Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Edexcel A level- Geo > September physical mock > Flashcards

September physical mock Flashcards

1
Q

what is geological structure?

A

refers to how the rock is arranged on a macro-scale and looks at the arrangement of different rock types in relation to each other.It looks at the rock strata, deformation and presence of faulting.It looks at the rock strata, deformation and presence of faulting.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is beach morphology?

A

the shape of a beach including width and slope (profile) and other features such as berms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

explain the formation of headlands on discordant coastlines

A

1) wave action erodes the less resistant rock quicker due to hydraulic action and abrasion 2) the more resistant rock is left sticking out as a headland, causes waves to refract and as water becomes shallower and so waves energy is concentrated on the headlands and waves become higher increasing erosive power on the headland 3) the bay becomes sheltered as wave energy is dissipated, results in the formation of beaches as sediment is deposited in the low energy environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

explain joints

A
  • (vertical cracks), these are fractures caused either by contraction as sediments dry out or by earth movements during uplift - they are fractures created without displacement and occur in most rocks, dividing rock strata up into blocks with a regular shape - jointing increases erosion rates by creating fissures which marine erosion processes such as HA can exploit example: in bantry bay, the limestone is heavily pointed, leading to more rapid fluvial and marine processes in adjacent sandstones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

explain faults

A
  • formed when he stress of pressure not which a rock is subjected, exceeds its internal strength (causing it to fracture). the faults then slip along fault planes. - it significantly increases erosion since faulted rocks are much more easily jointed - huge forces are involved in faulting and displacing them and therefore either side of the fault line, rocks are often heavily fractured example: in bantry bay in cork in the republic of Ireland there is a major fault which runs SW-NE down the centre of the bays. the limestone is weakened allowing rapid fluvial erosion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

explain folds

A
  • they are bends in rocks formed by pressure during tectonic activity which makes rocks buckle and crumple - the main two types are anticlines and synclines - folden rock is often more heavily fissured and jolted, meaning they are more easily eroded, also increases erosion by increasing angle of dip and causing joins through the stretching along anticline crests an compressed in syncline troughs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

explain dips

A
  • refers to the angle at which rock strata lie (horizontally, vertically, dipping towards the sea or dipping inland) - its a tectonic feature, sedimentary rocks deposited horizontally can be tilted by faulting and folding by tectonic forces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a low angle of seaward dip

A

produces a steep profile that may even exceed 90 degrees, creating areas of overhanging rock, vulnerable to rock falls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is landward dipping strata?

A

produces a steep profile that may even exceed 90 degrees, creating areas of overhanging rock, vulnerable to rock falls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is landward dipping strata?

A

produces steep profiles on 70º-80º as downward gravitational force pulls loosened blocks into place, very stable with few rock falls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a cliff profile?

A

the height and angle of a cliff face, plus its features such as wave cut notches or changes in slope areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the difference between macro, meso and micro scale?

A

macro scale- concordant and discordant coastlines (encourages headlands and bays or coves)

meso scale- dip of strata (bedding planes), differential erosion from mixed lithology layers

micro scale- joints, these are vulnerable to HA, freeze thaw, salt crystallisation and bio weathering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is lithology?

A

refers to the physical characteristics of the rock. igenous, metamorphic, sedimentary and unconsolidated rock each have different characteristics.

it also influences geological structure on ameso (medium scale) and micro scale (some types of rocks are more likely to have joints and bedding planes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

give examples of areas from the most resistant rock to the least resistant rock

A

most resistant: IGNEOUS- Land’s End, South Cornwall (granite)

resistant rock: METAMORPHIC- St Ives, Cornwall (slate)

resistant sedimentary rock: SEDIMENTARY- Blackers hole, south Purbeck, Dorset (Limestone)

least resistant rock: Holderness, NE Coast, (boulder clay)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

explain igneous rocks

A
  • their crystalline structure (interlocking cystals) means they are well connected and impermeable with few lines of weaknesses (resistant)
  • these rock types create rocky coastlineswith steep profile cliffs
  • erosion rates: 0.1-.0.3 cm/yr
  • e.g. granite, basalt
  • example: lands end, Cornwall (granite)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

explain metamorphic rocks

A
  • they are also well-connected and impermeable
  • however they are often folded and faulted so have weaknesses
  • these rock types create rocky coasltines with steep profile cliffs (depending on folding and dip) and erode slowly
  • erosion rates: 0.5-1 cm/yr
  • e.g. marble, slate, schist
  • crystalline rocks are resistant to erosion
  • example: St Ives, Cornwall (slate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

explain sedimentary rocks

A
  • they are clastic meaning they are made up of cemented sediment particles rather than interlocking crystals
  • formed in stratas (layers) with joints which provides weaknesses and makes limestone permeable along with other jointed sediemntary rocks whereas other ones are porous due to the presence of air spaces
  • rocks that are younger erode faster than the others as they are softer and weaker, older sediment is buried deeper and is subject to more intense compaction with strongersedimentation- making them more resistant
  • limestone erosion rates: 1-2cm/yr, chalk erosion rate: 1-100 cm/yr
  • example: Old Harry, Purbeck, Dorset (chalk)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

explain unconsolidated sediment

A
  • they are the least resistant, they are not cemented together in anyway so are very vulnerable to erosion, fast recession rates
  • can create slumped coastlines due to mudslides/landslides causing slumping
  • the boulder clay of Holderness coast in Yorkshire retreats at a rate of 2-10 m p.a
  • boulder clay erosion rates: 100-1000 cm/yr, sandstone rate: 10-100 cm/yr
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

explain psammosere

A

1) there is a plentiful supply of sand, a large area for sand to dry out and onshore winds to that blow sand landwards. sand accumulates to form an embryo dune.
2) pioneer species like marram grass colonise the dune, stabilising it and helps to trap more sand
3) a fore dune develops when enough sand has bee ntrapped an the dune starts to become more stable
4) now an established dune will become more vegetated by marram grass which provides organic matter to the sand and soil to devleop, improving the conditions
5) with soil now developed on the dune, it becomems a grey dune. this is permanent and conditions ar suited to a greater variety of species including heather and gorse
6) between dunes, dune slack develops. wind erosion can deepen them and they may be waterlogged in high tide conditions.
7) furthest inalnd is the climax community. there the soil is fully developed and the dune is fully stabilised and biodiversity is at its highest, trees can grow (birch)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

explain the 4 processes of erosion

A

abrasion- the rubbbing together of hard load, sand paper effect

attrition- rocks bashing into one another breaking them down

hydraulic action- air trapped in cracks and fissures is compressed by the force of the waves crashing against the cliff face. when the wave retreats, pressure is released explosively which can widen cracks and dislodge blocks friom the cliff face

solution- where water in waves dissolves rock minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

explain the cave-arch-stack-stump sequence

A
  • the headland protrudes out into the sea as it is more resistant which means wave energy is concentrated on it due to wave refraction
  • wave action attacks weaknesses in the headland due to abrasion and hydraulic action leading to cavitation
  • this widens cracks into crevices and into caves
  • caves can be eroded to form blowholes as the ceiling collapses
  • marine erosion deepens the caves until they connect up andan arch is created and erosion continues and the roofof the arch becomes unstable from the widening of the arch due to weathering and other sub-aerial processes
  • the arch eventually collapses by blockfallto form a stack
  • continual undercutting and HA in the joints at the base of the stack creating a stump like Old Harry’s wife
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

explain the formation of a wave cut platform

A

1) wave action at the base of the cliff between high and low tidemeans that hydraulic action and abrasion undercuts the clif to form a wave cut notch
2) this continues and the cliff above the notch is left unsupported and eventually collapses
3) the cliff retreats leaving a wave cut platform which is the base of the cliff that is left
4) this process maintains a steep cliff profile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is a wave cut notch

A

a curved indentation of about 1-2m high extending along the base of a cliff. it forms between the high and low tide marks, where destructive waves impact against the cliff.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a spit and how is it formed?

A

it is a long narrow feature made of sand or shingle which extends from the land into the sea
1) sediment is moved along the coast by a process called LSD

2) when there is a change in the direction of the coastline (river mouth), the waves lose energy in the slacker water behind the headlandand the largest sediments are deposited here first in the same direction (gravity settling), flocculation helps to settle fine clay, forming the start of the spit
3) the spit grows and may form a hook if the wind direction changes
4) the end of the spit will start to curve round as wave refraction carriers material round into the more sheltered water behind the spit, this is known as a recurved spit
5) in the slacker water behind the spit, more deposition takes place and a saltmarsh may develop with halophytic plants helping to trap sediment. e.g. spurn head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is a bar and how does it form?

A

where there are no river currents, it prevents longshore drift depositing in a straight line across and so evenutally the spit joins with land to form a bar, e.g. chesil beach

it is when a beach or spit extends across a bay to connect two headlands,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is a tombolo?

A
  • this is an island joined to the mainland. it develops when deposition occurs behind an island due to the low energy environment. eventually, the island becomes connected to the mainland.
  • occur on drift aligned coastlines, when longshore drift builds a spit out from land until it contacts with an offshore island
  • tombolos may be covered during high tide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are double spits?

A
  • Double spits are where two spits extend out in opposite directions from both sides of the bay, towards the middle.
  • They form where longshore drift is operating in different directions on opposite sides of the bay
  • They can also form when rising sea levels drive ridges of material onshore from the offshore zone.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what are cuspate forelands?

A
  • low-lying triangular shaped headlands, extending out from a shoreline, formed from deposited sediment
  • forms when longshore drift current from opposing directions converge at the boundary of two sediment cells, forming a natural triangular shape as it builds
  • They can extend from a few metres to several kilometres.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what are barrier islands?

A
  • a ridge of material emerging just offshore to form a chain of beaches parallel to the coast
  • these are offshore sand bars thought to have formed when a plentiful supply of sediment was deposited in sand dunes along the eastern seaboard of the USA by waves and winds
  • as sea level has risen, land behind was flooded to create a lagoon but the sand dunes themselves became elongated islands running parallel to the coast (USA Atlantic coast)
  • as sea level continues to rise, they migrate inland
  • they provide protection to the coastline during storms as they absorb wave energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is a offshore bar

A
  • Offshore bars are ridges of sand or shingle running parallel to the coast in an offshore zone.
  • forms in shallow water offshore where the slope is gentle, often following large erosion events during a storm
  • They are also called breakpoint bars because the offshore/nearshore boundary is where waves first begin to break.
  • They can sometimes be exposed by neap tide.
  • LSD can add to them or change their shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is weathering?

A

the decay and disintegration of rock in situ (where they are) by mechanical, biological or chemical agents.

32
Q

what is mass movement?

A

the movement of material downslope as the result of gravity. water commonly acts a lubricant in mass movement.

33
Q

what are landslides?

A

rocks that have jointed or having bedding planes parallel to the slope are susceptible to landslides. increased water leads to less friction, leading to sliding

34
Q

what is rotational slumping?

A

common where softer rock overlies harder rock, it causes rotational scars, repeated slumping creates a terraced cliff profile

  • A rotational scar is a fresh, curved, unweathered and unvegetated rock surface on the cliff face.
  • The detached slope section, often with vegetation intact on top of the slump, forms a beach or terraced cliff profile.
  • Slumping is facilitated by the presence of water, which adds weight (increasing the gravitational force) as well as lubricating it, reducing friction.
35
Q

what is rock fall

A
  • most likely to occur when strong, jointed and steep rock faces/cliffs are exposed to mechanical weathering or marine erosion,happens on slopes over 40 degres
  • once broken away, it can form scree at the bottom of the cliff

blockfalls- similar to rock falls but here a large block of rock falls away from the cliff as a single piece.

36
Q

what are the different types of biological weathering explained

A

plant roots

  • tree and plant roots growing into cracks can slowly widen them and cause them to break apart. important process on vegetated cliff faces.
  • seeds falling into cracks in rocks can germinate, nourished by rainwater and nutrients from wind-blown sediment.as the plant grows its roots expand and thicken,tree roots exert sufficient tensional force to widen the crack

rock boring
clams and molluscs bore (dig) into rock to make their homes. they can also secrete acids that dissolves rocks. sedimentary rocks in the intertidal zone are vulnerable.

-piddocks drill depressions into sock rocks by rotating their shell equipped with sharp edges

seaweed acids
- some seaweed species like kelp contain pockets of sulphuic acid that can burst on rocks and dissolve them

-when the cells break sulphuric acid attacks rock minerals like calcium carbonate leading to a chemical reaction similar to carbonation

37
Q

what are the different types of chemical weathering explained

A

carbonation
- limestone slowly dissolves as it reacts with weak carbonic acid

-This attacks calcium carbonate in limestones, other carbonate rocks and sedimentary rocks with calcite sediment.

oxidation
- oxygen combines with iron based minerals in a rock causing a chemical breakdown of the minerals shown by red rusty colour on the rock face. it produces iron oxides and increases in volume, leading to mechanical breakdown.sandstones and shales often contain iron so are vulnerable.

38
Q

what are the different types of mechanical weathering explained

A

freeze thaw
- water gets into the cracks and freezes and expands up to 9%. this exerts pressure on the cracks which loosens and breaks apart rock. most vulnerable are well jointed rocks, only happens when daily temperatures fluctuate around zero degrees.

wetting and drying
- rocks rich in clay expand when they get wet and contract when they dry. this repeated process causes them to crack and break apart

  • effects: cracks form in cliffs so they become vulnerable to slumping.
    salt crystallisation
  • salt spray or waves hitting cliffs makes them wet with seawater. this evaporates and leaves salt in cracks on the cliff. overtime, salt crystals form and grow, exerting pressure on the crakcs and pores which loosens and breaks apart rocks. most vulnerable are well jointed rocks (limestone) and porous rocks (sandstone). happens most in hotter climates
39
Q

what is a talus scree slope?

A

The angular blockfall debris accumulates at the cliff foot to form atalus scree slope, a fan shaped mound of material.

40
Q

examine the influence of dips on cliff profiles

A

Landward dipping- they are relatively steep and stable, decreasing recession rates

Seaward dip- high angle produces low-angle profile with one rock layer facing the sea, low angle produces steep face with overhanging rocks

Horizontal dipping- vertical profiles with notches where weaker strata have been eroded, reflecting weathering and small scale mass movement

41
Q

why is holderness vulnerable to coastal risk

A

Landward dipping- they are relatively steep and stable, decreasing recession rates

Seaward dip- high angle produces low-angle profile with one rock layer facing the sea, low angle produces steep face with overhanging rocks

Horizontal dipping- vertical profiles with notches where weaker strata have been eroded, reflecting weathering and small scale mass movement

42
Q

what is hard engineering and what are the 5 types

A

hard engineering is the use of built structures (rocks or concrete). it aims to protect the coast by working against the forces of nature.

sea walls

rip-rap

rock breakwaters

revetments

groynes

43
Q

what is soft engineering and what are the 3 types

A

it makes use of natural systems such as beaches, sand dunes and salt marshes to help with coastal defence

beach nourishment

cliff stabilisation

dune stabilisation

44
Q

explain groynes and their pros and cons

A

they are wooden (or rock)structures that are positioned along a beach at right angles from the coast. they trap sediment that is moved by LSD and build up the beach. the beach absorbs wand increases its recreational value.

example: holderness coast

advantages:

  • the built-up beach increases tourist potential and protects the land behind it
  • groynes work with natural processes to build up the beach

disadvantages:

  • can starve areas downdrift of sediment
  • wood can rot and so may not be a good long-term solution, high levels of maintenance
  • groynes are unnatural and rock groynes can be very unattractive
45
Q

explain revetments and their pros and cons

A

they are concrete or wooden structures that are placed across a beach or coastline to take the full force of the wave energy, preventing further erosion of the coast. air spaces allow the backwash of the wave to drain away but the sedimemnt is trapped behind, reducing removal by destructive waves.

example: Overstrand, North Norfolk

advantages:

  • they are relatively inexpensive to build
  • effective for many years

drawbacks:

  • wood can rot so may not be a good long-term solution, high levels of maintenance
  • does not cope well with powerful storm waves so needs maintenance
  • not aesthetically pleasing
  • reduced access to the beach
46
Q

explain gabions and their pros and cons

A

they are cages of small rocks stacked to make a wall along the coast. the small boulders are contained within stel wire-mesh cages and can be joined together to form larger structures or walls.

example: Overstrand, Norfolk

advantages:

  • cheap, approx £100/metre
  • flexible as can be added in different places
  • absorbs wave energy

disadvantages:

  • not suitable for high energy coasts as cages can break and spill contents
  • unnatural, not aesthetically pleasing
47
Q

explain rip rap and its pros and cons

A

large boulders dumped in front of a cliff or sea wall to take the full force of the waves.

example: Minehead, Somerset

advantages:

  • their large surface areas means they absorb wave energy
  • the gaps left are able to let water filter through, again mitigating thieir impact on the coast
  • it’s often used for fishing from or for sunbathing by tourists

disadvantages:

  • can be under scoured by strong backwash, could be moved during weather events
  • some erosion will still occur on the backshore in storng storms
  • the rocks used are usually from somewhere else so they don’t fit in with the local geology and so can look out of place
  • decreased access to beach
48
Q

explain a recurved sea wall and its pros and cons

A

it is a concrete barrier that is recurved to reflect the waves and their energy. sea walls must have a continuous facing because any slight gap will be exploited by HA. they also need drian outlets so that if water does get over them it doesnt accumulate inland.

example: Minehead, Somerset

advantages:

  • they often have a promenade for people to walk along
  • effective prevention of erosion, long-lasting
  • gives people confidence on the future of the coastline

disadvantages:

  • most expensive defense (£5000/linear m)
  • they can be intrusive, unnatural
  • need deepfoundations to stop being undercut by waves
  • destruction of the natural cliff face and foreshore environment
  • they reflect the wave energy rather than absorbing it
49
Q

what are offshore breakwaters

A

they are granite rock boulders that are dropped and aligned in short lengths in shallow offshore waters parallel to the coast.

example: Sea Palling, Norfolk

advantages:

  • an effective permeable barrier
  • create sheltered areas for recreation and boats and a tombolo effect
  • they absorb and dissipate waves before they reach the foreshore

disadvantages:

  • may look unaesthetically pleasing during low tides
  • still may need further hard engineering
  • it’s a potential navigation hazard
  • expensive (between £1m and £2m)
50
Q

explain beach replenishment and its pros and cons

A

sand is dredged from the seabed and pumped onto the beach to replenish it from the effect of LSD or destructive waves. the beach can be ‘reprofiled’ to recreate its original shape.

example: Pevensey Bay, Sussex

advantages:

  • it looks natural and blends in with the existing beach
  • it increases tourist potential by creating a bigger beach
  • beach absorbs wave energy

disadvantages:

  • will need to be done every few years as LSD/destructive waves will continue to remove beach sediment, ongoing costs are high
  • can disrupt the marine ecosystem or the natural sediment cycling and deepening offshore so waves have more energy
51
Q

explain cliff regrading and its pros and cons

A

if the cliff lithology is unstable and vulnerable to slumping after heavy rainfall, engineers calculate a stable angle for the particular rock and the cliff is artificially cut back, changing its shape and reducing its angle to make it more stable.

example: Barton-On-Sea, Hampshire

advantages:

  • regrading can work on clay or loose rock where other methods won’t work
  • allows the build up of the beach

disadvantages:

  • very expensive (about £1 million)
  • unaesthetically pleasing, not natural, can be disruptive during construction
  • cliff line retreats into valuable land land when constructed
  • not full proof in extreme conditions, other measures needed
52
Q

explain cliff drainage and its pros and cons

A

if the cliff consists of a permeable layer above an impermeable layer it can become unstable after heavy rain due to pore pressure. so by inserting pipes to take out the water that has percolated through, saturation is prevented and it is less likely to slump

example: Barton-On-Sea, Hampshire

advantages:

  • drainage is cost-effective
  • In-cliff drainage reduces pore-water pressure and mass movement risk

disadvantages:

  • not aesthetically pleasing
  • can weaken the cliff when inserted, they dry outleading to them to collapse
  • cannot prevent weathering and subsequent rock fall
  • difficult to insert enough without disturbing the cliff stability
53
Q

explain dune restoration and its pros and cons

A

protecting this ecosystem can provide natural protection for the coastline. it is mainly damaged by vegetation removal which can lead to blowouts. strategies include:

  • geotextile netting can reduce erosion but still allow water in
  • vegetation planting (marram grass) to encourage sand deposition
  • fences and boards put up so tourists don’t stand on the dunes, they are given an area to walk on
  • afforestation with quick-growing conifers
    example: Studland, Dorset

advantages:

  • can be very cost effective in the long term
  • it provides important wildlife habitats

disadvantages:

  • only effective if public access controlled by fences and signs which reduces amenity value
  • strong storms can still cause damage
  • time consuming to plant marram grass
  • people may respond negatively to being kept off certain areas
54
Q

explain the management that was previously in place in Happisburgh

A
  • a wooden revemtnet stretched from happisburgh to the cart gap seawall but in 1990 a storm destroyed about 300 metres of revetment to the east of Happisburgh. this led to rapid erosion of the cliffs which had agricultural land on top. the remaining revetment was damaged by storms and by 1996, another length was lost.
  • in 2007, the council spent £200,000 on emergency works where an extra 1000 tonnes of rip rapwere placed on the beach
  • in 2008 Natural England said they plan to allow the sea to flood the area, covering six villages and creating a new bay
55
Q

what are the shoreline management plan drawbacks in Happisburgh

A
  • not appropriate to defend the area due to the impact on the shoreline, the coastal retreat would lead to the formation of a healand, significantly impacting LSD
  • although they will see a loss of residential properties and amenities, these are not sufficient to economically justify building new defences
  • the existing rock armour will continue to have a limited effect on the rate of retreat in the short trm (5-10 years) but will not prevent cliff erosion
56
Q

explain the management in sea palling

A

it is a small settlement on a low-lying area of the North Norfolk coast with a sea with a line of sand dunes and if the sea were to break through tge dunes, 6000 hectares of land could be flooded with salt water. 95% of coastal strip agriculture

groynes were built along the coast at Eccles and so prevented lots of sediment reaching sea palling which posed threats to their sea wall.

  • 150,000 tonnes of rip rap placed at the foot of the sea wall to prevent undercutting
  • 1.4 million cubic metres of sand added to beach
  • offshore bars built in 1995, length of240m and cost £5.9 million
  • in 1996, 5 more reefs built 160m long, cost £10.5 million

HOLD THE LINE

57
Q

explain coastal management in Holderness

A
  • Bridlington has a 4.7km long sea wall as well as groynes
  • sea wall, wooden groynes and rock armour at Hornsea
  • in Withernsea, there are groynes and a sea wall. some rock armour was placed in front of the wall after it was damaged in severe storms in 1992
  • eastern side of Spurn Head protected by groynes and rip rap. this also protects the Humber estuary behind Spurn Head
  • defences include two rock rocks which were built in Mappleton in 1991 and cost £2 million.
58
Q

explain the drawbacks of management in holderness

A
  • the groynes built at Hornsea starved Mappleton (further south) of sediment. By 1990s nearly 4m of cliff were being eroded at Mappleton each year
  • Hornsea’s defences have changed the natural pattrn of erosion and transferred the problem further south
  • Golden Sands holiday park have seen 100 chalets fall into the sea despite management strategies
  • sea defences at Mappleton are causing problems further along the coast as there is less sediment to travel down
  • some sea defences negatively impact tourism and reduce the amount of money coming in

losers

  • residents (some disagree on where defences are being placed, benefitting some and not others)
  • business owners
  • holiday parks
  • farmers
59
Q

what is sustainable coastal management?

A

it is about meeting the needs of today’s coastal areas as well as those of the future. you must take into consideration the three strands of social, econmic and environment.

it is increasingly based on adaptation strategies due to increasing recession rates, ICZM takes a holistic approach to a coastline and it required cooperation from stakeholders so conflcit is inevitable

60
Q

how should sustainable management be done?

A

by taking the area as a whole, taking into consideration each littoral cell and how they interlink. it requires makinguse of the cocnept of intergrated coastal zone management.

coastal communities face the dynamic nature of the coast’s everyday environment and the threats we face such as rising global sea levels and increased frequency of storms and increased erosion and flooding

it requires co-operation from people in order to ensure the well-being of people and the coastal environment. the management needs to be sustainable in the sense of ensuring that the coastal zones and all its inhabitants havea. reasonably secure future.

61
Q

what is ICZM?

A

it dates from the Rio Earth summit in 1992 and it has three main features:

  • that the entire coastal zone needs to be managed
  • the importance of the coastal zone to people’s livelihoods and well-being
  • the need to make the management of the coast sustainable

ICZM works well with the concept of sediment cells, each cell can be managed as a holisitic unit
- plan for the long term

  • involve all stakeholders and ensure that they have a say in any policy decisions
  • follow an ‘adaptive’ approach to unforseen changes
  • try to work with natural processes rather than against them
62
Q

what are the 4 possible actions for an SMP and what is the hardest

A

the hardest part is the decision making process to decide what actions to take. in the UK there are four different management options to follow:

1) no active intervention
- no investment will be made in coastal defences
- letting nature take its course and allowing the sea to erode and flood low-lying land
2) hold the line
- trying to eliminate any further retreat of the coast, involves a mixture of hard and soft engineering
- maintaining the current position of the coastline
3) advance the line (build new coastal defences on the seaward side of the existing coastlines. this usually involves land reclamation.)
- may involve drainage as well as other hard engineering techniques
- extending the coastline out to sea through encouraging the build up of a bigger beach

the choice is generally not straightforward due to a number of factors:

  • the economic value of the assets that might be protected
  • the technical feasibility of different engineering solutions
  • the environmental sensitivity
  • the cultural and ecological vaule of the land that might be protected
  • pressure from local communities, developers and environmental groups
    4) managed realignment/retreat
  • involves allowing the coastline to retreat but in a managed way
  • removal of existing hard engineering defences and using more natural and sustainable techniques including protection, management or restortion of coastal ecosystems such as salt marshes and sand dunes, e.g. porlock bay
63
Q

explain the successful sustainable management in blackwater estuary, essex

A
  • they have adopted a ‘finding space for water’ philosophy which involves managed retreat
  • coastal squeeze due to future sea level rise and storm surges make maintaining flood embankments unsustainable
  • 5 breaches in the embankemnts 2002
  • the Essex Wildlife Trust purchased the Abbot’s Hall estate in Essex on Blackwater estuary and convered more than 84 hectares of farmland into salt marsh and greenland by breaching old embankments in 4 places in 2002, farmers were compensated
  • it is sustainable as the 49 ha of additional mudflats and saltmarshes absorb incoming higher seas and storm surges without any local damage
  • wading birds and other wildlife returns for feeding and nesting
  • CBA showed that sea wall was not cost-effective, soil quality poor

players

  • landowners
  • the RSPB (royal society for the protection of birds)
  • the essex wildlife trust
  • fisherman
64
Q

explain the conflicts and winners and losers for blackwater estuary

A

conflicts

  • the west mersea fisherman were concerned that sediments could choke and kill oysters and water sea level changes could remove oyster habitats
  • the RSPB were concerned about the increased erosion and flooding of their site opposite the farm which could change bird habitats

winners/losers

  • however, all conflicts were resolved, research showed that the sediment didnt affect the oysters and bird habitats actually improved as a result
  • landowners and farmers have discussed giving up land to sea
  • a CBA concluded that since the soil quality and land value were low, it was not worth maintaining the embankments
  • it was the largest coastal realignment project in europe, costing £645,000, CHEAP
  • reduces the volume of water travelling up the essex estuaries and creeks which could flood settlements
65
Q

explain the successful sustainable management on the Namibian coast, SE Africa

A

1) Skeleton coast in the Namib desert with isolated rural settlements and many wildlife areas

LOW COST MANAGEMENT OPTIONS

  • prevent future development of coasal buffer zone experiencing recession
  • conserve wetland habitats
  • stabilise and protect sand dunes
  • monitor SLR for future planning
  • reduce poverty so people are able to prepare themselves (build better homes)
    2) Small tourist settlements like Henties Bay

MODERATE COST OPTIONS

  • beach nourishment
  • protecting Kelp beds and restoring sand dunes
  • rehabilitation of wetland ecosystems
  • early warning systems for residents of high tides
    3) Larger settelemt important for industryand trade like Walvis bay

EXPENSIVE OPTIONS

  • sea walls
  • relocation of vulnerable communities
  • raising of infrastrcture (ports and roads)
  • building barrages and barriers
66
Q

explain the conflict over coastal management decisions and help from NGOs in the Maldives

A
  • in the maldives there is conflict over adaption to SLR. CUrrently the gov have prioritised protecting the capital city of Malé and its tourismindustrybut is not prioritising smaller communities that rely on traditional industries (farming,fishing)
  • mangroves for the future is an organisation that promotes sustainable development and is helping the maldives to become more sustainably managed for the future by:
    1) educating communities on the importance of maintaining coastal mangrove swamps as a natural defence against coastal erosion and flooding
  • the Global Environment Facility (GEF) has provided small grants to islanders to help them develop sustainable and organic farming as an alternative food and income source to coral reef fish (threatened by both overfishing and global warming)
  • the Japanese gov have funded mangrove nurseries on the maldives so that damaged mangrove areas can be replanted
67
Q

what are the costs and benefits of erosion of happisburgh

A

costs

  • affected residents could get up to £2k each in relocation expenses plus the cost of the council to find plots of land to build new homes
  • grade 1 listed St Mary’s church and Grade 2 listed manor house lost
  • social costs as the village is slowly degraded, including health effects and loss of jobs

benefits

  • by 2105, 20-35 properties would’ve been saved from erosion with a combined value of £4-7 million
  • aorund 45 hectares of farmland would be saved, with a value of £945,000
  • the manor caravan park would be saved, which employs local people
68
Q

explain the shoreline management plan in Happisburgh

A
  • by 2105, the shoreline may recede by 200m
  • they have repeatedly failed to quanitfy for gov grants for coastal defences. managed retreat has been operated which has caused conflict among locals and especially residents of beach road on the coastline
  • the gov started proviidng grant aid of £5000 to assist with demolition costs and £1000 for relocation costs
  • £1.4million was set aside for ‘purchase and lease-back’ of 11 houses on beach road to create a buffer zone between the eroding cliff and the main village
  • they have spent lots of money relocating important sites like the caravan park (450k) and taking out the defences
  • lobbying by the CCAG and others have led to a change in the SMPZ policy for them to follow ‘managed realignment’ which allows for some coastal defences if funding can be found
69
Q

what are the pros and cons and winners and losers in Happisburgh

A

positives:

  • the gov started providing grant aid of £5000 to assist with demolition costs and £1000 for relocation costs
  • they obtained a gov allocation of £3 million partly because of its emphaiss on ICZM and stakeholder engagement
  • all but caravan park were able to relocate due to difficulties of finding an alternative site
  • the community remains the same size and profits from the sale of the new houses will be used in the future to buy properties of those under threat from CE

negatives

  • by 2105, the shoreline may recede by 200m with a loss of a further 50 homes, caravan sites and property losses totalling £6m
  • in 2003, the lifeboat and beach access ramp were lost, prompting concerns for their tourism
  • house values are very low and people cannot afford to move elsewhere
  • there is no national system of compensation but campaigning led to pathfinder project where people along beach road were offered half the non blighted value of thri home to help them relocate, houses now demolished to create buffer, all but one took it
  • there could be a promontary effect where erosion comes either sides and comes round the back
  • the existing rip rap will have limited effect on the rate of recession in the short term

winners:

  • those who have successfully relocated
  • losers:
  • those who are closest to cliff face
  • businesses relying on tourism industry
  • local council, large costs of relocating
70
Q

explain the shoreline management plan in chittagong, Bangladesh

A

a coastal climate resilient infrastructure project (2012) supported by the Asian Development Bank (ADB) aims to ‘climate-proof’ the area

this involves:

  • improving road connection for farmers and markets whilst raising embankments to 60cm above normal flood levels and making them resilient to CE
  • creating new market areas with sheds raised on platforms above the expected 2050 sea level
  • constructing, improving or extending 25 tropical cyclone shelters, taking account of SLR and higher wind speeds
  • training in climate resilience and adaptation measures
  • it was loaned US$60 million by the IFAD and project was rated as satisfactory
71
Q

what are the pros and cons and winners and losers in Bangladesh

A

positives:

  • helped alleviate poverty by 10% by generating income opportunities
  • reduced disaster risk, road flooding 5 days a year rather than 20
  • environmental enhancement through growing trees

negatives:

  • disturbance of people and habitats especially during construction
  • permanent removal of natural vegetation
  • relocation of 200 people by road realignment
  • slow progress on road embankments

winners:

farmers, local community seeking jobs

losers:

environmentalists to some extent, community who are relocated, market sellers

72
Q

how can conflicts between players develop over management decisions? give case studies

A

Essex

  • the west mersea fisherman were concerned that sediments could choke and kill oysters and water sea level changes could remove oyster habitats
  • the RSPB were concerned about the increased erosion and flooding of their site opposite the farm which could change bird habitats

Chittagong, Bangladesh

  • environmentalists concerned about the permanent removal of natural vegetation
  • local communities concerned about the fact that 200 people would have to be relocated, breaking up communities
  • there is conflict over adaption to SLR. Currently the government have prioritised protecting capital city of Malé and its tourism industry but it is not prioritising smaller communities that rely on traditional industries (farming, fishing)

Here they have chosen no active intervention approach as they have used a CBA in order to justify that the cost of protecting is much higher than its worth however this will cause conflicts between local residents and the authorities as they will lose their home and community. They would argue that their homes are worth a lot more.

73
Q

why are there different ways to manage a coastline?

A
  • range of stakeholders so needs a holistic strategy that takes all of them into account (ICZM), e.g. Namibia
  • land value, e.g. london (thames barrier vs blackwater estuary)
  • feasibility with rapidly retreating coastlones, it is not viable to protect them, e.g. maldives
  • environmental sustainability: blackwater estuary, whether it is in a protected area
  • impact on downdrift areas
74
Q

explain the formation of a sand dune

A

1) there is a plentiful supply of sand, a large area for sand to dry out and onshore winds to that blow sand landwards. sand accumulates to form an embryo dune.
2) pioneer species like marram grass colonise the dune, stabilising it and helps to trap more sand
3) a fore dune develops when enough sand has bee ntrapped an the dune starts to become more stable
4) now an established dune will become more vegetated by marram grass which provides organic matter to the sand and soil to devleop, improving the conditions
5) with soil now developed on the dune, it becomems a grey dune. this is permanent and conditions ar suited to a greater variety of species including heather and gorse
6) between dunes, dune slack develops. wind erosion can deepen them and they may be waterlogged in high tide conditions.
7) furthest inalnd is the climax community. there the soil is fully developed and the dune is fully stabilised and biodiversity is at its highest, trees can grow (birch)

75
Q

what are blowouts?

A

they are created when storm events erode sections of the yellow dune through wind or wave erosion. however, over time, deposition of sediment and recolonisation of vegeation will rebuild the dune’s damaged areas.

76
Q

explain the pioneer specie plant of marram grass on a sand dune

A
  • xerophyte
  • has extremely long roots which binds the dunetogether, up to 3m long
  • it has rhizomes which helps it keep anchored into the ground
  • holds the beach together, allows the dune to develop as it builds up dense vegetation
  • leaves roll inwards to kepp in moisture
  • when it dies out, it adds lots of organic matter in the soil, leading to further plant growth

Edexcel A level- Geo (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions