Coastal landscapes and management
Geography · GCSE · The School
Erosion into landforms
Where hard and soft rock meet the coast, the soft rock erodes faster and retreats into a BAY while the hard rock stands out as a HEADLAND. On the headland, waves attack lines of weakness: a crack widens into a CAVE, the cave erodes through into an ARCH, the arch collapses leaving a STACK, and the stack is undercut to a STUMP. Learn it as one sequence and it is one answer, not five.
Longshore drift and deposition
Waves approach at an angle, so swash carries material up the beach diagonally and backwash drags it straight down under gravity. Repeat and the sediment zigzags along the coast. Where the coastline turns, that sediment continues and builds a SPIT; if it reaches across a bay it becomes a BAR, and behind it a sheltered lagoon forms.
Hard and soft engineering
HARD: sea walls, groynes, rock armour, gabions — effective, expensive, and they interrupt the sediment supply. SOFT: beach nourishment, dune regeneration, managed retreat — cheaper, work with natural processes, need maintaining. Managed retreat allows low-value land to flood deliberately, which costs less than defending it and creates habitat, and is examined as a genuine option rather than a failure.
Longshore drift here runs west to east. Town A builds GROYNES: sediment piles against the western side of each one and Town A gets a wide, protected beach. That sediment was on its way to Town B. Starved of supply, Town B loses beach, waves reach the cliff foot with full energy, and erosion there speeds up. Town B then builds its own defences, which starves Town C. This is why coastal management is now planned along whole SEDIMENT CELLS rather than by each town separately — and why the exam answer on hard engineering must always name what happens down-drift. Note the cost too: a sea wall runs into thousands of pounds per metre, while beach nourishment is a fraction of that per year and keeps the sediment moving.