Curriculum Portal

neurologyYou need to know

• A coast is the boundary between the land and the sea, and it can include cliffs, beaches, dunes, estuaries, mudflats and salt marshes.
• Coastal landscapes in the UK include rocky coasts, sandy beaches, mudflats and estuaries, and these landscapes vary because of geology, wave energy, sediment supply and human activity.
• Coasts are important because they support ecosystems, attract tourism, provide jobs, and contain settlements, roads, railways and ports.
• Coasts are dynamic environments because waves, tides, weather, sea-level change and human activity constantly change coastal landforms.
• Waves are created when wind transfers energy to the surface of the sea. Wave size and energy are mainly controlled by fetch, wind strength and wind duration.
• Constructive waves have a stronger swash than backwash, so they deposit sediment and build up beaches.
• Destructive waves have a stronger backwash than swash, so they remove sediment and erode beaches.
• Coastal erosion occurs when waves and currents wear away and remove rock and sediment, while weathering breaks down rock in situ and mass movement transfers weakened material downslope.
• Hydraulic action happens when waves force air into cracks in rock, increasing pressure until the rock breaks apart.
• Abrasion happens when waves throw sand and pebbles against cliffs, grinding the rock away like sandpaper.
• Attrition happens when rocks carried by waves collide with each other and become smaller, rounder and smoother.
• Solution happens when seawater dissolves soluble rocks such as limestone and chalk.
• Headlands form where hard, resistant rock such as chalk or limestone erodes slowly and sticks out into the sea. Bays form where softer, less resistant rock such as clay or sandstone erodes quickly and retreats inland.
• On a discordant coastline, bands of hard and soft rock meet the coastline at right angles, helping to form alternating headlands and bays such as Swanage Bay and Ballard Point.
• Longshore drift transports sediment along a beach in a zigzag pattern because swash moves material up the beach at an angle and backwash pulls it straight down the beach under gravity.
• A spit forms when longshore drift carries sediment beyond a bend in the coastline or into open water, where deposition builds a narrow ridge of sand or shingle.
• Hard engineering uses man-made structures such as sea walls, groynes and rock armour to protect coasts, while soft engineering works with natural processes through methods such as beach nourishment, dune regeneration and managed retreat.
• The Holderness Coast is in East Yorkshire, and it erodes rapidly because its soft boulder clay cliffs face powerful North Sea waves and sediment is moved away by longshore drift.
• Along the Holderness Coast hard engineering methods such as sea walls, groynes, and rock armour are used in some places to reduce erosion.
• At Mappleton, groynes and rock armour protect the village, so erosion has slowed down locally.
• Coastal management can protect one area but increase erosion down drift, meaning not all communities benefit equally.

• Identify coastal features such as cliffs, beaches, dunes, estuaries, headlands, bays and spits using maps and photographs.
• Classify coastal impacts as social, economic or environmental, using evidence such as loss of homes, damage to businesses, cost of defences and habitat loss.
• Explain the formation of headlands and bays by linking rock resistance, differential erosion and the retreat of softer rock.
• Describe longshore drift accurately by explaining angled swash, straight backwash and the resulting zigzag movement of sediment along the beach.
• Explain the formation of a spit by sequencing longshore drift, a change in coastline direction, loss of wave energy and deposition.
• Compare constructive and destructive waves by referring to swash, backwash, erosion, deposition and beach shape.
• Evaluate hard engineering strategies by explaining how sea walls, groynes and rock armour work and weighing their effectiveness, cost and environmental impacts.
• Evaluate soft engineering strategies by explaining how beach nourishment, dune regeneration and managed retreat work and judging their long-term sustainability.
• Assess coastal management at Holderness by linking causes of erosion, impacts on people and environments, and the effectiveness and knock-on effects of defences such as groynes and rock armour.