MATSEC IM Geography cheat sheet

Plate boundaries: divergent (constructive) plates move apart, forming mid-ocean ridges and rift valleys; convergent (destructive) plates collide, producing fold mountains, ocean trenches and volcanic arcs; transform (conservative) plates slide past each other, producing faults and earthquakes but little volcanism.

Rock cycle: igneous rocks crystallise from magma (intrusive = coarse-grained, e.g. granite; extrusive = fine-grained, e.g. basalt); sedimentary rocks form by compaction and cementation of deposited sediment; metamorphic rocks form when heat and pressure alter existing rock (e.g. limestone becomes marble).

Weathering is in-situ breakdown: mechanical (freeze-thaw, exfoliation), chemical (carbonation, oxidation, hydrolysis) and biological. Erosion involves transport of material by water, ice, wind or gravity; mass movement is downslope transfer of material under gravity.

Long-profile of a river: steep gradient and vertical erosion in the upper course, lateral erosion and meanders in the middle, deposition and floodplains in the lower course. Base level controls the lower limit of erosion.

Coastal processes: constructive waves (low frequency, strong swash, weak backwash) build beaches; destructive waves (high frequency, strong backwash) erode them. Longshore drift moves sediment along the coast in the direction of the dominant wave approach.

Glacial landforms: cirques (corries) are armchair-shaped hollows formed by rotational erosion; arêtes are knife-edge ridges between two cirques; U-shaped valleys result from glacial abrasion and plucking; moraine is deposited till marking former ice limits.

Climate controls: latitude determines solar insolation angle; altitude lowers temperature by about 6.5 °C per 1000 m; distance from the sea moderates temperature range; ocean currents warm or cool adjacent coasts; relief creates orographic rainfall on windward slopes.

Demographic Transition Model stages: high stationary (high birth and death rates), early expanding (death rate falls, birth rate stays high), late expanding (birth rate falls), low stationary (both low), and declining (birth rate below death rate).

Population structure is shown on population pyramids: broad base indicates high birth rate and youthful population; narrow top indicates low life expectancy; bulges indicate past migration or baby booms. Dependency ratio = (population aged under 15 plus over 64) divided by population aged 15–64, multiplied by 100.

Push factors drive migration away from a place (poverty, conflict, unemployment, environmental hazard); pull factors attract migrants (employment, education, safety, higher living standards). Migration can be voluntary or forced, internal or international.

Settlement site factors: flat land, reliable water supply, defensive position, fertile soils, bridging points and route nodes. Settlement function may be residential, commercial, industrial, administrative or touristic, and functions change over time.

Urban land-use models: the Burgess concentric-zone model (CBD, inner city, suburbs, commuter zone) and the Hoyt sector model describe land use in relation to distance from the CBD and transport routes. Land value generally falls with distance from the CBD.

Economic sectors: primary (extraction), secondary (manufacturing), tertiary (services), quaternary (knowledge and research). Economic development typically shifts employment from primary to secondary to tertiary activity.

Globalisation: transnational corporations locate production where labour and regulation costs are low, creating a new international division of labour. Impacts include job creation and export growth in host countries, but also dependency and uneven development.

Renewable resources can be replenished within a human timescale (solar, wind, hydro, biomass); non-renewable resources are finite (fossil fuels, minerals). Resource availability depends on technology and economic viability as well as physical supply.

Energy mix decisions balance cost, reliability, energy density, emissions and land use. Fossil fuels have high energy density but emit greenhouse gases; renewables have low running costs but variable output requiring backup or storage.

The enhanced greenhouse effect: greenhouse gases (carbon dioxide, methane, nitrous oxide, CFCs) absorb outgoing long-wave radiation and re-radiate it back to the surface, raising global mean temperature.

Impacts of climate change include sea-level rise from thermal expansion and ice melt, more frequent extreme weather, shifts in agricultural zones, and increased water stress in already arid regions.

Hazard risk can be modelled as risk = hazard × vulnerability ÷ capacity to cope. Physical magnitude alone does not determine disaster impact; exposure, preparedness and wealth also matter.

Sustainable development meets present needs without compromising the ability of future generations to meet theirs. Indicators include the Human Development Index, ecological footprint and per-capita resource consumption.

Management strategies: reduce, reuse, recycle for waste; water management through storage, transfer and demand reduction; conservation through protected areas, zoning and sustainable forestry; mitigation and adaptation for climate change.

Map scale: 1:25,000 means 1 cm on the map represents 250 m on the ground; 1:50,000 means 1 cm represents 500 m. To convert, divide the ground distance by the scale denominator and convert to metres or kilometres.

Grid references: four-figure references give the grid square (eastings then northings); six-figure references give position within the square by subdividing each side into tenths, again reading eastings before northings.

Contour lines join points of equal elevation. Closely spaced contours indicate steep slopes; widely spaced contours indicate gentle slopes; concentric closed contours indicate a hill or a depression.

Graph choice: bar charts compare discrete categories, line graphs show continuous change over time, scatter graphs show correlation between two variables, pie charts show proportions of a whole, and choropleth maps show density or rate by area.

Mean = sum of values divided by number of values; median = middle value when ordered; mode = most frequent value. Use median for skewed data and mean for symmetrical data.

Interquartile range = upper quartile minus lower quartile, showing the spread of the middle 50 % of data. A large IQR indicates high variability; a small IQR indicates consistency.

Spearman's rank correlation coefficient formula: rs = 1 − (6 × Σd²) ÷ (n³ − n), where d is the difference between ranks and n is the number of pairs. Values close to +1 or −1 indicate strong correlation; close to 0 indicates weak correlation.

Fieldwork sequence: define an aim or hypothesis, select sampling strategy (random, systematic, stratified), collect primary data with standardised recording sheets, record secondary data, then present, analyse and evaluate.

Sampling: random sampling avoids bias but may miss key sites; systematic sampling along a transect detects change across a gradient; stratified sampling ensures representation of defined sub-groups.

Field measurement techniques: quadrats for vegetation cover and species frequency; flow meters for river velocity; callipers or pebbles for sediment size; clinometers for slope angle; pH meters and thermometers for water quality.

Environmental quality surveys and bipolar rating scales convert qualitative observations into ordinal data. To reduce observer bias, use fixed criteria, multiple observers and repeat readings.

River fieldwork: measure width, depth and velocity at intervals across the channel to calculate discharge (Q = cross-sectional area × velocity). Velocity typically increases downstream as channel efficiency rises.

Map interpretation: identify settlement patterns (nucleated, linear, dispersed), land use from symbols and colours, relief from contours and spot heights, drainage patterns, and communications. Compare old and modern maps to detect change.

Data presentation and evaluation: choose presentation to match data type, label axes and include units, and evaluate by discussing sampling limitations, measurement error, anomalous results and whether the evidence supports the original hypothesis.