The UK's Evolving Physical Landscape Flashcards
1
Q
What is glacial abrasion?
A
A process of erosion involving the wearing away of the valley floor and sides. It also wears away shorelines in coastal zones.
2
Q
What is glacial plucking?
A
A process of erosion involving individual rocks being plucked from the valley floor and sides as water freezes them to the glacier.
3
Q
Outline the process of freeze thaw weathering and any outcomes of it:
A
Erosion caused due to water freezing in a crack, expanding, widening the rock and melting again.
This causes moraine and piles off scree.
4
Q
What is the cause of meltwater and what does it do?
A
Ice melting in summer.
Lubricates the glacier, letting it move (basal/ rotational slip).
5
Q
Why do glaciers move downhill in winter?
A
The glacier is frozen to the surface so its weight and gravity cause individual ice crystals to move. This is called internal deformation.
6
Q
What are the 4 types of moraines?
A
- Lateral moraine
- Medial moraine
- Terminal moraine
- Ground moraine
7
Q
How are Corries formed?
A
1) Snow accumulates in a hollow hillside
2) Snow turns to ice, compressing the land and forming a small Corrie glacier
3) The glacier repeatedly scoops out rock (due to rotational slip and plucking)
4) A raised lip is formed as ice is thinner near the Corrie edges
5) After a glacial period, the ice melts to form a Corrie lake (tarn)
7
Q
How are arêtes and pyramidal peaks formed?
A
2 or more Corries form back to back
9
Q
What is a hanging valley?
A
A valley which has been cut across by another deeper valley (usually resulting in a waterfall)
10
Q
Name 7 glacial features of upland areas
A
- Arêtes
- Corries
- Tarn (Corrie lake)
- Hanging valley
- Plucking
- Misfit river
- Dry valley
11
Q
What is carbon dating?
A
Using radioactive testing to determine the age of rocks, which contained living material
12
Q
What are the three types of rock?
A
Sedimentary, Metamorphic, Igneous
13
Q
What are layers of rock called?
A
Strata
14
Q
What types of rock are found in high relief areas?
A
Igneous and Metamorphic as they are more resistant
15
Q
What type of rock is found in low relief areas?
A
Sedimentary rock as they are less resistant
17
Q
Where is sedimentary rock found?
A
East of England
18
Q
How did tectonic processes affect the Pennines?
A
- Convection currents beneath the plate, uplifted rocks from below the sea, to form land
- Some rocks snapped and moved along faults over thousands of years in a series of earthquakes
- Each earthquake raised faults to different heights
18
Q
Where is Metamorphic rock found?
A
West of England
19
Q
Why are some parts of a valley worn away more easily than others?
A
They are made from a less resistant type of rock
21
Q
How do V-shaped valleys form?
A
Rivers erode into the valley over time
22
Q
How do U-shaped valleys form?
A
Glaciers erode further into the V-shaped valleys making wide troughs
23
Q
How is igneous rock formed?
A
Molten magma or lava cools slowly, forming crystals.
23
Q
Give an example of an igneous rock.
A
Granite
25
Q
How is metamorphic rock formed?
A
Igneous or sandstone rocks get pushed under continental plates. The heat and pressure changes them into new rocks.
26
Give 2 examples of metamorphic rocks.
Schists
| Slate
27
How is sedimentary rock formed?
Rocks and dead fossils which has been weathered, eroded and deposited on the sea- bed are compacted to form new rocks.
27
Give 3 examples of sedimentary rocks.
Chalk
Carboniferous limestone
Clay
28
What are the characteristics of igneous rock?
Heavy, dark, very resistant
29
What are the characteristics off metamorphic rock?
Resistant
30
What are the characteristics of sedimentary rock?
Soft and crumbly (Clay)
Permeable (Carboniferous limestone)
Porous and very resistant (Chalk)
31
What is slate made of?
Heated mud or shale
32
Where in the UK can you find sedimentary rock?
London- clay
| Yorkshire dales- limestone
33
Where in the UK can you find igneous rock?
Dartmoor
| Grampians
34
Where in the UK can you find metamorphic rocks?
Giants causeway
| Stornaway
35
What are the 3 types of weathering?
Physical- weather
Chemical- acid rain
Biological- plants
36
Give an example of an upland UK landscape, the weathering types, the slope processes and the post-glacial processes:
The Lake District
Weathering: freeze thaw
Slope processes: rockfalls and landslides (large volumes of rain) forming steep, rocky crags
Post-glacial processes: misfit rivers and silt and mud deposition
37
Give an example of a UK lowland landscape, the weathering types, the slope processes and the post-glacial river and slope processes:
The Weald
Weathering: chemical and biological weathering
Slope processes: steep escarpments and flat vales (scarp and vale topography)
Post-glacial processes: dry valleys and flat land
38
What are the advantages and disadvantages of agriculture in the South Downs on the landscape?
+Hedgerows/field margins provide wildlife corridors
| -Chemicals reduce soil fertility, erosion of chalk and shrub encroachment
39
What are the advantages and disadvantages of forestry in the South Downs on the landscape?
+
| -
40
What are the advantages and disadvantages of settlement in the South Downs on the landscape?
+
| -
41
What is a coastal zone?
A changing boundary between land and sea.
42
Give 2 examples of hard rock coasts.
Flamborough Head
| Lulworth cove
43
Give 2 examples of soft rock costs.
Holderness coast
| Happisburgh
44
What is a concordant coastline?
A coastline where the rocks are parallel to the wave front. Similar erosion rates throughout.
45
What is a discordant coastline?
A coastline were differential erosion may occur due to bands of hard and soft rock. This causes bays and headlands.
46
What is a joint?
A small, vertical crack found in many rocks
47
What is a fault?
A larger rack caused by past tectonic movements where rocks have formed
48
Describe how caves, arches, stacks and stumps are formed from hard rock cliffs.
- A large crack is opened up by hydraulic action
- The crack grows
- A cave forms and becomes larger
- The cave breaks through the headland forming a natural arch
- The arch collapses to form a stack
- The stack erodes into a stump
49
What causes waves?
Wind blowing across the sea causing friction.
50
What does wave size depend on?
Wind strength
Length of time wind is blowing for
Length of water
51
Describe a constructive wave.
Small, slow summer waves with long wavefronts and low amplitudes that break as spilling waves. They have a strong swash so lots of sand is deposited. They also have low backwash due to a gentle slope.
52
Describe a destructive wave.
Tall, quicker winter waves with a larger amplitude but shorter wavelength which breaks as a plunging wave. They have a strong backwash due to a steep beach which can form a rip current and offshore bars.
53
What is rotational slumping?
The rapid movement of a mass of earth or rock sliding along a concave surface. This occurs due to heavy periods of rain, human activity like new buildings and the nature of the material.
54
What is longshore drift?
Process by which sediment such as sand is transported along a beach. The direction is controlled by the direction of the dominant wind.
55
How do you find evidence of longshore drift?
Slanted beach
Groynes
Spits or sand dunes
56
What is a spit?
A neck of sand formed by deposition of sand on a river, halting its flow.
57
What is a beach?
Sediment on a coast forming a barrier between land and sea. This is usually due to a cove or bay.
58
What is a bar?
A line of sand covering/ blocking a bay from the sea due to longshore drift. This may form a lagoon.
59
What is a salt marsh?
A marsh behind a curved spit, protecting it from storms.
60
Which 4 human activities cause most risk to coasts?
Development
Agriculture
Industry
Coastal management
61
How does development impact coasts?
Tourism- pollution
Housing- slumping
Commercial activity/ businesses- slumping
Retirement homes- slumping
62
Why does development take place at the coast?
Businesses have easy access to trading ports.
Less money has to be spent on transport.
Fishing businesses have easy access to their docks.
63
How is agriculture impacted by coasts?
Sea level rise floods pastures with salt water
| Increased coastal erosion leads to loss of farmland as it has low economic value
64
How does industry impact coasts?
Roads, railways and ports are built to link coasts to the rest of the world.
Oil refineries can cause leaks into the sea
Gas terminals and chemical plants produce many waste products
Wildlife is disturbed by ferry and shipping ports
Erosion due to sand and gravel removal disturbs wildlife
65
How does coastal management impact coasts?
Hard engineering protects coasts with artificial structures
| Soft engineering protects coasts with natural process
66
Give a named example of coastal change and conflict in the UK.
The Holderness Coast, Yorkshire
67
Where is the Holderness Coast located?
The East Coast of England.
61km from Flamborough head to Spurn head.
It is in Yorkshire
68
Why is there such a high level of erosion along the coast?
Narrow beaches
| Made of soft boulder clay
69
Name the type of erosion on a named location along the Holderness coast made of resistant chalk.
Flamborough Head
| Hydraulic action causes the collapse of arches and stacks
70
Name the type of erosion on a named location along the Holderness coast made of boulder clay.
Mappleton
| Cliffs fall into the sea due to cliff-foot erosion and cliff-face weathering
71
How does the presence of people impact the Holderness coast?
Leisure facilities, retirement homes, houses, etc. accelerate the rate of slumping on natural slip planes
72
How does interfering with natural processes impact the Holderness coast?
Interfering with longshore drift with coastal defences can increase erosion rates in other areas due to the sediment starvation effect.
73
Which coastal defences are implemented along the Holderness coast?
Hornsea: groynes and sea walls
Withersea: groynes and sea walls
Mappleton: groynes
11km of hard engineering
74
How many people does the costal defences along the Holderness coast protect?
14000
75
How are rising sea levels increasing flood risk?
- Higher tides
- More material is removed (cliff erosion)
- Narrows beaches + exposes coasts to erosion
Threat to low- lying and coastal areas
76
How is increased storm frequency increasing flood risk?
- The sea has more erosional power
- The sea has more transportation energy
- More frequent and powerful storm surges (flood coast)
77
What threats does coastal flooding have on people?
- Low lying areas become uninhabitable
- Coastal industries may have to shut down (equipment, building or land damage)
- Damaged flood defences
- Damaged infrastructure (e.g. roads)
78
What threats does coastal flooding have on the environment?
- Ecosystems are damaged by increased salt levels
- Reduced soil fertility
- Trees are uprooted and plants are drowned (flood water)
- Threatened conservation areas
79
Name the marine cliff foot processes that cause cliffs to collapse:
Erosion by hydraulic action and abrasion
The cliff face is made steeper
80
Name the sub-aerial cliff face processes that cause cliffs to collapse:
Weathering weakens the cliff (mechanical, chemical + biological)
Heavy rain- saturation at cliff top, erosion and adds weight
81
Name the human actions that cause cliffs to collapse:
Building- adds weight
82
Define hard engineering:
Man- made structures built to control the flow of the sea and reduce flooding and erosion. E.g. sea walls
83
Define soft engineering:
Schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion. E.g. beach replenishment
84
What are sea walls? Assess the costs and benefits:
```
A wall made of hard materials (mainly concrete) to reflect waves.
+Acts as a barrier to prevent flooding
+Prevents erosion
-Strong backwash, erosion under wall
-Expensive to build and maintain
-Ugly
```
85
What are groynes? Assess the costs and benefits:
Wooden or stone fences that trap material transported by longshore drift.
+Create wider beaches with slow waves which gives greater flood protection.
+Cheap
-Starve beaches further down the coast
-Erosion further down the coast where beaches become narrower
86
What is beach replenishment? Assess the costs and benefits:
Sand and shingle from elsewhere added to the upper beach.
+Wider beaches slow waves
+Greater protection from flooding and erosion
-Taking materials from the seabed can kill organisms
-Very expensive
-His to be repeated
87
What is slope stabilisation? Assess the costs and benefits:
Concrete nails inserted into a slope for reinforcement. The slope is also covered with a metal netting.
+Prevents mass movement by increasing slope strength
-Very expensive
-Very difficult to install
88
What is strategic realignment? Assess the costs and benefits:
Removing an existing defence and allowing the land behind it to flood.
+New habitats created by land becoming marshland
+Flooding and erosion are reduced behind marshland
-Disagreements over which land should be flooded
89
What is Holistic management?
Coastal management that takes into account the needs of different groups of people; the economic costs and benefits in the short a long term; and the environment on land and in the sea.
E.g. Integrated Coastal Zone Management (ICZM)
Shoreline management plans (SMPs) are drawn up to visualise the impacts.
90
What are the 4 Holistic coastal flooding management choices?
- Hold the line: sea defences stop erosion so coast stays in same place (expensive)
- Advance the line: sea defences move coast further into the sea (v. Expensive)
- Strategic realignment: gradually let the coast erode whilst moving people and businesses away (usually includes financial compensation)
- Do nothing: no action. This can cause conflict as people may lose land, business or homes
91
What 3 factors effect the rate of coastal erosion?
Geology of rocks
Cliff processes
Waves and wave energy
92
Outline the hydrological cycle (a closed system) starting with evaporation:
Evaporation: Change of state from liquid to gas
Transpiration: Evaporation of water from the pores of plant leaves
Condensation: Change of state from gas to liquid
Precipitation: Any form of moisture that falls from the sky
Infiltration: Movement of water from land surface into the soil
Water table: The level below the surface where soil and rock is saturated
Ground water: Underground water which flows into water stores
Storage: Rivers, lakes, seas, etc.
93
A drainage basin is...
The land surrounding a river where all the water flows int one river
94
Define confluence:
Where two rivers meet
95
Define mouth:
Where rivers meet the sea or lake
96
Define source:
The beginning of a river
97
Define store:
Water is kept in one place for a period of time
98
Define tributary:
Smaller streams that flow into a river
99
Define watershed:
The edge of a river basin
100
Define estuary:
The tidal mouth of a large river, where the tide of the sea meets the stream of the river
101
Define meander:
A river following a winding course
102
Define river discharge:
The water that moves from the river’s flow into the sea
103
Define groundwater flow:
The movement of water through saturated ground
104
Define stem flow:
When intercepted water travels down the branches and trunks of vegetation
105
Define through flow:
The movement of water through unsaturated ground
106
Define percolation:
When water travels from unsaturated ground to saturated ground
107
What is the rainfall like at each stage of the river Severn?
Upper course: Over 2500mm/ year
Middle course: Under 700mm/ year
Lower course: Less rainfall/ year
108
What is the geology like at each stage of the river Severn?
Upper course: Shales, slates and grits (hard and impermeable)
Middle course: Sandstone, conglomerates, coal and marls (all covered in sand and grit)
Lower course: Clays, sands, sandstone, soft mudstones, etc. (All covered in sand and gravels)
109
What is the channel shape like at each stage of the river Severn?
Upper course: Shallow and narrow
Middle course: Wider and deeper
Lower course: Widest and deepest
110
What is the type of erosion like at each stage of the river Severn?
Upper course: Vertical- hydraulic action, abrasion and attrition
Middle course: Vertical and lateral- hydraulic action
Lower course: Lateral- very little erosion
111
What are the landforms like at each stage of the river Severn?
Upper course: Waterfalls, gorges and v-shaped valleys
Middle course: Meanders and oxbow lakes
Lower course: Floodplains, estuaries and deltas
112
What are the river processes like at each stage of the river Severn?
Upper course: Erosion
Middle course: Transport
Lower course: Deposition
113
What is the particle size and shape like at each stage of the river Severn?
Upper course: Angular stones
Middle course: Rounder
Lower course: Sands
114
How does discharge change at each stage of the river Severn?
It increases
115
How does velocity change at each stage of the river Severn?
It increases
116
What is the Bradshaw model?
A summary of how a river changes as you move down the course.
Factors that increase include: discharge, channel width and depth, velocity, load quantity
Factors that decrease include: particle size, channel bed roughness, slope gradient
117
What does a river’s long profile show?
Height
Distance downstream from the source
River shape
118
What is abrasion?
Abrasion cours when the load of the river repeatedly hits the river bed and banks, causing material to break off.
119
What is attrition?
Attrition is when stones and boulders the river is carrying knock against each other, causing bits to fall off and reduce in size.
120
What is hydraulic action?
The sheer force of water hitting the bed and banks causes air to become trapped, weakening the sides and causing them to wear away
121
What is solution (corrosion)?
River flowing over certain types of rocks causes them to dissolve ans become part of the water
122
What is solution (in terms of transportation)?
The dissolved load of the river
123
What is suspension?
A means of carrying very fine material so that it floats with the river
124
What is saltation?
The movement of small stones and grains of sand my bouncing them along the river bed
125
What is traction?
The movement of the largest material which is too heavy to lose contact with the bed. Boulders are rolled along slowly.
126
The more energy a river has, the _______ the river can erode.
The more energy a river has, the _______ the load it can carry.
The _____ energy a river has, the more material the over deposits.
Faster
Larger
More
127
Which factors influence erosion?
```
Volume of water
River gradient
Rock type
Friction
Type of flow
```
128
Which factors influence deposition?
Gradient (reduction)
Volume of water (reduction)
Friction (increase)
129
How are waterfalls (and gorges) formed?
| Hint: this is vertical erosion
1) Hard, resistant rock is on top of softer rock in a river.
2) The soft rock gets eroded, leaving an undercut and an unstable overhand of hard rock. A plunge pool contains the eroded material.
3) Hard rock falls to the ground due to gravity, leaving large angular stones.
4) A gorge forms as this process continues. The sides are very steep.
130
What is an interlocking spur?
Near their source, rivers are small without a lot of power. They mainly erode vertically so flow around valley side slopes (called spurs) instead of through them. The spurs are left interlocking are ove valley side overlaps the other.
131
How are meanders and oxbow lakes formed?
1) The flow is the fastest around the external angles of a meander, widening that area.
2) The force of he river erodes the end further.
3) Where the flow is slower, material is deposited, making the meander neck narrower and weight ending the horseshoe shape.
4) The curve is eventually cut off, leaving an oxbow lake.
132
How are levees and floodplains formed?
1) A flood occurs, causing excess water to ever flow its’ banks into the floodplain
2) Sediment is also moved from the river bed and is deposited near the river
3) The larger the sediment, the closer the the river it stays
4) The rocks stay out of the water after the water recedes, leaving a levee
133
How are deltas formed?
1) The velocity of the river decreases and loses power to carry sediment nearer to the mouth
2) The sediment is deposited at the mouth of the river
3) Over time sediment develops a flat area of new land called a delta
4) The slow flowing river spreads out in many different channels over the new delta
134
Erosion rate is influenced by climate because...
Erosion rate is greater where discharge and river energy is greater. These both occur more in wet climates rather than dry ones so there is more erosion there.
135
Transportation rate is influenced by climate because...
Transportation rate is greater where the water energy is greater. This means that wet climates transfer more material.
136
Weathering is influenced by climate because...
Weathering of rocks is greater in certain climates. E.g. freeze thaw weathering occurs mainly in cold climates (below freezing).
137
The amount of discharge is influenced by climate because...
Wetter climates cause more discharge as there is greater water energy. Hotter climates have less discharge as there is more evaporation.
138
Define biological weathering:
Plants and animals- small cracks in rocks allow plants into the rocks, widening the cracks and breaking them apart
139
Define physical weathering:
Weather/ climate- physical force breaks rocks e.g. freeze thaw weathering
140
Define chemical weathering:
Chemical changes- decay of solid rock. Rainwater often mixes wit acidic atmospheric gases and dissolves alkali rocks.
141
Define mass movement:
The movement of weathered materials downslope due to gravity.
Mudflows are rapid and from heavy rain
Soil creep is slow and from light showers
142
Define slumping:
Valley sides are eroded by the river, making the sides steeper and increasing the downward movement of material. Heavy rainfall can trigger this movement.
143
What is the equation for river discharge?
Cross sectional area x rivers mean velocity
This is for a particular point in the river’s course.
144
Label the parts of this storm hydrograph:
...
145
What Dora’s a storm hydrograph show?
The response of a river to a rainfall event. It plots rainfall and discharge.
146
What is lag time?
The time between peak rainfall and peak discharge
147
Which factors give a river a short lag time?
```
Impermeable rocks
Frozen soil
Round drainage basin (many tributaries)
Heavy precipitation
Towns and cities
Saturated antecedent conditions
```
148
Which factors give a river a long lag time?
Long slim drainage basin
Slow light rain
Vegetated areas
149
Which tributary meets the river Severn at Tewkesbury?
Warwickshire Avon
150
Why does Tewkesbury have a high flood risk?
Flat land
Many buildings close to the river
Many tributaries
Built on floodplains
151
What human processes cause flooding?
Urbanisation- less available soil for absorption
Building on floodplains- vulnerable to flooding
Overland flow from farms decreases infiltration and causes downstream flooding (can be combated with flood drains)
152
Why is there an increased frequency of storms?
>Climate change
>More intense storms
>More periods of wet weather- more saturated ground is vulnerable to storms and flooding
153
What land use changes cause flooding?
>Population growth
>Urbanisation
>Removal of vegetation
>Development on floodplains
154
How are people threatened by floods in Tewkesbury?
- Many local schools and businesses have to close
- Roads, railways and bridges are damaged, destroyed or blocked
- Repair costs £20,000 to £30,000 per home
155
What are flood walls? What are the costs and benefits?
```
Artificial barriers built along river banks designed to increase the height of river banks.
+Allow river channels to hold more water
-Very expensive
-Unsightly
-Block view of river
```
156
What are embankments? What are the costs and benefits?
High banks that are built near or along river banks which stop the river flowing into built up areas during a flood.
+Protect buildings and infrastructure on flood plains
+Less unsightly as natural materials are used
-Quite expensive
-Risk of severe flooding if they break
157
What are flood gates? What are the costs and benefits?
Gates built on river estuary to stop floods from storm surges and high tides. They can be shut when a surge is forecast.
+Protect a large area of land
-Very expensive
158
What are demountable flood barriers? What are the costs and benefits?
Barriers that provide temporary protection against flooding. They are only put up when there’s a flood forecast.
+Don’t spoil the look of the land
-Quite expensive
159
What is floodplain retention? What are the costs and benefits?
Maintaining a floodplain by not building on it. This slows down floodwaters and maintains the floodplains ability to store water.
+No money has to be spent on it
-Restricts development
-Can’t be used in urban areas
160
What is river restoration? What are the costs and benefits?
Makes a river more natural e.g. removing man made levees. Let’s the floodplain flood naturally. This reduces river discharge and leaves the river in its natural state.
+Very little maintenance is required
- Can increase local flood risk
161
Where is Tewkesbury located on the rivers course?
Between the middle and lower course
162
How is flooding reduced on the river Severn?
Trees are planted upstream
| The environmental agency has restored 2km of river
