Coastal Environments Flashcards
(167 cards)
1
Q
What is the coast
A
The zone of transition between land and sea
2
Q
How far does the offshore zone extend from land
A
As far as 370km
3
Q
How far does the onshore zone extend
A
Up to 60km inland
4
Q
What affects the size and energy of a wave (3)
A
- The strength of the wind
- The length of time the wind has been blowing for
- The distance over which the winds had been blowing (the fetch)
5
Q
How do waves work
A
- Created by wind blowing over surface of sea
- As the wind blows, friction is created producing a swell in the water
- Energy in the wind causes water particles to rotate inside the swell, moving the wave forward
- As waves near the coast, they enter shallower waters friction with the sea bed causes the wave to tip forwards so that it eventually breaks
6
Q
What is the backwash
A
The water that flows back towards the sea
7
Q
What is the swash
A
The water that rushes up the beach
8
Q
What is a constructive wave and what effect will it have on the beach
A
Where the swash is greater than the backwash - the beach is built up as sediment is deposited
9
Q
What is a destructive wave and what does it do to the beach
A
The backwash is stronger than the swash - the beach is eroded
10
Q
What is wave refraction and what does it cause
A
The “bending” of wave fronts caused by the speed of the waves being reduced by friction with the sea floor, causing headlands to receive high energy waves and bays to receive low energy waves, so there is more erosion on the headlands
11
Q
How do constitutive and destructive waves differ on the eye (2)
A
- Destructive are tall and steep and close together, but constructive are low and further apart
- Destructive 13-15 per minute, constructive 6-8 per minute
12
Q
What conditions form constructive and destructive waves
A
Stormy - destructive
Clear - constructive
13
Q
What is hydraulic action
A
Waves smashing against cliff. Air becomes trapped in cracks and causes rocks to crack
14
Q
What is the biggest contributor to erosion of the processes of erosion
A
Hydraulic action
15
Q
What is abrasion
A
When pebbles grind along a rock platform, making it smooth, like sandpaper
16
Q
What is attrition
A
When rocks in the sea knock against each other, breaking apart to become smaller and more rounded
17
Q
What is solution as a process of erosion
A
When sea water dissolves certain rocks e.g. limestone and chalk
18
Q
What is longshore drift
A
Sediment is carried by the waves along the coastline - straight up onto the beach from the swash, but then the backwash is diagonal. This is repeated along a zigzag movement
19
Q
What is deposition
A
When the sea loses energy it drops the material it has been carrying. This can be due to 1. Shallow water 2. Sheltered areas e.g. bays 3. Drop in wind, e.g. after a storm
20
Q
What is solution as a process of transportation
A
When minerals in rock e.g. chalk and limestone are dissolved in seawater and carried in solution
21
Q
What is suspension
A
Small particles such as silts and clays are suspended in the flow of the water
22
Q
What is saltation
A
Where small pieces of shingle or large sand grains are bounced along the sea bed
23
Q
What is traction
A
Where pebbles and larger material are rolled along the sea bed
24
Q
What are the 3 types of weathering
A
Mechanical
Biological
Chemical
25
What is freeze-thaw
Water gets into cracks in rock. When temperature drops, the water freezes and **expands by 9%** causing the crack to widen
26
What is salt crystallisation as weathering
When seawater evaporates out of cracks in rock, salt crystals are formed, which over time expand, breaking the rock
27
What is biological weathering
Animals and plants e.g. roots pushing down into rocks or animals burrowing into rocks
28
What is chemical weathering
Mildly acidic water reacting with minerals in the rock, most commonly calcium carbonate
29
What is slumping and why does it happen
Waves erode the cliff base, then rainwater saturates the cliff material, so it slumps in step-like layers. Usually happens to softer rock
30
What is sliding and why does it occur
When material just slides down the cliff - mud (mudslide) or rocks (landslide). Happens when the surface of the cliff is much weaker than the underlying layers
31
What is geology in coastlines
The arrangement of rock types that make up a costal environment e.g. discordant or conorcdant.
Rocks are made up of bedding planes (layers). The direction of these can make cliffs more susceptible to collapsing
32
What is a discordant coastline
The cliffs are perpendicular to the way the sea hits
33
What is a concordant coastline
The cliffs are parallel to the direction of the waves
34
What is lithology in coastlines
Refers to the characteristics of a specific rock e.g. mudstone is a soft rock.
Permeable, grainy rock types will erode quickly
35
How could vegetation affect a coastline (3)
Vegetation e.g. mangroves can protect coastlines and reduce erosion
On sand dunes, vegetation encourages deposition of material by wind
Afforestation (planting vegetation that was not there before) schemes are often used to strengthen vulnerable coasts.
36
What is a wave cut notch
An overhang created because the seas only attacks the base of the cliff
37
What process creates a wave cut notch
Undercutting
38
How do cliffs retreat
1. Overhangs are created through undercutting
2. Eventually the overhanging part of the cliff becomes too unsupported and falls
3. The cycle again repeats
39
Why are headlands and bays created
Soft rock is eroded quicker than hard rock so areas with soft rock become eroded (bays) whereas areas of harder rock erode much slower (headlands). This process is called differential erosion
40
What is a wave cut platform and how is it formed
In cliff retreat, as overhangs fall, a gently sloping platform of hard rock visible at low tide is formed
41
Why are bays sheltered from waves
As waves approach the coast, many are refracted and converge on the headlands, so they stay away form bays
42
What is a cave
A hollow formed within a headland but that does not go all the way through
43
What is an arch
A cave that goes all the way through the headland
44
What is a stack
An isolated column of rock where an arch has collapsed in on itself
45
What are stumps
Bases of stacks that have collapsed
46
How are stumps formed (last step, but e.g. for arches you can just stop explaination at the arch part)
1. The joints between bedding planes are eroded via hydraulic action, creating cracks
2. The cracks eventually turn into caves after more hydraulic action
3. When 2 caves back into each other, an arch is formed
4. Weathering processes especially freeze-thaw weaken the roof of the arch, so it eventually falls, leaving behind a stack
5. As the stack is further impacted by weathering, it eventually becomes a stump, which cannot be seen at high tide
47
What is a spit and how is it formed
An extended stretch of beach material that projects out to sea and is joined to the mainland at one point.
1. Sudden change in coastline shape/direction
2. Longshore drift momentum keeps taking the material the original way
3. Over time sediment builds up
48
How is a salt marsh formed
In an area behind a spit - the water here is stagnant and low energy
49
How is a lagoon formed
An area of water enclosed by a bar
50
What is a bar and how is it formed
Formed the same as a spit - a bar is just a spit that extended far enough to reach the mainland again. They form over the mouth of a river, harbour or bay
51
What is a tombolo
A spit that connects the mainland to an island
52
Where are most of the world’s coral reefs
Intertropical (between +-30º)
53
What conditions are needed for coral reefs to form (6)
1. Shallow water (to get sunlight)
2. 23-25ºC water
3. Clear water (sunlight)
4. Specific PH
5. Clean water
6. Salt water
54
What is the organism that is symbiotic with coral polyps
Zooxanthellae
55
What is coral made of
Calcium carbonate
56
What is the animal in coral
Polyps
57
What are the 3 types of coral reef
Fringing reefs
Barrier reefs
Atolls
58
What are atoll reefs
Circular reefs encircling a lagoon
59
What are Barrier reefs
Reefs forméd in shallower zones of ocean out to sea
60
What are fringing reefs
Reefs that form in shallow waters around landmasses
61
What can the word mangrove mean
The plant or the ecosystem
62
What must plants be if they live in a mangrove (3)
1. Salt-tolerant
2. Able to thrive in oxygen-poor soils
3. Able to cope with frequently changing aquatic conditions due to tides, because it is on the margin between land and sea
63
Where do mangroves grow in the world (3 requirements)
1. Between 32ºN and 38ºS
2. In sheltered, intertidal areas
3. High annual rainfall
64
Which 4 countries have 41% of the world’s mangroves
Indonesia
Brazil
Nigeria
Australia
65
What conditions do mangroves need in order to form (5)
1. The average temperature of the coldest month must be above 20ºC
2. The seasonal temperature range should not exceed 5ºC
3. A fine-grained soil base e.g. silt, mud and sand
4. The shores must be free of strong wave action and tidal current
5. They need salt or brackish (half salt half fresh) water
66
Why are mangroves a vital ecosystem to protect (3)
1. They provide a habitat for many fish and crustacean species, the twists and turns in the roots are a very good hiding place for young fish and crustaceans
2. Mangrove trees can store a lot more carbon than normal trees (4x more)
3. 100m of mangrove can reduce the energy of a wave by 2/3
67
What must a plant growing on a sand dune be able to adapt to (6)
Conditions that are:
Conditions that are:
1. Dry
2. Salty
3. Alkaline
4. Mobile
5. Lacking in nutrients
6. Windy
68
How is a sand dune formed
1. An obstacle (rock, shell, rubbish etc) is on the beach
2. Sand is blown against this obstacle and eventually it forms a dune
69
What is the pioneer stage
1. Seeds are blown in or washed onto the dune
2. Low embryo dunes form which are colonised by sea couch and sea rocket, then marram grass
3. Over time the embryo dunes grow and form a line known as a fore dune
4. This is then moved inland by the wind
5. Meanwhile, a new embryo dune can be forming nearer the sea
70
What are pioneer plants
The first plants that inhabit sand dunes
71
What are some characteristics of pioneer plants (5)
1. High vertical growth rate to keep up with continuous sand deposition
2. Extensive root systems to bind the plants over a large area and to access water
3. Adaptations to decrease water loss or increase water storage capacity
4. Xermophic - plants adapted to lose less water
5. Halophytic - plants adapted to live in salty conditions
72
What is the building stage
1. Plants trap sand and grow with it, binding the sand with their roots
2. The organic matter (humus) created by decaying pioneer plants creates more fertile growing conditions and the soil becomes less alkaline as pioneer plants grow and trap rainwater
3. Less hardy plants can now grow and start to shade out the pioneers
4. As plants colonise the dunes, the sand begins to disappear and the dune changes from yellow to grey
5. The dune system can now support shrubs
73
What are mature dunes
The climax stage in the development of a sand dune
1. Taller plants like trees and more complex plant species like heather can now grow.
2. Plants from earlier stages die out because of competition for light and water
74
What are dune slacks
Depressions between yellow and mature dunes
Regularly flooded because the ares is below the water table (water level in the area)
75
What is the water table
The water level in that area
76
What is a psammosere
A sequence of changes in vegetation types along the sand dunes with increasing distance from the sea
77
What is a stakeholder
Individuals, groups or organisations that have an interest in a particular project or issue
78
What is conservation
Protection of aspects of the environment
79
What is development
Making use of land for a variety of purposes e.g. shopping, industry, retailing and tourism
80
What are most conflicts on coastal management
Human needs vs coastal ecosystem conservation
81
Where can conflict happen around the coast
On the shore, more inland waters or further out to sea
82
What is a salt marsh
A coastal ecosystem found between land and open salt water or brackish water that is regularly flooded by the tides
83
What are mudflats
Salt marshes that have had so much mud deposited in them that the mud breaks to the surface
84
How is salt removed from a mudflat
Rainwater washes it out
85
How do salt marshes become marsh uplands and what do marsh uplands contain in terms of vegetation
1. Lots of mud is deposited in the salt marshes
2. The salt marsh turns into a mudflat
3. Pioneer plants grow
4. Salt is washed out by rainwater
5. The second generation plants (bigger and less salt tolerant) grow
6. Over times bigger and hardier plants grow until in the end, marsh uplands form, that have trees and plants.
86
What is a biotic factor
Any living factor that affects another organism or shapes the ecosystem in some way
87
What is an abiotic factor
Non-living parts of the environment e.g. light intensity, temperature etc
88
What 3 ways are nutrients stored in coral ecosystems
1. Sea water. The ‘soil’. Nutrients supplied through onshore ocean currents and rivers
2. Biomass - the coral, the seaweeds and the fish, crustaceans and invertebrates
3. Litter - dead coral and remains of dead fish, crustaceans, invertebrates and seaweeds
89
What are the biotic characteristics of a coral reef (6)
1. Coral
2. Fish
3. Molluscs
4. Crustaceans
5. Plants
6. Bacteira
90
What are the abiotic characteristics of a coral reef (8)
1. Water temperature
2. Salinity
3. Nutrient levels
4. Ocean PH
5. Sedimentation
6. Currents
7. Light level
8. Water depth
91
What are the benefits of a coral reef ecosystem (4)
1. Generates tourism
2. Lots of fish for food
3. Provides protection from strong waves
4. Promotes biodiversity
92
What are the threats to coral reefs (5)
1. Bleaching
2. Pollution
3. Overfishing
4. Human physical contact
5. Urban development
93
What are the benefits of salt marshes (2)
1. Good nurseries (lots of food, sheltered)
2. Offer protection from sea level rise
94
What are the threats to salt marsh ecosystems (2)
1. Agricultural pollution - eutrophication
2. Industrial pollution
95
What are the benefits of sand dunes (1)
1. Coastal protection
96
What are the threats to sand dunes (2)
1. Used for recreation by humans
2. When they are disturbed, precious vegetation can be lost
97
What are the benefits of mangroves (6)
1. Protection from storms
2. Rich wildlife
3. Roots trap silt which makes land
4. Abundance of timber
5. Many places for fish to hide
6. Good nursery (same reason as 5)
98
What are some threats to mangroves (2)
1. Deforestation
2. Reclaiming land
99
What was our fieldwork enquiry question
What are the costal processes and form occurring at Pett Level
100
Why was pett level a good location (4)
1. Measurable stretch of beach
2. Suitable access points
3. Dynamic coastline
4. Away from hazards
101
Why was our research question good (4)
1. Links to the syllabus
2. Clear and achievable question
3. Concise
4. Focused
102
What was our hypothesis (2)
1. The waves at pett level are constructive
2. As distance northeast increases the cross-sectional area of beach will increase
103
What secondary data did we use and why (3)
1. Maps - to show which areas may be eroding quicker
2. Weather - stormy weather could lead to more destructive waves
3. The beach size will change due to tides
104
How to consider reliability of secondary data (2)
The date
Bias
105
What is qualitative data
Non-numeric data that describes characteristics, qualities or categories
106
What is quantitative data
Numeric data that can be measured and quantified
107
What is random sampling and what are the advantages and disadvantages
Each sample has an equal probability of being chosen. +: removes human bias and no prior knowledge of the area needed. -: can lead to poor representation of the overall area
108
What is systematic sampling, what are the positives and negatives of it
Chosen data is evenly distributed e.g. every 100m. +: no prior knowledge of area needed, no bias and doesn’t need random numbers. -: may lead to misrepresentation of the area
109
What is stratified sampling, what are the positives and negatives
Each aspect of a population is proportionally represented. E.g. measurement taken every time the gradient of the beach changes +: gives an accurate representation of the whole area, removes bias. -: must have detailed prior knowledge and may not have access to each category
110
How do you get a beach profile (cross-sectional view)
1. Put a ranging pole 2m from the shoreline
2. Place another ranging pole at the first obvious change of gradient up the beach
3. Measure the distance between them
3. Place the clinometer against the ranging pole
4. Point it to the same point of the second ranging pole
5. Record the angle of incline/decline
6. Place the first ranging pole at the next obvious change in gradient
111
How do you sample sediment
1. Place a quadrat at the second ranging pole
2. Use a random number generator to select 10 squares within the grid
3. Select one piece of sediment from each selected square
4. Compare it to the powers index of roundness chart and record its roundness (1-6; 1=angular, 6=well-rounded)
5. Using calipers measure along its longest axis and record its length
112
What is wave period
The average time between crests
113
What is swash time
The time between a wave breaking and the time on reaching its highest point of swash (take an average of 10)
114
Why is a risk assessment completed
To identify hazards and how to control the risks
115
What were some risks of the coastal fieldwork day (3)
1. Drowning
2. Stormy weather
3. Trips and slips
116
What is a pilot study
A small scale test done before taking actual data, to assess feasibility, safety and to test the proposed methods
117
What did the formation of Hastings harbour cause
Pett Level’s cliffs to go from relic cliffs to active cliffs
118
What is a relic cliff
Old coastal cliffs now located inland
119
What is a field sketch and what are the pros and cons and improvements
A drawing of the area
+ helps to show shape of landscape, allows for annotations, helps to analyse the area
- requires good artistic skill, hard to draw on paper if its raining
Improvements: annotate a photo, do it when dry
120
What is beach profiling, what are the pros and cons and what are some improvements
A cross section of the beach area
+ simple and easy to repeat, helps to answer hypothesis
- lots of room for human error, difference of opinion, hard to see change of gradient, hard to use clinometer, tides can change beach profile
Improvements: repeat, do different times of day for full tidal range, use a laser clinometer
121
What is pebble sampling, what are the pros and cons and what are some improvements
Picking up pebbles to assess roundness and size
+ measuring longest axis is easy with proper equipment, many repeats give good show of area, explains is longshore drift is happening - smaller and rounder pebbles show this
- roundness is very opinion based, humans tend to pick up nicest looking / biggest pebble
Improvements: more repeats, pick up pebble with blindfold, ask others for opinion on roundness
122
What are wave counts, what are the pros and cons and what are some improvements
Counting how many waves there are in a set amount of time e.g. 5 mins
+ doesn’t require much skill, no equipment needed, easy to repeat
- can easily lose count when wave activity is high, hard to see what is a fresh wave and what isn’t, weather conditions can have an impact
Improvements: take a video, get more people to count at the same time then average, collect secondary data, use a clicker
123
What are the three main sources of error when collecting data
1. Measurement error
2. Operator error (human error/ differing opinions)
3. Sampling error - biased samples
124
What is validity
The suitability of the method to answer the question that it was intended to answer
125
What is reliability
How trustworthy the data is for answering our question. Good things are bigger samples, averages etc
126
What is accuracy
How precise the data is
127
If asked to evaluate the reliability and accuracy of data collection methods (8 marks) how many methods of data collection should you include
4
Beach profiling
Field sketch
Pebble sampling
Wave count
128
What is geolocating and what are the advantages and disadisadvantages
Putting data on a map, using proportional circles for cross sectional area. Quite hard to see exact figures bur trends can be easily seen and anomalies can be more easily explained because they are geolocated
129
What are positives and negatives of stacked bar charts and what are they used for
Good when data is in descriptive categories with groups in each category. Often used to show how quantities have changed over time. The data is easy to read and anomalies are easy to spot but it can be rather overwhelming and it can be difficult to read exact figures and compare width of strips
130
What are the disadvantages and advantages of a pie chart
Advantages - simple and easy to understand
Disadvantages - if there are too many segments it becomes less effective and confusing. Try to limit it to 7
131
Why are scattergraphs good and bad
+ they are great for overviews, finding anomalies, showing patterns and trends
- the characteristics of data e.g. you can only compare two sets of data at a time
132
What does measures of dispersion mean
The spread of the data around the average
133
What is the interquartile range
The range that covers the middle 50% of the data
134
What is good and bad about the mean
+ all values taken account of
- affected by very small or very large values (anomalies)
135
What is good and bad about the median
+ not affected by very big or very small values (anomalies)
- if there is an even number, the median is the average of the middle 2, so the median might not actually be a number in the original data set
136
What is good and bad about the mode
+ the only average that can be used if the data set is not in numbers e.g. colour of cars in a car park
- there can be more than one or no mode, so the mode is not always representative of the data
137
What did we conclude from our investigation at pett level and how did it link back to our hypothesis
Longshore drift was occurring, because as you went northwest the pebbles became smaller and more rounded. This is in line with our hypothesis
The cross sectional area also increases, in line with our hypothesis, except for one time, but this was likely due to human activity.
138
Were the waves likely constructive or destructive at pett level and why do we know that
Destructive - there were 13.4 waves per min, which is in the 13-15 per min range for destructive, but too many for the 6-8 range of constructive. This was against our hypothesis
139
What are sediment cells
Self contained (sediment does not normally transfer from one segment to another) stretches of coastline (very large)
140
What are the four key coastal management options
1. Hold the line
2. Managed retreat
3. No active intervention
4. Advance the line
141
What is advance the line
Extending the coast into what is currently the sea by building defences like groynes in the sea rather than on the beach
142
What is hold the line
Intervene against coastal erosion with hard or soft engineering to prevent further shoreline retreat
143
What is no active intervention as a coastal strategy for defence
Permit natural systems to modify the coastline as they are currently operating. It usually means allowing erosion and cliff retreat to continue
144
What is managed retreat as a coastal defence
The controlled flooding of areas to let the sea reclaim them, to realign the coastline and to create salt marshes to protect against future flooding and erosion
145
What factors determine what defence system is used to protect the coast (4)
1. The rate of coastal change
2. The economic value of the land under threat
3. The cost of intervention strategies
4. Stakeholder opinions
146
What is hard engineering
Building or creating something which will interfere with coastal processes, usually to reduce the power of breaking waves against cliffs
147
What is soft engineering
Working with the natural processes of sea and sand in a more environmentally sustainable way. Using the natural processes to bring about an intended effect
148
What are groynes, their advantages and disadvantages
Narrow structures built at right angles to the coastline, made of timber, concrete or rock. They aim to slow longshore drift by trapping sediment
+ more beach material to dissipate wave energy which results in slower cliff erosion, cheap in comparison to other hard engineering strategies
- beaches further along are starved of beach material because of the lack of longshore drift, alters the usage of the beach
149
What are sea walls, what are their +s and -s
Concrete curved walls placed at the foot of the cliff to prevent erosion. Curved to reflect wave energy back into the sea.
+ effective at protecting base of cliff, sea walls usually have promenades for people to walk on
- waves are still powerful and can break down and erode the sea wall, expensive - around £5,000 per meter
150
What is rip rap, +s and -s
Rock armour - large boulders placed at the foot of a cliff or on a slope. They break the waves and absorb their energy
+ cheaper and easier to maintain than sea wall
- look different to local rocks as the rocks are imported, and they are expensive to transport
151
What are gabions +s and -s
Steel wire cages filled with rocks
+ cheap and fairly effective
- unattractive - can leave rusting metal wire on the beach, cannot withstand strong waves
152
What are revetments +s and -s
Wooden slotted barriers constricted towards the rear of beaches to protect the base of cliffs
+ less beach material eroded compared to sea wall, cheaper and less intrusive too.
- short life span, unsuitable where wave energy is high
153
Offshore reef explaination, +s and -s as a coastal defence
Enormous concrete and natural blocks are sunk offshore to alter wave direction
+ waves break further offshore so erosive power is reduced, the build up of sand is allowed
- they may be reduced by heavy storms, they are difficult to install and the cost can be fairly high
154
What is beach nourishment +s and -s
Sand is pumped onto the beach to build it up. The source of the material is usually offshore dredging.
+ retains natural appearance of beach
- offshore dredging increases erosion in other areas and affects ecosystems, can be expensive as needs to be done regularly, large storms will require beach replenishment
155
What is cliff regrading +s and -s
Making the cliff face longer so that it is less steep.
+ cheap, natural - will encourage wildlife back into the area
- not effective on its own - needs other defences at the base of the cliff, some homes on the cliff may need to be demolished
156
Mangrove rehabilitation or revegetation +s and -s as a coastal defence system
Mangroves can absorb power of waves, especially during ‘freak’ events like storm surges or tsunamis
+ provides habitats, popular with wildlife enthusiasts, low cost and naturally occurring
- can restrict access to beaches, take up large areas of land which could be developed for tourist industry
157
What is managed retreat, the positives and negatives of it
The controlled flooding of low-lying coastal areas
+ cheap solution, creates a salt marsh which can provide habitats and a natural defence against erosion and flooding, salt marshes are diverse ecosystems supporting many species
- land is lost as it is reclaimed by the sea, landowners need to be compensated - can be between £5,000 to £10,000 per hectare
158
What are some common coastal issues in developing countries (6)
1. Increased water pollution
2. Erosion of the coastline
3. Exposure to tsunamis and storm surges
4. Overfishing
5. Mining of coral and sand
6. Continued loss of coral reefs, mangroves and wetlands
159
What is the Coastal Management Plan (CZMP)
A plan established in 1990 in Sri Lanka to conserve, develop and sustainably use the coastal region, to improve the quality of the coastal environment and to promote economic development
160
What can be used to mitigate river flooding
Barriers and floodgates
161
How to answer an 8 marker
AO3 - figure 6a shows that (4 marks so do it 4 times) make sure first sentence of each paragraph uses this
AO4 - explain - answer the question itself. Use PEEL structure
162
what threats does the sri lankan coastline face
1. Pollution of waters
2. Reclamation of mangroves
3. Loss of coral reefs
4. Erosion
5. Tsunamis
163
What does the CZMP actually do
It shows that the government acknowledge that the coastline needs to be managed, so that means that their management plan is coordinated in aims like improving quality of coastal environment while promoting economic development
164
What is significant about the holderness coast
One of the fastest eroding coastlines in europe
165
How is the holderness coast being managed
1. Gabions have been built on private coastline
2. The Hornsea holiday resort - groynes have been built and repaired for £5.2m.
3. The withernsea resort has seen groynes and a sea wall built, as well as beach nourishment, for a cost of £6.3m
4. Rock armour near gas terminal
166
What are the advantages and disadvantages of the groynes used at Hornsea
+: locally effective, low cost, acceptable visually and the low lying land can now be developed on
-: trapping of sand has caused beach deprivation down the coast.
167
Give the mark scheme for explaining longshore drift (3 marks)
Swash carried materials up the beach at an angle to the coast (1) backwash carries it back down at rights angles to the coast (1) which carries material along the beach in a zig-zag pattern. (1)
