Coasts Flashcards
1
Q
What is the littoral zone?
A
Part of the coast between high and low water marks.
2
Q
What are the 4 zones of the littoral zone?
A
- Offshore: Area of deeper water further out to sea, beyond the influence of the waves.
- Nearshore: Area of shallow water beyond the low tide mark where the friction between the seabed and waves causes this to be the breaker zone of the waves.
- Foreshore: The area between the high tide and the low tide, covered by high tide, exposed at low tide (known as the intertidal zone).
- Backshore: The area above the high tide mark, not covered even at high tide, affected by wave action only during major storm events.
3
Q
Which coastal zone has the most deposition and amount of marine erosion without major storms?
A
Foreshore zone.
4
Q
What zone has the most amount of erosion with storms and the most amount of mass movement?
A
The backshore zone.
5
Q
What is transportation influenced by?
A
- Tides and currents: Currents are the flow of water in a particular direction, including tidal currents, which can transport sediments in different directions in the nearshore and offshore zones.
- Angle of wave attack: If winds blow directly onshore, material is moved up and down the beach by the waves, but is not transported along the beach (known as swash aligned beach). If waves/wind come in from an angle, material is transported along the beach in a zigzag fashion by longshore drift (known as drift aligned beach).
6
Q
What are the two methods of deposition?
A
- Gravity settling: The wave’s velocity decreases, so sediment begins to be dropped and deposited.
- Flocculation: Occurs in salt and tidal marshes as well as delta formation. Clay particles clump together due to their chemical attraction, gain mass, and sink due to their higher density.
7
Q
What is sub-aerial processes?
A
Land-based processes which alter the shape of the coastline, a combination of weathering and mass movement.
8
Q
What is weathering?
A
The breakdown of rocks by biological, mechanical, or chemical processes.
9
Q
What is mechanical weathering?
A
The breakdown of rocks through physical processes.
Types include freeze-thaw weathering and salt cracking.
10
Q
What is freeze-thaw weathering?
A
Occurs when water seeps into the cracks of rocks, freezes, expands by 10%, generating pressure that cracks and disintegrates the rocks.
11
Q
What is salt cracking?
A
Similar to freeze-thaw weathering, but with salt crystals deposited by seawater, which can expand up to 300%.
12
Q
What is biological weathering?
A
The breakdown of rocks by living organisms.
Includes plant roots growing in cracks and animals wearing away rocks.
13
Q
What is chemical weathering?
A
Occurs when rain on cliffs, combined with high temperatures, provides optimal conditions for the decomposition of rocks through chemical reactions.
14
Q
What are the two types of mass movement as sub-aerial processes?
A
Slumping/rotational slide and rock fall.
15
Q
How does slumping/rotational slide occur?
A
Occurs on permeable and water-absorbent rock such as clay and sandstone, creating slip planes due to erosion and increased weight from rainwater.
16
Q
What does slumping produce?
A
- Terraces: Step-like features where surface and grass are visible.
- Rotational scars: Visible grass on terraces or at the bottom of the cliff.
- Slumping movement is not steep.
17
Q
Example of slumping mass movement or rotational slide?
A
Dorset coast, April 2003, where 4000 tonnes of rock slumped onto 30 beaches.
18
Q
What is rock fall and how does it occur?
A
Occurs when erosion at the base of the cliff creates an overhang, often in resistant rock types.
Conditions include hydraulic action, abrasion, and heavy rainfall.
19
Q
What does rock fall produce?
A
- Steep cliff profiles.
- Talus: Group of scree at the bottom of the cliff.
- Semicircular shape around the area of the rockfall.
20
Q
Example of rockfall mass movement event?
A
White Cliffs of Dover experienced rockfall in 2012.
21
Q
What is coastal morphology?
A
The shape of the coastline.
22
Q
What is geological structure?
A
The arrangement of rocks in layers or folds and the joints and bedding planes between them.
23
Q
What are the 6 small scale geological structures of rock?
A
- Strata
- Bedding planes
- Joints
- Folds
- Faults
- Dip
24
Q
What is strata?
A
The layers of rock.
25
What are bedding planes?
Horizontal cracks in rocks.
26
What are joints?
Vertical cracks in rocks.
27
What are folds?
Formed by pressure during tectonic activity, causing rocks to buckle and crumble.
28
What is a dip?
The angle at which rock strata lie (horizontally, vertically, dipping towards the sea or inland).
29
What sub-aerial and marine erosion processes may a well-jointed rock cliff be vulnerable to?
1. Chemical weathering
2. Biological weathering if plants are present
3. Mechanical weathering due to cracks in rock
4. Hydraulic action due to cracks in rock.
30
What is horizontally bedded strata?
Rock layers going in the same direction as the tide, creating steep vertical cliff profiles.
31
What is seaward dipping strata?
Cliff face slopes down towards the sea, allowing for easier sliding of loosened rock.
32
What is landward dipping strata?
Strata rock layers at an angle away from the sea, making dislodging difficult.
33
What are the three dips of strata?
1. Horizontally bedded strata
2. Seaward dipping strata
3. Landward dipping strata.
34
What does the dip of strata do?
Offers lines of weakness that both sub-aerial and marine erosional processes can exploit.
35
What increases the areas of weakness in the dips of strata in cliffs?
The more fault lines and folding, the more weakness.
36
On a large scale, what are the two geological structures?
Discordant and concordant coastlines.
37
What are discordant coastlines?
Coasts where the cliffs are structured with alternating bands of more resistant and less resistant rock at right angles.
38
What features do discordant coastlines create?
Wave cut notches, bays, and beaches due to the erosion of softer rock.
39
What are concordant coastlines?
Coasts structured with alternating bands of hard and soft rock parallel to the coast.
40
Example of a concordant and discordant coastline?
The Isle of Purbeck, Jurassic Coast.
41
Example of a bay and headland due to discordant coastlines in the Isle of Purbeck?
Studland Bay and Peveril Point.
42
What can also form on concordant coastlines?
Coves and little bays formed by wave erosion through resistant rocks to less resistant ones.
43
Cove example in Isle of Purbeck Jurassic Coast on the concordant coastline?
Lulworth Cove.
44
What are the two types of concordant coastlines?
Dalmation coasts and haff coasts.
45
What are dalmation coasts?
A type of concordant coastline formed by folded limestone into anticlines and synclines, with flooded synclines creating long narrow islands.
## Footnote
Example: Croatian Dalmation Coast.
46
What are haff coasts?
Concordant coastlines that form in low energy environments, creating lagoons between ridges and shorelines.
47
How are waves formed?
Created by the action of wind blowing over the sea, with friction causing surface water to move in ripples that form waves.
48
What are three factors that influence the size of waves?
1. Long fetch
2. Faster wind
3. Wind duration.
49
How long is the fetch coming into Cornwall?
8000 km.
50
What are constructive waves?
1. Lower energy
2. Lower height
3. Less frequent
4. Weak backwash carrying away little sediment
5. Strong swash depositing and moving a lot of sediment up the beach
6. Creates a gentler and less steep beach profile.
51
What are destructive waves?
1. Larger height
2. More frequent
3. Strong backwash carrying away more sediment
4. Weaker swash, moving little sediment up the beach
5. Creates steep beach profile
6. High energy.
52
Steps of how waves form?
1. Sea surface creates friction.
2. Results in frictional drag across the sea.
3. Causes water particles to rotate in a circular orbit, transferring energy forward as a wave.
4. Waves break in shallow water when the wave shape becomes more elliptical.
5. Water approaches the beach as swash and returns as backwash.
53
What does beach morphology refer to?
1. Shape of beach: width, slope features including ridges and runnels.
2. Type of sediment: e.g., shingle, sand, or mud at different locations.
54
What is the time period that beach morphology can change?
A day to a year.
55
What are the 5 processes that affect the coast?
1. Deposition: The laying down of sediment carried by wind and water.
2. Coastal erosion: The process in which cliffs are worn away and transported by the sea.
3. Transportation: The movement of material.
4. Mass movement: The large scale movement of materials such as landslides or rock falls.
5. Weathering: The breakdown of rocks by action of rainwater, extreme temperatures, and biological activity.
56
What are the 4 types of erosion?
1. Abrasion: Material hurled against the cliff by waves wearing it away.
2. Attrition: Pieces of material knock into each other, becoming smaller and smoother.
3. Hydraulic action: Waves crash into the base of the cliff, forcing air and water into cracks, exerting pressure that grows the cracks.
4. Solution: Soluble particles dissolved by acids in seawater.
57
What are the 4 types of transportation?
1. Traction: Large materials rolled along the seabed.
2. Saltation: Smaller particles float in the sea.
3. Suspension: Pebbles lifted by the sea when it has enough energy, dropped when it loses energy.
4. Solution: Particles dissolved in the sea, moved with the water.
58
What is coastal recession?
How fast a coastline is moving inland, affected by geological structure and lithology to form differential erosion.
59
What are the three factors that influence the resistance of rock?
1. Exposure of minerals to chemical weathering.
2. Whether the rocks are clastic or crystalline.
3. The degree of cracks, fractures, and fissures in rocks.
60
Example of how minerals in rock are exposed to chemical weathering?
Calcite in limestone can be weathered by acidic rainwater, while quartz in sandstone does not undergo chemical weathering.
61
Example of clastic and crystalline rocks?
Clastic rocks are sedimentary (e.g., sandstone), while crystalline rocks are igneous and metamorphic, made of interlocking crystal particles.
62
What happens to rocks weathered by acidic rainwater?
They are turned into solution.
63
Why does quartz in sandstone not undergo chemical weathering?
Quartz does not contain calcium carbonate like calcite.
64
What are clastic rocks?
Sedimentary rocks like sandstone made of cemented sediment particles.
65
What are crystalline rocks?
Igneous and metamorphic rocks made of interlocking crystal particles.
66
How do cracks and fractures in rocks affect erosion rates?
Weaknesses in the rock make it more prone to erosion.
67
Give examples of igneous rocks and their erosion rate.
Granite, basalt, and dolerite have very slow erosion rates due to being crystalline rocks.
68
What are examples of metamorphic rocks and their erosion rate?
Slate, schist, and marble exhibit slow erosion but not as slow as igneous rocks.
69
What are examples of sedimentary rocks and their erosion rate?
Sandstone, limestone, and shale have moderate to fast erosion rates.
70
What are lithology exceptions?
Some limestones are crystalline, some ancient sandstones are resistant, and recently erupted lava is weak.
71
What is the weakest rock?
Unconsolidated sedimentary rock.
72
What determines the rate of erosion in lithology?
Bedrock lithology, permeability, and mineral content.
73
How does bedrock lithology affect erosion rates?
Different lithologies have varying resistance to erosion.
74
How does permeability influence erosion rates?
Higher permeability can lead to increased erosion.
75
How does mineral content influence erosion rates?
Different minerals have varying strengths affecting erosion.
76
How does vegetation stabilize coastal sediment?
Roots bind sediment, provide protection from water and wind.
77
What is plant succession?
The changing structure of a plant community over time.
78
What is a climatic climax community?
The end result of plant succession, with two types: psammosere and halospere.
79
Why is plant succession important on coasts?
It helps in coastal accretion, building up sediment.
80
What is the first step of sand dune succession?
Embryo dunes form as sand is trapped around obstacles.
81
What is the second stage of sand dune succession?
Pioneer plants like prickly saltwort stabilize the embryo dunes.
82
What is the third stage of sand dune succession?
More plants like lymegrass grow, forming yellow dunes.
83
What is the fourth stage of sand dune succession?
Humus from decaying plants creates fertile conditions, leading to grey dunes.
84
What is the fifth stage of sand dune succession?
Climax community forms with pine or oak forests up to 1km inland.
85
What is a sediment cell?
A length of coastline where sediment movement is largely self-contained.
86
What are the boundaries between sediment cells?
Two headlands, with 11 primary sediment cells in the UK.
87
What are barriers between sediment cells called?
Sub cells.
88
What can rarely overcome sub cells?
Big storms can change the coastline shape.
89
What maintains dynamic equilibrium in sediment cells?
Sources, transfers, and sinks of sediment.
90
What is negative feedback in sediment cells?
A process that reduces previous actions to gain balance.
91
What is positive feedback in sediment cells?
A process that increases previous actions to gain balance.
92
What is eustatic change?
Global sea level rise and fall occurring relatively quickly.
93
What causes eustatic change during glacial periods?
Ice sheets store water, causing sea levels to fall.
94
What causes eustatic change during interglacial periods?
Melting ice sheets and thermal expansion of water raise sea levels.
95
What is isostatic change?
Local land level change relative to the sea, occurring very slowly.
96
What is isostatic subsidence?
Land sinking due to the weight of ice sheets.
97
What is isostatic recovery?
Land rising after ice sheets melt and weight is reduced.
98
What does climate change cause?
Contemporary sea level rise.
99
How much has the Earth's temperature risen since pre-industrial times?
1 degree Celsius.
100
What causes increasing global temperatures?
Enhanced greenhouse effect from gases like CO2 and methane.
101
How does global warming risk coastlines?
Increases frequency and magnitude of storms, raising flood risk.
102
How does global warming influence storm frequency?
More regions experience temperatures required for tropical storms.
103
How does global warming influence the magnitude of storms?
Increased moisture storage in warm air raises storm intensity.
104
What are two ways global warming increases sea level?
Melting polar ice sheets and thermal expansion of seawater.
105
How fast is average sea level predicted to rise by 2100?
Between 30cm and 1m, causing flooding.
106
What is an example of an island affected by climate change?
Kiribati in the Pacific Ocean with a population of 100,000.
107
Describe the relief of Kiribati.
33 low-lying islands full of mangroves and sands, only 1m high.
108
How much is sea level rising in Kiribati?
4 times faster than the global average at 1.2cm a year.
109
What has sea level rise caused in Kiribati?
Environmental refugees and government land purchases in Fiji.
110
Why is it difficult to predict climate change impacts on coastlines?
Uncertainty in temperature rise, ice sheet melting, and cause-effect relationships.
111
What are three local factors increasing flood risk on low-lying coasts?
Height, degree of subsidence, and vegetation removal.
112
What percentage of the world's population will live in low elevation areas by 2060?
12%.
113
Which countries are more likely to protect against flooding?
Developed countries.
114
What is a population fact about Bangladesh?
Most populated country, lying on floodplains of major rivers.
115
How much of the Bangladesh population lives less than 10m above sea level?
46%.
116
What causes flood risk in Bangladesh?
Sinking estuarine islands and deforestation for agriculture.
117
Why is removing vegetation bad in Bangladesh?
It destroys ecosystems and reduces protection against flooding.
118
What are the three risks of coastal flooding?
Economic, social, and environmental losses.
119
What causes most short-term coastal flooding events?
Storm surges.
120
What are the four causes of storm surges?
Low air pressure, high wind speeds, high tides, and coastline funneling.
121
How much does sea level rise for every 1 millibar change in pressure?
1 cm.
122
What is the definition of sustainability?
Protecting current generations' needs without compromising future generations.
123
What is an example of sustainable management of coastal flooding?
Reinstalling mangrove forests.
124
How do mangrove forests protect against erosion?
By stabilizing sediment with their roots.
125
What is the National Adaptation Programme of Action (NAPA)?
A program by the Bangladesh government to address climate change impacts.
126
What initiative did Friendship NGO undertake in Bangladesh?
Organized international donors and supplied half a million mangrove trees of over 5 species along coastal embankments.
127
How does mangrove replanting in Bangladesh help socially?
It involves locals in planting mangrove seeds.
128
What are the three reasons erosion rates vary?
1. Time variations: seasonal peaks in erosion.
2. Time variations: some years have more recession.
3. Spatial variations: different locations have varying erosion rates.
129
What is a case study of a rapidly retreating coast in the UK?
Holderness Coast, North East England.
130
What are two statistics about the rate of erosion at Holderness Coast?
1. Fastest eroding coastline in the UK.
2. Eroding at an average rate of 2m per year.
131
What are two examples of economic losses due to coastal erosion on Holderness Coast?
1. Golden Sands Holiday Park lost 100 chalets in the past 15 years.
2. By 2100, 200 homes will disappear, making them hard to sell.
132
What is a social loss due to fast erosion on Holderness Coast?
16 houses have already been relocated.
133
What is one example of human activity that increases coastal recession and erosion?
Offshore dredging, which removes sand and gravel for construction, causing deeper water and less wave friction.
134
What are three examples of offshore dredging?
1. Nile Delta Coast.
2. 3.3% of land removed to build Aswan Dam.
3. Half of the Rosetta promontory eroded.
135
What can increased erosion lead to?
Increased deposition down the coast due to longshore drift.
136
How does bedrock lithology affect rates of coastal erosion?
Metamorphic and igneous rocks are more resistant to erosion than sedimentary rocks.
## Footnote
Typical granite erosion rate is 1m, while limestone is 2.5cm.
137
How does permeability affect the rate of coastal erosion?
Rocks with cracks and joints, like limestone, are more permeable, affecting weathering and mass movement.
138
What are three descriptions of constructive waves?
1. Result in a gentle beach profile due to strong swash.
2. Smaller pebbles as they lack energy to transport large materials.
3. Generally associated with spring and summer.
139
What are four facts about destructive waves?
1. Steeper beach profile due to strong backwash.
2. More common in winter due to higher wind speeds.
3. Throw sediment up the beach creating ridges (berms).
4. Smaller sediment found due to attrition.
140
What are the four main types of erosional coastal landforms?
1. Headlands and bays.
2. Cliffs.
3. Caves, arches, stacks, and stumps.
4. Wave cut platforms.
141
How are cliffs formed?
Resistant rocks like limestone allow undercutting by erosion, leading to rockfalls and vertical profiles.
142
What is an example of steep cliffs?
The White Cliffs of Dover, which are 350 feet high and erode at 1cm per year.
143
What is an example of gentle cliffs?
Mappleton on the Holderness Coast, made of glacial till, eroding at 1-2m per year.
144
How do wave cut platforms form?
Formed by destructive waves eroding cliffs faster than subaerial processes, creating wave cut notches.
## Footnote
Example: Southern Down Coast in Wales.
145
What is an example of caves, arches, stacks, and stumps?
Old Harry Rock on the Dorset coast, formed through erosion processes.
146
What factors affect the rate of coastal erosion and recession?
1. Geological structure such as bedding planes and joints.
2. Marine factors like wave type and size.
3. Geological factors including rock type and consolidation.
147
What is a coastal plain?
Flat, low-lying land adjacent to a seacoast, resulting from sediment supply in low energy environments.
148
What is the role of transportation in depositional landforms?
Transportation methods move sediment along coastlines to low energy areas where deposition occurs.
149
What is longshore drift?
The movement of sediment along a coast by waves approaching at an angle.
150
What are the two main ways material is deposited?
1. Gravity setting: larger sediment deposited first as energy decreases.
2. Flocculation: small particles clump together in saltwater and sink.
151
What is an example of a sediment cell?
Sediment cell 2 has Flamborough Head.
152
What are the sources in the Flamborough Head sediment cell?
Soft boulder clay that slumps when saturated, and chalk cliffs eroding at 2m per year.
153
What are the transfers in Flamborough Head sediment cell?
Spurn Point has longshore drift.
154
What are the sinks of Flamborough Head sediment cell?
Spurn Point has a pit called Spurn Head, where about 3% of material from Holderness Coast is deposited.
155
What are some disruptions to Flamborough Head's sediment cell?
Mappleton has an erosion rate of 2m per year due to rock groynes, leading to faster erosion south of it.
156
What is another reason why isostatic change can occur?
Sediment accretion from rivers.
157
Describe the land in the North West UK.
Rising due to isostatic recovery from the last ice age.
158
Describe the land in the South West of the UK.
Sinking due to sediment accretion from rivers, causing the crust to sink and increasing flood risk.
159
What are the two main emergent landforms?
Raised beaches and fossil cliffs.
160
What are raised beaches?
Old beaches left exposed above the tideline due to isostatic uplift.
## Footnote
Example: North of Drumadoon on the island of Arran.
161
What are fossil cliffs?
Cliffs lifted above wave impact by isostatic uplift, creating raised wave cut platforms.
## Footnote
Example: Langerstone Point.
162
What are rias?
Old river valleys flooded by eustatic sea level rise.
## Footnote
Example: Kingsbury Estuary in Devon.
163
What is a fjord?
A previously glacial mountainous valley flooded by isostatic readjustment and eustatic sea level rise.
## Footnote
Example: Sognefjord in Western Norway.
164
What are dalmation coasts?
Limestone features flooded from eustatic sea level rise, resulting from tectonic movement.
## Footnote
Example: Dalmation Coast in Croatia.
165
What are the three types of submergent landforms?
1. Rias.
2. Fjords.
3. Dalmation coasts.
166
How do weather systems influence coastal recession rates?
Low pressure systems create larger waves, especially in winter, increasing erosion rates.
167
How do rates of coastal recession vary along the Holderness Coast due to geology?
Boulder clay is weak and erodes easily, while chalk creates more resistant cliffs.
168
How does fetch influence coastal recession rates at Holderness?
Fetch determines wave energy; small fetch from NE is exaggerated by Atlantic currents and low pressure systems.
169
How does longshore drift influence coastal recession rates at Holderness?
Boulder clay erodes easily and is not deposited on beaches, leading to narrow beaches and increased erosion.
170
How does the sea floor affect wave energy at the Holderness coastline?
The sea floor is relatively deep, meaning the waves reach the cliffs without losing energy from the friction of the sea floor.
171
How does longshore drift influence coastal recession rates at Holderness?
Longshore drift transports sediment south, leaving cliffs poorly protected, which increases erosion.
172
What is the impact of boulder clay on beach formation?
Boulder clay is easy to erode and transport, creating narrow beaches with little friction to absorb wave energy, leading to more erosion.
173
What role do tides play in coastal erosion at Holderness?
Tides transport sediment south with longshore drift, contributing to the erosion of cliffs.
174
What are the effects of chemical and mechanical weathering on the Holderness coastline?
Chemical weathering occurs only at chalk cliffs, while mechanical weathering is significant due to freeze-thaw cycles and water in boulder clay, leading to slumping.
175
How does coastal management affect erosion rates at Holderness?
Higher erosion rates occur south of Hornsea due to coastal defenses like groynes and sea walls, which disrupt sediment supply.
176
What is an example of mismanaged coastline?
Hallsands was mismanaged due to dredging of nearby beaches, leading to larger waves that destroyed homes.
177
What are the pros of hard engineering against coastal recession?
1. Some sea walls are designed to last up to 100 years. 2. Provides visible management to protect people.
178
What are the cons of hard engineering against coastal recession?
1. Can cause increased erosion down coast. 2. Often unattractive. 3. High construction and maintenance costs. 4. Harmful to coastal ecosystems.
179
What are the pros of soft engineering?
1. Better for the environment as it works with natural processes. 2. Less visually intrusive. 3. Generally cheaper.
180
What are the cons of soft engineering?
1. Not always effective at halting erosion. 2. Requires regular maintenance, such as beach nourishment.
181
What is beach nourishment?
Adding sand or pebbles to an existing beach to make it higher or wider, typically using dredged material.
182
What is cliff regrading and drainage?
Reduces the angle of the cliff to stabilize it and drains water to prevent slumping.
183
What is dune stabilization?
Planting marram grass to stabilize dunes and fencing off areas to protect them.
184
What is marsh creation?
Managed retreat allowing low-lying areas to be flooded by the sea, creating salt marshes.
185
What are the pros of beach nourishment?
1. Cheap. 2. Looks natural and blends with the beach. 3. Increases tourism due to larger beaches.
186
What are the cons of beach nourishment?
1. Requires constant maintenance due to natural erosion. 2. Can cause further erosion down coast.
187
What are the pros of cliff regrading and drainage?
1. Effective on clay or loose rock. 2. Reduces future drainage costs.
188
What are the cons of cliff regrading and drainage?
1. Causes the cliff to retreat. 2. Drained cliffs can lead to rock falls.
189
What are the pros of dune stabilization?
1. Maintains natural coastal environment. 2. Provides wildlife habitat. 3. Cheap and sustainable.
190
What are the cons of dune stabilization?
1. Time-consuming to plant. 2. People may be annoyed by restricted access.
191
What are the pros of marsh creation?
1. Cheap. 2. Natural defense against powerful waves. 3. Provides wildlife habitat.
192
What are the cons of marsh creation?
1. Loss of agricultural land. 2. Financial loss for farmers.
193
What are groynes?
Timber or rock structures built at right angles to the coast to trap sediment moved by longshore drift.
194
What are sea walls?
Stone structures at the foot of cliffs or top of beaches designed to reflect waves back to sea.
195
What is rip rap or rock armor?
Large rocks placed at the top of the beach or foot of cliffs to break up wave energy.
196
What are revetments?
Sloping structures made of wood, concrete, or rock that break up wave energy.
197
What are offshore breakwaters?
Partially submerged rock barriers designed to break up waves before they reach the coast.
198
What are the pros of groynes?
1. Increases tourism by building up land. 2. Relatively inexpensive. 3. Works with natural processes.
199
What are the cons of groynes?
1. Can starve beaches further down the coast of sediment. 2. Often considered unattractive.
200
What are the pros of sea walls?
1. Effective at protecting the coast. 2. Provides a promenade for walking.
201
What are the cons of sea walls?
1. Reflect wave energy instead of absorbing it. 2. Unattractive appearance. 3. Expensive to build and maintain.
202
What are the pros of rip rap?
1. Cheap and easy to maintain. 2. Often used by fishermen and tourists.
203
What are the cons of rip rap?
1. Rocks sourced from elsewhere can look unattractive. 2. Can be intrusive. 3. Dangerous for climbing.
204
What is the pro of revetments?
Relatively cheap.
205
What are the cons of revetments?
1. Intrusive and unattractive. 2. High maintenance levels.
206
What is the pro of offshore breakwaters?
Effective permeable barrier.
207
What are the cons of offshore breakwaters?
1. Visually unappealing. 2. Potential navigation hazard for ships.
208
What are the seven different depositional landforms?
1. Spits (recurved). 2. Spits (double). 3. Tombolos. 4. Beaches. 5. Barrier beaches. 6. Offshore bars. 7. Cuspate forelands.
209
What are recurved spits?
Spits that curve into a hook shape due to changing wind direction and wave refraction, creating salt marshes. Example: Spurn Head.
210
What are tombolos?
Beaches that connect an island to the mainland, formed by longshore drift. Example: Chesil Beach.
211
What are cuspate forelands?
Triangular-shaped headlands formed by converging longshore drift currents. Example: Dungeness, Kent.
212
What are double spits?
Two spits extending in opposite directions from both sides of a bay due to longshore drift. Example: Poole Harbour.
213
How are normal beaches formed?
Through the accumulation of sand and shingle in the foreshore and backshore zones, produced by constructive waves.
214
How are curved beaches formed?
Formed at the back of a bay where wave refraction disperses energy, leading to deposition in the bay.
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What are barrier beaches?
Islands or bars that form parallel to the coastline, separated by lagoons. Example: Barrier islands along western Florida.
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What are offshore bars?
Ridges of sand or shingle formed by erosion from destructive waves, deposited in the offshore zone. Example: Scroby Sands wind farms.
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How is the Holderness coast managed through hard and soft engineering?
Withersea has a new sea wall and rip rap, while soft engineering like beach nourishment is replenished every 1-2 years.
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What are sustainable management schemes against coastal recession?
1. Mangroves against storm surges in Bangladesh. 2. Beach nourishment in Withersea. 3. Relocating people and businesses. 4. Creating alternative livelihoods. 5. Educating communities.
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What does coastal management in the UK involve?
Adapting policies to use more sustainable approaches, evaluating new developments, and ensuring long-term sustainability.
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What is an example of sustainable management in the UK using coastal realignment?
In Medmerry, £28 million was spent to create a natural wall further inland, forming a new saltwater marsh.
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What is an example of sustainable management in the UK using coastal realignment?
Abbots Hall Farm was turned into salt marshes to reduce wave impact, but raised concerns from local fishermen and the RSPB.
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What is a coastal management adaptation strategy in Bangladesh?
600 km of embankments in the Sundarbans delta region, but it's unsustainable as people should relocate due to cyclone risks.
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What is a coastal management adaptation strategy in India?
NGO Wetlands International is working with the Indian government to plant mangrove seeds along the Odisha coast.
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What are the five factors to consider in Integrated Coastal Zone Management (ICZM)?
1. Engineering feasibility. 2. Environmental sensitivity. 3. Land use and value. 4. Impacts on coastal processes. 5. Political, social, and economic factors.
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How does the government decide on ICZM?
Through cost-benefit analysis (CBA) and environmental impact assessments (EIA).
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What is the EIA for Chittagong, Bangladesh?
The coastal resilient infrastructure project aims to improve road connections and raise embankments, enhancing climate resilience.
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How has the EIA for Chittagong helped and not helped?
Flooding reduced from 20 days to 5 days a year, but 200 people had to relocate.
228
What area in Holderness has been chosen to 'hold the line'?
Easington, due to its gas terminal that provides a quarter of the UK's gas, is protected by rip rap.
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What area in Holderness has been chosen for 'do nothing/no active intervention'?
Cowden, a small hamlet with minimal economic value, is not protected.
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What is an example of managed retreat in Holderness?
Spurn Head, where no one lives and minimal costs are involved, providing a habitat for birds.
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What is the status of Withersea?
Withersea has a population of 6200 and is protected by a sea wall due to its popularity.
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What is the status of Mappleton?
Mappleton has economic value due to the B1242 road and is protected by two rock groynes.
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Who manages the Shoreline Management Plan (SMP) in Holderness?
The East Riding of Yorkshire Council, in collaboration with national agencies, local government, stakeholders, and environmental groups.
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Why does the RSPB want to protect Spurn Head?
It is one of the UK's largest coastal spits, essential for creating mudflats that support important birdlife.
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What are some conflicts between stakeholders in Holderness?
Local businesses, such as holiday parks and farms, are affected by the 'do nothing' policy.
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What stakeholders are involved in the Holderness Coast?
Farmers, residents of towns, and the tourism industry, along with environmental stakeholders such as the RSPB.
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Why does the RSPB want to protect Spurn Head?
It is one of the UK's largest coastal spits and essential for continuing the flow of sand southwards by longshore drift, creating mudflats of the Humber Estuary, which is one of the UK's most important birdlife reserves.
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What are some conflicts between stakeholders in the Holderness Coast?
Local businesses such as holiday parks and farms in the 'Do Nothing Zone' like Cowden face income destruction. Economic benefits often conflict with environmental costs.
239
How is the concept of a sediment cell relevant when managing a coastline?
There are physical processes that need a long timescale to be managed, and specific human activities in the area also impact the land and sea.
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What is the Integrated Coastal Zone Management (ICZM)?
Introduced in 1992 at the Earth Summit meeting, it involves coastal towns managing themselves to support ecosystems, economy, and tourism more effectively.
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Why is the ICZM called a holistic strategy?
Because it considers all stakeholders.
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What is the Shoreline Management Plan (SMP)?
It is part of the policy decisions for the ICZM, focusing on the planning, management, and protection of a specific coastline for the next 100 years.
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What criteria does the SMP follow in sediment cell two?
1. Environmentally acceptable protection measures. 2. Economically viable coastal measures considering land use and property loss. 3. Long-term sustainability and preserving natural ecosystem processes. 4. Maintenance and repair costs. 5. Good technical coastal engineering that works with natural processes.
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What are the four main management policies allocated in the SMP ICZM of sediment cell 2?
1. Hold existing shoreline with maintenance of defenses and building new ones. 2. Advance existing shoreline by building new defenses. 3. Managed realignment of shoreline where natural processes operate. 4. No active intervention, allowing the coastline to retreat naturally.
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Why have SMPs been controversial in some places?
When policies change from holding the line to no active intervention, property prices drop, and farmers lose income.
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What is an example of a failed cost-benefit analysis for holding the line?
Happisburgh in North Norfolk failed to secure funding as the area was not economically valuable enough.
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What management shoreline policy was originally in place for Happisburgh, Norfolk?
Residents of Beach Road have lost homes, with a further 35 homes expected to be lost by 2025. The policy changed from managed retreat to no intervention.
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What happened eventually in Happisburgh, Norfolk?
The government provided a £5,000 grant to assist with demolition costs. Campaigning by CCAG secured £1.4 million for help, including building new roads and farmland landward.
249
How is a salt marsh formed?
See book page 32 for steps.
250
How many people does the Nile Delta host and why does it need protection?
Almost a quarter of Egypt's population and generates 20% of Egypt's GDP.
251
What is being done to protect the Nile Delta from flooding and rising sea levels?
The Egyptian Ministry of Water Resources and Irrigation partnered with the UNDP and GCF to launch a climate project with 69 km of low-lying dikes and an agricultural drainage system.
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Evaluate the Nile Delta coastal management and ICZM.
At least 500 families will have raised agricultural income, fostering a closer community with cheap and natural solutions. Dikes have blocked storm surges.
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What is an example of a storm surge and its effects?
Cyclone Sidr in Bangladesh, 2007, had surges up to 6m high, causing damage to 900 tube wells and 8,075 roads due to flooding.
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What is the SMP?
Part of the ICZM, it establishes rules for holding the line and other management strategies.
255
What is the pattern in sand dune formation?
pH becomes more alkaline further from the sea, with lower water content and higher dunes with more humus.
256
How are salt marshes formed? (6 steps)
1. Mud is deposited on the other side of a shingle ridge. 2. Salty conditions allow only green algae to grow. 3. Eelgrass starts growing, allowing for more deposition. 4. Extra thick vegetation blocks currents and creates creeks.
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What is an example of a salt marsh?
Scolt Head, North Norfolk.
