Section C- Physical Landscapes In The UK Flashcards
(171 cards)
1
Q
what is hydraulic action?
A
force of water against river bed
2
Q
what is abrasion?
A
river throws particles against river bed at high velocity
3
Q
what is attrition?
A
loads bumps into each other being smoothed and broken into small particles
4
Q
what is solution?
A
chemicals in water dissolved the bed and banks
5
Q
what is traction?
A
large material rolled along the river bed
6
Q
what is saltation?
A
small pebbles bounce along river bed
7
Q
what is suspension?
A
fine material carried in waters flow
8
Q
what is soltuion? (transportation)
A
dissolving loads that are soluble in rainwater
e.g chalk and limestone
9
Q
name the two types of waves
A
constructive
destructive
10
Q
give characteristics of a constructive wave
A
strong swash and weak backwash 8-10 waves per minute build up beaches occur in summer under 1m long
11
Q
give some characteristics of a destructive wave
A
over 1m very high and short weak swash and strong backwash 10-14 waves per min erodes beaches occurs in winter
12
Q
what landforms form as a result of erosion?
A
headlands and bays
cliffs ad wave cut platforms
caves,archers,stacks,and stumps
13
Q
how do headlands and bays form
A
alternate bands of resistant+ non resistant rock align at right angle to coast
less resistant rock eroded more quickly hydraulic action and abrasion
more resistant rock protruding into sea forming a headland
14
Q
what happens to the bays that are formed once the less resistant rock has been eroded?
A
become low energy environments in which deposition occurs
exposed headlands becomes erosion target
beaches are built up by constructive waves
15
Q
what is a headland?
A
a cliff promontory which juts out into the sea
16
Q
what is a bay?
A
a crescent shaped indentation in the coastline found between two headlands
17
Q
what is a cliff?
A
a steep or vertical face of a rock often found at a coast
18
Q
what is wave cut platform?
A
a wide gently sloping rocky surface at the foot of the cliff
19
Q
what is weathering?
A
Weathering is the breaking down or dissolving of rocks and minerals on Earths surface.
20
Q
what is longshore drift?
A
Waves approach coast at angle.
Swash carries sediment up beach at an angle.
Backwash carries sediment down beach with gravity – at right angles to beach.
zig-zag movement of sediment along the beach.
21
Q
how do wave cut platforms form?
A
destructive waves hits against cliff face causing undercutting (HA + Corrasion)
cliff face is unsupported too heavy so falls off
this sediment broken down by attrition and thrown back at the cliff by abrasion
cycle repeats leaving a platform
22
Q
how do cliffs form?
A
weathering wears down rock
rock left behid is more resistant- typically vertical
weathering weakens top and erosion wear bottom away
23
Q
what are the characteristics of a wave cut platform?
A
gentle slope
bare rock interspersed with rock pools
barnacles on rocks
24
Q
what are the characteristics of cliffs?
A
horizontal bedding
layers of hard rock jutting out
verticle bare rock cliff face
25
how are caves,achers and stacks formed?
1) headland made of chalk and limstone natural cracks
2) sea finds cracks,erodes them wi HA+abrasion until caves
3) continues this on both sides of headland forms an arch
4) erodes the arch till roof collapses leaving stack
5) headland retreats
6) sea attacks stack causing it to weaken and fall into a stump
26
what are the characteristics of a sandy beach?
shallow,flat,formed by constructive waves, sand dune back of beach.long
27
what are the characteristics of a pebbled beach?
steep,formed y destructive waved, large pebbles at back of beach, short
28
how does a sandy beach form?
1) low energy constructive waves transport material into sheltered bay
2) sediment constantly moved up beach-swash stronger than backwash
29
how does a pebbled beach form?
1) destructive waves have stronger backwash-pebbles dont move far up beach
2) this makes a steeper beach- usually form when there is strong winds
30
how do sand dunes form?
1) wind blowing inland transports sand particles by saltation up the beach
2) height of sand builds up and becomes unstable
3) sand slips down the leeward slope
31
what is a spit?
an area of sand or shingle which either extends at a gentle angle out to see or which grows across a river estuary
32
How do spits form?
prevailing wind-Longshore drift move material along coastline.
spit forms when the material is deposited.
Over time,spit grows + develops a hook if wind direction changes further out.
Waves cannot get past so creates a sheltered area wherw mud flats or salt marshes form.
33
What is a bar?
Where a spit grows across a bay
34
how is a bar formed?
longshore drift continues to extend the length of the spit and forms a bar which has a lagoon behind it
35
which part of the UK coastline did we study to identify its main landforms?
swanage bay
36
where is swanage bay located?
Dorset
37
what features does swanage bay show?
headland (ballard point)
| bay (swanage)
38
where can good examples of cliff erosion and wave cut platforms be found?
Flamborugh head (yorkshire)
39
what are hard engineering strategies?
man made structures built to control flow of sea
40
what are gabions?
wire mesh cages filled with small rocks+ pebbles
| can be stacked to form wall like barrier at back of beach
41
what are the economic benefits of gabions?
£110 a meter- cheap
easy to construct
constructed on site wi local pebbles- cheaper
last 20-25 years
42
what are the environmental benefits of gabions?
blend in better
43
what are the economic costs of gabions?
restricted to sandy beach- shingle hurled at them would degrade it on pebbled beaches
expensive to repair vegitated ones
maintenance
44
what are the social costs of gabions?
people trip or cut themselves on wire mesh if broken
45
what are the environmental costs of gabions?
sea birds damage feet
| damaged ones can look unsightly
46
what is a sea wall?
wall made out of a hard material reflects waves back into the sea
47
what is a groyne?
wooden or stone fences built at right angle to coast
48
what is rock armour?
boulders that are piled up usually at back of beacj
49
what are the economic benefits of sea walls?
last for many years if well maintained
50
what are the social benefits of sea walls?
sense of security
| double as a cycle route/walk
51
what are the environmental benefits of sea walls?
don't impede movement of sediment
52
what are the social costs of sea walls?
restrict access to beach
53
what are the economic costs of a sea wall?
£5,000 per linear meter-expensive+costly repairs
54
what are the environmental costs of sea walls?
ugly to look at
| destroy habitats
55
what are the social benefits of groynes?
act as wind breaks
| people can sit on them
56
what are the economic benefits of groynes?
£5,000 each- cheap
| if well maintained last up to 40 yrs
57
what are the social costs of groynes?
stop people walking along beach
| wind surfers collide wi them
58
what are the economic costs of groynes?
restrict supply of sediment down drift
ineffective in stormy conditions
need regular maintenance so don't rot
59
what are the environmental costs of groynes?
unattractive
60
what are the economic benefits of rock armour?
£1000-3000 a metre
quick + easy to build
versatile
61
what are the social costs of rock armour?
access to beach difficult
| collect slippery seaweed hazard risk
62
what are the economic costs of rock armour?
foreign rocks used inflates the cost
| maintaining regularly as storms move rocks
63
what are the environmental costs of rock armour?
ugly+ covers vast areas of beach
| don't blend in with local geology
64
what is beach nourishment?
sand and shingle from somewhere else is added to beach
65
what is sand dune regeneration?
creating/restoring sand dunes either by nourishment or planting vegetation
66
what is beach reprofiling?
direct transfer of material from the lower to the upper beach
67
what are the social benefits of beach nourishment?
more room for people
| people living along sea front more protected from flooding
68
what are the economic benefits of beach nourishment?
protects expensive properties
69
what the environmental benefits of beach nourishment?
natural and blends in
70
what are the social costs of beach nourishment?
during re-nourishment beach access restricted
71
what are the economic costs of beach nourishment?
£300,000 to hire a dredger
72
what are the economic benefits of beach reprofiling?
nourishment and maintenance £30mill over 25 yrs
73
what are the social benefits of beach reprofiling?
residents feel safe
74
what are the environmental benefits of beach reprofiling?
looks reasonably natural
75
what are social costs of beach reprofiling?
bulldozers restrict access especially in winter
76
what are the economic costs of beach reprofiling?
can be expensive if major
77
what are the environmental costs of beach reprofiling?
steep high crested beach may look unatural
78
what are the social benefits of sand dune regeneration?
protect land behind
| popular for picnics and walking areas
79
what are the economic benefits of sand dune regeneration?
minimal costs as small planting projects use volunteers
80
what are the environmental benefits of sand dune regeneration?
maintain habitats
| dragonflies
81
what are the social costs of sand dune regeneration?
fenced off areas
82
what are the economic costs of sand dune regeneration?
checked twice a year-fertilisers applied
| expensive systems put in place to protect them
83
what are the environmental costs of sand dune regeneration?
grass becomes damaged from storms
84
what is managed retreat?
allows land to flood as old defences are breached and new line of defences built inland
85
what are the social benefits of managed retreat?
takes the pressure off areas further along the cosst and reduce their risk of floods
86
what are the economic benefits of managed retreat?
cheaper in the long term rather than maintaining hard engineering strategies
87
what are the environmental benefits of managed retreat?
enhances natural environment
new intertidal habitats
encourages development of salt marshes + beaches
88
what are the social costs of managed retreat?
relocation of people to new homes causes disruption
89
what are the economic costs of managed retreat?
high short term costs
| relocation costs have to be paid
90
what are the environmental costs of managed retreat?
agricultural land is lost
| habitats of coastal birds affected (decline numbers)
91
give an example of an area of the Uk which needed coastal relignment
the area west of Selsey (west sussex)
92
Why was coastal management needed in selsey?
The EA considered it to be the area of SW england most at risk of flooding
93
what was the only protection Selsey had against flooding?
a shingle ridge
94
From the 1990s what did selsey start doing to maintain the beach?
beach reprofiling (£200,000 a yr)
95
what happened when Selseys beach management strategies were breached?
£5 mill of damage
96
how was managed retreat achieved in Selsey?
- new clay embankment 2km inland
- channel behind embankment collect drainage
- 4 outfall structures to take water in intertidal area
- rock armour on embankment
- shingle bank in case of breach
97
what were the social benefits of Selseys managed retreat?
- new cycle routes and footpaths
| - 1 in 1,000 chance of flooding- reassuring
98
what are the economical benefits of selseys managed retreat?
- increase tourism
- gained a rep with nature lovers brings money in
- fishing nursery boost industry
- salt marsh used for cattle farming
99
what are the environmental benefits of selseys managed retreat?
- 300 hectres of new intertidal habitats
| - turning into a huge nature reserve
100
what were the social conflicts of selseys managed retreat?
-resentment from outside area as alot of money spent on a sparsly populated area
101
what were the econmic conflicts of selseys managed retreat?
cost £28 million could of been 0.2 a year on shingle wall
| 3 farms had to be abandoned for scheme losing money
102
what were the environmental conflicts of selseys managed retreat?
habitats such as badgers may have been disturbed
103
what landforms form as a ressult of just erosion?
| upper course
interlocking spurs
waterfalls
gorges
104
what landforms form as a result of erosion and depostion? (middle course)
meanders
| oxbow lakes
105
what landforms form as a result of just depostion?
| lower course
levees
flood plains
estuaries
106
what are interlocking spurs?
projecting ridges that extend alternately from the opposite sides of the wall of a V-shaped valley
107
what are the key characteristics of interlocking spurs?
steep gradient
convex slopes
separated by narrow valley floor
108
how are interlocking spurs formed?
- winding path of river due to obstacles of harder rock
- river takes easiest route
- results in projections of high land
109
what is a waterfall?
water falling vertically down a drop in the channel
110
what are the characteristics of a gorge?
narrow valley
steep, high sides
located immediately downstream of waterfall
fast flowing
111
how does a waterfall create a gorge?
```
1- waterfall flows over resistant rock
2-plunge pool is formed
3-splashback from pool erode soft rock behind waterfall
4-over hang collapses
5-waterfall retreat forming gorge
```
112
what are the characteristics of a meander?
slip of slopes
bends
gentle sloped sides
113
how is a meander formed?
1-fast flowing water, outside bank lateral erosion HA+A
2-helicoidal flow down inside bend deposits load due to friction
3-vertical erosion on outside bend
4- more depostion on inside bend
114
what is an oxbow lake?
small horse shoe lake found in lower courses
115
how is an oxbow lake formed?
1- meander loop becomes large- narrow neck
2-river floods cutting across neck
3-this new short cut carves out new banks
4-floods recede-goes bank to old route
5-process keeps happening until loop detaches due to deposition
116
what are the characteristics of levees?
raised river banks
made of gravel and stones
flat top
117
how is a levee formed?
1-river bursts its bank
2-low velocity-sediment is deposited
3-each time banks are built higher
4-bed becomes thicker and water level rises
118
what is a flood plain?
large area of flat land ether side of a river
119
what is the width of a flood plain due to?
meander migration
120
what materials build up a flood plain over time
silt and alluminuim are deposited making land more fertile aswell
121
what is an estuary?
where the channel broadens out to reach the sea
122
what are the characteristics of an estuary?
wide
high tidal range
mudflats
tidal bores
123
how is an estuary formed?
low lying valley sides are flooded
| the original channel is now the estuary floor
124
facts about the river tees
100km long
north east england
high rainfall
altitude-600m
125
what landforms are found in the upper course of the river tees
interlocking spurs
rapids
waterfalls
gorges
126
what landforms are found in the middle course of the river tees?
meanders
| oxbow lakes
127
what landforms are found in the lower course of the river tees?
meanders
oxbow lakes
floodplains
levees
128
which fours precipitation factors increase flood risk?
continous heavy rain
sudden bursts of heavy rain
prolonged light rainfall
sudden snow melt
129
how can geology increase flood risk?
rocks found in mountains is impermeable (slate) therefore runs off very easily- nothing to intercept it
130
how can relief increase flood risk?
low lying areas contain impermeable clay soil so cant infiltrate. also soil is these areas is very compacts
131
how does urbanisation increase flood risk?
more impermeable surfaces
drainage routes altered-no capacity for excess water
lack of vegetation=more surface run off
water runs quicker through drains then if on land-get to river quicker
132
how does deforestation increase flood risk?
leaves catch water and it evaporates off them
reduces impacts of rain on soil-soil erosion
roots absorb water from soil-less saturated so
can hold more
133
how does farming increase flood risk?
harvest crops leaves bare soil no veg to intercept
| field ploughing creates channels for water
134
what is a hyrdograph?
shows how a rivers discharge changes in respose to rain
135
what are dams and reservoirs?
dam- huge wall built in upper course
| reservoir-artificial lake behind dam
136
what are the benefits o dams and reservoirs?
rservoirs store water= reduces flood risk can power HEP and used for drinking
137
what are the disadvanatges of dams and reservoirs?
dams are expensive
138
what is channel straightening?
meanders are cut out and river is artificially straightened
139
what are the benefits of channel straightening?
water moves out of the area more quickly which stops flooding
140
what are the disadvanatges of channel straightening?
flooding may happen downstream as it is traveling faster toward it
141
what are embankments?
artificially raised river bank
142
what are the benefits of an embankment?
channel has an increased carrying capacity
low cost
provides a habitat
143
what are the disadvantages of an embankment?
deprive people easy access for fishing/boats
can be unreliable-prone to erosion
maintenance cost
144
what is a flood relief channel?
back up channel- works like a bypass
145
what are the benefits of a flood relief channel?
house values increase
cycle paths built
lower insurance costs
provide new habitats
146
what are the disadvantages of flood relief channels?
settlements downstream effected
expensive
unattratcive
147
what are the hard engineering river management strategies?
embankments
flood relief channel
dams and reservoirs
channel straightening
148
what are the soft engineering flood management schemes?
```
flood warnings
preparation
flood plain zoning
'do nothing'
river restoration
planting trees
```
149
what are flood warnings?
environment agency warns people through tv/radio
150
what are the benefits of flood warnings?
impact of flood is reduced- people have time to move things
151
what are the disadvanatges of flood warnings?
people may not hear/lack access to warnings
it doesn't actually stop a flood
places with lots of warnings makes it harder to get insurance
152
what is preparation?
modifying buildings
| make plans of what to do in a flood
153
what are the benefits of preparation?
impact of flood reduced
| people know what to do-less worried
154
what are the disadvantages of preparation?
doesn't guarantee safety
false sense of security
expensive buildings
155
what is flood plain zoning?
restrictions to prevent buildings on parts of flood plain that are likely to be affected
156
what are the benefits of flood plain zoning?
risk of flood reduced-less impermeable surfaces
| impacts is reduced-no homes
157
what are the disadvantages flood plain zoning?
expansion of urban area limited
158
what is 'doing nothing' ?
no money spent on new engineering
| flooding is a natural process
159
what are the advantages of 'doing nothing'?
farmland becomes more fertile from deposition
160
what are the disadvantages of 'doing nothing'?
impacts aren't reduced-lots of damage
161
what is planing trees as a soft engineering strategy?
shelter belts of trees across woodlands in floodplains
162
what are the benefits of planting trees?
reduce surface run off
more CO2 absorbed
new habitats
inexpensive
163
what are the disadvantages of planting trees?
less open space
| loss of grazing land
164
what is river restoration?
river restored to natural channel after previously being hard engineered
165
what are the benefits of river restoration?
new habitats
| increase water storage
166
what are the disadvantages of river restoration?
loss of agricultural land
expensive
not always effective/practical
167
why was the Jubilee river flood scheme required?
thames flood plain prone to flooding
increased impermeable surfaces
contains royal settlements/eton
168
what measures were taken in the Jubilee scheme?
created to take overflow water from river thames
169
what social issues arose from the jubilee scheme?
is it ethical to protect more expensive properties
170
what are the economic issues that arose from the jubilee scheme?
most expensive scheme in the uk
| £330 million aswell as repairs
171
what environmental issues arose from the jubilee scheme?
ugly concrete weirs
extensive flooding downstream
habitats disturbed
