Glaciers and ice balance — A glacier is moving land ice formed from accumulated and compacted snow. Accumulation adds mass while ablation removes it through processes such as melting. A glacier can flow downhill while its front retreats if loss exceeds supply there. Retreat does not mean the whole glacier moves backwards, and sea ice is not the same as a valley glacier.
Glacial erosion — Abrasion occurs when rock debris carried by ice scrapes a surface; plucking removes blocks where conditions allow ice to grip fractured rock. Moving ice can deepen and widen valleys, depending on ice flow, rock and debris. Erosion is not performed only by clean ice acting like a knife. Distinguish removal from deposition of the material later.
Glacial landforms — Corries can develop in mountain hollows, while glaciers can reshape earlier river valleys into broader U-shaped troughs. A smaller side glacier may erode less deeply than the main glacier, leaving a hanging valley above the main trough. Erosion of neighbouring hollows or valleys can leave a sharp ridge between them. The Lake District contains inherited glacial landscapes, including valleys now occupied by lakes. Use contours, photographs and process explanation together rather than identifying a landform from a name alone.Schematic comparison of a narrow river-cut valley and a wider glacially shaped trough. Real valleys vary and later processes continue; these are cross-section models rather than surveyed dimensions. Full-size diagram
Deposition and postglacial change — Glaciers deposit debris as ice melts, producing features including moraines, accumulations of rock debris deposited by a glacier. Meltwater can sort and transport material differently from direct ice deposition. After ice retreats, rivers, slope processes, vegetation and people continue changing the landscape. A glacial valley is not frozen in time simply because its main trough was shaped under an earlier climate.
Hydrology and drainage basins
The water cycle — Water moves among atmosphere, land, oceans and living things through transfers such as evaporation (liquid water becoming vapour), transpiration (water vapour leaving plants), condensation (vapour becoming liquid), precipitation (water falling as rain, snow or other forms) and runoff (water flowing over land). Stores hold water for different periods. The cycle is a connected system, not one drop following the same fixed route every time. Human actions can alter pathways and storage without creating an unlimited new water supply.
Drainage-basin systems — A drainage basin is the area supplying water to a river and its tributaries, bounded by a watershed, the higher land separating one drainage basin from another. Tributaries are smaller rivers that join a larger river; evapotranspiration combines evaporation and water loss from plants. Rainfall enters; water can be intercepted, infiltrate soil, move through soil and rock, run overland or leave through river flow and evapotranspiration. The boundary follows relief rather than administrative borders. Locate a real basin on a map to connect processes with terrain.A drainage basin includes several possible pathways and stores rather than one fixed route for every raindrop. Relief defines its watershed; the sequence here is a conceptual summary, not a map of a real basin. Full-size diagram
Infiltration, stores and runoff — Permeable ground, vegetation and available soil storage can slow some water transfers, while saturated, compacted or impermeable surfaces can increase rapid runoff. Effects depend on rainfall intensity, previous conditions and the wider basin. Trees do not prevent every flood, and a dry-looking surface does not show how much water deeper soil can store.
Discharge and hydrographs — River discharge is the volume of water passing a point per second; a storm hydrograph shows how it changes over time. Discharge can be measured in cubic metres per second (m³/s). Lag time is the time between peak rainfall and peak discharge. For a fictional storm with peak rainfall at 12 noon and peak discharge at 3 pm, lag time is three hours. A rapid rise can reflect several interacting basin and storm conditions. A graph's peak is a rate, not the total volume of all water moving during the event.
Flood risk and management — Flooding occurs when water covers normally dry land, including from rivers, surface water or the sea. Risk depends on the hazard, exposure and vulnerability. Floodplains can provide storage but also contain homes and infrastructure. Compare warnings, land-use planning, storage, river restoration and engineered defences, considering costs, maintenance and whether risk shifts elsewhere.
Rivers and changing channels
Erosion, transport and deposition — Rivers erode beds and banks, transport dissolved and solid material and deposit sediment when transport conditions change. Hydraulic action is removal caused by the force of moving water. Abrasion happens when carried material scrapes the bed or banks. Solution happens when water dissolves soluble minerals. Material can roll, bounce, remain suspended or dissolve depending on size and flow. A river does not simply become more erosive everywhere whenever it carries more water; local conditions matter.
Waterfalls — A waterfall can form where resistant and less-resistant rock create a step. Water can erode the less-resistant rock more quickly, making a hollow beneath the harder layer. This undercutting leaves an overhang that may collapse. Falling water and debris deepen the plunge pool below; repeated undercutting and collapse can move the waterfall upstream. High Force on the River Tees provides a named example involving a resistant rock layer. Explain a sequence and geological context rather than treating every waterfall as having exactly the same origin.
Meanders and floodplains — A meandering channel can erode an outer bank and deposit on an inner bend, causing lateral migration. Floodplain development involves channel movement and repeated deposition during floods over time. As a bend grows, the neck between its two sides can narrow. Water may cut through the neck, and deposition can seal the ends of the old bend, leaving an oxbow lake, but not every curved river reach immediately becomes one. Read maps at more than one date to investigate change.
Coasts as connected systems
Waves, sediment and longshore drift — Waves transfer energy to the coast, while sediment moves through erosion, transport and deposition. When waves approach at an angle, swash carries material up the beach at an angle. Backwash flows down the slope under gravity, usually more directly towards the sea. Repeating these movements can move sediment in a zigzag along the shore: longshore drift. The direction depends on wave approach and local conditions. A beach is a changing sediment store connected to a wider coastal system.
Erosional coastal landforms — Hydraulic action, abrasion, weathering and slope movement can contribute to cliff change. Differences in rock resistance, fractures and wave exposure help create headlands (land projecting into the sea) and bays (inlets). Waves may enlarge a crack into a cave; a cave through a headland can become an arch. If the arch roof collapses, a separate pillar called a stack can remain. These are possible linked developments, not a compulsory sequence at every coastline. The Jurassic Coast illustrates varied geology and landforms that require a place-specific explanation.
Depositional coastal landforms — Beaches, spits and dunes form where sediment supply, transport and deposition create suitable conditions. A spit can extend across part of a bay or estuary while river flow or other currents keep some routes open. Vegetation can help stabilise dunes. Removing sediment or blocking its supply can affect landforms beyond the immediate intervention site.
Managing coastal change — Sea walls form a barrier against waves. Groynes are barriers across a beach that trap moving sediment. Beach nourishment adds sediment. Managed realignment deliberately allows the shoreline to move inland in an agreed area, sometimes creating flood-storage or habitat space. These approaches address different goals and conditions. A groyne can retain sediment locally while affecting supply farther along the coast. Coastal choices involve homes, habitats, access, costs and timescales. Compare a named reach and affected groups rather than declaring one defence best everywhere or assuming protection means no residual risk.
People, systems and evidence
Interacting landscape processes — Climate, rock, ice, water, vegetation and human decisions combine to shape landscapes. Urban paving can change runoff, a dam can trap sediment and coastal management can alter sediment distribution. Follow a causal chain at local and basin or coastal-cell scales, distinguishing observed evidence from a prediction. A local intervention can have distant and delayed effects.
Landscape investigation — Combine maps, photographs, measurements and reliable accounts to explain a changing place. State dates and methods and distinguish inherited forms from currently active processes. A single photograph can show a cliff or channel but rarely establish its rate of change alone. Safe field observation needs school-approved sites and procedures; do not enter floodwater, unstable cliffs or uncontrolled channels.
Test yourself
50 questions · Random sets of 10. These quick checks support revision; practise longer explanations and justified judgements too.
Mind map
Use the branches to recall the ideas and explain their connections. Check the revision notes for the full detail.
KS3GEO4 · 1
View KS3GEO4 · 1 mind mapOpen the full-size map to zoom. Use the printable view for A4 landscape or enlarge to A3.
Mr Kidman's Classroom
