Management of Coasts

Question 1

Define Hard Engineering

Answer 1

Making a physical change to the coastal landscape using restraint material, like concrete, boulders, wood and metal.

eyesore

Question 2

Define Soft Engineering

Answer 2

Using natural systems for coastal defence, such as beaches, dunes and salt marshes, which can absorb and adjust to wave and tide energy.

Question 3

What is a Sea Wall ?

Answer 3

-Their main aim is to dissipate wave energy, the recurved structure throws waves back into sea of the path of the next incoming wave, reducing its impact.
-They provide a physical barriers against flooding

Question 4

What is Rock Armour ?

Answer 4

-Consists of large boulders placed in front of a cliff or sea wall and take full force of the waves.
-The boulders are deliberately left angular in appearance to present a large surface area to the waves and create gaps for water to filter out.

Question 5

What are Gabions ?

Answer 5

Smaller boulders that are contained within steel wire mesh cages, each of which can be joined together to form larger structures or walls.

Question 6

What are Revetments ?

Answer 6

Concrete or wooden structures placed across a beach or coastline to take the full force of the wave energy, preventing further erosion of the coast.

Question 7

What are Groynes ?

Answer 7

Wooden, stone or steel breakwaters built perpendicular to the coast. They are built to control longshore drift. This could lead to less sediment being deposited along the coastline.

Question 8

What is Beach Nourishment ?

Answer 8

Aims to replace material that has been lost through longshore drift.

Question 9

What is Dune Regeneration ?

Answer 9

Dunes are fragile to human activity, most damage is caused by the removal of vegetation. This can loosen the sediment making the sand viable to blowouts.
-replanting venerable areas with plants such as marram grass
-afforestation
-restricting human access
-providing broad walks for humans.

Question 10

What is Managed Retreat ?

Answer 10

Abandoning the current line of sea defence and developing the exposed land in some way, perhaps with salt marshes to reduce wave power.
-the scale of hard engineering can be reduced
-In California there are requirements that buildings must be a certain distance from the shore.

Or do nothing

Question 11

What is Land-Use Management ?

Answer 11

If erosion and flooding is inevitable, a local authority will educate the community on how locals can still use the land at risk, for example; caravan parks, using the land for grazing.

Question 12

Describe a case study of Hard Engineering in the UK

Answer 12

The coastal town of Morecambe has used numerous strategies.
- 1) Rock Armour / locally sourced / placed along the promenade
- 2) Groins / a million tonnes of locally sourced limestone / built in intervals along the towns coast
- 3) Repaired Seawall / cost £11million / 4km of new seawall / designed to last 100 years.
- 4) Gabions / over 500 cages filled with small limestone boulders / various locations to reinforce the coast.

Question 13

Describe a Case study of Soft Engineering in the UK

Answer 13

The Sefton Coast, north of Liverpool, has the largest dune area in England extending over 17km
- 1) planting, used Christmas trees on the seaward edge of the dunes to trap more sand and encourage dune regeneration.
- 2) fencing off areas of sand dunes to restrict pedestrian access
- 3) wooden posts placed in front of the dunes to encourage dune regeneration.

Question 14

What are the Sundarbans ?

Answer 14

The Sundarbars is a coastal zone occupying the world’s largest delta that extends over 10,000km sq. The Ganges, Brahmaputra and Meghan all deposit sediment into this delta. The natural climax of the Sundarbans are mangrove forests and swamps.

Recent Cyclone Mocha affecting the Sundarbans

Bangladesh

Question 15

What Coastal processes occur in the Sundarbans ?

Answer 15

The silt and clay deposits are quite resistant to erosion, with small interconnecting river channels flowing. The larger channels are generally 2km wide flowing north to south due to strong tidal currents.

Sediments like sand are washed out and deposited on banks, leading to dunes when southwesterly monsoon winds blow.

Question 16

What is the importance of Mangroves in the Sundarbans ?

Answer 16

Mangroves are extremely important to the ecosystem providing timber, and protecting the shoreline from floods and shoreline erosion.

Question 16

What is the importance of Mangroves in the Sundarbans ?

Answer 16

Mangroves are extremely important to the ecosystem providing timber, and protecting the shoreline from floods and shoreline erosion.

Question 17

What are the Natural Challenges for the people of the Sundarbans ?

Answer 17

• Coastal Flooding
• Cyclones
• High Levels of Salinity in the Soil
• Instability of the islands
• Accessibility
• Human eating tigers (Bengal Tiger)

Question 18

What are the Human Challenges for the people of the Sundarbans ?

Answer 18

• Over-exploitation of coastal resources from vulnerable habitats.
• Conversion of wetlands to intensive agriculture and settlements
• Destructive fishing techniques
• Lack of awareness of the environmental and economic importance of the region
• Resource conflicts

Question 19

What are the Mitigation processes undertaken the Sundarbans ?

Answer 19

• Good level of social capital
• Threat of natural disasters means there has been a significant investment in infrastructure.
• Recent human pressures like deforestation
  could utilize a number of open access natural resources.
• Density of 30 trees per 0.01
  hectares can reduce the force of tsunami by 90%

Question 20

What are the different options of coastal management ?

Answer 20

• Do nothing
• Hold the line
• Advance the Line
• Managed retreat / realignment

Question 21

What are the Shoreline Management Plans (SMPs)

Answer 21

Introduced in 1995. DEFRA overseas the UK coastal management, each cell has its own management plan. The management objectives of SMPs are continually reviewed;
* provide an assessment of the risks associated with the evolution of the coast
* provide a framework to address the risks to people and to the developed, historic and natural environment
* address risks in a sustainable way
* provide the policy agenda for coastal defence management planning
* promote long-term management policies for the twenty-second century
* aim to be technically sustainable, environmentally acceptable and economically viable
* ensure management plans comply with international and national nature conservation and biodiversity legislation

Question 22

What is the ICZM ?

Answer 22

The integrated coastal zone management, recognises coastal shorelands, lowlands, intertidal areas, lagoons, and open waters as a single interacting and indivisible resource unit that lies between the upland and the open sea and whose future must be planned and managed in combination.

Question 23

What is the difference between SMP and ICZM ?

Answer 23

The shoreline management plans are the actual PLANS invovling defences and holding the line etc.

ICZM - integrating would be for example beach stabilisation, as it INTEGRATES - fits in- with the environment and wildlife. Creates, not destroys.

Question 24

Where is the Holderness Coast located ?

Answer 24

The Holderness Coast is located on the east coast of England. It extends 61km from Flamborough in the north to Spurn Point in the south.

Question 25

What are the important aspects of the Holderness Coastline ?

Answer 25

The Holderness Coastline is one of Europe’s fastest eroding at an average annual rate of around 2 metres per year. This is around 2 million tonnes of material every year.

Question 26

What is the Geology of the Holderness Coastline ?

Answer 26

Underlying the Holderness Coast is bedrock made up of Cretaceous Chalk. However, in most places, this is covered by glacial till deposited over 18,000 years ago. It is this soft boulder clay that is being rapidly eroded.

Question 27

Why is the Holderness Coastline eroding so rapidly ?

Answer 27

There are two main reasons why this area of coast is eroding so rapidly. The first is the result of the strong prevailing winds creating longshore drift that moves material south along the coastline. The second is that the cliffs are made of soft boulder clay which erodes rapidly when saturated.

Question 28

What is an examples of erosion on the Holderness Coastline ?

Answer 28

The exposed chalk of Flamborough provides examples of erosion, features such as caves, arches and stacks.

Question 29

What is an example of Hard engineering on the Holderness coastline ?

Answer 29

Hornsea
- groynes, create wide and steep beaches // also has led to erosion beyond the terminal groyne syndrome

• seawall, to protect the front of the town
• rock armour
• gabions formed from old railway lines.

Withernsea
- groynes

-concrete sea wall

-rock armour

Coastal defences were built at Withernsea during the 1870s. Nine extensions have followed. Replacement of timber groynes and a strengthening of the sea wall were carried out at Withernsea’s north end in 2017/2018.

Question 30

Have the coastal protection of Withernsea been effective?

Answer 30

The beach profile above the beach is relatively steep indicating a wide beach which helps protect the coast from erosion. Also, there is no evidence of cliff retreat which suggests the coastal defences are effective along the sea front at Withernsea.

Rates of coastal erosion have increased to the south of the defences at Withernsea. This is because the material is trapped by the groynes along the seafront. This means beach material that is transported away by longshore drift is not replaced leaving little sediment on the beaches. Waves can then reach the base of the cliff at high tide causing erosion of the soft boulder clay cliffs. (Terminal Groyne Syndrome)

Question 31

Describe an example of human impacts that have been caused by erosion along the Holderness Coast ?

Answer 31

Skipsea Sands Caravan park - loss of 10 caravan pitches per year.

Decrease in land value, no gov. compensation

The coastal road that once linked village to Ulrome has now been eroded.

Question 32

What is an example of coastal management along the Holderness Coastline ?

Answer 32

Mappleton

The village of around 50 properties has been subject to intense erosion at a rate of two metres per year, resulting in the access road being only 50m from the cliff edge at its closest point.

It was cheaper to protect Mappleton than construct a new route.

In 1991 almost £2 million was spent on two rock groynes and a rock revetment to protect Mappleton and the B1242 coastal road. In addition, blocks of granite were imported from Norway for the sea defences.

The cliffs have been reprofiled, forming gentle slopes which have been stabilised with vegetation. This has protected the cliffs from mass movement

Protecting the B1242 coastal road and 50 properties.

Question 33

What is the example of the Spit along the Holderness Coast ?

Answer 33

Spurn Point (5.5km long)
most southernly point of the Holderness Coastline

Marram Grass (Stabilisation)

Salt Marsh formation due to stationary water