MATSEC IM Geography key terms

The continuous movement of water between the ocean, atmosphere and land through evaporation, condensation, precipitation, runoff and storage, driven mainly by solar energy and gravity.

The whole area of land drained by a river and its tributaries, bounded by higher ground such as a ridge, so that all rain falling inside it flows to one outlet.

A graph showing how a river's height above sea level changes from its source to its mouth, typically a concave curve that is steep upstream and gentle near the coast.

The downward movement of water from the ground surface into soil and rock pores. It is faster on loose, vegetated, gentle slopes and slower on compacted or clay-rich surfaces.

The ability of a rock or soil to allow water to pass through its connected pore spaces or cracks. Permeable rocks store and transmit water; impermeable rocks do not.

The breakdown of rock in place by physical, chemical or biological processes, without the material being moved away. It prepares rock for erosion and soil formation.

The downslope transfer of rock, soil or mud under gravity, ranging from slow creep to rapid landslides and mudflows. Water content and slope angle strongly influence its speed.

The zigzag movement of sediment along a coast caused by waves approaching at an angle and returning straight down the beach, producing a net drift in one direction.

The laying down of eroded material such as sediment or boulders when the transporting agent loses energy, for example where a river slows or a wave loses power.

A narrow ridge of sand or shingle extending from the shore into open water, built by longshore drift where the coastline changes direction and deposition continues offshore.

A large area of high pressure with sinking air, giving light winds, clear skies and settled weather. In summer it brings heat; in winter it can bring frost and fog.

A low-pressure weather system where rising air forms cloud and rain, often with warm and cold fronts meeting at a front. It typically brings changeable, windy, wet weather.

A line on a weather map joining places with equal atmospheric pressure. Closely spaced isobars indicate strong winds; widely spaced isobars indicate light winds.

The number of live births per 1,000 people in a population in a given year. It is used with death rate to describe natural population change.

The number of deaths per 1,000 people in a population in a given year. Comparing it with birth rate shows whether natural increase or decrease is occurring.

A paired bar graph showing the number or percentage of males and females in each age group, used to interpret the age and sex structure of a population.

The number of people too young or too old to work, expressed as a proportion of the working-age population. A high ratio means more people rely on fewer workers.

A negative condition at a place of origin that encourages people to leave, such as unemployment, conflict, drought or poor housing. It works alongside pull factors attracting people elsewhere.

A positive condition at a destination that attracts migrants, such as better-paid work, education, safety or family ties. It is often paired with push factors in migration models.

The rising proportion of a country's population living in towns and cities, driven by rural-to-urban migration and natural growth. It changes land use and demand for services.

An area of a town or city dominated by one main function, such as a central business district, inner-city housing, suburbs or an industrial estate, arranged in recognisable patterns.

The commercial core of a city, with the highest land values, tallest buildings and greatest concentration of shops, offices and transport routes. It is usually small in area.

Meeting the needs of people today without reducing the ability of future generations to meet their own needs, balancing economic growth, social well-being and environmental protection.

A natural resource that is replaced or replenished by natural processes within a human lifetime, such as solar energy, wind, timber and fish, provided use does not exceed replacement.

A non-renewable energy source formed from buried plant and animal remains over millions of years, including coal, oil and natural gas. Burning it releases carbon dioxide.

The total amount of greenhouse gases released by a person, organisation or product, usually measured in tonnes of carbon dioxide equivalent over a set period.

The largest population of a species, or level of use, that an environment can support indefinitely without being degraded, given available food, water, space and technology.

A body of permeable rock that can store and transmit significant quantities of groundwater, often tapped by wells. Over-abstraction can lower the water table and cause subsidence.

A shortage of usable fresh water, either because supplies are low (physical scarcity) or because people lack the money, infrastructure or technology to access it (economic scarcity).

A set of numbers locating a point on a map using eastings first and northings second, read along the bottom and up the side of the grid. Six figures give a 100-metre square.

A line on a map joining points of equal height above sea level. Closely spaced contours show steep slopes; widely spaced contours show gentle slopes.

The relationship between distance on a map and distance on the ground, shown as a ratio, a statement or a line bar. It allows real distances and areas to be measured.

A profile drawn along a line across a map to show changes in height and shape of the land, produced by transferring contour heights onto a graph.

A map where areas are shaded or patterned in proportion to a value such as population density, using graded classes. It shows broad spatial patterns but hides variation within areas.

Selecting a smaller set of points or people to represent a larger whole, using methods such as random, systematic or stratified sampling to reduce bias in fieldwork data.

A quick labelled drawing made on location to record the main features of a landscape or site, noting direction, scale and key observations that a photograph alone might not show.

A formal process that predicts the likely environmental effects of a proposed project before it is approved, and sets out measures to reduce harm.