Coastal Case Studies

Spec mapping (AQA 7037): Paper 1, §3.1.3 Coastal Systems and Landscapes — case studies at a local scale and of a contrasting coastal landscape beyond the UK, to illustrate and analyse the interaction of processes, landforms, sediment cells, and management responses, and to engage with the changing relationship between people and the coast. This synthesising lesson is where the entire systems framework, the process geography of Lessons 2–6, the sea-level context of Lesson 7, the integrative landscape model of Lesson 8 and the management evaluation of Lesson 9 are applied to real, contrasting places. It links synoptically to §3.1.5 Hazards (storm surges, the 1953 and 2013 events), §3.1.6 contemporary issues (the people–coast relationship, climate justice) and §3.1.4 Glacial Systems (till as the Holderness input). The dominant Assessment Objectives are AO1 (located factual knowledge with data), AO2 (applying and evaluating across contrasting contexts) — and these case studies provide the located evidence that lifts an AO3 data-response or a 20-mark essay from generic to authoritative.

Why this lesson matters. AQA examiners are emphatic that place-specific detail — named locations, dates, costs, rates, schemes — is the single biggest discriminator between mid- and top-band scripts. Two thoroughly evidenced, evaluated case studies beat five thinly-described ones every time. This lesson supplies a contrasting pair (rapidly-eroding, lightly-managed Holderness versus heavily-engineered, densely-populated coasts) plus international examples, with the figures you need to write with authority.

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Case Study 1: The Holderness Coast, East Yorkshire

The Holderness coast is arguably the most important single case study for AQA Coastal Systems and Landscapes. It illustrates rapid erosion, sediment transport, deposition, management conflicts and the systems approach in a single, coherent example.

Physical Characteristics

Feature	Detail
Location	East coast of England, between Flamborough Head and Spurn Point
Length	Approximately 60 km
Geology	Primarily glacial till (boulder clay) deposited during the Devensian glaciation (~26,000-13,000 years ago)
Wave environment	Exposed to waves from the North Sea; maximum fetch ~800 km (to Norway); prevailing waves from the north-east
Tidal range	Macrotidal (approximately 5 m spring range)
Average retreat rate	1.8 m/year (one of the fastest in Europe)

Why Does the Holderness Coast Erode So Rapidly?

graph TD
    A["Rapid Erosion at Holderness"] --> B["Soft geology: unconsolidated glacial till"]
    A --> C["High wave energy: long fetch, frequent storms"]
    A --> D["Narrow/absent beach: limited natural protection"]
    A --> E["Sub-aerial processes: slumping when clay is saturated"]
    A --> F["Limited vegetation: clay cliffs support little plant cover"]
    B --> G["Till dissolves and collapses when wetted by waves"]
    C --> H["North Sea storms generate destructive waves"]
    D --> I["Eroded till breaks down quickly — clay washed away"]

The combination of these factors produces retreat rates that vary from 0.5 m/year in years with few storms to over 10 m/year during exceptionally stormy winters. The winter of 2013-14, with its succession of powerful storms, caused retreat of up to 7 m at some locations.

Historical Loss

The scale of land loss at Holderness is dramatic:

• Since Roman times (~2,000 years ago), approximately 4 km width of land has been lost to the sea
• Over 30 settlements recorded in the Domesday Book (1086) have been completely destroyed, including the once-important town of Ravenser Odd, which was a thriving port and market town in the 13th century before being engulfed by the sea by 1360
• Currently, approximately 100,000 m² of land is lost per year
• Individual properties continue to be lost — in 2024, several clifftop houses near Skipsea were demolished as they teetered on the cliff edge after a winter of rapid retreat, a recurring reminder that the headline retreat rate translates into real homes lost within a single human lifetime

Sediment Transport and Deposition

The material eroded from the Holderness cliffs does not simply disappear:

• Approximately 3.4 million m³ of material is eroded annually
• Of this, roughly 1.65 million m³ (about 50%) is transported southward by longshore drift
• Much of this sediment feeds the growth of Spurn Point spit (see Lesson 6)
• Fine material (clay and silt) is deposited in the Humber Estuary, contributing to its extensive mudflats
• Some sediment is carried offshore, contributing to sand banks in the southern North Sea
• The Holderness coast is part of Sediment Cell 2 (Flamborough Head to The Wash)

This sediment pathway is the analytical key to the whole Holderness case, because it makes the coast a single linked system in which erosion and deposition are two faces of one process. The till eroded from the cliffs does not vanish; it is the raw material that builds Spurn Point and floors the Humber with mudflats and the Lincolnshire/north-Norfolk coast with sand. Three consequences follow that examiners reward. First, cause and effect are spatially separated: a decision at Mappleton has effects at Cowden (down-drift) and, cumulatively, at Spurn (cell terminus) tens of kilometres away. Second, the coast cannot be defended piecemeal without consequence — defend one frontage and you intercept the throughflow that the next frontage, and ultimately Spurn, depends on. Third, and most strikingly, this means erosion at Holderness is functionally necessary to sustain the depositional landforms and the internationally important Humber and Spurn habitats down-drift; "stopping erosion" along the whole coast would starve and degrade those very features. The Holderness coast is therefore the definitive demonstration that a sediment cell must be managed as a whole — the founding lesson of the entire course, written in 60 km of disappearing clay.

Coastal Management at Holderness

The Holderness coast demonstrates the full range of management responses and their consequences:

Location	Management	Outcome
Bridlington	Sea wall, groynes, rock armour	Town protected; beach maintained by groynes; funded due to high BCR (large population, tourist economy)
Mappleton (1991)	Two rock groynes + rock armour; cost £2 million	Village of 80 properties protected; but erosion at Cowden (2 km south) increased from 1.8 m/year to over 4 m/year — classic terminal groyne effect
Withernsea	Sea wall, groynes	Town centre protected; erosion continues either side
Hornsea	Sea wall, groynes, rock armour	Protected; but downdrift erosion accelerated at Mappleton before the 1991 scheme
Easington	Rock armour (protecting gas terminal)	The Easington gas terminal (receiving North Sea gas worth billions of pounds) is protected; surrounding agricultural land is not
Spurn Point	No active intervention since 2013 storm	Following the breach in December 2013, the Environment Agency adopted a policy of allowing the spit to evolve naturally

The Holderness Management Dilemma

The fundamental dilemma at Holderness illustrates key themes in coastal management:

1. Cost-benefit asymmetry: Towns like Bridlington and Withernsea have sufficient asset value to justify expensive defences. Rural areas with scattered farms and few properties do not meet the BCR threshold for government funding
2. Interconnected system: Protecting one section of coast (e.g., Mappleton) disrupts sediment supply to areas downdrift, accelerating erosion there
3. Sediment supply: If all cliffs were defended, the sediment supply to Spurn Point and the Humber mudflats would be cut off, potentially causing these features to deteriorate
4. Social justice: Residents losing their homes in unprotected areas receive no compensation and cannot sell their properties — raising questions about fairness and equity

Exam Tip: The Holderness coast is ideal for 20-mark essay questions on coastal management conflicts. Structure your answer around the interplay between physical processes (erosion rates, sediment transport) and human factors (economic value, social justice, environmental importance). Always reference specific places and data.

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Case Study 2: The Dorset Coast (Jurassic Coast)

The Dorset coast provides outstanding examples of geological influence on coastal landscapes and has been designated a UNESCO World Heritage Site (2001) as the Jurassic Coast, stretching 155 km from Orcombe Point (Devon) to Old Harry Rocks (Dorset).

Geological Diversity

The Dorset coast exposes rocks spanning 185 million years of Earth history, from the Triassic through the Jurassic to the Cretaceous:

Location	Rock Type	Age	Landforms
Lulworth Cove	Portland limestone, Wealden clay, chalk	Jurassic-Cretaceous	Almost circular cove; concordant coast breakthrough
Stair Hole	Portland limestone, Purbeck beds	Jurassic	Early-stage cove formation; the Lulworth Crumple (folded beds)
Durdle Door	Portland limestone	Jurassic	Natural arch — one of the most photographed landforms in England
Old Harry Rocks	Chalk	Cretaceous	Stacks and stumps at Handfast Point
Chesil Beach	Flint, quartzite shingle	Quaternary deposit	29 km tombolo/barrier beach
The Fleet	Behind Chesil Beach	N/A	Tidal lagoon — largest in England
Kimmeridge Bay	Kimmeridge clay	Jurassic	Wide wave-cut platform; oil-rich shale

Key Landform: Lulworth Cove

Lulworth Cove is perhaps the single most important concordant coast example in the UK:

• The outer band of Portland limestone is approximately 120 m wide at sea level, with near-vertical bedding
• A breach in this limestone (possibly along a fault) allowed the sea to erode the softer Wealden clay behind
• The clay was rapidly eroded, creating a roughly circular cove approximately 450 m in diameter
• The back wall of the cove is formed by more resistant chalk, which has slowed further retreat
• The cove is almost perfectly symmetrical because erosion proceeded at roughly equal rates in all directions once the outer barrier was breached

Key Landform: Durdle Door

Durdle Door is a natural limestone arch on the Jurassic Coast, approximately 1 km west of Lulworth Cove:

• Formed from a band of Portland limestone that extends from the cliff as a narrow ridge
• Marine erosion (principally hydraulic action) exploited a weakness (joint or bedding plane) in the limestone, eroding through the ridge to form the arch
• The arch is approximately 60 m wide and stands about 25 m above sea level
• It is considered geologically unstable and is expected to collapse in the coming decades to centuries, leaving a stack

Management of the Jurassic Coast

As a World Heritage Site, the Jurassic Coast presents particular management challenges:

• Conservation vs. access: Over 10 million visitors per year visit the coast, creating pressures of erosion (footpaths), pollution and disturbance
• Fossil collecting: The coast is world-renowned for its fossils (ichthyosaurs, ammonites, belemnites). The Jurassic Coast Fossil Collecting Code of Conduct permits responsible collecting from the beach and fallen cliff material but prohibits hammering from the cliff face
• Natural processes: The World Heritage designation is based on the geological exposures created by natural erosion. Coast protection works that obscure geology could undermine the site's heritage value
• The Jurassic Coast Trust coordinates management across multiple local authorities, landowners and stakeholders

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Case Study 3: The Nile Delta, Egypt (International)

The Nile Delta provides an international example of how human intervention has dramatically altered coastal dynamics.

Background

• The Nile Delta covers approximately 24,000 km² and is home to over 50 million people
• For thousands of years, annual Nile floods deposited 100-150 million tonnes of sediment on the delta, sustaining its growth and fertility
• The delta's coastline is approximately 225 km long, with low-lying, sandy beaches and salt marshes

Impact of the Aswan High Dam (1970)

The completion of the Aswan High Dam in 1970 transformed the delta's sediment budget:

• The dam traps approximately 98% of the Nile's sediment in Lake Nasser, upstream
• Sediment delivery to the delta fell from ~130 million tonnes/year to less than 3 million tonnes/year
• Without fresh sediment input, the delta coastline has shifted from progradation (advance) to recession (retreat)

Consequences

Impact	Detail
Coastal retreat	The Rosetta promontory has retreated by up to 5 m/year since 1970 (Stanley and Warne, 1993); the Damietta promontory has retreated by similar rates
Subsidence	Without new sediment deposits, the delta surface is compacting and subsiding at rates of 3-5 mm/year
Saltwater intrusion	Reduced river flow and land subsidence have allowed saltwater to penetrate further into the delta, contaminating groundwater and reducing agricultural productivity
Sea level rise	Combined with subsidence and reduced sediment, global sea level rise of 3+ mm/year compounds the problem
IPCC projections	A 0.5 m rise in sea level could inundate approximately 30% of the delta, displacing ~6 million people and destroying 12-15% of Egypt's agricultural land
Defence works	Concrete sea walls and breakwaters have been built along parts of the delta coast, but these are expensive and have redistributed erosion to adjacent, unprotected areas

Key Definition: Coastal progradation is the seaward advance of the coastline due to sediment deposition exceeding erosion. Coastal recession is the landward retreat of the coastline when erosion exceeds deposition.

Lessons from the Nile Delta

The Nile Delta case study illustrates several important principles:

1. Systems interconnectedness — intervention far upstream (the Aswan Dam, 900 km from the coast) has dramatic consequences at the coast
2. Sediment budget — reducing sediment input shifts the coastal system from positive to negative budget
3. Unintended consequences — the dam brought enormous benefits (flood control, hydroelectric power, irrigation) but at the cost of coastal stability
4. Hard engineering limitations — concrete defences along the delta coast are expensive and create problems elsewhere
5. Climate change amplification — sea level rise compounds the effects of reduced sediment supply and subsidence

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Case Study 4: The Maldives (International)

The Maldives provides a case study of a low-lying island nation facing existential threats from sea level rise (see also Lesson 7).

Coastal Management in the Maldives