How is the coastal landscape an interrelated system, and what processes and landforms develop within it?
The coastal landscape as a system within a sediment cell; sources of energy and sediment; marine and sub-aerial processes; erosional and depositional landforms; the influence of sea-level change; and how human activity and climate change modify coastal landscapes.
An OCR A-Level Geography answer to the Coastal landscapes option in Landscape Systems, covering the coast as a system within a sediment cell, sources of wave, wind, tide and current energy, marine and sub-aerial processes, erosional and depositional landforms, the landforms of sea-level change, and how human activity and climate change alter coastal landscapes.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
OCR wants you to treat the coast as a system within a sediment cell, identify its sources of energy and sediment, explain the marine and sub-aerial processes that operate, link those processes to erosional and depositional landforms, account for the landforms of sea-level change, and explain how human activity and climate change modify coastal landscapes.
The answer
The coast as a system within a sediment cell
Treating the coast as an open system with inputs, stores, transfers and outputs is the foundation of the topic. The energy inputs are waves, generated by wind blowing over the fetch; constructive waves (low, long, spilling) have a strong swash and build beaches, while destructive waves (high, steep, plunging) have a strong backwash and erode them. Tides set the vertical range over which processes act, and currents redistribute sediment. Coasts are classified by energy (high-energy, exposed, erosional versus low-energy, sheltered, depositional) and by geology: concordant coasts (rock bands parallel to the sea) form coves, while discordant coasts (bands at right angles) form headlands and bays.
Marine and sub-aerial processes
Marine erosion works by hydraulic action (compressed air and water in joints), abrasion (sediment hurled at the cliff), attrition (particles rounding each other) and solution (dissolution of carbonate rock). Sediment is transported by traction, saltation, suspension and solution, and along the coast by longshore drift, driven by the dominant wave approach. Deposition occurs where energy falls below the transport threshold, in sheltered bays and behind obstructions.
Erosional and depositional landforms
On a discordant coast, differential erosion forms headlands and bays. On a headland the sequence runs crack to cave to arch to stack to stump (Old Harry Rocks, Dorset, is the textbook chalk example). Undercutting and cliff retreat leave a wave-cut platform exposed at low tide. Depositional landforms form where the budget is positive: beaches (swash- or drift-aligned), spits (Spurn Head at the Humber mouth), bars and tombolos (Chesil Beach linking the Isle of Portland), plus sand dunes and salt marshes in sheltered, vegetated settings. The same sediment cell can show erosion updrift and deposition downdrift, which is why management in one place affects another.
Landforms of sea-level change
Sea level changes eustatically (a global change in the volume of ocean water, for example as ice sheets melt) and isostatically (local vertical movement of the land, for example rebound after ice unloading). Falling relative sea level produces emergent landforms such as raised beaches and abandoned cliffs; rising relative sea level drowns the coast to produce submergent landforms, rias (drowned river valleys) and fjords (drowned glacial troughs). These set the boundary conditions within which marine and sub-aerial processes then operate.
Examples in context
Example 1. The Dorset coast (UNESCO Jurassic Coast). Dorset shows the whole option in one place. The discordant section around Swanage forms headlands of resistant chalk and limestone with bays in weaker clays, and the chalk headland of The Foreland carries the Old Harry Rocks arch-and-stack sequence. Just west, Lulworth Cove is a classic concordant feature where the sea has breached a resistant Portland limestone band and eroded the softer clays behind. Chesil Beach, an 18 mile tombolo of graded shingle, links the Isle of Portland to the mainland and shelters the Fleet lagoon. Located figures like these turn a generic process answer into a high-Level response.
Example 2. The Holderness coast, East Yorkshire. Holderness is among the fastest-eroding coastlines in Europe, retreating at roughly m per year, because weak glacial till cliffs meet a long North Sea fetch and a narrow beach. Sub-aerial slumping after wet winters dominates the cliff form, while marine processes remove the slumped debris. Defences at Mappleton (rock groynes and a revetment, 1991) trap longshore drift, so the cliffs immediately south are starved of sediment and erode faster, a clear sediment-budget deficit shifted downdrift and a synoptic link to coastal management.
Try this
Q1. Describe how a wave-cut platform forms. [4 marks]
- Cue. Waves erode a notch at the cliff base; the cliff above is undercut, collapses and retreats, leaving a gently sloping platform exposed at low tide.
Q2. Distinguish between a ria and a fjord. [3 marks]
- Cue. Both are submergent valleys drowned by rising sea level; a ria is a drowned river valley with a V-shaped cross-section, a fjord is a drowned glacial trough with a U-shaped cross-section and often a shallow entrance threshold.
Exam-style practice questions
Practice questions written in the style of OCR exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
OCR H481/01 (style)4 marksUsing Fig. 1 (a sediment cell diagram with labelled arrows), describe the movement of sediment within the cell.Show worked answer →
A low-tariff AO3 resource question: read the figure, then describe what it shows in coastal terms. Reward candidates who read off the dominant longshore drift direction from the arrows, identify the sources (cliff erosion and river inputs at the updrift end), the transfers (drift moving sediment along the coast), and the sinks (spits and offshore bars at the downdrift end). A strong answer states the cell is largely closed, bounded by headlands, so sediment cycles within it, and quantifies any figures the resource provides (for example noting a labelled input volume). The skill is precise reading of the resource, not recall of a learned cell.
OCR H481/01 (style)16 marksAssess the extent to which marine processes are more important than sub-aerial processes in shaping coastal landscapes.Show worked answer →
A 16-mark extended response across four Levels (AO1 and AO2). Marine processes act from the sea: erosion by hydraulic action, abrasion, attrition and solution, transport by longshore drift and the swash-backwash system, and deposition that builds beaches, spits and bars. They dominate landforms at and below the wave-attack zone, headlands and bays, caves to stacks, wave-cut platforms and the whole depositional suite.
Sub-aerial processes act from the land: weathering (freeze-thaw, salt crystallisation, carbonation) and mass movement (rockfall, slumping) that retreat and reshape cliff faces and supply sediment to the system. A strong AO2 judgement argues that the balance is context-dependent: on a high-energy, resistant coast marine erosion leads, whereas on a low-energy coast with weak, saturated cliffs (such as glacial till) sub-aerial slumping can dominate cliff form and sediment supply. Reward a supported conclusion that the two are interdependent, marine processes remove the debris that sub-aerial processes deliver, rather than a simple ranking.
Related dot points
- The landscape as an open system of inputs, stores, flows and outputs in dynamic equilibrium; the operation of weathering, erosion, transport and deposition; and how energy, sediment, climate and human activity drive landscape change at varied scales and timescales.
An OCR A-Level Geography answer to the landscape-systems framework underpinning the coastal, glaciated and dryland options. Covers the landscape as an open system of inputs, stores, flows and outputs, dynamic equilibrium and feedback, the geomorphological process families, and how energy, sediment, climate change and human activity drive landscape change across scales.
- Human influences on landscape systems and the management of landscape risk; hard and soft engineering and managed realignment; conflicts between players; and the sustainability of management in a changing climate.
An OCR A-Level Geography answer to how human activity and management modify landscape systems, with a coastal focus that also reaches glaciated and dryland environments. Covers human influences on sediment systems, hard and soft engineering and managed realignment, shoreline management planning, the players and conflicts involved, and the sustainability of management as climate change raises risk.
- The glaciated landscape as a system governed by mass balance; glacial, fluvioglacial and periglacial processes; the erosional and depositional landforms they create; the distribution of past and present ice; and the value, threats and management of cold environments.
An OCR A-Level Geography answer to the Glaciated landscapes option, covering the glacial system and mass balance, glacial, fluvioglacial and periglacial processes, erosional landforms (corries, aretes, troughs) and depositional landforms (moraines, drumlins, eskers), and the value, threats and sustainable management of cold environments.
- The dryland landscape as a system shaped by climatic and tectonic controls; aeolian and fluvial (and weathering) processes; the erosional and depositional landforms they create; desertification and landscape change; and the human use and sustainable management of drylands.
An OCR A-Level Geography answer to the Dryland landscapes option in Landscape Systems, covering arid and semi-arid landscapes as systems, climatic and tectonic controls, aeolian and fluvial processes, weathering, the landforms of erosion and deposition (dunes, yardangs, wadis, alluvial fans, mesas), desertification and landscape change, and the human use and sustainable management of drylands.
- Plate tectonic theory and the processes generating earthquakes, volcanoes and tsunamis; the relationship between hazard, vulnerability and risk; the variation in impact by development and governance; and the synoptic evaluation of tectonic hazard management.
An OCR A-Level Geography answer to the Hazardous Earth debate in Geographical debates, covering plate tectonic theory and the processes generating earthquakes, volcanoes and tsunamis, the hazard-vulnerability-risk relationship, why impacts vary by development and governance, and the synoptic evaluation of tectonic hazard management for Paper 03.
Sources & how we know this
- OCR A-Level Geography (H481) specification — OCR (2016)