Coastal Management (Edexcel IGCSE Geography) : Revision Note

Jacque Cartwright

Written by: Jacque Cartwright

Reviewed by: Bridgette Barrett

Updated on

Coastal strategies

  • Management of coastal regions is performed by identifying coastal cells

  • This breaks a long coastline into manageable sections and helps identify two related risks:

    • The risk of erosion and land retreat 

    • The risk of flooding

  • Identification of the risks allows resources to be allocated effectively to reduce the impacts

  • The 'cost-benefit' is easier to calculate using coastal cells

Shoreline management plans

  • Shoreline Management Plans (SMP) set out an approach to managing a coastline from flooding and erosional risk

    • The plans aim to reduce the risk to people, settlements, agricultural land and natural environments (salt marshes etc.)

  • There are four approaches available for coastal management, with differing costs and consequences:

    • Hold the line

    • Advance the line

    • Managed realignment

    • Do nothing

Hold the line

  • Long-term approach and the most costly

  • Build and maintain coastal defences so the current position of the shoreline remains the same

  • Hard engineering is the most dominant method used with soft engineering used to support

Advance

  • Build new defences to extend the existing shoreline

  • Involves land reclamation

  • Hard and soft engineering is used

Managed realignment

  • The coastline is allowed to move naturally

  • Processes are monitored and directed when and where necessary

  • The most natural approach to coastal defence

  • Mostly soft engineering with some hard engineering to support

Do nothing

  • Cheapest method, but the most controversial of the options

  • The coast is allowed to erode and retreat landward

  • No investment is made in protecting the coastline or defending against flooding, regardless of any previous intervention

Which approach to coastal management?

  • Decisions about which approach to apply are complex and depend on:

    • the economic value of the resources that would be protected, e.g. land, homes etc

    • engineering solutions - it might not be possible to 'hold the line' for moving landforms such as spits, or unstable cliffs 

    • cultural and ecological value of land - historic sites and areas of unusual diversity

    • community pressure - local campaigns to protect the region

    • social value of communities - long-standing, historic communities

Hard engineering methods

  • Hard engineering involves building some form of sea defence, usually from concrete, wood or rock

  • Structures are expensive to build and need to be maintained

  • Defences work against the power of the waves 

  • Each type of defence has its strengths and weaknesses

  • Protecting one area can impact regions further along the coast, which results in faster erosion and flooding

  • Hard engineering is used when settlements and expensive installations (power stations etc) are at risk - the economic benefit is greater than the costs of building structures

Hard engineering strategies

Sea wall

  • A wall, usually concrete, and curved outwards to deflect the power of the waves

Advantages

Disadvantages

  • Most effective at preventing both erosion and flooding (if the wall is high enough)

  • Very expensive to build and maintain

  • It can be damaged if the material is not maintained in front of the wall

  • Restricts access to the beach

  • Unsightly to look at

Groynes

  • Wood, rock or steel piling built at right angles to the shore

  • Groynes trap beach material being moved by longshore drift

Advantages

Disadvantages

  • Slows down beach erosion

  • Creates wider beaches

  • Cheap in comparison to other hard engineering methods

  • Stops material moving down the coast where the material may have been building up and protecting the base of a cliff elsewhere

  • Starves other beaches of sand. Wood groynes need maintenance to prevent wood rot

  • Makes walking along the shoreline difficult  

Rip-rap

  • Large boulders which are piled up to protect a stretch of coast

Advantages

Disadvantages

  • Cheaper method of construction

  • Works to absorb wave energy from the base of cliffs and sea walls

  • Boulders can be eroded or dislodged during heavy storm

  • Heavy and expensive to transport

Gabions

  • Wire cages filled with stone, concrete, sand etc

Advantages

Disadvantages

  • Cheapest form of coastal defence

  • Cages absorb wave energy

  • Can be stacked at the base of a sea wall or cliffs

  • Wire cages can break and they need to be securely tied down

  • Not as efficient as other coastal defence

Revetments

  • Sloping wooden or concrete fence with an open plank structure 

Advantages

Disadvantages

  • Work to break the force of the waves

  • Traps beach material behind them

  • Set at the base of cliffs or in front of the sea wall

  • Cheaper than sea walls but not as effective

  • Not effective in stormy conditions

  • Can make beach inaccessible for people

  • Regular maintenance is necessary

  • Visually unattractive

Off-shore barriers

  • Large concrete blocks, rocks and boulders are sunk offshore

  • These alter wave direction and dissipate wave energy 

Advantages

Disadvantages

  • Effective at breaking wave energy before reaching the shore

  • Beach material is built up

  • Low maintenance

  • Maintains natural beach appearance

  • Expensive to build

  • Can be removed in heavy storms

  • Can be unattractive

  • Prevents surfing and s

Soft Engineering Methods

  • Soft engineering works with natural processes rather than against them

  • Usually cheaper and do not damage the appearance of the coast

  • They are considered to be a more sustainable approach to coastal protection

    • However, they are often not as effective as hard engineering methods

Beach replenishment

  • Pumping or dumping sand and shingle back onto a beach to replace eroded material

Advantages

Disadvantages

  • Beaches absorb wave energy 

  • Widens beachfront

  • It has to be repeated regularly which is expensive

  • Can impact sediment transportation down the coast

Fences, hedging and replacing vegetation

  • These help to stabilise sand dunes or beaches 

  • Additional vegetation or fencing also reduces wind erosion

Advantages

Disadvantages

  • Cheap method to protect against flooding and erosion

  • Hard to protect larger areas of coastline cliffs

Cliff regrading

  • The angle of a cliff is reduced to reduce mass movement

Advantages

Disadvantages

  • Prevents sudden loss of large sections of cliff

  • Regrading can also slow down wave cut notching at the base of cliffs as wave energy is slowed

  • Does not stop cliff erosion

Managed retreat

  • Existing coastal defences are abandoned allowing the sea to flood inland until it reaches higher land or a new line of defences

Advantages

Disadvantages

  • No expensive construction costs

  • Creates new habitats such as salt marshes

  • Disruptive to people where land and homes are lost

  • The cost of relocation can be expensive

  • Compensation to people and businesses may not be paid

  • There are conflicting views about using a particular type of engineering for coastal defence

  • Most coastal managers aim to use a range of methods depending on the value of what is being protected

  • This method is known as Integrated Coastal Zone Management (ICZM)

  • ICMZ aims to use a combination of methods to meet as many stakeholder needs as possible

Case Study - The Holderness Coast

  • The Holderness Coastline is located on the East Coast of Yorkshire and runs for 61 km

  • It stretches from Flamborough Head in the north down to Spurn Head, where it meets the Humber Estuary in the south

  • It is the fastest-eroding coastline in Europe at 2 m per year

  • It is made of soft boulder clay and chalk

  • The coastline has naturally narrow beaches, which give less protection from erosion as wave power is not reduced

  • Longshore drift is the dominant process due to North Sea waves

  • Waves along the coastline have a long fetch (travel long distances), which increases wave energy

Map of the Holderness coast showing erosion features with a prevailing wind direction, areas of chalk and boulder clay, and a UK locator inset.
Map showing the Holderness Coast
  • The biggest issue of the Holderness coastline is that it is retreating too quickly

Management of the Holderness Coast

  • Bridlington is protected by a 4.7 km long sea wall

  • Gabions have been built at Skipsea

  • Hornsea's cliffs are formed from soft boulder clay

    • As a popular tourist destination, management is aimed at protecting hotels, and arcades and creating a sandy beach

    • Hornsea has spent money on repairing its wooden groynes at a cost of £5.2 million

    • It also has a concrete seawall

    • Recently, a stone and steel gabion along with a concrete revetment have been built south of Hornsea, helping to protect the caravan park

  • Riprap, at a cost of £2 million, and groynes and beach nourishment at Mappleton have produced a sandy beach and protect the town 

  • Withernsea has a sea wall, groynes, riprap and beach nourishment to widen the beach and reduce wave energy

  • Approximately, 2.25% of all UK gas comes through the gas terminal at Easington and £4.5 million was spent on riprap, but the scheme protects the terminal and not the village

  • Spurn Head is protected with groynes and rock armour

Conflicts

  • Careful management of coastal regions is necessary to ensure sustainability

  • Conflict arises when coastal development is seen as being given a higher priority than overall coastal conservation

  • Management along the Holderness Coast has been successful in part, with the village of Mappleton and the B1242 road no longer at risk from erosion

  • Due to the use of groynes at Mappleton, sediment has been prevented from moving south, which has increased erosion at Great Cowden 

  • Erosion has destroyed farms, along with the loss of 100 chalets at the Golden Sands Holiday Park

  • Locals have disagreed about where sea defences are located, especially if community land is not protected

  • Some sea defences negatively impact tourism and reduce the amount of money coming into the area

  • Spurn Head is at risk of losing habitats due to a lack of sediment to maintain the spit

  • Overall, maintaining coastal defences is expensive and the cost may be too great to continue defending an area that is eroding quickly and will continue to erode 

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Jacque Cartwright

Author: Jacque Cartwright

Expertise: Geography Content Creator

Jacque graduated from the Open University with a BSc in Environmental Science and Geography before doing her PGCE with the University of St David’s, Swansea. Teaching is her passion and has taught across a wide range of specifications – GCSE/IGCSE and IB but particularly loves teaching the A-level Geography. For the past 5 years Jacque has been teaching online for international schools, and she knows what is needed to get the top scores on those pesky geography exams.

Bridgette Barrett

Reviewer: Bridgette Barrett

Expertise: Geography Lead

After graduating with a degree in Geography, Bridgette completed a PGCE over 25 years ago. She later gained an MA Learning, Technology and Education from the University of Nottingham focussing on online learning. At a time when the study of geography has never been more important, Bridgette is passionate about creating content which supports students in achieving their potential in geography and builds their confidence.

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