LGCSE Geography cheat sheet

Rock cycle: igneous (cooling magma), sedimentary (compaction of deposited grains), metamorphic (heat/pressure); each can transform into the others.

Tectonics: divergent plates form ridges and rift valleys; convergent (ocean-continent) gives subduction, trenches and volcanic arcs; transform gives strike-slip faults.

Weathering is in situ; erosion is transport. Freeze-thaw needs water in cracks and repeated crossing of 0 °C.

Mass movement controls: slope angle, water content, vegetation cover, rock structure; rotational slumps on weak clay, rockfalls on steep joints.

River erosion processes: hydraulic action, abrasion, attrition, solution; long profile concave, cross profile steepens upstream.

Glacial erosion: plucking and abrasion; features include cirque, arête, U-shaped valley, hanging valley, truncated spur, drumlin, moraine types.

Coastal landforms: headlands with cliffs, wave-cut platforms, caves-arches-stacks; deposition gives beaches, spits, bars, tombolo.

Karst: carbonation solution of limestone forms swallow holes, gorges, stalactites and stalagmites; pervious rock drains surface streams.

Hot desert: high diurnal temperature range drives exfoliation; wind deflation, abrasion, and dunes (barchan, seif) shaped by prevailing wind.

Insolation is concentrated at low latitudes; the equator receives more energy per unit area, driving the Hadley cell and trade winds.

Air pressure falls with altitude; highs bring subsidence and clear skies, lows bring convergence, uplift and rain.

Frontal rain: warm air forced over cold air along a front; relief rain: air forced up a mountain; convectional rain: intense heating and rapid uplift.

Climate controls: latitude, altitude, distance from sea, ocean currents, prevailing winds, relief, and human land cover.

Enhanced greenhouse effect: CO2, CH4, N2O, CFCs absorb outgoing longwave radiation; feedbacks such as albedo loss and permafrost melt amplify warming.

Evidence for climate change: ice cores, tree rings, pollen, historical records, instrumental series, sea-level rise, glacier retreat.

Adaptation (adjust to impacts) vs mitigation (reduce causes): sea defences, drought-resistant crops vs renewables, afforestation, carbon tax.

Urban heat island: city centres warmer than rural surroundings due to concrete, low albedo, reduced evapotranspiration and vehicle heat.

El Niño: weakened trade winds and warm water in the eastern Pacific change rainfall patterns worldwide.

Ecosystem = community of organisms + abiotic environment; energy flows one way, nutrients cycle (carbon, nitrogen, water).

Trophic levels: producers, primary consumers, secondary consumers, decomposers; roughly 10 % of energy transfers to the next level.

Food chains and webs show feeding relationships; pyramids of numbers, biomass and energy reveal losses at each level.

Biome distribution is controlled by temperature and precipitation; examples: tropical rainforest, savanna, desert, temperate deciduous, taiga, tundra.

Tropical rainforest: high rainfall, high biodiversity, nutrient-poor soils, rapid decomposition; deforestation causes soil erosion and biodiversity loss.

Nutrient cycling in rainforests is tight; most nutrients sit in living biomass, not soil, so clearance depletes fertility fast.

Succession: pioneer species colonise bare ground, then seral stages to a climax community; primary vs secondary succession differ in starting conditions.

Biodiversity threats: habitat loss, invasive species, pollution, overexploitation, climate change; conservation includes protected areas and corridors.

Sustainable management: agroforestry, selective logging, ecotourism, buffer zones, and community-based quotas reduce degradation.

Natural increase = birth rate − death rate (per 1,000); net migration adds or subtracts; growth rate expressed as a percentage.

Doubling time ≈ 70 ÷ annual growth rate (%).

Demographic Transition Model: Stage 1 high birth/high death; Stage 2 death falls; Stage 3 birth falls; Stage 4 low/low; Stage 5 possible decline.

Population pyramids: wide base = high birth rate; narrow base with bulge higher up = ageing population; dependency ratio = (young + old) ÷ working age.

Push factors: poverty, war, drought, unemployment; pull factors: jobs, safety, services, family ties; intervening obstacles reduce flows.

Ravenstein and Lee models: most migration is short distance, stepwise, and produces counter-flows; economic motives dominate.

Settlement site factors: water supply, flat land, defence, bridging point, fertile soil, aspect; situation describes relation to surroundings.

Settlement patterns: dispersed, nucleated, linear; hierarchy follows threshold population and range of goods (central place theory).

Urbanisation rate = urban population ÷ total population; megacities exceed 10 million inhabitants.

Sectors: primary (extraction), secondary (manufacturing), tertiary (services), quaternary (knowledge); economic structure shifts with development.

Clark-Fisher model: employment moves from primary to secondary to tertiary as incomes rise.

Development indicators: GDP per capita, HDI (life expectancy, education, income), GNI, literacy, infant mortality; no single measure is complete.

HDI ranges 0–1; higher values indicate longer, healthier, better-educated lives; it omits inequality and environmental cost.

Brandt line and core-periphery models describe global inequality; dependency theory argues poor countries are structurally disadvantaged.

Globalisation drivers: containerisation, ICT, trade liberalisation, TNC investment, cheaper transport; effects include outsourcing and cultural diffusion.

TNCs locate by market access, labour cost, political stability, infrastructure and agglomeration economies.

Aid types: bilateral, multilateral, emergency, project, tied; fair trade guarantees minimum prices and premiums to producers.

Sustainable development goals balance economic growth, social inclusion and environmental protection; carbon footprint measures emissions per person or product.

Urban land-use zones: CBD (high land value, accessibility), inner city, inner suburbs, outer suburbs, rural-urban fringe.

Burgess concentric zone model, Hoyt sector model and Harris-Ullman multiple nuclei model describe different city growth patterns.

Bid-rent theory: land value peaks in the centre and falls outward; competition allocates land to the highest bidder.

Urban problems: congestion, air and noise pollution, housing shortage, waste, crime; solutions include congestion charging, green belts, public transport.

Urban sprawl at the rural-urban fringe causes loss of farmland, increased car dependence and pressure on services.

Counter-urbanisation moves people from cities to smaller towns; causes include high house prices, remote work and quality of life.

Squatter settlements (shanty towns) arise from rapid urbanisation outpacing housing supply; upgrading schemes provide water, sanitation and tenure.

Sustainable cities: compact form, mixed-use zoning, green infrastructure, cycle networks, waste recycling, urban greening.

Land-use conflict resolved through planning controls, zoning, environmental impact assessment and public consultation.

Water cycle stores: oceans, ice, groundwater, atmosphere; fluxes: evaporation, transpiration, condensation, precipitation, runoff, infiltration.

Water scarcity: physical (low supply relative to demand) vs economic (lack of infrastructure and investment).

Hard engineering on rivers: dams, levees, channel straightening, embankments; soft engineering: afforestation, floodplain zoning, wetland restoration.

Coastal defences: sea walls, groynes, riprap, revetments, offshore breakwaters (hard); beach nourishment, dune stabilisation, managed retreat (soft).

Sediment cell concept: inputs, transfers and outputs along a coastline; groynes trap sediment and starve downdrift beaches.

River discharge = cross-sectional area × velocity; hydrographs show lag time and peak discharge; urbanisation shortens lag time.

Dams provide hydropower, irrigation and flood control but displace people, trap sediment and alter downstream ecosystems.

Integrated water resource management balances abstraction, recharge and ecosystem needs; groundwater overdraft causes subsidence and salinisation.

Coastal management policy favours shoreline management plans choosing hold, advance, managed realignment or no active intervention.

Sampling methods: random (avoid bias), systematic (regular interval), stratified (proportional to strata); sample size affects reliability.

Hypothesis testing: state hypothesis, collect data, present, analyse, accept or reject; use mean, median, mode, range and interquartile range.

Correlation coefficient ranges −1 to +1; near 0 means weak or no linear relationship; scatter graphs reveal trends.

Fieldwork sequence: aim, risk assessment, method, data collection, presentation, analysis, evaluation of limitations.

Primary data collected first-hand; secondary data from published sources; both need reliability and accuracy checks.

Environmental quality surveys use bipolar scales and repeat points; transects and quadrats sample along gradients.

Cross-sections and profiles show relief; isolines join points of equal value (contours, isohyets, isotherms).

Ethical fieldwork: consent, safety, minimal environmental impact, and honest recording of anomalous results.

Scale: 1:50,000 means 1 cm on map = 500 m on ground; 1:25,000 means 1 cm = 250 m.

Grid references: four-figure gives a square (eastings then northings); six-figure gives a point within the square.

Contour interval is the vertical distance between contours; closely spaced contours indicate steep slopes.

Spot heights and trig points give elevation; hachures and cliff symbols show relief and coastal features.

Map symbols: blue = water, green = vegetation, brown = contours, black = buildings and boundaries, red = roads.

GIS layers combine spatial data (e.g., flood zones, population, land use) for overlay analysis and decision-making.

Choropleth maps show density by shading; proportional symbols show magnitude; isoline maps show continuous values.

Data reliability: check source, date, sample size and bias; interpolation estimates between known values, extrapolation beyond them.

Cross-sections drawn from maps reveal valley shape and slope steepness; aspect can be derived from contour orientation.