks
* Relatively cheap
* Most effective when used with groynes
100
Describe how offshore reefs work and some of their features
Physical barrier to sea: Concrete rocks and boulders are positioned offshore, forcing waves to break before they reach the coast
* Very expensive
* Not reliable
101
Describe how managed retreat works and some of its features
Allows coast to flood or erode naturally
* Only suitable when coastal land is considered to be low value
* No direct cost
102
# 4 points
How have human activities worked in combination with geomorphic processes to impact the landscape of the Jurassic Coast?
* Managed retreat (Chesil beach - natural beach) - erodes naturally
* Beach nourishment (Lulworth cove) - increases transportation
* Sea wall and rock armour (Dawlish - railway to London) - reduces terosion of cliff
* Building on cliff tops as this makes mass movement more likely.
103
What does the Thames River Basin look like?
104
How did geomorphic processes lead to the Thames River Basin's formation?
* The river Thames has many meanders along its course from the Cotswold hills to the North Sea.
* Although the river has a gentle gradient and lacks energy for vertical erosion, it has enough energy for lateral erosion and so forms meanders.
* Water flows faster around the outskirts of the bends, eroding the bank to form a river cliff.
* The water flows slower around the inside of the bend, depositing its load to form a slip-off slope.
* This slowly changes the course of the river, widening the meanders.
105
# 4 needed with explanation
Which factors increase the risk of flooding?
Impermeable rock (seen in urban areas) - water gets to river channel quickly by surface run off as it is not absorbed
Soil saturated after weeks/months of rain - water can no longer be absorbed by the soil - it travels straight to the river channel
Frozen ground - water cannot be absorbed and travel directly to the river channel
Intense rainfall (e.g. in thunderstorms) - water level builds up quicker than it can drain away
106
# 5 needed
What human activities increase the risk of flooding?
* Urbanisation - impermeable surfaces allows water to get to river channel quickly by surface run off as it is not absorbed
* Use of drainage systems - rainfall flows in here and too river
* Deforestation - reduces interception
* Farming practices - some methods of farming increase the amount of water reaching rivers (e.g. cattle farming)
* River straightening - increases flood risk downstream
107
What are two schemes to reduce flooding in the Thames River Basin? Are they hard or soft engineering?
* Thames Barrier (hard)
* Barking Riverside (soft)
108
How does the Thames River Barrier work?
When high tides are forecast the gates on the barrier are raised to prevent tidal water from reaching London.
109
What is the advantage of the Thames Barrier?
Large scale flood defence which has been effective in prevent serious flooding in London since it was built - the potential for loss of life in the densely populated central London due to flooding would be devastating
110
What is the disadvantage of the Thames Barrier?
It is very expensive and there will need to be a higher barrier to cope with predicted sea level rise.
111
How does Barking Riverside work?
* Water will be allowed to spread naturally to fill local creeks and cover the floodplain.
* Green corridors (vegetation in urban areas in corridors) will exist and these are designed to contain water as they intercept rainfall.
* Trees and parkland will help slow the rate of infiltration and increase water absorption.
* Residential areas are on raised land to protect them
*don't need to know all these - of course*
112
What are the advantages of Barking Riverside?
* In harmony with the existing environment.
* Alleviates a housing shortage
* Relatively cheap as it is incorporated into an existing project
113
What is the disadvantage of Barking Riverside?
Flooding will still pose a threat and damage could still be caused in the event of a major flood.
114
# 4 points
How has geology affected the geomorphic processes at the Thames River Basin?
* The geology of the Thames Basin is largely clay deposits and some areas of chalk:
* Clay is impermeable and this contributes to periods of flooding. Erosion takes place during storm events, clay makes flooding events more likely to take place and this causes a greater rate of erosion at these times
* Clay is a very soft rock and the Thames basin does not have any areas of granite or very resistant rock. It has a lowland geology. Therefore, the source is relatively low (108m) and this means that there is very little vertical erosion and consequently the landforms found are lowland features: meanders, oxbow lakes etc
* There is chalk (soft) in the Thames Basin, this is prone to chemical weathering.
*if stuck on these, list facts about geology/climate in the area and link to the 5 geomorphic processes*
115
# 3 points
How has climate affected the geomorphic processes at the Thames River Basin?
* The climate of the Thames Basin is relatively dry compared to other areas of the uk. This means that river flow is usually steady. Combined with the shallow gradient of the river this encourages deposition and depositional features (e.g floodplains and levees).
* However, the Thames Basin is also prone to periods of wet weather as the climate is quite variable. Wet weather combined with impermeable clay geology can lead to flooding events which makes erosion more dominant and can lead to mass movement.
* The temperature goes above and below zero degrees allowing freeze thaw weathering to take place - there is chalk in the Thames Basin, this is prone to chemical weathering.
