changing landscapes (geology,rivers,coasts) Flashcards
(84 cards)
1
Q
what and where are the 3 main rock types found in the uk?
A
sedimentary - south eastern UK
Igneous - north western
Metamorphic- north western
2
Q
what are the features of sedimentary rock?
A
have layers called beds contain fossils
3
Q
what are the features of igneous rock?
A
contain crystals not easily eroded usually impermeable
4
Q
what are the features of metamorphic rock?
A
highly resistant to erosion, formed when either igneous or sedimentary rock changes
5
Q
what are two named examples of sedimentary rock?
A
chalk, sandstone
6
Q
what are two named examples of igneous rock?
A
granite and basalt
7
Q
what are two named examples of metamorphic rock?
A
slate, schist
8
Q
how has geology shaped the uks upland and lowland landscapes?
A
north western uk is mainly harder igneous rock forming upland landscapes while south eastern uk is mainly softer sedimentary rock forming lowland landscapes.
9
Q
how have past tectonic activity shaped the uks upland and lowland landscapes?
A
millions of years ago the uk was close to plate boundaries, 520 million years ago two plated collided forming upland landscapes like the north of Scotland. 50- 60 million years ago diverging plate boundaries caused the atlantic ocean to open rising lava produced basalt rock.
10
Q
how have different processes made upland and lowland landscapes?
A
GLACIAL EROSION - stickle tarn in the north where glaciers formed during the ice age carved out a corrie
DEPOSITION - prolonged heavy rainfall cause rivers to flood water spreads out causing flat food plain
WEATHERING- leads to rocks breaking off and falling to the edge of the cliff => scree slope
CLIMATE - high rainfall- > lots of surface drainage over impermeable rocks leads to lots of streams
POST GLACIAL RIVER SLOPE PROCESS -the valley floor at the bottom is too wide for the stream to have eroded it. The flat bottom and steep sides shows that is is a u shaped valley and formed by a glacier
11
Q
how have distinctive landscapes resulted from human activity? (agriculture)
A
low land area’s drainage ditches built to drain water away from low lying agricultural land the staight aren’t natural shows human activity easier to build in lowland area
12
Q
how have distinctive landscapes resulted from human activity? (forestry)
A
upland areas plant trees in straight lines maximise space easy to see human activity easier
uk has naturally deciduous trees some plant coniferous trees to make more timber
13
Q
how have distinctive landscapes resulted from human activity? (settlement)
A
lowland landscapes easier to build on things like meanders easier to defend tube stations under ground can’t see
14
Q
what are the 5 physical processes?
A
Erosion
weathering
mass movement
transportation deposition
15
Q
what is erosion?
A
the wearing away and removal of land surface material by natural forces
16
Q
what is weathering?
A
the breakdown of minerals in situ due to the action of the atmosphere
17
Q
what is mass movement?
A
the downhill movement of material under the force of gravity
18
Q
what is deposition?
A
material such as sand is dropped or lift behind by rivers,wave or wind when the force carrying it looses energy
19
Q
what is transportation?
A
the movement of material like eroded rocks or sand by a river or the sea
20
Q
what are the 4 types of erosion?
A
abrasion
hydraulic action
attrition
solution
21
Q
what is solution?
A
the water is slightly acidic wearing and breaking of pieces of rock
22
Q
what is attrition?
A
rocks and pebbles carries by the waves push together and break off pieces
23
Q
what is hydraulic action?
A
waves compress air in the joints and cracks in rock forcing them apart
24
Q
what is abrasion?
A
material carried by the river or sea rubs against the beds and banks and wears the rock away
25
what are the three types of weathering?
chemical
biological
mechanical
26
what is chemical weathering?
rocks react with slightly acidic water and wear them away
27
what is biological weathering?
actions from plants and animals causing roach to split apart
28
what is mechanical weathering?
water falls into cracks of rocks and freezes repeated thawing and freezing causes rock to split apart
29
what are the two types of mass movement?
slumping
sliding
30
what is slumping?
saturated soil and rock fragments move downhill in a curved rotational manner leaving behind a curved surface
31
what is sliding?
downhill movement of large blocks of rock or soil along a relatively flat linear plane maintaining contact with the surface throughout
32
what are the 4 types of transportation?
traction
saltation
suspension
solution
33
what is traction?
large boulders rolled along the sea/river beds by waves and current
34
what is saltation?
smaller stones bounces along sea beds
35
what is suspension?
sand and small parietals carries along in the sea or river flow
36
what is solution?
some minerals dissolved in water carried along in the flow
37
how can geological structure affect the coastline?
Concordant/discordant - on concordant there is one front layer of the same rock type but on discordant it is alternating rock types which can form headlands and bays
joints/faults - joints are small cracks faults are larger both make rock more prone to erosion coastline quickly erroded
38
how can rock type affect the coast?
soft rock like clay is more easily eroded cliffs are less ragged and steep and they usually have bays
but hard rock like granite resistant to erosion cliffs are steep and ragged usually,y have wave cut platforms
39
how can different waves effect the coastline?
destructive waves - coat destroying weak swash strong backwash coast more easily erroded
constructive waves- coast building strong swash weak backwash coast less easily eroded
40
how can the uks weather and climate affect rates of costal erosion and retreat? (seasonality)
uk has 4 seasons have different impact on the coast winter cold temperatures freeze for weathering on coast
41
how can the UK weather and climate affect rates of coastal erosion and retreat? (storm frequency.)
Storm frequency is high in many parts of the UK coast often have strong winds increased erosion of coastline
42
How are errosional landforms developed headlands and bays?
discordant coastline hard rocks like chalk often left jotting out in the sea forming headlands, soft rock such as sand are eroded quickly forming bays
43
how are erosional landforms developed cave arches stacks and stumps?
Caves= wave erodes a weakness in the rock such as a joint or a fault
Arch = two caves erode back from either side of the headland meeting in the middle
Stack = formed when our collapses
Stump = when stack is further eroded collapses to form a stump
44
How are erosional landforms developed wave cut platforms?
see a road, bottom of cliff forms wave cut notch showing under cutting by the waves rock rock above overhangs overhanging rock collapses material brought in by destructive waves cliff retreats in land wave cut platform is formed
45
how are dispositional landforms developed bars?
Formed the same way as spit with longshore drift depositing material away from the coast until a long ridge is built up but the bar grows all the way across the bay so that a stretch of water is cut off and danned to form a lagoon
46
how are depositional landforms developed beaches?
Accumulations of sand and shingle formed by the deposition and shape shaped by transportation and erosion and disposition
47
how are depositional landforms developed spits?
prevailing winds bring waves in from an angle material moved along the beach in a zigzag way by longshore drift coastline changes direction usually due to a headland material deposited in shallow calm water to form a bit curves with wind direction river runs alongside stops spit from growing
48
how have human activities affected landscapes urbanisation?
Weight of buildings makes cliffs more vulnerable, changes to drainage increase soil saltration, raises interest in protecting coastal landscapes
49
how have human activities affected landscapes agriculture?
Increases soil erosion, increases sedimentation, creates wildlife habitats
50
How have human activities affected landscapes industry?
Increases air noise and visual pollution, can destroy habitats for birds, animals and sea life, brings wealth and jobs to the community
51
What are the effects of coastal recession and flooding on people?
loss of peoples homes, businesses, caravan parks Cafes ECT cliffs become dangerous to walkers, destruction to networks roads railways difficult for commuters, decreasing property value, difficulty finding home insurance
52
what are the effects of coastal recession and flooding on the environment
Wildlife habitats destroyed, increased disposition further along the coast
53
What is hard engineering?
Hard and engineering is artificial man-made structures used to try to control natural processes
54
what is soft engineering?
Soft engineering is working with nature to help maintain the coastline
55
what are the advantages and disadvantages of using groynes (hard engineering)?
Advantages prevent sea from removing sand cheap to use
Disadvantages exposes other coastal areas, the wood used can rott, looks ugly
56
what are the advantages and disadvantages of using riprap hard engineering to protect the coastline?
Advantages rocks absorb wave energy cheaper £1000-£3000 per meter
Disadvantages, ugly looks natural
57
What are the advantages and disadvantages of using a sea wall hard engineering to protect the coastline?
advantages protects cliffs and buildings, gives people place to walk along the coast
Disadvantages more expensive can look ugly destroys spaces for natural habitats
58
what are the advantages and disadvantages of using soft engineering methods to protect the coastline beach, Norishment?
Advantages looks good. Sound reduces wave energy maintains tourism cheaper.
disadvantages damage ecosystems require requires ongoing maintenance
59
What are the advantages and disadvantages of soft engineering methods to protect the coastline? Managed retreat?
advantages creates natural habitats sustainable
Disadvantages land loss potential for conflict economic cost
60
how do rivers change from upper course to lower course?
Upper course= gradient is deep discharge is small depth is shallow channel narrow steep sides valley profile seat sides velocity quite fast features waterfall into locking spurs sediment angular boulders
Middle course = gradient less steep discharge, large death deeper channel flat steep sides, value profile flat steep sides, velocity fast, fast features, flood planes sediment more rounded rocks
Lower course= gradient shallow discharge very large depth deep channel flat floor gently sloping sides will profile flat gently inside velocity very fast features beers flood planes leaves Ox Bay Lakes sediment smooth round pebbles
61
how can the U.K.’s weather and climate affect river processes?
Short-term weather increase frequency of storms means more periods of really intense rainfall meaning more water flowing into rivers they can overflow
The U.K.’s climate increasing periods of hot dry weather breaks up a soil when it does rain water runs off the surface it can’t soak in reaching rivers and rapidly increasing discharge
62
how does erosion and ideology help to create landforms upper course waterfalls and gorges?
increase vertical erosion, layer of hard resistant rock over a layer of soft rock soft rock roots quicker undercutting leaving hard rock overhanging eroded by hydraulic action pool is formed by hydraulic action and abrasion rocks were way bad overhang collapses over a long repeated process the waterfall retreats to form a gorge
63
how does erosion and geology help to create landforms in the upper course interlocking spurs?
The river source is small and has little energy it flows naturally from side to side, around ridges of valley sites called spas this is become interlocking with those on the other side of the valley.
64
how does erosion and geology help create landforms in the upper course of the river river cliffs?
Form on the outer side of the Meander when the faster water velocity laterally erroded the riverbank, they are almost vertical
65
how does deposition help to create landforms flood planes?
in the lower course the river is near the sea and carries a huge amount of sediment when the river floods excess water spills over the surrounding area area during flooding. The velocity of the river is reduced. It loses energy and deposit sediment forming the floodplain. The floodplain is shaped by lateral erosion of the meander as they gradually migrate downstream and by position of material on the inner band.
66
what is a flood plain?
plane is a wide flat area of land either side of a river and experiences floods when the river tops its banks
67
how does deposition help to create landforms leeves?
before a flood, the river is normal when flooding occurs the heaviest material is deposited on either side of the rivers banks due to the decrease in the rivers energy. This material creates a natural embankments called leeves. After a flood the smaller and fine settlement is deposited further from the river because it requires less energy to carry it.
68
How does disposition help to create loan forms point bar?
Point bars are formed by deposition on the inside bends of meander, the river current is relatively slow and therefore low in energy. This means that the river is not able to transport its load due to the low velocity and the load is deposited on the inside bend. Overtime deposits of sand and silt and pebbles buildup to form a point bar.
69
how does erosion and disposition work together to create landforms in rivers? (meanders and oxbow lakes)
Meanders = in the middle course, the whips depth and velocity of the river all increase the river erodes sideways (laterally) and starts to form large Bends. The bands get bigger and wider and eventually develop into a horse shoe shape called meander the outer bend of a meander where the current is faster has greater erosion. This wears away the bank creating a Rivercliff on the inner bend of a meander the current is slower and there is greater position creating a point bar.
Oxbow Lakes = narrow neck of meander is gradually being eroded water now takes the quickest route takes place, ceiling of the old meander Meanders neck has been completely cut through by Lake left behind when Meander completely cut off
70
how have human activities affected processes urbanisation?
Towns grow meaning fewer permeable surfaces water flows into rivers increases discharge
Increase demand for houses houses then built on flood Plains changes in natural landscape
Channelisation erosion anddisposition can’t take place
71
how are human activities affected river processes, agriculture?
Field drains can improve farm land quickly move water into rivers destroys natural habitats, forests help reduce surface run-off moving trees means water gets into rivers quick quicker more likely to flood
72
how are human activities affected river processes industry?
Bigger water consumption means reduce water amount in rivers less erosion takes place
Industry can pollute rivers with chemicals and waste this destroys plants animals and changes the natural landscape
73
what are the physical and human causes of flooding?
Physical= rainfall intensity lots of rainfall over long periods prevent soil infiltration, geology rocks like granite or impermeable drainage basin lots of water enters rivers quicker
Human = urbanisation deforestation changes in land use
74
What are the human and physical effects of flooding?
Human= death, disease, damaged property, insurance claims, loss of livelihood, destruction to transport, loss of crops and animals
physical = landslides soil erosion, lots of natural habitats, contamination of water supplies
75
What are the advantages and disadvantages of using hard engineering on rivers such as channelisation?
Advantages deepening widening of channel allows more water to flow quicker away from areas of floods, disadvantages, more water taking downstream increasing flood risk
76
what are the advantages and disadvantages of using hard engineering like dams and reservoirs to prevent rivers from flooding?
Advantages, barriers to hold back water store large volumes of water until needed long lasting used to generate hydroelectric power
disadvantages, expensive to build sediment can build up in reservoirs
77
what are the advantages and disadvantages of using soft engineering techniques like flood pain zoning to prevent rivers from flooding?
Advantages prevents development of areas that are at risk reduces number of homes at risk of flooding allows infiltration so surface run-off takes place
Disadvantages restricts growth of settlements
78
what are the advantages and disadvantages of using soft engineering techniques like wash hands to prevent flooding?
Advanced areas are deliberately flooded to avoid flooding important things create an area for floodwater to go allows natural river processes like deposition
Disadvantages might limit use of land
79
What is our named river location and what is it like?
The River Dee source is DAUALT Upland area in Snowdonia Wales river flows south east formed of igneous and metamorphic rock
80
what factors have shaped and changed the river Dee?
Human = 1732 two 1736 generalisation of 8 km improve navigation increases discharge and velocity creating an artificial landscape breather built in like llyen cleyn large embankment built in to protect agricultural land preventing further flood plane development
Physical = if sea levels rise by 1 m by 2100 coastal landscape will replace salt and freshwater marsh landscapes in the dee eustary rises and sea level will destroy eustary landscape
81
how does the river dees location change downstream?
Source heavily glaciated land Upland area
Upper/middle Chester the river meander across a wide plane
82
What is our named coastal location and what is it like?
83
How was our name coastal location formed?
84
What is the most influential factor in coastal locations change?
