Coastal Systems And Landscapes Flashcards
1
Q
Define what a system is
A
A set of interrelated components working together forming a process
2
Q
Define Dynamic Equilibrium
A
Rate of input + output in a system are equal to
3
Q
Define what positive feedback loop
A
When a process or change in conditions causes a change to the landscape causing it to be more likely to happen again
4
Q
Define what a negative feedback loop is
A
When a process or change in conditions causes a change in the landscape making change less likely to happen again
5
Q
How are waves created
A
Created by the transfer of energy from the wind blowing over the surface of the sea.
6
Q
Why do waves break
A
As waves enter shallower waters waves circular orbits begin to become influenced by friction from the seabed, causing it to become elliptical (oval). Over time this friction slows the wave so much that it causes the wave to break.
7
Q
What waves occur on steeper beaches
A
Destructive Waves
8
Q
What waves occur on shallower beaches
A
Constructive waves
9
Q
Describe the swash and backwash characteristics of a constructive wave
A
Strong Swash, Weak Backwash
10
Q
Describe the swash and backwash characteristics of Destructive waves
A
Strong Backwash, Weak Swash
11
Q
Explain how headland wave refraction demonstrates negative feedback
A
- Along a discordant coastline, the soft rock is eroded faster
- This forms bays (soft rock) and headlands (hard rock)
- Waves then concentrate their energy onto the headland reducing rate of erosion on the soft rock
- This causes them to be eroded at the same rate rather than increased on bays, therefore considered negative feedback
12
Q
Describe what happens at a spring tide
A
When the sun, moon and earth align in a straight line, tidal raising forces (gravity) are at their strongest, producing the highest monthly tidal range
13
Q
Describe what happens at Neap tides
A
When the moon and sun form 2 perpendicular lines to earth the tidal raising forces are at their lowest so gives the lowest monthly tidal range.
14
Q
Which tidal range increases concentration of erosional processes
A
Low tidal range
15
Q
Which tidal range increases exposure to subareal weathering
A
Low tidal range
16
Q
Which tidal range reduces concentration of erosion
A
High tidal range
17
Q
Which tidal range decreases exposure to subareal weathering
A
High tidal range
18
Q
What effect do tides have on a storm surge
A
At high tide the storm surge is amplified, at low tides the storm surge is weakened
19
Q
What beach has the highest tidal range in the world
A
The Bay of Fundy
20
Q
How large is the roll that riptides play in the formation of coastlines
A
Very little as riptides are localised
21
Q
Where do riptides form
A
Between sandbars
22
Q
Name at least 3 forms of mechanical weathering
A
Any From:
- Freeze Thaw
- Wetting + Drying
- Pressure Release
- Salt Crystallisation
- Exfoliation
23
Q
Describe + Explain the process of freeze thaw weathering
A
- Occurs when water enters a crack in a rock due to precipitation
- A following period of cooler conditions freezes this water
- As ice is less dense than water it expands, exerting pressure on the rock causing cracks to widen or break open, causing scree to fall to the base of the cliff.
24
Q
Describe and explain the process of Wetting + Drying weathering
A
- Rock in the intertidal zone (and just above due to sea spray) may alternate between wet and dry.
- Shale and porous rocks expand when they are wet and contract when they are dry.
- This process repeats causing fissures to develop and the rock can fragment
25
Describe and explain the process of pressure release weathering
- Once overlaying sediment and material breaks off, sediment undergoes a pressure release.
- This causes it to develop weaknesses through mechanisms in the rock cause it to develop weaknesses, cracks or joints as it is allowed to expands.
26
Describe and explain the process of salt crystallisation weathering
- When salt water evaporates it drys up
- Salt crystals are left behind and grow over time, exerting stresses on the rocks over time (just like the ice during freeze thaw weathering)
- Salt can also corrode rock, particularly those containing iron
27
Describe and explain the process of exfoliation weathering
- Dry rock in the sun is likely to absorb considerable amounts of heat
- these warm rocks are then cooled rapidly when in contact with the sea causing repeated expanding and contracting of the rock, causing it to fracture
- some describe this erosion to occur like an onion skin
28
Describe and explain the process of biological weathering
Any One From:
-Thin plant roots grow and cause cracks in the cliff face, widening any cracks and causing them to break
- Water running through decaying vegetation can become slightly acidic, increasing chemical weathering
- Animals digging burrows into cliff faces can increase fractures
29
Name at least 3 forms of Chemical weathering
Any 3 from:
- Oxidation
- Hydrolysis
- Hydration
- Carbonation
- Solution
- Acid Rain
30
Describe the process of Oxidation weathering
The reaction of rock to oxygen e.g. rust can cause weakness in rock, increasing risk of fractures and breakages
31
Describe the process of Hydrolysis weathering
Where mildly acidic water reacts or combines with minerals in rock, weakening the rock
32
Describe the process of Hydration weathering
Water is added to minerals in the rock making it more susceptible to further weathering by causing the rock to expand causing it to disintegrate and cracks to form
33
Describe the process of carbonation weathering
Carbon dioxide reacts with water creating weak carbonic acid. This reacts with calcium carbonate to create calcium bicarbonate. This can dissolve easily in water.
34
Describe the process of solution weathering
Slightly acidic water/ water dissolving the rock it runs over
35
Describe the process of acid rain weathering
Nitrous oxides and sulphur dioxide can lead to acid rain forming which can be effective at dissolving certain types of rock
36
Why are sediment cells considered closed systems
Geographers consider sediment cells as closed systems as nothing is lost or gained. However some fine sediment can move between sediment cells by finding their way past the headland.
37
Define what a sediment cell is
A sediment cell is a distinct area of coastline, separated from other areas by well defined boundaries such as headlands and stretches of deep water.
38
Name an issue with the concept of sediment budgets
Any 1 from:
- The cells are based upon the movement of coarser particles rather than the movement of suspended fine material.
- Fine sediments can find their way into other cells meaning this closed cell concept is not always true
39
Describe the Mass Movement process of soil creep
Soil creep is a heave process whereby individual particles expand and contract due to the physical environment (particularly moisture) causing it to move downhill slowly. This is very common in clay.
40
Describe the Mass movement process of Slumping
A flow type of mass movement in which a major section of regolith, soil or weakened bedrock comes down a steep slope as a backward-rotating slump block. Common along coastlines on verges of main roads. Usually in weak rock, clay or soil.
41
Describe the mass movement process of rockfall
The fastest form of mass movement, the free fall or downslope rolling of rock pieces, loosened by weathering. These boulders shatter at the bottom and form a scree slope.
42
Describe the mass movement process of a Flow
Typically occurring in more damp/wet environments when there is a plentiful amount of water and a higher clay content. Over saturated sediment flows from a source area down the side of a slope.
43
Describe the mass movement process or landslides
When a significant amount of the cliff becomes detached and slides down. Often a block of rock moving along a plane or a slump but can be rotational or flow.
44
Give an example of a mass movement in the uk
Beachy Head - Landslide in Jan 1999 destroying the devils chimney
45
Describe wave quarrying
A type of erosion where a breaking wave traps air as it hits the cliff face. The force of the water compresses this air into any gap in the rock face, creating enormous pressure within the fissure/joint. As the water pulls back there is an explosive effect of the air under pressure being released.
46
Describe Abrasion/Corrosion
A type of erosion where the material that the sea picks up wears away rock faces. Sand, shingle and boulders hurled against a cliff line will do enormous damage. This is also apparent on intertidal rock platforms where sediment is drawn back and fourth grinding away at the platform.
47
Describe Hydraulic Action
A type of erosion that refers to the impact on rocks of the sheer force of the water itself (without debris). This can exert enormous pressure upon a rock surface, thus weakening it. Such activity is sometimes referred to as wave pounding.
48
Describe Attrition
A type of erosion where the smaller rocks in the sea which carry out abrasion are slowly worn down into smaller and more rounded pieces.
49
List 3 factors that effect rate of erosion
Any 3 From:
-Wave Steepness + Breaking Point
- Fetch
- Sea Depth
- Beach Presence
- Human Activity
- Lithology (Rock Characteristics)
- Dip (Angle at which rock lies)
- structure (Discordant/Concordant)
50
Describe the transportation method of traction
Large stones + Boulders rolled along the sea bed
51
Describe the transportation process of Saltation
Small stones being bounced along the sea bed
52
Describe the transportation process of Suspension
Very fine, small particles of sand and silt carried in ocean currents waves + tides.
53
Describe the transportation process of Solution
Chemicals dissolved in water and carried about in ocean currents, waves and tides
54
Describe and explain the process of longshore drift
- Swash in the direction of the prevailing wind deposits sediment along the beach at that angle of incidence.
- They are then backwashed perpendicular to the coastline back to sea.
-This process is repeated over time causing sediment to be moved done the beach in the direction of the prevailing wind.
55
What is a Tombolo
A beach that connects the mainland to an offshore island and is formed due to wave refraction off of the coastal island therefore reducing wave velocity and energy. This results in sediment being deposited. Sometimes these landforms are covered at high tide if the are low.
56
What is an offshore bar
An offshore region where sand is deposited, as the waves don’t have enough energy to carry the sediment to shore. They can be formed when the wave breaks early, instantly depositing its sediment as a loose sediment offshore bar.
57
What is a barrier beach/bar
A barrier beach occurs when a beach or spit extends across a bay to join two headlands. This traps water behind it, leading to the formation of a brackish lagoon which is separated from the sea. Some barrier beaches can also be formed due to rising sea levels.
58
Name the 4 phases of dune growth
- Embryo Dune
- Foredune
- Grey Dune
- Mature Dune
59
Describe the process of the formation of a Wave Cut Platforms
- Erosion occurs on the base of the cliff forming a wave cut notch
- Weathering weakens the top of the cliff
- The weight of the unsupported cliff causes it to collapse
- Over time this process repeats and the cliff retreats inland
- Backwash transports material from broken cliffs back out to sea forming a wave cut platform at the base of the cliff
60
Why is a wave cut platform, negative feedback
As the platform is formed by erosion to the cliff and the platform blocks erosion to the cliff
61
What coastlines do bays and headlands occur on?
Discordant
62
Describe and explain the formation of bays and headlands
- On a discordant coastline, soft rock erodes faster than hard rock causing it to retreat behind the hard rock.
- Due to wave refraction, hard rock headlands receive more erosion than bays, forming a negative feedback loop causing the coast to retreat uniformly
- this retains the extruding hard rock headlands and soft rock bays
63
Define dip
The angle at which the strata (layers of rock) lie on a cliff face
64
What is a bedding plane
A horizontal natural breaks in the strata caused by gaps in time during periods of rock formation
65
What is a joint
Vertical fractures caused by weathering or the earths movements
66
Describe the process of cove formation
- Along a concordant coastline, harder rocks and be jointed and can become easily punctured through processes such as wave quarrying, hydraulic action and abrasion
- This eventually reaches the soft rock laying behind
- The softer rock is rapidly eroded so rapidly into a cove
- The hard rock remains for far longer, forming 2 extruding headlands, protecting the bay from erosion thanks to wave refraction.
67
What is a storm beach
A ridge composed of the beaches largest sediment i.e. boulders thrown by the largest waves on a spring tide
68
What is a Beach Berm
Ridges forming below storm beaches that are formed as constructive waves deposit sediment.
69
What is a beach cusp
Semi-Circular shaped depressions formed when waves break directly onto the beach when Swash and backwash are strong
70
What is a ripple (beach feature)
Developed in the sand by wave/tidal action altering the sea bed where friction has influence
71
What is a runnel (beach feature)
Occurring before a ridge, runnels are channels that run parallel to the shoreline and are caused by lack of water percolation.
72
What are the main characteristics of a Swash aligned beach
- Usually perpendicular to the direction of longshore drift, therefore experience minimal longshore drift.
- Can be found on an irregular coastline where waves hit the beach head on.
73
What are the main characteristics of drift aligned beaches
- Usually parallel to the direction of longshore drift, therefore lots of transport occurring
- Waves are angled to the beach
74
Explain how a wave cut platform forms
- Erosion occurs at the base of the cliff (hydraulic action, wave quarrying and abrasion) forming a wave cut notch.
- Weathering weakens the top of the cliff
- The weight of the unsupported cliff causes it to collapse and over time for the cliff to retreat inwards.
- Backwash transports material from broken cliffs back out to sea forming a wave cut platform
75
Describe how a spit forms
- These landforms occur in areas where the coastline changes direction in an aggressive manner and where sediment is actively being transported down the beach via longshore drift.
- Due to longshore drift the sediment extrudes from the coast in the general direction of longshore drift, extending out and curving backwards due to wave energy.
- This forms the spit, which shelters the area behind to form a salt marsh
76
Explain the difference between a summer and winter beach
Winter Beach:
- Erosion of berm
- Erosion of dunes
- Bar Formation
Summer Beach:
- Formation of Berms
- Regeneration of Dunes
- No bar
77
What is the difference between a simple and compound spit
Simple:
- Either straight or recurved
- Do not have minor spits of recurved ridges along the landward edge
Compound:
- May have similar features to simple spits
- Have a number of recurved ridges or minor spits along their landward side.
78
List 3 submergant landforms
Any 3 from:
- Rias
- Dalmatian coastlines
- Fjords
79
Explain the formation of a Ria
- when a river valley is submerged by the rising sea level, it will flood, sharing the same long and cross profile of the previous river with higher sea levels
- They tend to be rather wide
80
Explain the formation of a Dalmatian coastline
- Forming similarly to rias but along a concordant coastline. As the sea level rises it submerges the lowlands of valleys where the old coast used to be.
- this leaves islands spotted along the coastlines offshore area, sheltering the new coastline from errosion.
81
Explain the formation of a Fjord
- Formed when rising sea levels submerge a glacial valley or glacial trough.
- These are formed as glaciers cut through existing valleys, aggressively eroding the surrounding sediment through aggressive abrasion.
- This forms straight and narrow U-Shape valley with very steep sides.
- They also have a shallower part near the mouth near to where all of the sediment carried by the glacier was deposited.
82
List 2 Emergent coastline landforms
Any 2 from:
- Raises beaches
- Relict Cliffs
83
Explain the formation of raised beaches
- These are deposits of sand and pebbles on gently sloping platforms, backed by an old (relict) cliff line. These may contain fossil caves, wave cut platforms and even arches.
- these are formed as the sea level lowers the beach is left without erosion leaving it on a ledge above the new beach
84
Explain the formation of relict cliffs
The old cliffs/cliff line of a coast that has now become exposed as the land has risen from the sea as ice sheets clear from an area. These cliffs are likely to contain fossils and old land features such as wave cut platforms, caves, arches and stacks
85
How far has the Isle of Jura in Scotland emerged by
40m
86
Define Eustatic Change
A global change in sea level resulting from an actual fall or rise in sea level itself
87
Define Isostatic change
Local changes in sea level resulting from the land rising or falling relative to the sea
88
Define tectonic change
Land being shifted up, down or sideways due to tectonic plate movement
89
What is isostatic readjustment
- The process of land that was previously covered by ice sheets during the glacial period that is now thawed in the interglacial period causing the land to rebound upwards as there is less weight pushing the land mass down.
- This can also cause other areas of land mass to fall rapidly as the land mass rotated, as the areas of ice coverage rise, areas without prior ice coverage fall.
90
What areas in the UK suffer the most extreme isostatic readjustment
Western Scotland - +2m/year
South East England - -2m/year
91
How much have sea levels risen since the end of the the last ice age period
120m
92
What are the 2 reasons that sea levels are rising
- Ice thawing into the sea, increasing its volume.
- Thermal expansion as temperature of ocean rise reduces its density, increasing its volume.
93
If global sea levels rises 2m how many properties in the uk will be effected
Just under 500,000
94
What case study is used for sustainable coastal management
The Holderness coast
95
What is the SMP in Bridlington and why
Hold the line - a cost-benefit analysis has been done and it has been proven economically and socially important to keep this town from being submerged.
96
What is the SMP for Easington and why
Hold the line until 2026 - As there is a gas terminal supplying 20% of the UK’s natural gas, it is extremely important to protect it for the time being. However the gas is likely to run out and a new terminal will have to be built so holding the line is not a permanent plan
97
What is the SMP at spern head and why
Managed Realignment to no active intervention - The spit is home to a lifeboat station that already receives limited access and it is only a matter of time before this spit is submerged and completely flooded. The coastline management have decided it is not worth the cost to protect this coastline.
98
What is the rate of erosion on the holderness coast
3.3m/year on average but 10m/year in some areas
99
What is the rock types of the holderness coastline
An unconsolidated boulder clay laying (high erosion) in front of chalk
100
Which towns along the holderness coastline are currently considered “hold the line”
Bridlington, Hornsea, Mappleton, Withernsea, Kilnsea, Easington
101
Since Roman times, approximately how many villages have been lost along the Holderness Coastline
Approximately 20-35 villages
102
What percentage of the UK’s natural gas is supplied at Easington’s Gas terminal
20%
103
Define what is meant by a rollback scheme
The expenses incurred as a result of an individual’s decision to replace a threatened coastal property with a new home inland.
104
Give an example of a rollback scheme on the holderness coastline
At kilnsea there is a caravan park where the government paid for every 4 caravans destroyed by the sea, 5 are paid for and placed further back.
105
Describe AND explain the stages in formation on sand dunes
- Continually moving around sand requires an obstruction to break the force of the wind so that sand begins to accumulate (This could include seaweed, dead seabirds or driftwood)
- This leads to the formation of embryo dunes which are unstable but may eventually be colonised by plants (e.g. marram grass) to form foredunes.
- These grasses can trap more sand, seeing them grow in height to form yellow dunes at 5-10 meters in height. These dunes host a larger variety of plants.
- As further sand gathers, grey dunes covered in dense vegetation such as brambles, reaching over 10 meters in height.
- Finally as you travel further inland, you find mature dunes. These dunes develop a soil which can support shrubs and trees. Dune slacks (an area of water between mature dunes) can also form here. This is because depressions in sand altitudes can sometimes fall below the water table.
106
Name the 6 Phases of sand dune formation in order
- Embryo Dune
- Fore Dune
- Yellow Dune
- Grey Dune
- Dune Stack
- Mature Dune
107
108
What are salt marshes?
Coastal areas that form behind mud flats, often in sheltered locations like creeks and estuaries
109
Where do salt marshes typically form?
In well-sheltered areas such as creeks, inlets, and estuaries
110
What type of vegetation can grow in salt marshes?
Salt resistant forms of vegetation
111
What happens to salt marshes at low and high tide?
Exposed at low tide and partially flooded at high tide
112
What are the characteristics of salt marsh landscapes?
Very flat with numerous muddy channels and creeks
113
What is a significant danger in salt marshes?
The tide coming in can make them dangerous places
114
What do mudflats at the edges of estuaries frequently experience?
Net deposition of fine sediment
115
What can evolve from mudflats over time?
Saltmarsh ecosystems with salt-tolerant plants
116
What role do submerged and semi-submerged plants play in salt marshes?
They trap more sediment and reduce water velocity, leading to increased deposition
117
What is the positive feedback mechanism in salt marshes?
Submerged plants trap sediment, leading to more deposition
118
How do plant life cycles contribute to salt marsh elevation?
They deposit decaying material on which new plants grow
119
What occurs as the height of the salt marsh increases?
Saline conditions reduce and inundation is less frequent
120
What is a hydrosere?
Plant succession occurring in water
121
What is a halosere?
A hydrosere occurring in salt water
122
Fill in the blank: Salt marshes form in areas where fine sediments can be deposited behind _______.
[spits and artificial sea defences]
123
True or false: Mudflats occur in areas of net deposition
True
124
Explain how plants use decaying matter to gradually raise salt marsh height
Plant life cycles deposit decaying materials on top of new plants. These grow and eventually raise the height of the salt marsh.
125
What are the 3 types of relative sea level change
- Eustatic Change
- Isostatic Change
- Tectonic Change
126
What is a Eustatic Change in sea level?
A global change in sea level due to a change in volume of water in the ocean.
127
What is Isostatic Change of sea level
Localised changes in land levels relative to the sea level primarily caused by melting of glacial sea ice leading to post glacial rebound. This process is because continental crust rebounds upwards now that the weight of large ice sheets no longer remains. This leads to localised changes in sea level.
128
What is Tectonic change in terms of sea level
- Land being shifted up or down due to tectonic movement can lead to a change in sea level compared to land level of a continental plate.
129
How does Isostatic change effect the UK
Melting of ice in the northern half of the UK has meant that North Western areas in the highlands to rise as fast as 2 meters per year. This tilt of the UK’s land mass has also caused areas of east anglia to fall at 2m per year due to Isostatic change)
130
What are contributing factors to Eustatic Changes
- Melting of Antarctic Ice Sheets overlying continental mass
- Thermal Expansion as higher temperatures reduce density of water
131
What marks the onset of a new glacial period?
An increasing amount of precipitation falls as snow
132
What does snow and ice act as in the hydrological cycle?
A store for water
133
What happens to sea levels globally during the onset of a glacial period?
They fall
134
What is the term for the movement caused by the weight of ice causing land surface to sink?
Isostatic movement
135
How does isostatic movement affect eustatic sea level fall?
It moderates the eustatic sea level fall in some areas
136
What occurs when the climate begins to get warmer after a glacial period?
The ice mass on the land begins to melt
137
What does the melting ice lead to in terms of sea level?
Sea level rises worldwide (eustatic)
138
What are some submergent features produced by rising sea levels?
Flooded river valleys (rias) and flooded glacial valleys (fjords)
139
What happens to land areas as ice is removed?
They begin to move back up to their previous levels (isostatic readjustment)
140
What results if isostatic movement is faster than eustatic movement?
Emergent features such as raised beaches are produced
141
How does isostatic recovery vary?
It affects different places in different ways
142
Which part of the British Isles is currently sinking?
The southeast
143
Which part of the British Isles is currently rising?
The northwest
144
The fact that the ice sheets were thicker in which region explains the differential movement in the British Isles?
Northern Scotland
145
What is the time scale of all factors for change in sea level
- Tectonic Uplift or Downthrust - Short Term
- Isostatic Change - Medium Term
- Continental Seperation - Long Term
- Thermal Expansion - Short Term (Due to human activity)
- Global Warming and Ice Melting - Medium Term
146
List all submergant land features
- Rias
- Fjords
- Dalmatian Coastlines
147
List all Emergent features
- Raised Beaches
- Relict Cliffs
- Marine Platforms
148
Describe what a Ria is
A river valley at the coast that has been inundated by the sea as relative sea level has risen, resulting in a ‘drowned valley’.
149
Describe what a Fjord is
A glaciated valley at the coast that has been inundated by the sea. Has steeper rising walls, a straighter long profile and is deeper than a ria due to glaciers over-deepening the valley.
150
Describe what a Dalmatian coastline is
A series of longitudinal river valleys next to the coast that have been inundated leaving parallel ranges of watershed ridges as islands.
151
Describe what a raised beach is
A beach that was at sea level but is now well above it, forming a beach with little to no contact with the ocean.
152
Describe what an elevated marine platform is
A wave cut platform that now exists as an extensive flat area in front of a relict cliff above active wave action.
153
Describe what a Raised sea cave/ raised sea arch is
Features of past coastal erosion that are now well above the active coastal zone.
154
155
What are Emergent Coastal Landforms?
Landforms where the land has been raised in relation to the coastline.
156
What is a raised beach?
A common feature before cliffs which are also raised, indicating historical marine erosion.
157
What are relic cliffs?
Cliffs that have been raised in relation to the coastline.
158
What evidence indicates historical marine erosion?
Wave-cut notches and similar features.
159
What are Submergent Coastal Landforms?
Landforms that occur when the sea level rises or the coastline sinks in relation to the sea.
160
What are Rias?
Landforms formed when rising sea levels flood narrow winding inlets and river valleys.
161
How do Rias differ in water depth?
They are deeper at the mouth of the inlet, with water depth decreasing further inland.
162
What are Fjords?
Natural inlets and harbours formed when rising sea levels flood deep glacial valleys.
163
How do Fjords differ in water depth?
They are deeper in the middle than at the mouth, with shallower sections indicating where the glacier left the valley.
164
What are Dalmatian Coasts?
Coasts formed when valleys running parallel to the coast become flooded due to sea level change.
165
What is the characteristic feature of Dalmatian Coasts?
A series of narrow, long, and rugged islands.
166
What is the case study for the Shoreline Management Plan
The Holderness Coast
167
Define Hard Engineering in terms of coastal management
Making physical change to the coastal landscape using resistant materials (e.g. Concrete, Boulders, Wood, metal) that reduce coastal erosion
168
Define Soft Engineering in terms of Coastal Management
Using natural systems for coastline defence such as beach dunes or salt marshes which absorb and adjust to wave energy, reducing erosion.
169
List 3 Hard Engineering Strategies
Groynes
Sea Walls
Gabions
Revetements
Rock Armour
Cliff Fixing
Offshore Breakwater
Barrage
170
List 3 Soft engineering techniques
Beach Nourishment
Drainage and Regrading
Dune Stabilisation
Marsh Creation
171
Describe what Groynes Are
Timber/Rock structures built at right angles to the coastline, designed to trap sediment being moved along the coastline by long shore drift building up the beach.
172
What are advantages and disadvantages of Beach Groynes
Advantages
- Work with natural processes to build up the beach, this larger beach could increase tourist potential and protect the land behind it.
- Fairly cost effective.
Disadvantages
- Starves beaches further along the coastline of fresh sediment (because the interrupt long shore drift) often leading to larger rates of erosion elsewhere.
- Can be considered Unsafe and aesthetically displeasing.
173
Describe what a sea wall is
Stone or concrete walls at the foot of a cliff or at the top of a beach, usually built with a curved surface to reflect waves back into the sea.
174
What are the advantages and disadvantages of sea walls
Advantages
- Effective at preventing errosion
- Often have a promenade that people can walk on, could potentially boost tourism
Disadvantages
- They reflect wave energy instead of absorbing it
- Can be intrusive to the natural land
- Can be expensive to maintain
175
Describe what gabions are
Open wire cages filled with rocks placed at the foot of soft cliffs to absorb wave force
176
What are the advantages and disadvantages of Gabions
Advantages
- Cheap
- Can be built quickly
Disadvantages
- Can house rodents in the gaps between rocks
- Can deteriorate quickly and pollute the environment
177
Describe what a revetments are
Sloping wooden, concrete or rock structures placed at the foot of a cliff or the top of a beach, designed to break up the waves energy
178
What are the advantages and disadvantages of revetments
Advantages
-They are relatively inexpensive
Disadvantages
- Very unnatural and intrusive on the natural ecosystem
- May require high levels of maintenance
179
Describe what Rock Armour is
Large rocks placed at the foot of the cliff or at the top of a beach. It forms a permeable barrier to the sea, breaking up the waves but allowing some to break through.
180
What are the advantages and disadvantages of Rock Armour
Advantages
- Relatively cheap and easy to construct and maintain.
- Can be used for recreation and fishing
Disadvantages
- Can be environmentally intrusive, the rocks are usually not sourced locally, can look out of place with local geology
- Can be dangerous with people climbing on them
181
Describe what cliff fixings are
Iron bars driven into the cliff face both to stabilise it and absorb some wave power
182
What are the advantages and disadvantages of cliff fixings
Advantages
- After a few years fixings can look natural
- Effective at keeping the cliff from eroding and eventually collapsing
Disadvantages
- Negatively impact natural beach profiles, having a negative impact on coastal habitat and wildlife
183
Describe what an offshore breakwater is
A partially submerged rock barrier, designed to break up the waves before they reach the coast
184
What are the advantages and disadvantages of offshore breakwaters
Advantages
- An effective permeable barrier
- Can be used to build small scale docks
Disadvantages
- Visually displeasing
- Potential navigation hazard
185
Describe what a Barrage is
A sophisticated engineering construction across estuaries that contain sluice gates to permit passage of tidal water but close when unusually high tides are occurring due to storm surges or flood tides
186
What are the advantages and disadvantages of Barrages
Advantages
- Effectively hold areas from flooding
Disadvantages
- Don’t actually stop erosion
- Very expensive
- Negative impact on the environment
187
Describe the process of beach nourishment
The addition of sand or pebbles to an existing beach to make it higher or wider. The sediment is usually dredged from a nearby seabed.
188
What are the advantages and disadvantages of beach nourishment
Advantages
- Relatively cheap and easy to maintain
- Looks natural
- Larger beach increases tourist potential
Disadvantages
- Needs constant maintenance because of erosion and long shore drift
189
Describe the soft engineering method of drainage and regrading
Cliff regrading reduces the angle of the cliff to help stabilise it, drainage removes water to prevent landslides and slumping
190
What are the advantages and disadvantages of Cliff drainage and regrading
Advantages
- Can be effective on clay and loose rock where other methods will not work
- Usually cost effective
Disadvantages
- Regrading of the cliff effectively causes it to retreat
- Can lead to increased occurrence of rockfalls
191
Describe the process of dune stabilisation
Marram grass can be planted to stabilise dunes. Areas can be fenced in to keep people off newly planted dunes
192
What are the advantages and disadvantages of dune stabilisation
Advantages
- Maintains a natural coastal environment and provides habitat
- Relatively cheap and sustainable
Disadvantages
- Time consuming to plant
- People may be restricted from walking on certain areas
193
Describe the soft engineering strategy of marsh creation
A form of managed retreat, by allowing low lying coastal areas to be flooded by the sea. This land then becomes a low wave energy salt marsh.
194
What are the advantages and disadvantages of marsh creation
Advantages
- Relatively cheap
- Creates a natural buffer to powerful waves
- Creates an important wildlife habitat
Disadvantages
- Agricultural land is lost, farmers have to be compensated for.
195
What is the case study a managed realignment scheme
Medmery, Selsey
196
Why does medmery need a managed realignment scheme
High tides and storms put over 300 houses, a water treatment plant and a major road from Chichester to Selsey at risk
197
What did the Medmery Managed Realignment Scheme involve?
- Construction of a 7km long flood bank made of locally excavated clay
- Introduction of large Norwegian rock armour to reduce errosion
198
What are the 3 main aims of Medmery Management Realignment Scheme
- Stop flooding of areas of high impact
- Creates an intertidal wildlife habitat
- Maximise community involvement where possible
199
200
How many SMPs correspond to the sediment cells around the coast of England and Wales?
22
201
What do SMPs aim to provide?
The basis for sustainable coastal defence policies within a sediment cell
202
What is the purpose of SMPs?
To identify the most sustainable approach to managing different sections of coastline
203
What time frames do SMPs set objectives for in coastal management?
* Short term (0-20 years)
* Medium term (20-50 years)
* Long term (50-100 years)
204
Who primarily funds the SMPs?
The national government agency - DEFRA, along with the Environment Agency and local councils
205
What is the Holderness SMP?
A plan for managing coastal flood and erosion risk for stretches of coastline in the short term (up to 2025), medium term (2026 - 2055), and long term (up to 2105).
206
What coastline does the Holderness SMP cover?
The coastline from Flamborough Head to Gibraltar Point, including the outer Humber Estuary.
207
What do Shoreline Management Plans (SMPs) identify?
Policies for sections of coastline to best manage coastal flood and erosion risk to people and the developed, historic, and natural environment.
208
What is the main aim of the Holderness SMP?
To develop a sustainable management approach for the shoreline that considers key issues and balances all values and features over the next 100 years.
209
What relationship does the SMP recognize?
The strong relationship with social, economic, and environmental activities around the shoreline.
210
How often are SMPs reviewed?
Every five to 10 years.
211
What is the purpose of reviewing the first round SMPs?
To take into account updated information and changing circumstances.
212
Fill in the blank: The Holderness SMP aims to achieve the best possible balance of all the _______ and features that occur around the shoreline.
[values]
213
True or False: The Holderness SMP only focuses on the short-term management of the coastline.
False
214
What is a key consideration in the actions proposed by the SMP?
Actions that do not cause problems elsewhere.
215
What 2 points does the holderness coastline span
From Flamborough head to Spurn Head
216
What is the direction of longshore drift along the holderness coastline
South from Flanborough head to Spurn Point
217
Describe the lithology of the Holderness Coastline
Unconsolidated boulder clay lines the coastline with a layer of harder chalk behind
218
Which coastline is the fastest eroding in Europe
The Holderness Coastline
219
Name the key settlements and places of interest along the Holderness coast
- Flamborough Head
- Hornsea
- Mappleton
- Withernsea
- Easington
- Spurn Head
220
What defence strategies are used in Hornsea
- Sea Wall with Promenade and steel doors
- Groynes
221
What defence strategies are used in Mappleton
- Beach nourishment
- Beach Regrading
222
What defence strategies are used in Withernsea
- Wave Return wall protected by rock armour
- Beach nourishment
- Groynes
223
What defence strategies are used in Easington
- Rock Revetements
224
What defence strategies are used in Spern Head
- No defence (managed retreat)
225
What is the significance nationally of protecting Easington
A natural gas terminal is present in Easington, handling 25% of all North Sea production
226
What percentage of North Sea natural gas travels through Easington gas station
25%
227
What knock on impact does the Groynes present in Hornsea have
This starves all beaches further down the coast of sediment, putting them at a higher risk of errosion. This has led to Mappleton relying on beach nourishment to retain sediment and beach profile
228
What is important about Spurn Head
Home to an RNLI Life Boat Station
229
What is the management policy at Spern Head
Managed realignment until the RNLI Lifeboat Station is destroyed, will result in no further intervention
230
What is the management policy at Easington
- In the short term, hold the line
- In the medium term it is possible to be either hold the line or no intervention
231
How many villages have been destroyed on the Holderness Coast since Roman times?
33
232
Which sea defences best represents a “Hold the Line” management policy
- Sea Walls
- Rock Armour
- Gabions
233
Which sea defences best represents a “Advance the Line” management policy
- Offshore Breakwaters
- Groynes
- Salt Marshes
- Sand Dune Replenishment
234
Which sea defences best represents a “No Active intervention” management policy
Marsh Creation
235
What economic and environmental opportunities does the coastal plain provide?
Relatively flat land for settlement, marine and coastal flora and fauna, offshore wind, tidal and wave power, placer minerals, clay and limestone resources, offshore oil and natural gas, seabed mining, coastal fishing, aquaculture, tourism, cultural and archaeological sites.
236
What types of flora and fauna are found in Odisha's coastal zone?
Mangroves, sea grasses, salt marshes, sand dunes, estuaries, lagoons, fish, marine mammals, reptiles, Olive Ridley turtles, seagrass meadows, abundant seaweeds.
237
What percentage of the coastal stretch is laden with substantial placer minerals?
Thirty-five percent.
238
What are the important resources found in the north of Odisha?
Clay and limestone.
239
What types of power generation have potential in Odisha's coastal area?
Offshore wind, tidal, wave power.
240
What employment opportunities exist for local people in Odisha's coastal region?
Coastal fishing and aquaculture such as shrimps.
241
What is significant about the Chilika Lake Bird Sanctuary?
It boasts over 150 migratory and resident species of birds.
242
True or False: Tourism is an important aspect of Odisha's coastal economy.
True.
243
Fill in the blank: The coastal plain supports a variety of _____ and coastal flora and fauna.
[marine].
244
What major attractions draw visitors to Odisha's coastal area?
Coastal beaches and wildlife sanctuaries.
245
What cultural aspects are present along Odisha's coast?
Cultural and archaeological sites.
246
What was released by the Ministry of Environment and Forests in 2011?
Assessment of Shoreline Change for the state of Odisha
247
What has contributed to the increased rates of coastal erosion in Odisha?
Natural processes and human intervention methods
248
Why is the Indian government concerned about coastal communities in Odisha?
Increased vulnerability to storm surges, tsunami, climate change, and rising sea levels
249
What does coastal erosion provide important inputs for?
Sediment that forms beaches, dunes, and barrier beaches
250
What seasonal variations occur along the Odisha coast?
Accretion in summer and erosion in winter
251
Fill in the blank: Erosion occurs in the winter when high-energy destructive waves remove and deposit sediment _______.
offshore
252
What effect do seawalls and other hard structures have on natural coastal processes?
They shift the problem to downdrift coastal areas
253
What is threatened by the elimination of sediment transport?
Beaches, dunes, barrier beaches, salt marshes, and estuaries
254
True or False: The majority of Odisha's population lives inland and is not affected by coastal erosion.
False
255
What natural processes characterize the Odisha coastline?
Seasonal variations of accretion and erosion
256
257
What percentage of the coast of Odisha is accreting?
46.8 per cent
## Footnote
The coast is largely accreting, with erosion at 36.8 per cent and stability at 14.4 per cent.
258
Where is most of the accretion occurring along the coast of Odisha?
In the north, focused on the major deltas
## Footnote
Accretion is primarily concentrated in northern regions.
259
What percentage of the coast of Odisha is eroding?
36.8 per cent
## Footnote
Erosion is predominantly found in the southern regions.
260
What major structures are present in the southern coast of Odisha that affect erosion?
Sea walls, breakwaters, and rock armour
## Footnote
These structures protect infrastructures like ports but interfere with natural processes.
261
Which coastal districts in Odisha show higher levels of accretion due to dense mangrove vegetation?
Kendrapara, Bhadrak, and Baleshwar
## Footnote
These areas show levels of accretion more than 50 per cent higher than other coastal regions.
262
What dynamic feature is noted at the mouths of rivers along the Odisha coast?
Shoreline change is extremely dynamic
## Footnote
Inflow patterns significantly influence the rates of accretion and erosion.
263
What is the percentage of the coast of Odisha that is considered 'stable'?
14.4 per cent
## Footnote
This indicates a very dynamic coastal system.
264
What factors affect the coastline's dynamic nature in Odisha?
Seasonal variation in wave energy and sediment input
## Footnote
These factors are influenced by the region's major rivers.
265
How has human intervention impacted the coastal system of Odisha?
Interfered with sediment transfer and destabilized wave energy patterns
## Footnote
This has resulted in severe erosion in specific localities.
266
What are the concerns for state authorities regarding the Odisha coastline?
Economic value of the coastal strip and threats from storm surges, tsunami, and sea level rise
## Footnote
These factors make the coastal changes a significant concern for authorities.
267
What percentage of the coast of Odisha is accreting?
46.8 per cent
## Footnote
The coast is largely accreting, with erosion at 36.8 per cent and stability at 14.4 per cent.
268
Where is most of the accretion occurring along the coast of Odisha?
In the north, focused on the major deltas
## Footnote
Accretion is primarily concentrated in northern regions.
269
What percentage of the coast of Odisha is eroding?
36.8 per cent
## Footnote
Erosion is predominantly found in the southern regions.
270
What major structures are present in the southern coast of Odisha that affect erosion?
Sea walls, breakwaters, and rock armour
## Footnote
These structures protect infrastructures like ports but interfere with natural processes.
271
Which coastal districts in Odisha show higher levels of accretion due to dense mangrove vegetation?
Kendrapara, Bhadrak, and Baleshwar
## Footnote
These areas show levels of accretion more than 50 per cent higher than other coastal regions.
272
What dynamic feature is noted at the mouths of rivers along the Odisha coast?
Shoreline change is extremely dynamic
## Footnote
Inflow patterns significantly influence the rates of accretion and erosion.
273
What is the percentage of the coast of Odisha that is considered 'stable'?
14.4 per cent
## Footnote
This indicates a very dynamic coastal system.
274
What factors affect the coastline's dynamic nature in Odisha?
Seasonal variation in wave energy and sediment input
## Footnote
These factors are influenced by the region's major rivers.
275
How has human intervention impacted the coastal system of Odisha?
Interfered with sediment transfer and destabilized wave energy patterns
## Footnote
This has resulted in severe erosion in specific localities.
276
What are the concerns for state authorities regarding the Odisha coastline?
Economic value of the coastal strip and threats from storm surges, tsunami, and sea level rise
## Footnote
These factors make the coastal changes a significant concern for authorities.
277
What is rockfall?
Fastest form of mass movement that involves the free fall or downslope rolling of rock pieces loosened by weathering
## Footnote
Rockfall results in the formation of a talus cone or scree slope at the base of the cliff.
278
What do boulders from rockfall form at the base of cliffs?
Talus cone or scree slope
## Footnote
These features are created from the accumulation of rock debris that has fallen.
279
True or False: Rockfall is a slow process of mass movement.
False
## Footnote
Rockfall is characterized as the fastest form of mass movement.
280
Fill in the blank: Rockfall involves the _______ or downslope rolling of rock pieces.
free fall
## Footnote
This process is initiated by weathering that loosens the rocks.
281
What is soil creep?
A heave process whereby individual particles expand and contract due to the physical environment.
282
Where is soil creep very common?
In the UK and on clay slopes.
283
What is a landslide?
A significant section of the cliff becomes detached and slides down.
284
What is often involved in a landslide?
A block of rock moving along a plane or a slump.
285
What are the types of movements that can occur during a landslide?
It can be rotational or a flow.
286
Which Mass Movement does this Image Represent
Landslide
287
Which Mass Movement does this Image Represent
Mudflow
288
Which Mass Movement does this Image Represent
Slumping
289
Which Mass Movement does this Image Represent
Soil Creep
290
Describe the process of Mudflows
Over saturation of soil resulting in a flow of wet soil down a cliff face. This is particularly common in areas of high clay content.
