How can landscapes be viewed as systems, and what makes them change over time?
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.
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 any landscape, coastal, glaciated or dryland, as an open system, explain the geomorphological processes that move sediment through it, and explain how energy, sediment, climate change and human activity make landscapes change across different scales and timescales. This is the framework that the whole Landscape Systems option is built on.
The answer
The landscape as an open system
Thinking in systems is the unifying skill of the whole option. Inputs are energy (kinetic energy from wind and waves, potential energy from gravity on slopes, thermal energy from the sun, and chemical energy) and matter, chiefly sediment from rivers, cliffs, weathering and longshore drift. Stores are the landforms themselves, beaches, dunes, moraines, alluvial fans, where sediment rests. Transfers are the processes that move sediment between stores, and outputs are sediment lost offshore or downwind and energy dissipated as heat. The same diagram describes a coast, a glacier and a desert; only the dominant energy source and process set change.
The four process families
All landscape change comes down to four linked process families. Weathering is the in-situ breakdown of rock by mechanical (freeze-thaw, salt crystallisation, pressure release), chemical (carbonation, hydrolysis, oxidation) and biological means; it prepares material for removal. Erosion detaches and wears away rock through processes such as hydraulic action, abrasion and attrition. Transport moves the sediment, by traction, saltation, suspension and solution in water and air, or frozen within ice. Deposition drops the load when energy falls below the threshold needed to carry it. Mass movement (rockfall, slumping, solifluction) is the gravity-driven transfer that links slopes to the rest of the system.
Equilibrium, feedback and thresholds
Over time a landscape system tends towards dynamic equilibrium, a balanced state in which the overall form is maintained even though sediment is constantly moving through it. Stability is enforced by negative (balancing) feedback: a storm strips a beach, but the offshore bar it creates then dissipates wave energy and the beach rebuilds under gentler waves, returning the system towards its former profile. Positive (reinforcing) feedback amplifies change instead, as when ice melt exposes darker ground that absorbs more heat and melts more ice. When a disturbance is large enough to cross a threshold, the system cannot recover its old state and settles into a new equilibrium, the basis of irreversible change.
Scales of change and the human role
Landscape change runs across timescales from seconds (a rockfall) through years and decades (a beach cycle) to thousands of years (glacial-interglacial cycles), and across spatial scales from a single landform to a whole sediment cell or ice sheet. Long-term drivers include climate change (altering process rates and sediment supply), tectonic activity and sea-level change (eustatic and isostatic). Increasingly, human activity is itself a driver: damming and dredging cut sediment inputs, hard engineering interrupts transfers, deforestation and land-use change alter runoff and slope stability, and greenhouse warming amplifies several physical processes at once.
Examples in context
Example 1. A coastal sediment cell in dynamic equilibrium. On a swash-aligned beach, fairweather constructive waves build a wide berm (a positive sediment budget phase), while a winter storm sequence flattens the profile and moves sediment offshore into a bar (a negative phase). The bar then trips and dissipates incoming waves, so the beach slowly rebuilds. Over a year the beach volume oscillates around a stable mean: a textbook case of negative feedback maintaining dynamic equilibrium, and the reason a single storm survey can mislead unless set against the long-run average.
Example 2. Crossing a threshold through human interference. Where a feeder river to a coastal cell is dammed, the sediment input collapses and the budget turns sharply negative. The beach cannot rebuild after storms, the protective bar is lost, and waves begin to attack the dunes or cliffs behind. The system crosses a threshold into a new, lower-volume equilibrium that persists even if storms ease, showing how a human-driven change to one input can force an irreversible adjustment across the whole system.
Try this
Q1. Define an open system and give one geographical example. [3 marks]
- Cue. A system exchanging both energy and matter with its surroundings; for example a coastline exchanging wave energy and sediment.
Q2. Explain the difference between positive and negative feedback in a landscape system. [4 marks]
- Cue. Negative feedback restores equilibrium (a flattened beach rebuilding); positive feedback amplifies change (ice melt exposing dark ground that melts more ice).
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)6 marksExplain how the concept of dynamic equilibrium helps to describe the operation of a landscape system.Show worked answer →
This is a medium-tariff question marked on Levels of Response, splitting AO1 (the concept) and AO2 (applying it). Define a landscape system as an open system with inputs (energy and sediment), stores (sediment held in landforms), flows or transfers (the movement of sediment by processes) and outputs (sediment and energy leaving the system). Dynamic equilibrium is the balanced state in which inputs and outputs are roughly equal over time, so the overall form persists even though material is constantly moving through it.
For AO2, show how a disturbance (a storm, a sediment cut-off, a phase of warming) shifts the system away from equilibrium, triggering negative feedback that works to restore balance, for example a storm-flattened beach rebuilding its profile under fairweather waves. The strongest answers stress that equilibrium is dynamic, not static: the landscape adjusts continuously, and a sustained change in input (such as reduced sediment supply) establishes a new equilibrium rather than no change at all.
OCR H481/01 (style)16 marksAssess the relative importance of physical and human factors in driving change within landscape systems.Show worked answer →
A 16-mark extended response marked across four Levels on AO1 and AO2, so it needs balanced knowledge, applied analysis and a clear judgement. Physical factors dominate the baseline: energy inputs (wind, waves, gravity, solar and geothermal energy) drive the process families, while climate governs weathering regimes and process rates, sea-level and tectonic change reset boundary conditions, and sediment supply sets whether a system erodes or accretes. These operate over timescales from a single storm to glacial-interglacial cycles.
Human factors increasingly modify these systems: dredging and damming cut sediment inputs, hard engineering interrupts transfers, land-use change alters runoff and slope stability, and greenhouse warming amplifies several physical drivers at once. A strong AO2 judgement might argue that physical factors set the rate and direction of change while human activity, by altering inputs and transfers, can tip a system across a threshold into rapid, sometimes irreversible adjustment. Reward a supported conclusion that weights the factors rather than listing them, ideally anchored to a located example.
Related dot points
- 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.
- 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.
- 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 global water cycle as a closed system of stores and flows; the drainage basin as an open sub-system with inputs, flows, stores and outputs; the water balance; and the natural and human factors that change water stores and flows across scales.
An OCR A-Level Geography answer to the water cycle in Earth's Life Support Systems, covering the global water cycle as a closed system of stores and flows, the drainage basin as an open sub-system, the water balance equation, and how natural and human factors change water stores and flows across global to local scales.
Sources & how we know this
- OCR A-Level Geography (H481) specification — OCR (2016)