Pearson Edexcel iGCSE Geography - Coastal Environments

Essential vocabulary flashcards covering coastal physical processes, erosion, deposition, ecosystems, sea-level changes, and engineering management strategies based on the Edexcel iGCSE Geography specification.

Abiotic

Non-living components of an ecosystem (e.g. temperature, salinity, sunlight, pH).

Biotic

Living components of an ecosystem.

Fetch

The distance of open water over which the wind blows to generate a wave.

Destructive waves

High, steep-sided waves with short wavelength and high frequency ($10\text{--}12$ per minute) whose backwash is stronger than swash, dragging material offshore and eroding the coastline.

Constructive waves

Low, flat waves with long wavelength and low frequency ($6\text{--}8$ per minute) whose swash is stronger than backwash, pushing material up the beach to deposit sediment.

Swash

The movement of water up a beach as a wave breaks.

Backwash

The movement of water down a beach after a wave breaks.

Hydraulic action

The sheer force of air and water compressed into cracks in rock as waves break against the cliff.

Abrasion (corrasion)

Erosion caused by rock fragments carried by waves scraping and wearing away the cliff or shore like sandpaper.

Attrition

Erosion process where rock fragments carried by the sea collide with each other, breaking into smaller, more rounded pieces.

Solution (corrosion)

Chemical dissolving of soluble rock (such as calcium carbonate in limestone or chalk) by weak acids in seawater.

Mass movement

The downslope movement of weathered rock and soil material under the direct influence of gravity.

Slumping

A rotational movement of saturated soil or clay along a curved slip plane, frequently triggered by rainfall on weak cliffs.

Wave refraction

The bending of wave crests as they enter shallower water near an irregular coastline, concentrating wave energy on headlands and dispersing it in bays.

Longshore (littoral) drift

The net zig-zag movement of sediment along a coast caused by waves breaking at an angle to the beach and backwash returning at right angles under gravity.

Discordant coastline

A coastline where rock strata run at an angle or right angle to the coast (Atlantic-type), exposing alternating bands of hard and soft rock that form headlands and bays.

Concordant coastline

A coastline where rock strata run parallel to the coast (Pacific-type), where a outer resistant band protects softer rock until breached.

Wave-cut platform

A gently sloping expanse of exposed bedrock left at the foot of a retreating cliff as wave notches cause repeated overhang collapse.

Spit

A depositional ridge of sand or shingle attached to land at one end and projecting out into open water across an estuary or bay where coastline direction abruptly changes.

Bar

A ridge of sand or shingle that grows completely across a bay, connecting two headlands and enclosing a lagoon, or forming parallel offshore.

Tombolo

A depositional ridge of sand or shingle that connects the mainland to an offshore island.

Halophytic

Describes plants specifically adapted to tolerate saline or salty conditions.

Xerophytic

Describes plants specifically adapted to tolerate dry or drought conditions.

Eustatic change

A global change in sea level resulting from changes in the actual volume of water within world oceans.

Isostatic change

A local change in the height of the land relative to the sea, such as land rebounding upwards after the removal of glacial ice sheets.

Ria

A drowned river valley formed on a submergent coastline when sea levels rise or land sinks.

Fjord

A drowned, steep-sided glacial valley formed on a submergent coastline by rising sea levels or sinking land.

Coral bleaching

The expulsion of symbiotic algae (zooxanthellae) from coral polyps under prolonged ocean warming, leaving coral structures white and weakened.

Storm surge

A rapid, temporary rise in sea level produced by intense low atmospheric pressure and strong onshore winds pushing sea water toward the coast.

Tsunami

A giant sea wave typically produced by a sudden displacement of the ocean bed during an undersea earthquake, submarine landslide, or volcanic eruption.

Shoreline Management Plan (SMP)

A coastal management framework that divides a coastline into sediment cells and assigns specific policies (e.g. hold the line, managed retreat, no active intervention) to prevent unintended downdrift issues.

Integrated Coastal Zone Management (ICZM)

A holistic approach that balances coastal protection and socio-economic usage across multiple stakeholders, ecosystems, and geographic scales.

Stakeholder

Any user or party with a direct interest in a coastal zone, such as residents, local fishers, tourists, conservationists, or commercial industries.

Hard engineering

The construction of artificial, man-made structures designed to alter natural coastal processes and directly resist wave attack and flooding.

Soft engineering

Coastal management that works with natural processes to manage erosion and flood risk sustainably without erecting artificial barriers.

Sea wall

A hard engineering barrier built along the shoreline that reflects incoming wave energy directly back out to sea.

Groynes

Wood or rock barriers constructed at right angles to the shore that intercept sediment moved by longshore drift, creating a wider beach that absorbs wave energy.

Rock armour (rip-rap)

Large boulders piled at the base of a cliff or seawall to dissipate and absorb wave energy.

Beach nourishment

A soft engineering method where sand or shingle is artificially added from elsewhere to widen and elevate an existing beach.

Managed retreat / realignment

A soft engineering strategy involving the deliberate breaching or removal of defences to allow low-lying coastal land to be flooded and revert to natural wetland habitats.