OXFORD REVISE AQA A LEVEL GEOGRAPHY GLOSSARY
The key vocabulary you need to learn for your AQA A Level Geography paper. Find all the terms and definitions you need to understand, from ‘ablation zone’ to ‘zeugen’.
A - B (ablation zone to brackish)
ablation zone
The zone of a glacier in which losses exceed any addition through snowfall or accumulation.
abrasion
Erosion caused by rocks and boulders in the base of the glacier.
accumulation zone
The zone of a glacier in which the amount of snow and ice that is deposited exceeds that which is lost.
active layer
The surface layer that is thawed seasonally in periglacial environments.
adjustment/adaptation
Modifying behaviour and/or lifestyles to live with hazards.
afforestation
The process of planting trees in an area where there was previously no forest.
albedo
A measure of how reflective a surface is.
alluvial fan
Triangular fan-shaped alluvial deposit formed at the edge of a mountain front at the outlet of wadis and canyons.
Antarctica
The world’s most southern, fifth largest and coldest continent.
Antarctic convergence
Boundary zone between colder waters of the Southern Ocean and the warmer waters of adjoining oceans.
Antarctic Treaty
International treaty concerned with the use and protection of the Antarctic continent and its resources.
arête
A thin, jagged crest that separates – or that once separated – two adjacent glaciers.
aridity index
A measure of aridity – it is the ratio between mean annual precipitation (P) and mean annual potential evapotranspiration (PET).
asthenosphere
Zone of Earth’s mantle lying beneath the lithosphere.
atmospheric pollution
Contamination of indoor or outdoor air by chemical, physical or biological means.
bahada
Extensive apron of alluvium formed by the coalescence (merging) of alluvial fans.
bar chart
A way to present data that shows the frequency or amount of discrete datas in a number of different categories.
barchan dune
Crescent-shaped sand dune formed at right angles to the prevailing winds.
barrier beach
A landform created when a spit joins one headland with another, also referred to as a bar.
basal sliding
Large-scale and often quite sudden movement of a portion of ice in a glacier, usually lubricated by subglacial meltwater.
benefits
A positive outcome often leading to an advantage for people and places.
biodiversity
The range and variability of living organisms within a species, between species and in an ecosystem.
biologically transmitted disease
A communicable disease that is infectious, spread from person-to-person or from vector-to person.
biomass
The mass of living biological organisms in a given area or ecosystem at a given time.
biome
A large-scale ecosystem, such as a tundra or savanna.
blackwater
Foul water or sewage.
block and granular disintegration
A form of weathering where the grains of a rock become slackened and fall out due to repeated heating and cooling as a result of temperature changes.
blockfield
Extensive areas of angular fragments of rock and boulders caused by frost shattering and chemical weathering.
brackish
Water which is more saline than freshwater, but not as saline as seawater.
C - D (carbon budget to dynamic equilibrium)
carbon budget
A way of using data to describe the amount of carbon that is stored and transferred within the carbon cycle.
carbon farming
A framework for engaging with the agroecosystem processes that drive system change.
carbon sequestration
An umbrella term used to describe the long-term storage of carbon in plants, soils, rock formations and oceans.
carbon sink
Anything that absorbs more carbon than it releases.
carbon source
Anything that releases more carbon than it absorbs.
carcinogenic
A cause of cancer.
carrying capacity
The maximum population that a particular area can support sustainably.
catchment
The area of land where water collects when it rains.
catchment area
Area drained by a river and all its tributaries.
cavitation
When compressed air bubbles create mini explosions in the process of hydraulic action.
central tendency
The number used to represent the centre, or middle, of a set of data values.
Chi-squared
A test that can be used to see if there is a significant difference between two data sets.
choropleth map
A map that uses a scalke of graduated colours to show spatial variations of data across different areal units.
climatic climax
The vegetation that would evolve in a climate region if the seral progression is not interrupted by human activity, tectonic processes etc.
climax stage
The final stage of the vegetation succession.
closed system
A system with no inputs or outputs.
cold-based glacier
Glacier where the base temperature is too low to enable liquid water to be present so the glacier freezes to the ground.
combustion
The process where carbon is burned in the presence of oxygen and converted to energy, carbon dioxide and water.
compressional flow
Piling up or thickening of glacier ice due to a decrease in the long profile valley floor gradient.
conflict
Disputes between different groups.
consumption
The use of products and services.
coral bleaching
Whitening of corals when corals are stressed by changes in their environment.
core
Centre of the earth.
corrie
A horseshoe-shaped valley which is formed through erosion by ice or glaciers.
costs
A negative outcome often leading to a disadvantage for people and places.
counter-urbanisation
Movement of people out of an urban area to smaller towns and cities or rural areas.
crown fire
Fire which burns through the top layer of foliage on a tree.
crust
The outer layer of the Earth.
cultural diversity
Differences among groups within a community such as ethnicity, language and nationality.
dalmatian
A type of submergent concordant coastline consisting of narrow islands visible above the sea level.
decentralisation
People, industry and business moving out of city centres.
decomposition
The process where carbon from the bodies of dead organisms is returned to the air as carbon dioxide.
deflation
The process of wind erosion that involves the removal of loose material from the desert floor, often resulting in the exposure of the underlying bedrock.
deflation hollow
Enclosed depression produced by wind erosion.
deindustrialisation
Long term decrease of economic output from manufacturing industries in an area.
demographic dividend
Economic growth due to a change in population structure.
demographic transition model
A model which shows how the population structure and key vital rates of a country change over time.
deprivation
A low standard of living and quality of life.
dereliction
Built environment falls into disrepair through abandonment or lack of investment.
desalination
The process by which dissolved solids in sea water are partially or completely removed to make it suitable for human use.
desert pavement
Stony desert surface often resembling a cobbled street.
desertification
Turning marginal land into a desert by destroying its biological potential.
desire line
A line on a map that shows a general direction of movement from one place to another.
differential access to markets
Different countries have varying opportunities to enter and benefit from global markets, e.g. buying and selling of their products.
discharge
The volume of water flowing through a river channel.
disease vector
A living transmitter of disease, e.g. an insect.
dispersion
A diagram that shows how a data set can be distributed.
distant place
Somewhere that an individual/society perceives as being physically far away.
diversion
The transfer of water from one water source to another.
dot map
A map that uses small dots that each represent the same value to show the distribution of data within an area.
drumlin
Hills of sediment that have been streamlined by glacier flow.
dynamic equilibrium
A state in which a system stays in balance despite continuous change.
E - F (ecological footprint to frost creep)
ecological footprint
A measure of impact on the environment.
economic inequality
Unequal distribution of wealth and income between different individuals and groups.
economic migrant
Someone who moves from their place of origin to another for work.
economic water scarcity
When there is not enough water to meet population demands because of things related to money.
ecosystem
A system in which organisms interact with each other and with their environment.
edge city
Urban areas developed on the outskirts of towns and cities.
EIA
An environmental impact assessment (EIA) aims to anticipate the likely impacts of a resource extraction project on surface and ground water, soil, air, biota and humans – and then modify the project to try and minimise the negative impacts.
embryo dunes
Dunes formed when seaweed, driftwood or litter provides a barrier or shelter to trap sand.
emergent
A coastline formed when sea level falls.
endogenous factor
A key aspect of a place’s local geography – physical or human – that helps to shape its unique character, for example, geology.
endoreic
River that terminates in a desert region, usually in a lake.
energy
The capacity to do work or cause change within a system.
energy mix
The combination of different energy sources used to meet a country’s total energy consumption.
ephemeral
River that flows intermittently in a desert region.
epidemiological transition
The change in a country’s development level, demographic characteristics, incidence of disease and causes of death.
erratic
Rocks that have been transported by ice and deposited elsewhere.
esker
Sinuous (winding) ridge found on the floor of a glacial trough, created by sediment from subglacial rivers.
eustatic
A global change in the volume of water in the ocean.
evaluated
To critically assess information.
evapotranspiration
The combined losses of moisture through transpiration and evaporation.
exfoliation
The peeling or flaking of the outer skin of rocks due to intense heating and cooling.
exogenous
River that flows continuously through a desert and has its source in mountains outside the desert.
exogenous factor
A relationship with another place/s that help to shape the unique character of a place, for example, membership of the European Union; such relationships can be seen in the movement or flow of people, resources, money and ideas across space.
experienced place
A location or space which has meaning for an individual, as a result of their having visited it in person.
extensional flow
Stretching or thinning of ice (glacier) in response to an increase in gradient.
fatalism
Acceptance of disasters as something humans can do nothing to avoid or prevent.
fertility
The number of children born per woman.
fjord
A glacial U-shaped valley that has been flooded as sea levels have risen.
flow line
A line on a map that shows an exact direction of movement from one place to another.
flow of capital
Movement of finance and investment between places.
flow resource
A natural resource that is simultaneously used and replaced.
flow/transfer
The movement of energy or matter between stores within a system.
fold mountain
Mountains formed when two tectonic plates collide.
food chain
A simplified linear representation of energy transfer in an ecosystem.
food commodity
Raw or processed food products grown and sold for consumption.
food web
All of the food chains in an ecosystem.
foreign direct investment (FDI)
A country, organisation or individual invests money in another country.
formal representation
A representation closely linked to statistics and data linked to a place.
fortress developments
Communities with saftety and security measures such as gates and CCTV.
free trade
Importing and exporting goods, services and intellectual property between countries without barriers such as tariffs or quotas
freeze-thaw
Occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.
frost creep
The net downslope displacement that occurs when a soil, during a freeze-thaw cycle, expands perpendicular to the ground surface and settles in a nearly vertical direction.
G - H (gentrification to hypothesis)
gentrification
The transformation of an urban area as a result of the influx of more affluent individuals, often resulting in increased property values and a shift in its demographic, cultural and economic characteristics.
gentrified area
Part of an urban area where more affluent residents arrive and then renovate an area, changing its characteristics and the value of housing.
geolocated
Locating the geographical location of an electronic device using GPS.
geopolitics
The study of the ways in which political decisions and processes affect the use of space and resources; it is the relationship between geography, economics and politics.
glacial trough
A relatively straight, steep-sided, U-shaped valley that results from glacial erosion.
global commons
Areas of the planet that our outside national jurisdictions and accessible for all nations.
global governance
System where countries, intergovernmental, non-intergovernmental and other organisations make decisions about world affairs.
global marketing
The promotion and advertising of goods and services around the world.
global system
Interconnections and interdependence between countries that help make and develop the world, including economic, political, societal and environmental interactions.
globalisation
The process of increasing interconnectivity and interdependence within the world.
gravitational sliding
The movement of tectonic plates as a result of gravity.
greywater
Water that has been previously used and may contain some impurities
ground fire
Fire that burns beneath the ground surface with tree roots and peat layers burning.
halophyte
A salt-tolerant plant that grows in soil or waters of high salinity.
hanging valley
A side valley that enters a main valley at an elevation high above the main valley floor.
hazard management
Organising responses to minimise a disaster’s impact after it has occurred.
heritage quarter
Areas with a focus on thier historical characteristics and value.
horizon
The layers in soil throughout its profile.
hot spot
An area on Earth over a mantle plume where magma is hotter than surrounding magma.
hydrosere
Vegetation succession that originated in an area of fresh water.
hypothesis
A statement that can be tested by collecting and analysing data.
I - K (ice wedges to kame)
abiotic
An abiotic is the non-living environmental factors affecting an ecosystem (e.g. the atmosphere, water, climate, rock, soil, and light).
abrasion (glaciers)
Abrasion (glaciers) is when rocks frozen into the glacier scrape and scour away at the valley floor and sides.
ice wedges
V-shaped ice-filled features formed by the enlargement of a surface cracks by frost action. In time the cracks will become infilled with sediment.
impermeable
Surface or rock that does not allow water to pass through it.
incineration
Removal of waste material through combustion (burning).
Index of Multiple Deprivation (IMD)
A relative measure of deprivation.
indicated reserves
Quantity and quality of resources estimated with a high level of confidence.
inequality
The differences in quality of life between different people or groups of people.
inferred resources
An estimate of the quantity of resources.
infiltration
The process of water moving through soil and rock layers.
informal representation
A representation of a place that shows the geographical context of a place through the media, which offers sounds and sight of the place.
informal settlement
Residential areas, often unplanned, built on land without legal ownership and that do not comply with local authority regulations.
input
The resources, substances or energy that enter a system (or store in a closed system).
inselberg
Rounded isolated outcrop of rock, a relic of an eroded upland.
insider
Someone who feels safe, secure and ‘at home’ in a place; they understand the social norms of the society and feel included. They can play an active social and economic role in society.
insolation
The amount of heat (short-wave radiation) that reaches the ground surface.
integrated coastal zone management (ICZM)
The sustainable management of areas within a sediment cell.
integration
Increased links and connectivity between people and places.
interdependent
The reliance of people, places and countries on each other.
intergovernmental organisation (IGO)
Global or regional organisations made up of countries or other organisations. They are established through formal treaties and their members have common interests.
internal deformation
Small-scale inter- and intra-granular movement or deformation of ice crystals in response to gravity and mass.
International Monetary Fund
Intergovernmental organisation consisting of member countries which supports economic policies that promote financial stability and monetary cooperation. Gives advice, loans and other financial aid to member countries.
international trade
Imports and exports of goods, services and intellectual property between countries.
International Whaling Commission (IWC)
International organisation concerned with the management of whaling and the conservation of whales.
isoline map
A map that joins points of equal value to show how these values vary spatially.
isostatic
A local change in the land level, leading to a relative change in sea level.
IWC Whaling Moratorium
Pause on commercial whaling on all whale species to allow for species recovery.
kame
Mound or hillock found on the floor of a glacial trough formed by fluvioglacial deposition.
L - M (ladder effect to municipal solid waste)
ladder effect
The process by which fire spreads from the ground to the crown of trees
landfill
Burial of waste into or onto the land.
leaching
A process where percolating water removes nutrients from the soil.
line graph
Most commonly used to show temporal variations.
lithosere
A vegetation succession that originated on a bare rocky surface.
lithosphere
The outermost solid layer of the Earth, approximately 100 km thick, comprising the crust and upper mantle.
linkage
Flows or connections of materials and/or information between organisations or parts of organisations.
liquefaction
The jelly-like state of silts and clays resulting from intense ground shaking. This may result in subsidence and collapse of buildings following an earthquake.
littoral drift
The transportation of sediment along the coastline, in the direction of the prevailing wind, also referred to as longshore drift.
liveability
Combination of factors that affect an urban community’s quality of life.
logarithmic scale
Method used to show numerical data over a broad range of values.
magma plume
A rising column of hot rock usually at a plate margin, creating a hot spot; can also burn through a plate.
mantle
Layer of the Earth surrounding the core.
measured reserves
Resources that have been identified and examined through sampling to quantify the amount.
media place
A location or space which has meaning for an individual, as a result of their having been exposed to images and other information about it via television, radio, print, film or online resources.
megacity
Urban areas with a population of over 10 million people.
meltwater channel
Often narrow and steep-sided valleys formed by torrents of meltwater at the end of a glacial period.
mid-ocean ridge
A point where two oceanic plates diverge and are filled by magma from the asthenosphere.
mitigation
The steps taken to reduce the negative impacts of the hazard.
mixed development
Projects which include different types of land use within them.
moraine
Material left behind by a moving glacier.
mudflows
A form of mass wasting involving fast-moving flow of debris and dirt that has become liquified by the addition of water.
municipal solid waste
Rubbish thrown away by households, businesses and industry.
N - P (Natural population change to pyroclastic flow)
Natural population change
The way population structure changes based on birth and death rates.
natural resource
Things found in nature that exist without human intervention.
near place
Somewhere that an individual or society perceives as being close.
negative feedback
A cyclical sequence of events that reduces or neutralises the effects of a system.
net primary production (NPP)
The rate at which all the autotrophs in an ecosystem produce net useful chemical energy.
nivation
Snow-related processes, such as weathering and mass movement, that operate collectively to form shallow hollows in the landscape.
non-communicable disease
Diseases which are not infectious and not spread from person-to-person or vector-to-person.
non-governmental organisation (NGO)
A group, independent of governments, that focuses on a particular interest e.g. environment, human rights, quality of life.
norm
The attitudes towards, and standards of, what is acceptable in society.
nuclear fission
The process in which the nucleus of an atom splits into two nuclei.
nuclear fusion
The process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy.
nuée ardente
A turbulent, fast moving cloud of hot gas and ash erupted from a volcano.
nutrient cycle
Recycling of nutrients between living organisms and the environment.
objectives
An aim or goal.
ocean acidification
A reduction in the pH of the ocean over an extended period of time, caused primarily by uptake of carbon dioxide (CO2) from the atmosphere.
offshore bar
A narrow ridge of sediment which runs parallel to the coast, formed when backwash removes material from the beach and deposits it in the offshore zone.
open system
A system with inputs from and outputs to other systems.
output
The resources, substances or energy that leave a system (or store in a closed system).
outsider
Someone who feels homesick, alienated or excluded from society in a specific place; they may not be able to take an active role, for example, in work or study as a result of socially constructed barriers.
outwash plain
An extensive, gently sloping area of sands and gravels formed in front of a glacier.
particulate matter
Particles of solids or liquids that are in the air, a form of pollutant.
particulate pollution
Very small pieces of solids, or small qualities of liquids in the atmosphere e.g. dust, dirt, soot.
pathogens
A bacteria or virus that can cause disease.
patterned ground
Concentration of large stones on the ground surface, usually associated with polygonal patterns of ice wedges.
patterns of trade
Type, volume and flows of imported and exported goods and services between countries and how these change over time.
pediment
Gently sloping, usually concave rock surface at the foot of a mountain front.
periglacial
A landscape that undergoes seasonal freezing and thawing, typically on the fringes of past and present glaciated regions.
photochemical smog
A mixture of pollutants formed when nitrogen oxides and organic compounds react to sunlight.
photosynthesis
The process whereby plants use the light energy from the Sun to produce carbohydrates in the form of glucose.
playa
Salt lake formed on flat clay deposits on a desert plain characterised by high levels of salinity.
pie chart
A way to show data which uses segments in a circle to show proportions of a total.
pingo
Domed hills with an ice core.
place
More than its physical location, a place is a space given meaning(s) by people.
place meaning
The subjective emotional attachment to a place which gives it meaning.
place representation
How a place is portrayed or seen in society.
placelessness
The idea that a particular landscape ‘could be anywhere’ because it lacks unique features.
Some UK high streets have been criticised for being dominated by identically-branded chain stores.
plagioclimax
A sub-climax ecosystem where the arresting factor is human interference.
podsolisation
A process where water percolates through the soil, removing nutrients from the upper layers.
polyp
Tiny animals that comprise a coral reef.
positive feedback
A cyclical sequence of events that amplifies or increases change.
preparedness
Being ‘ready’ for a hazard to occur.
prevention
The methods that we can put into place as human beings to either prevent the hazard entirely or prevent some of the negative impacts of a hazard.
primary data
Data that is collected first hand.
primary product
Goods obtained directly from raw materials without manufacturing, e.g. from agriculture, fishing, mining and forestry.
primary sources of energy
Energy usually found in nature that has not undergone a conversion process.
proportional symbol map
Maps that use symbols, most commonly circles, that are proportionate to the value they are representing.
Protocol on Environmental Protection to the Antarctic Treaty
Part of the Antarctic Treaty System designating Antarctica as a natural reserve for peace and science.
psammosere
Vegetation succession that originated in a coastal sand dune area.
pyroclastic flow
A dense, fast-moving flow of solidified lava pieces, volcanic ash and hot gases.
Q - R (qualitative to rotational movement)
qualitative
Data that can only be organised into descriptive categories that are not numerical; such data may include oral sources such as interviews, reminiscences and songs, and visual media include artistic representations.
quantitative
Numerical data to which different techniques of statistical analysis may be applied to test a hypothesis.
rebranding
A process to rename and reimage a location to boost footfall, investment and the wider social and economic prospects of a place.
recovery
Post-disaster reconstruction and restoration including both the built environment and the natural environment.
recurved spit
A narrow ridge of material extending into the sea, with a curved end which is formed by a change in wind direction.
recycling
Process of changing waste material into usable products.
reforestation
The process of planting trees in a forest where the number of trees has been decreasing.
reimagining
Creating new place meanings by the rethinking of place functions, meanings and purposes.
remittances
Money sent by migrants back to family and friends in their place of origin.
resource development
Further development following initial exploitation of a resource.
resource exploitation
Extracting and using a resource.
resource exploration
The process of searching for available resources.
resource frontier
An area on the periphery of a country or territory which is being opened up for resource extraction as older, more accessible resource locations become exhausted.
resource peak
The moment when a maximum rate of resource exploitation is experienced.
respiration
A chemical process that happens in all cells, which converts glucose into energy.
response
Deploying emergency services and resources.
ria
A fluvial V-shaped valley that has been flooded as sea levels have risen.
ridge push
The pushing force that plates experience as they slide down the raised asthenosphere underneath oceanic plate ridges.
rift valley
A lowland region that forms where Earth’s tectonic plates move apart, or rift.
risk sharing
Distributing potential hazard costs among a larger group or community.
river restoration
Process of managing rivers to reinstate natural processes to bring back biodiversity.
roches moutonnée
Rock formation created by the passing of a glacier over underlying bedrock, resulting in asymmetrical erosional forms.
rotational movement
Glacial ice moving in a circular motion.
S - T (salination to truncated spur)
salination
The addition of salt.
salinisation
The increase of salt concentration in soil.
sampling
A specific group that data is collected from.
scatter graph
A graph used to show the relationship between two variables within a dataset.
secondary data
Data that is collected by someone other than the primary user.
secondary sources of energy
Primary energy converted into a transportable form.
sediment budget
The balance of sediment within a cell, taking into account losses of sediment and sediment gains.
sediment cell
A stretch of coastline which has sediment inputs, outputs and transfers of sediment within it.
sediment source
Places where sediment is generated.
sediment starvation
The reduction of sediment on one part of coastline, usually due to groynes limiting the movement of sediment by littoral drift.
seif dune
Linear sand dune formed parallel to the prevailing winds.
seismic hazard
Any physical phenomenon related to an earthquake that may create unfavourable consequences.
sere
A vegetation succession that relates to a specific environment.
shockwave
A form of energy propagation that result from earthquakes and travels through Earth’s layers.
shoreline management plan (SMP)
A sustainable set of policies for the management of the UK’s sediment cells.
slab pull
Following subduction, the lithosphere sinks into the mantle under.
social construct
Social processes produce and reproduce the social and economic relations between different groups of people in society, in different locations.
social segregation
Separation or limited contact between different social groups.
solifluction
The progressive movement of a mass down a slope caused by freeze-thaw activity.
solifluction lobe
Rounded, tongue-like features which form terraces on the sides of valleys.
spatial organisation
The location of different parts of a business in different places.
Spearman’s rank
A statistical technique used to analyse relationships.
stakeholder
An organisation, individual or group who have an involvement and interest in a project or issue.
statistical
The use of data to gather, review, analyse and draw conclusions.
stemflow
Water flowing down the stems of plants or the trunks of trees.
stock resource
Something that cannot be extracted and is only used once.
store
Where energy or matter is kept for a relatively long time in a system.
storm surge
A change in sea level that is caused by a storm.
structural deterioration
The compaction of soil.
sub-aerial weathering
Processes where rocks at the coastline break down, without the involvement of marine processes.
sub-climax
The development of an ecological community to a stage short of the expected climax because of some factor, such as repeated fires in a forest, that arrests the normal succession.
sublimation
Direct evaporation from ice.
submergent
A coastline formed when sea level rises.
suburbanisation
Outward growth of the urban population from the centre towards its edge.
succession
The changing phases of dominant plant species occupying a particular climatic habitat or ecosystem.
surface fire
Fire that burns along the forest floor, consuming dry vegetation.
sustainable city
Cities which aim to use resources to meet the needs of its population whilst having as little impact on the environment as possible.
sustainable development
Process of the improvement of societies through the responsible use and protection of resources.
sustainable resource development
Long-term planning that ensures extraction does not increase too quickly or rise to unsustainable levels.
Sustainable Urban Drainage Systems (SUDS)
Environmentally friendly ways to remove water from cities, causing minimal damage.
symbiotic
Diverse organisms that exist in the same environment, often depend on this relationship to survive and prosper.
synoptic chart
Weather maps that provide a snapshot of the weather over large areas.
tephra
Pyroclastic material that ranges in size from dust to blocks the size of cars.
terracette
Parallel ridges on vegetated slopes; formed on a slope caused by the freezing and thawing of the ground, causing particles to move downhill.
thermal fracture
A form of weathering brought about by the expansion and contraction of the outer surface of a rock caused by intense temperature fluctuations.
thermokarst
A typical periglacial landscape of hollows and hummocks.
till plain
An extensive flat plain of glacial till that forms when a sheet of ice becomes detached from the main body of a glacier and melts in place, depositing the sediments it carried.
tombolo
A spit which has joined an island to the mainland.
topography
The shape, size and arrangement of geographical features of the Earth’s surface in a given location.
trade agreement
Agreements between countries concerning imports and exports.
trading pattern
The recurring trends and characteristics in the international exchange of goods, services, and capital between countries.
transnational corporation
A company which operates in more than one country.
triangular graph
A method of showing data that has three variables.
trip line
Also known as a ‘desire line’.
trophic level
An organism’s position in the food chain.
truncated spur
A blunt-ended, sloping ridge which descends the flank of a valley, normally due to erosion by a glacier.
U - Z (United Nations to zeugen)
United Nations
IGO which provides a forum for and a basis for action on common global issues for the benefit of humanity and the planet.
United Nations Environment Programme
Global authority concerned with the environment and how it is used and protected to improve the quality of life of the world’s population without compromising that of future generations.
urban form
Physical characteristics of a city e.g. shape, size, layout, building density.
urban heat island effect (UHI)
Occurs when urban areas experience warmer temperatures than surrounding rural areas.
urbanisation
Increase in the proportion of the population living in urban areas.
urban regeneration
Schemes to renew urban areas through public and/or private investment.
vector-borne disease
Diseases which are spread through vectors, such as insects e.g. malaria.
vegetation succession
The evolution of plant communities at a site over time.
ventifact
Sharply angled individual rock usually found on a desert pavement and formed by abrasion.
virtual water
The volume of freshwater used to produce a product, measured at the place where the product was actually made.
volume of trade
Amount of imported and exported goods and services.
wadi
Dry river channel, gully or valley formed by periodic water erosion.
warm-based glacier
Glacier where the base temperature is high enough to enable meltwater to exist and therefore basal sliding to occur.
waste stream
Flow of waste from its source through to recovery, recycling, reuse or disposal.
water balance
An equation used to express the relationship between precipitation, runoff, evapotranspiration and storage.
water pollution
Contamination of water sources by substances e.g. parasites, chemicals and litter which make it unusable for drinking or other uses.
water scarcity
Severe water stress; it is largely accepted that this occurs when annual water supplies fall below 1000 m3 per person.
water stress
When the demand for water exceeds available water resources, or when poor quality restricts its use.
water-borne diseases
Diseases which are spread through the consumption of contaminated water.
waterlogging
When excess water is unable to drain away from soil.
water transfers
The diversion of water from one drainage basin to another.
wildfires
An uncontrolled fire, either natural or human-made, that occurs in open country or wilderness.
World Bank
Intergovernmental organisation funding loans and grants to promote poverty reduction and sustainable development. Funded by member country contributions and by issuing bonds.
world city
City with significant global influence.
World Trade Organization
Intergovernmental organisation dealing with global rules of trade and trade disputes.
xerophyte
Any plant adapted to life in a dry habitat.
yardang
Ridge formed by abrasion of vertical bands of resistant rock.
zeugen
Ridge formed in horizontal rocks, with a clear resistant cap rock.