Coasts Flashcards

(54 cards)

1
Q

Describe the features of soft engineering

A

Sustainable, long term, less expensive

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2
Q

Describe the features of hard engineering

A

Short term, expensive, visually unattractive

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3
Q

Give two methods of soft engineering that can be used to manage coastal erosion

A

Beach nourishment and manages realignment

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4
Q

Describe beach nourishment

A

The replacement of sand or pebbles onto a beach to make it higher and wider

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5
Q

What are the advantages of beach nourishment?

A

Inexpensive and retains natural appearance of beach

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6
Q

What are the disadvantages of beach nourishment?

A

Increases erosion in other areas of the coast and affects the eco system

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7
Q

Describe managed realignment

A

Areas are allowed to flood/erode by punching holes in embankments or not protecting the coast

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8
Q

What are the advantages of managed realignment

A

Produces salt marshes, which has potential for wildlife, and retains the natural balance of the coastal eco system

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9
Q

What are the disadvantages of managed realignment?

A

Farmers will lose their livelihood as their land is lost to sea and they will have to be compensated

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10
Q

Give three methods of hard engineering strategies used to protect the coast from erosion

A

Sea walls, gabions and groynes

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11
Q

Describe sea walls

A

Concrete blocks built along the front of cliffs to reflect wave energy

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12
Q

Describe gabions

A

Boulders encased in wire mesh

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13
Q

Describe groynes

A

Wooden barriers constructed at right angles to the beach. They retain material which can’t be transported by longshore drift

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14
Q

What are the advantages of sea walls?

A

They provide effective defence where wave energy is high and are also long lasting

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15
Q

What are the disadvantages of sea walls?

A

They are very expensive and can affect beach access

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16
Q

What are the advantages of gabions?

A

They are inexpensive and efficient

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17
Q

What are the disadvantages of gabions?

A

They are visually unattractive and have a shorter life span than sea walls

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18
Q

What are the advantages of groynes?

A

They are inexpensive and retain the white sandy beaches

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19
Q

What are the disadvantages of groynes?

A

Beaches to the south are starved of beach material due to their effect on longshore drift

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20
Q

Where has beach replenishment been used to combat coastal erosion?

A

In Jaywick, Essex, 250000 tonnes of sand from a sand bar was pumped onto the beach. It was expensive at a cost of £10mil but protects 2600 properties and against floods of up to 4.1m above sea level

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21
Q

Where has managed realignment been used to combat coastal erosion?

A

In Jaywick, Essex, holes were punched through old earth embankments. This allowed the sea to reclaim the land behind. Mud deposits absorb wave energy and act as a natural buffer against erosion

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22
Q

What term is used to describe creating a hole in embankments for the sea to flood land behind?

A

Retreating the line

23
Q

Where have sea walls been used to combat coastal erosion?

A

In Jaywick, Essex, sea walls made of concrete have been constructed to reflect wave energy. They are expensive and long lasting, which makes them effective

24
Q

Where have breakwaters been used to combat coastal erosion?

A

In Jaywick, Essex, breakwaters have been built using blocks of granite, that weigh up to 8 tonnes. They slow down the rate of erosion and also slow down the process of longshore drift

25
Describe a tombolo
The process of longshore drift joins an island to the mainland by a spit
26
Describe a sand bar
The process of longshore drift joins two headlands together, across a bay, by a spit
27
How are headlands and bays created?
The sea erodes soft rock more quickly than the more resistant rock, leading to retreat. This retreat forms a bay between two headlands made of resistant rock
28
How are caves formed?
A crack in a cliff is opened by hydraulic action. The crack grows into a cave by hydraulic action and abrasion
29
How are arches formed?
The cave breaks through the headland forming an arch
30
How is a stack formed?
An arch is eroded by hydraulic action and collapses
31
How is a stump formed?
The stack is eroded at the base by hydraulic action to form a stump
32
How is a spit formed?
Longshore drift moves material along the coastline- a spit forms when this material is deposited- The spit will develop a hook if the wind changes direction further out- Waves can't reach behind the spit so an area of deposited silt or salt marshes form
33
How is a wave cut platform formed?
The sea erodes the base of the cliff by hydraulic action and abrasion to form a wave cut notch. The notch is eroded further and the rock above is unstable and collapses. The collapsed rock is taken out to sea in the backwash and the process starts again. The cliff retreats leaving a wave cut platform
34
Why are sea levels rising?
Due to global warming ice caps are melting. Some areas are also experiencing post glacial rebound
35
Give two facts about the Maldives
It's highest point is 2.4m above sea level 30% of its GDP comes from tourism
36
What are the social impacts of rising sea levels in the Maldives?
Population will become environmental refugees due to loss of land. People have to find homes and work which is distressing as they are unsure where to move. Many of these people will be unskilled workers, as the island relies on tourism, and will find it difficult to find a job in their new country
37
What are the environmental impacts of rising sea levels in the Maldives?
Flooding of the island will increase coastal erosion and more land will be lost. Climate change also means more devastating storm surges
38
What percentage of the Maldives will be flooded by a 1m rise in sea levels?
75%
39
What are the economic impacts of rising sea levels in the Maldives?
The Maldives' main source of income comes from tourism and agriculture. Rising sea levels mean that tourism will be lost and people will subsequently lose their jobs- leaving them with a poorer standard of living. Salt water will salinise the soil so crops can't be grown. Business and jobs will be lost, so people will have less money
40
What are the economic impacts of rising sea levels in the UK?
In South East England, the Thames estuary, the government have invested in coastal protection due to previous flooding. Hard engineering strategies were put in place. However, in the future more may need to be invested due to rising sea levels. This requires more money, which has to come from the tax payer
41
How can rising sea levels be managed in the Maldives?
Artificial beaches extend the land. Beaches are created which acts as a barrier and protects against coastal erosion. Less land is lost so the tourist industry can be maintained- money therefore won't be lost. Artificial beaches are also cheap to maintain
42
How can rising sea levels be managed in Jaywick?
Managed realignment means that holes are punched through embankments, known as 'retreating the line.' The mud deposits will absorb wave energy and act as a natural buffer against erosion. This prevents flooding of homes and is a sustainable method. It also creates salt marches which benefits the wildlife
43
How can rising sea levels be managed in the Netherlands?
Amphibious houses can be built with flood preventions. The houses are on stilts and have waterproof containers to protect electrical items. The lower levels of the house are left empty so that there is less damage in the event of a flood. This strategy also means that housing can still be provided for the growing population in areas at risk of flooding
44
What are the positive effects of coastal landforms in Dorset?
Tourists from all over the world visit the Jurassic coast to see attractions such as Durdle Door and Old Harry. Visitors use local facilities such as hotels and purchase goods. This leads to the PME- locals have more money and can improve their standard of living
45
How much money does the Jurassic Coast generate for the Dorset and East Devon economy?
£111million a year
46
By how many metres has the Holderness Coast retreated in the last 150 years?
300m
47
What are the economic impacts of coastal erosion on the Holderness coast?
£250,000 houses have been destroyed. The properties devalue in price and people lose their homes. It is difficult to get insurance and so people end up paying to have the house demolished. They must move out of the area and buy a new property
48
What are the social impacts of coastal erosion on the Holderness coast?
People now live in caravans after losing their homes. They struggle financially after paying to have it demolished. They have to live away from the area and may be emotionally distressed
49
What are the economic and environmental impacts of coastal erosion on the Holderness coast?
Loss of farmland, tourist areas and businesses because of loss of land means that no money is generated and so people have a poorer standard of living
50
What is the economic (governmental) impact of coastal erosion on the Holderness Coast?
The government have spent £1.9mil on hard engineering strategies. This is unwise as the strategies are often unsuccessful and cost more in the long term
51
Describe constructive waves
Operate in calm conditions, less powerful, deposit material, swash is stronger than the backwash
52
Describe destructive waves
Formed by strong winds and erode the coastline. Occur when the fetch is greatest and tend to remove material from the beach
53
Define fetch
The distance the wave has travelled over the sea before reaching the coast
54
What factors affect coastal erosion?
Rock type, weathering, wave type, rock structure and beaches