IB Geography SL key terms

The physical and social area within which people and phenomena are located and interact. Geographers study how distance, distribution and accessibility shape what happens in a given area.

A location given meaning by the people who live in or visit it, through identity, memory and culture. Places are shaped by flows of people and ideas, not fixed.

The level of analysis at which a phenomenon is examined, from local to national to global. The same process can look different depending on the scale chosen.

The subjective feelings and attachments people develop towards a location, built from lived experience and cultural meaning. It can be strong, weak, contested or lost when a place changes.

A set of interconnected components that exchange energy or matter, with inputs, outputs, stores and flows. Change in one component usually triggers change in others through feedback.

A process in which a change in a system produces a response that either amplifies the original change (positive feedback) or reduces it (negative feedback). Feedback drives stability or rapid change in systems.

Meeting present needs without reducing the ability of future generations to meet theirs, balancing environmental, social and economic goals. It is contested because groups disagree on what should be sustained and for whom.

The maximum population or level of use an area can support without environmental degradation, given available resources and technology. It is not fixed, since technology and trade can raise or lower it.

The growing interconnection of economies, cultures and societies through trade, investment, migration and information flows. It links distant places but produces uneven benefits across and within countries.

A model showing how birth and death rates change over time as a country develops, moving through stages from high fluctuating rates to low stable ones. It explains population growth patterns but assumes all countries follow similar paths.

The change in population caused by the difference between births and deaths, excluding migration. It is usually expressed as a rate per 1,000 people per year.

A graph showing the age and sex structure of a population as horizontal bars. Its shape reveals past events such as war, migration or falling fertility, and indicates future dependency needs.

The number of people outside working age (children and elderly) compared with the working-age population, usually expressed per 100 workers. A high ratio means more pressure on a smaller labour force.

A population in which the proportion of older people rises, usually through falling fertility and longer life expectancy. It raises costs for pensions and health care and can shrink the labour force.

A government measure designed to raise the birth rate, such as cash bonuses, longer parental leave or subsidised childcare. Success is limited because fertility decisions depend on culture and cost of living.

A government measure intended to reduce the birth rate, through contraception access, education, later marriage or penalties for large families. Such policies raise ethical concerns about coercion and reproductive rights.

The movement of people across a boundary to settle temporarily or permanently. It is driven by push factors in the origin and pull factors in the destination, mediated by barriers and personal circumstances.

A person who has crossed an international border because of a well-founded fear of persecution, conflict or violence, and who is entitled to protection under international law. This differs from a person displaced inside their own country.

Money sent by migrants back to their home country, usually to family. Remittances can be a major share of national income and reduce poverty, but may create dependency and widen inequality.

A company that operates production or services in more than one country, often locating different stages of production where costs or skills are most favourable. TNCs spread investment and jobs but can shift profits and pressure host governments.

Economic activity that is unregistered and unregulated, such as street vending or casual labour. It provides income where formal jobs are scarce but offers little security, tax revenue or legal protection.

The process by which gases in the atmosphere absorb outgoing infrared radiation and re-emit it towards the surface, warming the planet. Human emissions have enhanced this natural effect and shifted the energy balance.

The additional warming caused by human emissions of greenhouse gases such as carbon dioxide, methane and nitrous oxide. It raises global mean temperature beyond the natural greenhouse effect, altering climate patterns.

The change in the balance between incoming solar energy and outgoing infrared energy at the top of the atmosphere, measured in watts per square metre. Positive forcing warms the climate; negative forcing cools it.

The proportion of incoming solar radiation reflected by a surface. Ice and snow have high albedo, so their loss exposes darker surfaces that absorb more energy and amplify warming.

A threshold beyond which a system changes irreversibly into a different state, even if the original cause is removed. Examples include ice-sheet collapse and Amazon dieback, which would create self-reinforcing change.

Action that reduces the sources of greenhouse gas emissions or enhances their removal, such as renewable energy, efficiency or reforestation. It addresses the cause of climate change rather than its consequences.

Adjustment to actual or expected climate impacts to reduce harm or exploit opportunities, such as flood defences, drought-resistant crops or early warning systems. It addresses consequences and has limits where impacts are severe.

The capacity of a community or system to absorb climate shocks, recover and adapt without losing its basic functions. It depends on infrastructure, institutions, wealth and social networks.

The area of biologically productive land and water needed to supply a population's resources and absorb its wastes, measured in global hectares. Comparing it with biocapacity shows whether consumption exceeds local or planetary limits.

Reliable access to enough water of acceptable quality to support health, livelihoods, ecosystems and production, with acceptable risk of hazards such as flood and drought. It depends on availability and on management and infrastructure.

A shortage of water relative to demand, which may be physical (limited supply) or economic (supply exists but is not accessible or affordable). It is measured by water availability per person and by use patterns.

The volume of water used to produce a good or service, which is effectively traded when that product is exported. Importing water-intensive goods lets water-scarce countries relieve pressure on their own resources.

The combination of energy sources a country uses, such as coal, gas, nuclear, hydro, wind and solar, and the share each contributes. It reflects resource endowment, cost, policy and security priorities.

The uninterrupted availability of energy at an affordable price, including diversity of supply and protection from political or physical disruption. Countries may pursue it through domestic sources, storage or trade partnerships.

When all people have physical, social and economic access to sufficient, safe and nutritious food that meets their needs. It has four dimensions: availability, access, utilisation and stability.

The area of land drained by a river and its tributaries, bounded by a watershed. It functions as an open system with precipitation inputs, stores such as soil and groundwater, and outputs of discharge and evaporation.

A graph plotting river discharge against time after a rainfall event. The lag time and peak height show how a basin's geology, land use, shape and soil moisture affect its response.

The probability of a flood multiplied by the potential harm to people, assets and livelihoods. Risk rises with exposure and vulnerability as well as with the physical hazard itself.

The movement of sediment along a coast by waves approaching at an angle, with swash carrying material up the beach and backwash returning it at right angles. It shapes beaches and spits and needs managing where it erodes land.

The wearing away of land by wave action, currents and weathering, through processes such as hydraulic action, abrasion and attrition. Rates depend on rock resistance, wave energy and human intervention.

A stretch of coastline considered as a closed system for sediment movement, from a source to a sink, with transfers along the shore. Managing one cell can affect sediment supply to neighbouring cells.

The likelihood of harm from a natural event, determined by the hazard's magnitude and frequency combined with exposure and vulnerability. It can be reduced by preparedness and planning, not only by controlling the event.

The degree to which people or places are likely to be harmed by a hazard, shaped by wealth, housing quality, age, information and governance. It explains why the same event kills many in one place and few in another.

A description of a hazard's characteristic magnitude, frequency, duration, speed of onset and spatial extent. Comparing profiles helps explain why different hazards require different management responses.

The situation where visitor numbers in a destination exceed its capacity to absorb them, damaging environments, resident quality of life and the visitor experience. It often results from cheap travel and short-term rental growth.

The process by which tourist spending generates further income as it circulates through a local economy, creating jobs and supporting suppliers. Leakage to foreign-owned firms reduces the size of the multiplier.

An area, often low-income or poorly served by transport, where residents cannot easily buy affordable fresh food. It contributes to poor diet and diet-related disease and is a matter of access, not just supply.

The method used to choose sites or respondents in a geographical investigation, such as random, systematic or stratified sampling. The choice affects how representative the data are and how far conclusions can be generalised.

Information collected first-hand by the researcher for a specific investigation, for example through surveys, measurements or interviews. It is tailored to the question but costly in time and prone to observer bias.

Information gathered by someone else and reused, such as census figures, maps or government statistics. It is quick and often large-scale but may be outdated, incomplete or collected for a different purpose.

The extent to which repeated measurements or collections would produce consistent results, reflecting the quality and consistency of the method. It is improved by standardised procedures, larger samples and repeat readings.

The extent to which data actually measure what they are intended to measure, so conclusions genuinely answer the research question. A reliable method can still be invalid if it measures the wrong variable.