Coasts - Case Studies

Holderness - Location

• Location: East Yorkshire, NE England.

• Extent: Flamborough Head (north) → Spurn Point (south), ~61 km long.

• Erosion: Fastest eroding coastline in Europe -

  2 m per year.

• Material loss: ~2 million tonnes/year.

• Historic losses: ~3 miles of coastline + 23 villages/towns since Roman times.

• Reason it’s studied: Classic UK case of rapid coastal retreat and conflict between protection vs sustainability.

Holderness - Reasons for Coastal Management

• Weak geology: Boulder clay cliffs slump when saturated.

• Narrow beaches: Provide little wave protection.

• Powerful waves: Long fetch across North Sea → high energy.

• Man-made interference: Groynes stop sediment transport, starving other beaches.

Holderness - Causes of Erosion

• Geology:

  • Predominantly boulder clay (glacial till) → weak, porous, easily saturated.

  • Collapses by slumping/mass movement when wet.

• Wave energy:

  • Long fetch across North Sea.

  • High-energy, destructive waves → strong hydraulic action and abrasion.

• Beaches:

  • Naturally narrow, offering little protection.

  • Groynes trap sediment locally but increase erosion downdrift.

• Climate change factor (added context): Rising sea levels + storm surges worsen erosion risk.

Holderness - Coastal Defences

Hard engineering:

• Seawalls (reflect wave energy).

• Groynes (trap longshore drift sediment, build beaches).

• Rock armour/rip-rap (absorb wave energy).

• Revetments + offshore reefs (e.g. Withernsea).

Key protected towns:

• Bridlington: 3.6 km of seawalls + groynes.

• Hornsea: 1.86 km seawall, groynes, rock armour.

• Withernsea: 2.26 km seawall, groynes, offshore rock reef.

Holderness - Mappleton

• Current defences constructed in 1991 after an economic case was made.

• It was predicted that cliff erosion was to erode the village and the main road that links many of the coastal villages (important B1242 road)

Defences built:

• 450 m of cliff protected.

• 61,500 tonnes of Norwegian rock → rock armour revetment.

• Two large rock groynes built.

Holderness - Mappleton 2

Positives:

• Saved village and road.

• Created a wider beach between groynes.

• Boosted local tourism (car park, businesses).

Negatives:

• Sediment starvation southwards → erosion at Great Cowden.

• Loss of farmland + 100 holiday chalets at Golden Sands Holiday Park.

• Cliffs downdrift retreating even at neap tide.

Holderness - Human Impacts, Conflicts & Sustainability

• Stakeholders: residents, farmers, holiday park owners, councils, Defra, environmental groups.

• Tourism: ~24 caravan parks within 200 m of cliff → many forced to “roll-back” (move inland).

• Conflicts:

  • Defended towns (Mappleton, Hornsea) vs undefended farmland.

  • Hard defences protect assets but increase downdrift erosion.

  • Farmers losing land (no compensation).

• Sustainability issues:

  • Expensive to maintain defences long-term.

  • Sea-level rise + storms = increasing cost/pressure.

  • Managed retreat is controversial but often more realistic.

• Exam angle: Holderness illustrates “winners and losers” in coastal management + cost-benefit decisions.

Holderness - Tourism & Roll-Back Policy

• Tourism depends on 3 main towns + 24 caravan/holiday parks (within 200 m of cliff).

• Main policy: roll-back — move caravan sites >400 m inland when too close to cliff.

• Aim: allow managed retreat while still maintaining local economy.

• Shows adaptation approach instead of costly hard defences

Odisha ICZM

Odisha is the 9th largest state in India and 11th by population. It is in the NE of India, bordering the Bay of Bengal. Odisha is largely low-lying coastal plains with six distinctive river deltas.

Odisha ICZM ecology and biodiversity

Odisha's coastline of 480km has 1435km squared of mangrove forest as well as large stocks of fish, reptiles, turtles and seaweed. It also has wind, solar, tidal and wave energy opportunities. Chilika lake is an example of this ecology, with over 150 bird species.

Odisha ICZM drawbacks

Human intervention to protect infrastructure has led to exacerbated erosion further down the coast. Dense mangrove forest leads to 50% higher deposition rates, with deforestation the mangrove is less effective.

Odisha ICZM climate change effects on human life

Low-lying settlements have flooded. Tropical storms are becoming more frequent and more powerful due to a warming ocean. Coastal properties are facing higher rates of erosion. Authorities now supply relief supplies to affected communities.

Odisha ICZM project

The integrated coastal zone management project in Odisha is a collaberation between local and national government, the World Bank and the ministry of forest and environment. The project aims to facilitate economic and social activity while protecting environmental assets and resolving stakeholder conflict.

Odisha ICZM project objectives

Criteria of objectives towards success: Formulation of ICZM, Coastal erosion, Vulnerability to disaster, Biodiversity conservation, Livelihood security, pollution and environment quality, cultural asset protection

Seaford - Coastal management

Seaford has a shingle beach, this shingle is transported along the coast from West (Newhaven) to East (Eastbourne) by long shore drift. Measures are in place to preserve shingle otherwise Seaford can suffer from intense flooding during storms.

Seaford - Terminal groyne

Seaford's terminal groyne was constructed in June 1986, at a cost of £620,000, it took 20 weeks to complete.

Advantages include:

• It traps sediment being transported by LSD therefore Seaford beach is built up.

• The terminal groyne is also relatively cheap for its effectiveness.

Disadvantages include:

• By trapping sediment from being transported by LSD, it starves the coastline further down the coast of sediment.

• It is also criticised for being unnatura

Seaford - Sea wall

• The sea wall cost £1.4m in 1986, at roughly £6000/metre.

• The concrete wave is designed to absorb wave energy.

Advantages include:

• Being effective in preventing erosion as the wall absorbs wave energy.

• Also, leisure opportunities arise as the sea wall becomes a promenade.

Disadvantages include:

• Wave energy often being reflected elsewhere,

• It looks unnatural and intrusive, also it is expensive to build.

Seaford - Rock armour

Rock armour in Seaford are piles of granite boulders behind the sea wall at a cost of £1.4m cost as the boulders were imported from Spain, 58,000 tonnes in total.

Advantages include; it stabilises the beach and is easy to construct with low maintenance.

Disadvantages include; it can look intrusive and is dangerous.

Seaford - Beach replenishment

Shingle pumped from offshore sea bed, builds up the beach, at a cost of £6.2m.

Advantages include; it keeps the beach built up and it allows the beach to remain natural-looking.

Disadvantages include; It is needed frequently as sediment is transported along the coast and lost from the beach and/or eroded.

Seaford - Beach Recycling

Diggers and trucks transport shingle from the East end of the beach (by the terminal groyne) at a cost of £300,000/year.

Advantages include; increased tourism opportunities and its natural appearance.

Disadvantages include; constant maintenance and restricted beach access during recycling.