BCS Written Geography key terms

The wearing away of rock and soil by running water through hydraulic action, abrasion, attrition, and solution, shaping channels and valleys over time.

A crescent-shaped body of water left behind when a meander loop of a river is cut off from the main channel by deposition of a neck cutoff.

A low-lying landform built where a river enters standing water and deposits sediment faster than it can be removed by tides, waves, or currents.

The theory that Earth's rigid outer shell is divided into plates that move over the asthenosphere, generating earthquakes, volcanoes, and mountain belts at their boundaries.

A seasonal reversal of prevailing winds, driven by differential heating of land and sea, that brings a distinct wet season and dry season to affected regions.

A dry area on the leeward side of a mountain range, created because rising air loses moisture on the windward slope and descends warmed and dry.

An intense low-pressure storm system forming over warm tropical oceans, with organised thunderstorms, strong rotating winds, and heavy rainfall around a central eye.

A steep wave front that travels upstream in a river or estuary when an incoming high tide meets a shallow, narrowing channel with strong opposing outflow.

A partially enclosed coastal water body where freshwater from rivers mixes with saltwater from the sea, often supporting rich fisheries and port development.

The inland movement of saltwater into rivers, soils, and aquifers, often caused by tidal flow, reduced upstream discharge, or excessive groundwater extraction near coasts.

A vertical section through soil showing distinct layers or horizons, each differing in colour, texture, organic content, and degree of weathering.

The average number of people living in a unit area of land, usually expressed as persons per square kilometre, used to compare settlement concentration.

A model describing the shift of a population from high birth and death rates to low birth and death rates as a society develops economically and socially.

The proportion of people outside working age, namely children and the elderly, compared with the working-age population that supports them economically.

The growing share of a population living in towns and cities, accompanied by the physical expansion of built-up areas and changes in employment and lifestyle.

Conditions that drive people away from one place, such as unemployment or disaster, and conditions that attract them to another, such as jobs or safety.

An explanation of inner-city change arguing that redevelopment occurs where the potential land value under intensive use exceeds the value realised under current use.

A model explaining the size, number, and spacing of settlements, proposing that towns of different orders form a nested hierarchy according to the range of goods they supply.

The export-oriented activities of a region that bring income from outside and thereby support local service employment and population growth.

The principle that regions or countries gain from specialising in goods they can produce at lower opportunity cost than trading partners, even if less efficient overall.

The paradox in which countries rich in minerals or fuels experience slower growth, weak institutions, and conflict rather than broad development from that wealth.

A coastal state's maritime area extending up to 200 nautical miles from its baseline, where it holds sovereign rights over living and mineral resources.

Newly formed or shifting islands and bars of alluvium within the braided channels of Bangladesh's major rivers, often settled and farmed between floods.

A large bowl-shaped depression in northeastern Bangladesh that holds water during the monsoon and is used for rice cultivation in the dry season.

A sudden, rapid rise of water in a small catchment or low-lying basin, usually following intense rainfall, dam failure, or drainage obstruction.

An abnormal rise of sea level near the coast, caused mainly by strong onshore winds and low atmospheric pressure during a cyclone, capable of deep inland flooding.

The relatively flat land bordering a river that is periodically covered by floodwater and gains fresh layers of fertile sediment from that flooding.

The world's largest continuous mangrove forest, shared by Bangladesh and India, protecting the coast from cyclones and supporting biodiversity and livelihoods.

A river whose catchment or channel crosses an international boundary, making water sharing, flood control, and pollution management matters of joint negotiation.

A high region in north-central China covered by deep wind-blown silt deposits, deeply gullied by erosion and heavily affected by soil conservation programmes.

A climate type with mild, wet winters and hot, dry summers, found on western margins of continents roughly between thirty and forty degrees latitude.

A line drawn on a map joining places that share the same temperature value at a given time or averaged over a stated period.

A line on a map connecting points of equal elevation above a datum, whose spacing and shape reveal slope steepness and landform features.

A systematic method of transforming positions on the curved Earth onto a flat surface, inevitably distorting area, shape, distance, or direction.

A thematic map in which administrative or statistical areas are shaded or patterned in proportion to the value of a variable they contain.

The acquisition of information about Earth's surface from a distance, using sensors on aircraft or satellites that record reflected or emitted electromagnetic radiation.

Computer software and data systems for capturing, storing, analysing, and displaying spatially referenced information as layered maps and attributes.

A satellite-derived index calculated from red and near-infrared reflectance, used to assess vegetation greenness, health, and seasonal change over large areas.

The degree to which a community, system, or place is likely to be harmed by a hazard, reflecting exposure, sensitivity, and capacity to adapt or cope.

A potentially damaging physical event, phenomenon, or human activity that may cause loss of life, injury, property damage, or environmental disruption.

Policies and practices aimed at preventing new disaster risk and reducing existing risk through mitigation, preparedness, early warning, and resilient development planning.