Glossary
3D printing A process of making three dimensional
solid objects from a digital file. The creation of
a 3D printed object is achieved using additive
processes. In an additive process an object
is created by laying down successive layers of
material until the entire object is created. Each
of these layers can be seen as a thinly sliced
horizontal cross-section of the eventual object.
A horizon The upper layer of a soil mainly
composed of mineral particles with some organic
material.
Aa lava A thick lava with a rough surface and steep
front that moves relatively quickly.
Abrasion Waves throw sand, shingle and cobbles at
the base of the cliff, eroding the cliff. Sometimes
called corrasion.
Absolute humidity The actual amount of water
vapour in a given volume of air.
Absorbed solar radiation The heat energy in shortwave rays from the Sun that is taken in by the
Earth’s surface and sub-surface.
Abstracting (water from rivers) Taking water from
rivers for people to use.
Accretion The process by which a water droplet
joins with an ice crystal and freezes, leading to
the formation of hail.
Accretionary wedge (accretionary prism) Sediments
deposited in the ocean then scraped up against
the leading edge of the continental plate and
added to it.
Acid rain This is caused by burning fossil fuels,
producing sulfur dioxide and nitrogen oxides
which dissolve in clouds to produce acid rain,
which has a ph similar to that of vinegar.
Active volcano A volcano that has erupted in
the last 80 years. (There is no single agreed
definition of this term.)
Actual evapotranspiration The amount of water
that leaves the drainage basin in the form of
water vapour going back to the atmosphere.
Adiabatic A change in temperature of an air parcel
resulting from a change in its pressure as it
rises into thinner air or sinks into denser air. No
transfer of heat to or from the air is involved.
Advance the line Building new coastal defences on
the seaward side of the existing defences.
Advection The movement of air horizontally across
the surface of the Earth.
Advection fog Tiny water droplets in the air near
the ground surface resulting from condensation
when a moist air mass moves over a cooler land
or sea surface.
Aeolian erosion Erosion by wind.
Aerosols Small solid substances in the
atmosphere, such as salt and dust.
Afforestation Planting trees in areas which
previously had no forests.
Agenda 21 Established at the 1992 Earth Summit
in Rio de Janeiro, Brazil, Agenda 21 states that
sustainability must be tackled on a local as well
as at the national and international scale. It can
be summed up by the phrase ‘Think global but
act local’.
Aggregation The process by which ice crystals
collide and join, eventually forming snow.
Agroforestry A managed agricultural system which
uses fast growing tree crops to protect the soil
from erosion and to shade the crops beneath
them. It gives the benefits of greater biodiversity.
Air mass A large body of air that has almost
uniform temperature and moisture content
throughout.
Air temperature The degree of heat in the
atmosphere.
Albedo The percentage of solar radiation reflected
back to space by a surface.
Algae Simple plants, some of which are the initial
colonisers in a vegetation succession because
they lack roots and have low nutrient demands.
Some are the primary producers in food chains
because they can make their own food from
inorganic sources.
Alluvial fan A fan of sand and gravel deposited by
short-lived torrents at the foot of mountains.
They are not restricted to arid climates, although
they are characteristic features of them.
Altocumulus Medium level white cloud with a flat
base and globular upper surface.
Altostratus Medium level layer cloud.
Amelioration Reducing the impacts or effects of
something, e.g. reducing the effects of river
flooding.
Anchor store A major retailer which attracts not
only customers but other stores to a location.
Annual hydrograph A graph showing how a river’s
discharge changes over the course of one year.
Annuals Plants having a life-cycle lasting only one
year.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
1
Antecedent drainage Where a mountain range
has been formed across the path of a river but
the vertical erosion of the river has been able to
keep up with the growth of the mountain range.
Anti-natalist Policies which discourage people from
having children. A policy which is designed to
reduce the birth rate.
Anticline An area of upfolded rock (more technically
a fold where the core of the fold is older than the
outside).
Anticyclone A roughly circular high pressure system
where central high pressure air is surrounded by
air with lower pressure.
Apartheid The system of segregation or
discrimination on grounds of race formerly
practised in South Africa. It was adopted as a
slogan in the 1948 election by the successful
Afrikaner National Party. Apartheid extended
and institutionalized existing racial segregation.
Despite rioting and terrorism at home and
isolation abroad from the 1960s onwards, the
white regime maintained the apartheid system
with only minor relaxation until February 1991.
Appropriate technology Small-scale technology,
simple enough so that people can manage it
directly and on a local level. An example would
be a micro-hydro power plant in an LIC or MIC.
Aquifer An underground rock layer that contains
significant amounts of groundwater in its pore
spaces that can be extracted and used.
Arch A hole with a roof that extends from one side
of a headland to the other.
Arcuate delta A fan shaped delta.
Arroyo (Spanish) A stream bed which is usually
dry except during flash floods. The term is often
used in Latin America and south-west USA.
Artesian effect Water rising to the surface under
pressure.
Artesian well Water that rises under its own
pressure through an artificial hole to the surface
from an underground permeable rock. It does not
need to be pumped.
Ash The smallest solid particles that result from a
volcanic eruption.
Asian Tiger The high-growth economies of Hong
Kong, Singapore, South Korea and Taiwan.
Aspect The direction that a settlement or feature
faces.
Assisted Areas Areas coming under a UK policy
which lasted for fifty years up to the 1980s.
Companies within these areas could acquire
grants or capital allowances in order to protect
jobs.
Asthenosphere The hotter, more plastic layer in
the upper mantle below the lithosphere. The
boundary between the two (the base of the
lithosphere) is taken at the 1 300 °C isotherm.
Asylum seekers Refugees who apply to live
permanently in the area of destination.
Atmosphere A mixture of gases that encircle the
Earth consisting of about 99 per cent nitrogen
and oxygen, with small amounts of other gases,
such as water vapour, methane and ozone.
Atmospheric disturbance A state in the
atmosphere in which strong pressure differences
cause storms and tornadoes, with violent winds.
Atoll A circular or oval coral reef around a shallow
lagoon.
Attrition A form of erosion that occurs when waves
move beach material around and the particles
become smaller as they rub together.
Austerity Cuts in government spending to reduce
debts.
B horizon The subsoil, which is formed by the
re-deposition of materials removed from the A
horizon above and from the C horizon below.
Baby boomers Those members of the UK
population born in the fifteen years after the end
of the Second World War (1945–1960), a period
of time when the UK birth rate was higher than
before or since.
Back-wearing The retreat of a slope parallel to
itself by weathering and erosional processes.
Backshore zone The upper part of the beach above
the mean high tide level but affected by spring
tides and storm waves.
Backwash The water which returns down the beach
after a wave has broken.
Backwash effects The way that capital, jobs and
people from peripheral regions are attracted to
core regions leading to even greater imbalance in
services and infrastructure.
Bahada A continuous gently sloping fringe of scree,
gravel and coarse sand along the base of a
mountain range in a semi-arid area. It has been
formed by the coalescence of a series of alluvial
fans.
Bankfull After it rains, a river’s discharge usually
increases. The bankfull discharge is the point
when the river channel is full of water, just before
it spills out onto its floodplain. The river is at its
most efficient at the bankfull stage.
Bar A ridge of sand or shingle that extends right
across a bay or inlet.
Barchans Crescent-shaped dunes which develop
transverse to winds; see also parabolic dunes.
Barrier beach Long, sandy beaches, detached from,
but parallel to, the coastline. In areas with a low
tidal range they can develop into barrier islands.
Barrier island Long islands running parallel to
the coastline. They probably started as barrier
beaches, but sand dunes formed on them and
vegetation then built them up above high tide
level.
Barrier reef A coral reef separated from the
mainland by a wide and deep lagoon.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
2
Barriers to movement The difficulties that the
migrant will face when making the journey to a
new home and the difficulties they may face once
they arrive.
Basal scour When waves are deflected downwards
from a vertical sea wall, basal scour can
undermine the foundations and cause the wall to
collapse.
Basal surface of weathering The varying depth
below the ground surface to which the rock has
been weathered.
Basalt A dark coloured, finely crystalline lava which
makes up the upper layers of the oceanic crust.
Base level (sea level) The lowest level to which a
river can erode the land. Base level is the current
sea level and a river cannot erode below this
level as water cannot flow uphill into the sea.
Baseflow There are two meanings of this term:
1. One of the three main ways that water reaches
a river. Groundwater that flows down through
the rocks towards the nearest river. The phrase
‘Groundwater Flow’ is an alternative.
2. The proportion of river discharge that is
provided by water seeping into the river from the
bedrock. Baseflow is often clearly labelled on a
storm hydrograph.
Bay An approximately semi-circular indentation in a
coastline, often between two headlands.
Bay beach A semi-circular beach found at the head
of a bay.
Beach cusps Semi-circular, scalloped depressions
cut into the lower edge of the storm beach.
Beach nourishment Artificial addition of beach
material (sand, shingle or pebbles) from another
location.
Bedload The part of the river’s load that spends all
or some of its time on the river bed.
Benioff Zone The inclined belt of earthquake foci
found in a subduction zone with deeper foci
further away from the ocean trench.
Berms Ridges which form at the top of the beach,
running parallel to the coastline. They are usually
made of stones or shingle and are produced by
the fortnightly spring tide.
Best-fit line A line drawn on a scatter-graph that best
represents the trend of the points on the graph.
Bid-rent theory Supposes that land in a city will
be occupied by the land-use that could afford to
pay the highest rent and that land values would
decrease from the city centre outwards.
Big Mac index A statistic published by The
Economist magazine as an informal way of
measuring the purchasing power parity (PPP) in
different countries. It is based on the amount of
time that an average worker in a given country
must work to earn enough to buy a Big Mac, a
burger sold in McDonald’s restaurants.
Bilateral aid Government aid between two countries.
Biodiversity The variety of plant and animal species
within an ecosystem.
Biofuel Any fuel which comes from biomass. It
includes solid biofuels (e.g. wood), liquid fuels
(e.g. biodiesel and bioethanol) and various
biogases (e.g. methane).
Biomass 1. The total mass of living organisms in a
unit area measured as dry weight, e.g. in kg/m².
2. Solid organic materials that can you be burnt
for energy or processed to produce liquid biofuels
or biogas. Examples include wood, maize used to
produce bioethanol and animal manure used to
produce methane in a digester.
Biomass productivity The amount of organic matter
produced in a unit of time.
Biome A global scale ecosystem distinguished by
and named after its climatic climax vegetation.
Biosphere reserve An internationally recognised
area, run by the national government, with a
core area protected by law, a buffer zone in
which activities that do not harm the ecosystem
are allowed and a transition area in which local
communities and conservationists work together
to sustainably manage the area’s resources.
Bird’s foot delta A delta where each distributary
channel builds the land out into the sea.
Birth control Where population growth is limited
by a fall in the death rate. This is the situation
typical of Stages 3 and 4 of the DTM.
Birth rate The number of live births per thousand
people per year.
Block disintegration When weathering causes
rocks to disintegrate into larger fragments or
boulders.
Blowhole A tube that grows upwards through the
rocks from the roof of the cave. It is caused by
wave quarrying and slowly erodes upwards along
a weakness in the rock and eventually breaks
through at the top of the cliff.
Bluff A low hill at the side of a flood plain.
Borehole A hole drilled down into the rocks, often
to allow water to be abstracted (a tube well).
Bornhardt An isolated mountain with a domed top
that rises from an extensive level surface; a
domed inselberg.
Bottom-up Aid which directly aids individuals rather
than governments.
Braided stream A stream which breaks into
distributary channels.
Breaker zone See nearshore zone.
Breakpoint bar A long thin ridge of sediment on
the sea bed, running parallel to the coastline, at
or below the level of the lowest spring tide. They
form at the point where waves begin to break.
The circular movement of water in the wave
touches the sea bed and sweeps material into a
ridge.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
3
BRIC Term used since 2001 for Brazil, Russia,
India and China, all countries which were
expanding rapidly.
Brownfield sites A previously occupied site which is
being re-developed.
Budget compliance How well a government has
stuck to its spending plans.
Built environment Buildings, as opposed to the
natural environment.
Burgess’s concentric zone model A model of
urban land-use developed in 1925, based on the
structure of American cities, including Chicago,
USA, where circular zones spread out from the
centre.
Butte A narrow, flat-topped inselberg.
Buttress root Roughly triangular projections which
grow out from the lower three metres of the base
of trunks of very tall trees in tropical rain forests
and give the tree added stability.
C horizon The layer of weathered rock below the
subsoil.
Calcification A soil forming process in which
calcium is deposited from solution as soil water
evaporates. It occurs during dry spells in hot
areas.
Calcrete A hard mass or layer in the soil
composed of deposited calcium carbonate by the
calcification process.
Caldera A very large depression formed by a large
volcanic explosion which removes the top of a
volcanic cone, with much of the summit area
sinking into the magma chamber.
Canalisation When rivers are straightened and
deepened in order to make them easier to
navigate by barges.
Canopy layer The level in a forest at which the
crowns of the majority of trees form a thick
surface.
Capacity (of a river) The total amount of load
that a river can carry. Usually measured at the
bankfull stage.
Capillary action The movement of water upwards
through small pores in the soil caused by surface
tension. Capillary action is also the method by
which plants draw water from the soil and move it
up to the leaves.
Capillary rise The upward movement of soil
moisture and minerals through pores in the soil.
Capital goods Something sold to another company
to produce something else.
Carbon cycle Carbon flows between the
atmosphere, land, and ocean in a cycle that
encompasses nearly all life on Earth. The
amount of carbon in the atmosphere helps to
determine global temperatures.
Carbon footprint A measure of the amount of
carbon dioxide that results from a specific human
activity or activities. It can be measured on a
variety of scales, e.g. for an individual, a country,
the world.
Carbon sequestration The capturing and storing of
carbon dioxide and other forms of carbon in an
attempt to slow down global warming.
Carbon-neutral An activity which results in no net
release of carbon dioxide into the atmosphere.
Using biodiesel is carbon neutral because the
CO2 released when it is burnt was extracted from
the atmosphere when the plant was growing.
Carbonation Process of chemical weathering where
carbonate minerals in rocks such as limestone
are attacked by carbonic acid in rainfall.
Carnivore Meat eater.
Carrying capacity 1. The maximum number of people
that can be supported in a given region without
damaging the area to an unsustainable extent. For
services, it is the number of people exceeding the
number that the local area can cope with.
2. The maximum number of animals that can be
grazed on pastures sustainably.
Cartel A group of people, companies or countries
that work together to influence prices.
Cash crop A crop produced to sell.
Catalytic converter A vehicle exhaust control box
that converts toxic pollutants into less toxic
pollutants by catalyzing a chemical reaction.
Catalytic converters are mainly used to clean
petrol engine exhaust gases.
Cation exchange A process by which one cation
on a clay and/or humus particle is replaced by
another to maintain a balance as the chemistry
of the soil water solution changes.
Cation exchange capacity (CEC) The amount
of cations that can be held by a clay or humus
particle or clay-humus micelle.
Cations A positively charged particle.
Cave An underground chamber left by removal of
the rock, usually limestone, with an entrance
from the surface. Coastal caves are usually at
the base of the cliffs.
Cavitation Erosion due to the force of exploding
air. Powerful eddies in the flowing river water
compress and decompress water in cracks in the
river bank. This can lead to the formation of air
bubbles in the water, which explode outwards,
weakening the crack and leading to pieces
breaking off. This process is especially important
where the water is moving very quickly, in rapids
and waterfalls.
Cavitation Water trapped in cracks in a cliff is
compressed by the pounding of the waves. When
the pressure is released, bubbles form in the
water and these bubbles escape from the crack
with explosive force.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
4
Census A survey of the size and nature of a
country’s population where every household has
to be counted and questioned.
Centrifugal force A force that acts on a body
moving in a curved path. Its force is outwards
from the centre and is balanced by the
centripetal force.
CFCs Chlorofluorocarbons, gases that reduce
atmospheric ozone and are responsible for the
ozone holes at the poles.
Channel flow One of the two main outputs of water
from a drainage basin. Water in the river channel
flowing downhill towards the sea.
Charter flights Air flights developed purely for the
tourist trade.
Check dams Small dams, often in small valleys, that
reduce the speed of runoff and prevent erosion.
Chernozem The black, deep, humus-rich soils of the
temperate grasslands.
Cinders Solid particles about 4 to 5 mm in diameter
thrown out from a volcanic vent or fissure.
Cirrocumulus Small, high level globular cloud.
Cirrostratus High level layer cloud.
Cirrus A wispy, fibrous cloud formed at a high level
and made of ice crystals.
Clear cutting The practice of cutting all the trees in
an area during logging operations.
Cliff drainage Drainage pipes are inserted into the
face of the cliff, especially where the cliff is made
of soft or unconsolidated material. This removes
water from the cliff, removing the potential for
mass movements.
Cliff re-grading A vertical cliff is turned into a more
gently sloping cliff by removing material from the
cliff top and adding it to the bottom of the cliff.
Climatic climax community A theoretical
vegetation community which has adapted to the
climate until it is in perfect equilibrium with the
climate. It contains the tallest vegetation that
can grow in the climate.
Closing-up The cost to a migrant of disposing of a
house or bulky possessions in the source area.
They may get money for these things but they
often have to settle for less than they are really
worth.
Cloud A collection of tiny water droplets hanging in
the air.
Coalescence The process by which water droplets
grow as they collide and join together.
Coastal management This has three main aims:
protecting the coastline from erosion, from
flooding by sea water and conserving fragile
coastal ecosystems.
Cockpit karst A limestone area that is made up of
deep depressions with conical or concave floors
and residual conical hills between them.
Cold front The surface along which cooler polar air
moves into, and displaces, warmer tropical air.
Colony A country controlled and governed by
another country.
Command economy System associated with
totalitarian regimes such as the former Soviet
Union. Individuals and groups respond only to
production targets set by the government and a
market controlled by the government.
Common Agricultural Policy (CAP) Introduced
in 1962, it is the EU system of controls and
subsidies of agricultural production and prices.
Common market An area or group of countries
with free trade of goods and services and free
movement of labour and capital.
Commonwealth The organisation many of the
former colonies of the UK.
Communal land tenure Land holding based on the
joint ownership of land by every member of the
community.
Commuting range The distance that people are
prepared to travel from their home to their jobs in
the city.
Competence (of a river) The maximum size of
particle that the river is capable of transporting
at the bankfull stage.
Components Items used by factories to be
assembled into a finished product.
Compound spit Spits occur when longshore drift
extends the beach part of the way across an
estuary, bay, or inlet. Compound spits have a
narrow base attaching them to the mainland
but they widen into a broad re-curved end,
consisting of a series of ridges which have grown
successively over time.
Compression Converging stresses that cause
shortening of the Earth’s crust.
Compulsory purchase A compulsory purchase order
allows governments and councils to buy land or
property without the consent of the owner.
Concretions A hard mass or nodule of a deposited
chemical in the soil. In tropical soils they are
usually composed of iron oxide whereas in
limestone areas they are formed of calcium
carbonate. They vary considerably in size and
colour.
Condensation The process by which a gaseous
substance (e.g. water vapour) changes into a
liquid (e.g. water) due to cooling.
Condensation nuclei Tiny particles of dust, smoke
or salt that have an affinity to water and form a
nucleus around which condensation occurs.
Conduction The transfer of heat or cold to an
object by contact with a hot or cold body.
Cone karst A limestone landscape with
depressions which are star-shaped in plan and
separate conical hills of greater height than in
cockpit Karst.
Conservative Area in which plates are sliding past
one another with no material being added to or
subducted from either side.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
5
Constraints Factors that might deter a person
from migrating, even if the push and pull factors
indicate that they should migrate.
Constructive waves Low, gentle waves that
add sediment to a beach. They have a long
wavelength and a low wave frequency.
Consumer goods Items sold to the public.
Consumption triangle The relationship between
population growth, resources and economic
development.
Containerisation A system of transport that uses
a standard size of steel box (container) to
transport goods. These containers can easily be
transferred between different modes of transport.
This makes transport and trade of goods cheaper
and more efficient.
Continental climate A climate where great distance
from the sea results in a very large annual
temperature range, with cold winters and hot
summers.
Continental drift The concept that the continents
might have moved their positions, first put
forward by Abraham Ortelius in 1596. The
concept was developed by Alfred Wegener in
1912 and accepted since the 1970s.
Continentality The extremes of temperature
associated with locations far from the
moderating influence of a sea.
Contour ploughing Ploughing horizontally on a
slope to prevent erosion.
Controlled grazing Limiting how many animals
can use a pastureland and the amount of time
the animals can graze in one area before being
moved to another area. It is achieved usually by
dividing the land into paddocks by fences and
moving the animals between them.
Conurbations A large urban area formed by the
merger of two or more towns or cities.
Convection The transfer of heat by air that rises
because it has been warmed from below,
causing it to expand and become lighter than the
surrounding air.
Convection drag Convection currents in the plastic
mantle dragging the overlying lithosphere.
Convergence This term has two meanings:
1. Air flow comes together and piles up as it
slows and changes direction.
2. Decreasing economic differences between
regions.
Convergent boundary Area in which plates
are moving towards each other. Includes the
destructive boundaries and collision boundaries
like the Himalayas where plates are moving
towards each other but there is no subduction
and destruction.
Coppicing A traditional method of woodland
management which takes advantage of the
fact that many trees make new growth from the
stump if cut down. In a coppiced wood, young
tree stems are repeatedly cut down to near
ground level in order to harvest the wood.
Core The innermost part of the Earth at 2700 km
below sea level.
Core and frame A concept of urban morphology
which distinguishes the land-use of the central
CBD and the outer CBD.
Core and periphery The differences between
regions within countries, particularly the
difference between metropolitan centres with
a high potential for innovation and growth and
remote regions where economic growth is slow.
(it is also used to describe the differences
between countries and between LICs and HICs).
Core regions Metropolitan centres with a high
potential for innovation and growth.
Corestone A boulder, usually of basalt, dolerite or
granite, with rounded corners that result from
spheroidal weathering.
Coriolis force An effect on wind direction, rather
than a force. As wind is moving over a rotating
Earth, its straight path appears as a curve when
plotted on a map.
Corrasion Waves throw sand, shingle and cobbles
at the base of the cliff, eroding the cliff.
Sometimes called abrasion.
Corrasion (abrasion) Erosion of rocks hit by
transported particles in the wind, rivers, glaciers
or the sea.
Counter-urbanisation The reversal of the previous
rural–urban migration and the process of people
moving out of cities into villages and country
towns since about 1970.
Cover cropping Growing a crop to prevent exposing
soil to agents of erosion.
Creek A small channel in a saltmarsh along which
the receding seawater drains as the tide goes
out.
Creep A type of mass movement involving the very
slow downslope movement of soil and weathered
debris.
Critical renewable resources Require careful
management as they can be used up at a faster
rate than they are being replaced, e.g. energy
produced from wood, biomass and animal
wastes.
Crop rotation Planting a different crop each year
over a three or four year cycle to maintain soil
fertility.
Crust The upper layer of the Earth’s surface,
between 6 and 90 km thick. Its base is marked
by the Mohorovicic discontinuity (‘Moho’) where
there is a sudden change to the more dense
rocks of the mantle.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
6
Cumulative causation The idea that the
development of one activity will stimulate the
growth of others. For example, industries attract
workers who get paid and spend their wages,
providing an affluent market. This market attracts
other industries and services which attract more
workers, and so on.
Cumulonimbus A very tall cloud, which can reach
from a very low level to the tropopause. It has
either a flat anvil head or a globular top.
Cumulus A low level white cloud with a flat base
and globular top.
Cuspate delta A delta shaped like an arrowhead or
a worn tooth.
Cuspate foreland Low features which extend
outwards from the shoreline in a triangular
shape. They are formed by the deposition of
sand and shingle at the point where two streams
of longshore drift sediment meet.
Cuspate tombolo When wave refraction causes
longshore drift to operate in opposite directions
either side of an offshore island, the beach
extends out to the island, joining it to the
mainland at low tide.
Customs union An area or group of countries with
common external tariffs on non-members.
Cuticle A protective film covering the surface of
leaves and young stems of plants.
Cyclone The term has two meanings:
1. An intense tropical storm in the Indian Ocean,
Bay of Bengal or Australia with wind speeds of
119 km/h and above.
2. An approximately circular low pressure system
anywhere in the world.
Dalmatian coastline A drowned coastline with long
narrow islands running parallel to the coastline.
The islands were the ridges of hills when sea
level was lower in the past.
Death control Occasional increases in the death
rate limiting population growth. This is the
situation typical of Stage 1 of the DTM.
Death rate The number of deaths per thousand
people per year.
Debt The cumulative deficits of more than one year.
Debt relief Measures to reduce the debt of
countries struggling to pay the interest on debts.
Debt service ratio The proportion of a country’s
export earnings needed to meet its debt
repayments.
Decentralisation Moving industry from the core to
the periphery to trigger growth.
Deficit When a government’s annual spending
exceeds the income that it generates through
taxes and other means.
Deflation A process of erosion involving the
removal of dry, unconsolidated material (soil,
dust, sand) from the surface by wind.
Deflation hollow A major depression excavated by
deflation.
Deforestation Cutting trees down.
Deindustrialisation The decline in manufacturing
employment in HICs in the second half of the
20th century; in this process, the secondary
industry moved out to other locations, and
services began to dominate production and
employment.
Delta An area of flat land (formed by river deposits)
where a river meets the sea or a lake.
Demand management Decreasing the demand for
energy to match the limited supply.
Demographic dividend Something a country
experiences in Stage 3 of the DTM when it has a
large and productive working population, a small
number of old people and a falling percentage of
young dependents. This is the situation in many
NICs where the proportion of the population that
is in the working age-group is higher.
Demographic Transition Model (DTM) A simplified
theory of how population has changed because
of changing birth and death rates as a country
develops over time.
Dependency ratio The relationship between the
working and the dependent population. The
dependent population can be split into young
dependents and old dependents.
Dependent population The non-economically
active groups in a population. The dependent
population can be split into young dependents
and old dependents.
Depopulation Population decline in a country or
area, when more people move out of a country
or area than are being replaced by births or inmigration.
Deposition The process by which the gas, water
vapour, changes directly to solid ice.
Depression A low pressure system in temperate
latitudes in which warm and cold air meet and
the warm air rises. Also known as a cyclone.
Desert varnish A film of iron and manganese
oxides deposited by evaporation of solutions
brought to the surface by capillary action.
Desertification The deterioration of soils and
vegetation in an area that results in it having
a desert-like appearance. Originally defined
as ‘land degradation in arid, semi-arid and dry
sub-humid areas caused by adverse human
impact’, today purely physical causes are usually
included.
Desiccation cracks A network of cracks formed
when a flood plain or temporary lake dries up.
Desire line map Map showing lines for the links
between places. The width of the line indicates
the amount of flow.
Destination area The place that the migrant has
moved to. Sometimes called the receiving area.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
7
Destructive boundary Area where material is
being destroyed or subducted and the plates are
moving together.
Destructive wave Waves that remove sediment
from a beach. They are steep, high waves
that have a short wavelength and a high wave
frequency.
Detrivore An organism, such as an earthworm, that
consumes dead organic matter, such as dung
and plant litter.
Development An increase in the total value of
goods and services produced by a country,
leading to an improvement in the people’s
welfare, quality of life and social well being.
Development aid Aid given by HICs to support
economic development or social development in
LICs. It aims to alleviate poverty in the long term,
rather than alleviate immediate crises.
Development continuum The concept that
countries do not fit easily into simply categories
of development and there is a gradual change of
different degrees of development.
Development gap The difference in social and
economic well-being between the various
countries of the world.
Dew Droplets of water that form on surfaces, such
as grass, due to condensation, usually an effect
of overnight cooling.
Dew point The temperature at which air is holding
the maximum amount of water vapour.
Diaspora An immigrant group and its areas of
residence.
Differential erosion Erosion which affects soft
rocks more than hard rocks.
Digester A vessel in which solid biomass ferments
to produce biogas.
Dilatation (pressure release) The cracking parallel
to the surface and sheeting of rock layers as
a result of expansion, following the removal of
the weight of overlying rocks by erosion and
weathering.
Disaster A hazard that has such a severe impact
on people that they and their built environment
cannot recover unaided.
Discharge The amount of water flowing down a river
at any one time. Discharge is measured in cubic
meters of water per second (cumecs).
Discordant coastline Where the different rocks run
at right angles to the line of the coastline.
Diseconomies of scale These are when economies
of scale have reached their limits and costs per
additional unit begin to increase.
Dispersed settlement Scattered or separated
dwellings.
Displaced people People who have been forced to
migrate by circumstances beyond their control
and who are probably homeless and suffering
from extreme poverty. Those who have crossed
into another country are known as refugees while
people who have moved within their own country
are IDPs (internally displaced persons).
Disposable income The money that people have
left over after paying their taxes and paying for
their necessities, money left over for luxuries and
non-essentials.
Disposable income A person’s income which
remains after the basic necessities have been
purchased and can be spent on non-essential
items.
Distance-decay The idea that the number of
migrants declines as the distance between
the area of origin and the area of destination
increases.
Distortion of culture The change brought about by
large numbers of people from outside, e.g. the
adoption of western dress and moral values, and
the English language.
Distributaries The channels formed when a river
divides, as in the braided channels in a delta.
Diurnal energy budget The difference during
the day between incoming solar radiationand
outgoing terrestrial radiation, added to the
total amount lost by scattering, reflection and
absorption by clouds.
Divergence This term has two meanings:
1. Air flow separates because it speeds up and
changes direction.
2. Increasing economic differences between
regions.
Divergent (constructive) boundary Area where new
ocean crust is being created and the plates are
moving apart.
Doldrums The Equatorial Low Pressure Zone with
rising air rather than horizontal wind, in which
ships would stagnate..
Dolerite A dark coloured, medium crystalline rock
found at intermediate depths in the oceanic
crust.
Dominant species The tallest plant species that
grows in a particular climate. It shades out other
competitors.
Dominant wind This is a strong wind, coming from
a different direction than the prevailing wind, less
common but more powerful than the prevailing
wind.
Dormant volcano A volcano that is inactive but may
become active again in the future.
Dormitory settlement A settlement which provides
residence, but little employment and residents
tend to commute to other places.
Double maxima of rain Two periods of higher
rainfall during a year, characteristic of the humid
tropical climate.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
8
Doughnut effect The CBD becomes ‘hollow’ as
population moves to the outer suburbs in search
of newer, larger or more affordable houses and
businesses move to edge-of-town locations which
have cheap land and good accessibility.
Downdrift starvation When groynes interfere with
longshore drift so problems are caused further
along the coastline (downdrift) where beaches
are depleted of sediment and erosion rates
increase.
Downward transition regions Areas declining
because of exhaustion of resources or because
of industrial change.
Drainage basin The area of land drained by a river
and its tributaries. A drainage basin supplies a
river with its water.
Drainage density The total length of surface
streams per square kilometre.
Drift-aligned Beaches that are aligned at an angle
to the crests of the prevailing waves. As a result,
long shore drift takes place.
Drought An abnormally prolonged period without
rain.
Drought resistant A plant or animal that has
adapted to survive long periods without rain.
Dry farming A range of farming practices used for
crop growing in areas of low rainfall.
Dune-slack If the surface of the sand dunes is
lowered by wind erosion until it reaches the water
table a dune-slack is formed where water loving
plants such as willow shrubs can grow.
Dust bowl The period of catastrophic soil erosion
by wind in the American Midwest in the 1930s.
Dvorak technique The analysis on satellite images
of patterns in tropical weather systems to
estimate their intensity on a scale from 1 to 8.
Earthquake A movement in the rocks from
which shock waves or tremors move out in all
directions.
Echo dunes Dunes that form in the sheltered lee
of hills. They can be fairly stable and sometimes
vegetated.
Ecocline A gradual change from one ecosystem to
another.
Ecological pyramids Diagrammatic representations
using scaled rectangles to show either the
numbers of individuals or the amount of biomass
at each trophic level. As both decrease up the
trophic levels, the diagrams form a pyramid
shape.
Economic leakage When money earned by an
activity does not stay within the local area.
Economic migrants Migrants who move in order to
obtain a better standard of living, e.g. a better or
more highly paid job.
Economic union (EU) An area or group of countries
with common economic policies.
Economies of scale These are the cost advantages
due to the greater size of a business.
Ecosystem A community of living organisms and
its physical environment. The non-living (abiotic)
components of an ecosystem include air, water
and soil. Energy and nutrients flow through the
system.
Ecotourism Sustainable tourism that aims to
preserve the local environment and cultures,
while increasing the standard of living of the local
people.
Edaphic Relating to soil.
Eddy (pl. eddies) A swirling or circular motion in a
moving fluid such as air or water. The water in
a river can flow back on itself and this causes
turbulence in the flow.
Edge city An American term for a concentration
of business, shopping, and entertainment away
from the CBD in what had previously been a
residential or rural area. It is much larger and
more self contained than a retail or business
park.
Effective precipitation The amount of precipitation
that remains after evaporation and other losses
and is available for plants to use.
El Niño (ENSO) The El Niño Southern Oscillation
(ENSO) is a reversal of the southern equatorial
ocean current that occurs in the Pacific Ocean
just south of the Equator; it flows from west to
east, warming the waters along the coast of
Peru.
Eluviation The soil forming process by which
materials are removed from a layer of soil in
suspension or solution.
Embryo dune Small sand dunes formed at the
top of a beach where there is an obstacle
encouraging the deposition of wind-blown sand.
They provide a very harsh environment for plants
but as sand builds up on them, they become
fore-dunes.
Emerged coastal plain In a part of the world with
a wide, shallow continental shelf, a fall in sea
level can produce a wide coastal plain, backed
by a relict line of cliffs which represent the old
coastline.
Emergency aid/humanitarian aid Help given to
people in distress or immediate threat of death.
It aims to relieve suffering and not to address
the causes of the problem.
Emergent layer The tallest trees in a tropical
rainforest that rise above the canopy layer.
Emerging markets Countries where the volume of
trade is expanding rapidly.
Emigrant Someone who moves out of a country.
Emigration People moving out of a country as part
of an international migration.
Employment structure The proportion of people
working in primary, secondary and tertiary activities.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
9
Endowment How much of something a person or a
country has.
Energy budget The difference between incoming
solar radiation and outgoing terrestrial radiation,
added to the total amount lost by scattering,
reflection and absorption by clouds.
Energy conservation Making sure that energy is not
wasted. Using energy as sparingly as possible.
Energy mix See primary energy mix.
Energy policies Strategies adopted by a country’s
government to influence the supply of energy.
Energy resource Something that can be used to
provide people with heat, light and power.
Energy security Ensuring the uninterrupted
availability of energy sources at a price that
people and industry can afford.
Enhanced greenhouse effect The addition of
greenhouse gases to the atmosphere by human
activity, leading to greater retention of heat in the
earth-atmosphere system.
Environmental Kuznets Curve A graph showing how
the amount of pollution in a country is linked
to its level of economic development. It shows
how pollution levels rise as a country becomes
industrialised but then they fall in a postindustrial society.
Epicentre The point on the Earth’s surface
immediately above the focus of an earthquake.
Epiphytes Plants that live supported on other
plants but take nutrients from the atmosphere.
Episodic rainfall Rainfall which falls in a rare,
irregular pattern.
Equable A small difference between summer and
winter temperatures, characteristic of places with
a coastal location.
Equinox An astronomical event (twice a year, on
21 March and 23 September) on which the
noonday sun is overhead at the Equator, giving
equal hours of daylight and darkness at every
latitude.
Erg Sandy area in a desert.
Etchplain The landscape that is exhumed when
weathered material is removed down to the level
of the basal surface of weathering.
Etchplanation The stripping away of layers
of regolith to expose the basal surface of
weathering at the surface. It requires periods of
uplift and climate change with periods of aridity.
Ethnic cleansing When people of one ethnic group
are forcibly evicted from their homes (or even
killed) by people from another ethnic group. It is
a form of forced migration.
Eurocentric Looking at things from a European
point of view, highlighting European history and
assuming other parts of the world will follow the
same course; biased towards European countries.
European Union An organisation of 28 member
states that are that operates through a system
of decision making by the member states. Its
institutions are the European Commission, the
Council of the European Union, the European
Council, the Court of Justice of the European
Union, the European Central Bank, the European
Court of Auditors, and the European Parliament.
The European Parliament is elected every five
years by EU citizens.
Eustatic A global change in sea-level.
Eutrophication The addition of large quantities of
nutrients to water, leading to the growth of plants
(such as algae), that use up oxygen when they
die and therefore harm other organisms.
Evaporation The change in state from a liquid to a
gas, such as from water to water vapour.
Evapotranspiration One of the two main outputs of
water from a drainage basin. Water evaporates
from leaves, puddles and streams. In addition,
plants draw water from the soil through their
roots and allow it to evaporate into the air
through their leaves - this is transpiration. The
two processes combined are evapotranspiration.
Exfoliation Weathering process which causes rock
surfaces to peel.
Exfoliation dome A rounded rock mound in
the tropics or sub-tropics showing signs of
exfoliation.
Exogenic river A river with its source outside the
area
Expansion cooling The reduction in temperature of
a gas as it occupies a larger volume.
Export processing zones (EPZs) These are a type
of FTZ set up generally by governments in ledcs
to promote industrial and commercial exports.
Incentives to companies choosing to operate
within such zones include duty free imports of
raw materials, flexibility of labour laws and tax
concessions.
Extension of cultivation Increasing the area under
cultivation.
Extensive production System based on low inputs
and outputs per unit.
Extinct volcano A volcano that will not erupt again.
Eye The calm central part of a tropical storm
(cyclone), where pressure is lowest
Eyewall The vertical bank of cumulonimbus cloud
that surrounds the eye of a cyclone.
Fair trade A movement whose goal is to help
producers in lics achieve better access to
markets and sustainability.
Fall A type of mass movement in which the loose
material moves down through the air under
gravity.
Fallow Leaving agricultural land without a crop.
Fallow periods The lengths of time during which
agricultural land is left without being cropped.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
10
Falls Mass movement when rock drops from
vertical faces.
Fault A fracture in rocks along which movement
occurs and causes displacement.
Felsenmeer A boulder field.
Ferrallitisation See latosolisation.
Ferrel cell A theoretical circulation of air in midlatitudes in each hemisphere between the Hadley
and Polar cells. It shows high altitude winds
blowing from the Polar Front to 30°N and S, but
this does not actually happen.
Ferrel’s Law Ferrel’s discovery that every moving
body in the Northern Hemisphere deflects to
the right and any moving body in the Southern
Hemisphere deflects to the left because of the
Coriolis effect.
Fertility rate The average number of children each
woman in a population will have in her lifetime.
It is also defined as the number of live births per
1 000 women aged 15–49 in one year.
Fetch Waves are caused by the frictional drag of
the wind as it blows over the water. The fetch is
the distance of sea over which the wind can blow.
Field layer The layer in the structure of a forest that
contains grasses and other herbaceous plants.
Filter-down process Where manufacturing moves
from economic core regions in HICs to lower-cost
peripheral regions, often in LICs and MICs.
Fixed dunes Sand dunes that are completely
covered in vegetation which stabilises them and
stops further movement of the sand.
Fjord A drowned glaciated valley.
Flash floods A flood that develops in a very short
time. It is usually caused by intense and heavy
rain.
Flocculation The way that charged ions in sea
water allows clay particles to coagulate together
and settle out of suspension.
Flood peak The highest level that a river reaches
during a flood.
Flow A type of mass movement in which the loose
material moves downslope under gravity, keeping
contact with the surface. Individual particles
move separately within the flow.
Flows (mud flows) Rapid downslope movement of
sediment mixed with water.
Focus The point at which the movement that
causes an earthquake occurs.
Fog Tiny droplets of water that hang in the air near
the ground so that they reduce visibility to less
than 1 km.
Fold mountains The great elongated mountain belts
of the world formed by compression and folding
at convergent plate margins. Fold mountains
form the highest of the world’s mountain ranges.
They are long, relatively narrow, they have parallel
ridges and valleys. The main range contains a
series of ranges.
Food security Food security means that food is
available for the population and at a price that
they can afford. It should provide for their dietary
needs and for their food preferences.
Footpath erosion Where the concentration of
people on paths causes erosion by people
trampling. Once vegetation is removed, natural
erosion may accelerate.
Forced migration When migrants feel they have
no alternative but to move, often because of a
natural disaster, a war, or persecution.
Fore-dune The first significant dune ridge in a sand
dune system. They are formed by the deposition
of wind-blown sand and are partly stabilised by
marram grass.
Forecast An imprecise statement of time, place
and nature of an expected event.
Foreign direct investment (FDI) When a company
or an individual from another country buys a
company in a country or expands an existing
business in that country (it does not include
investment in the securities of another country
such as stocks and bonds). FDI may be indicated
in the national accounts of a country.
Foreign exchange The process by which people in
different countries pay each other by exchanging
different types of money.
Foreshore Sometimes called the inter-tidal or surf
zone, the zone of the beach between the mean
low tide and the mean high tide level.
Formal economy When people have a job or own a
business that the authorities are aware of. They
pay tax as a result.
Fossil fuels A fuel produced from organic material
which was growing millions of years ago. When
we use these fuels we are using the sun’s energy
from millions of years ago, which has been
stored in the fossil fuels. The main fossil fuels
are coal, oil and natural gas.
Fracking Short for ‘fracturing’. Mud and liquids are
pumped into the rocks under pressure, cracking
the rocks and allowing natural gas to escape.
Fracture zone An elongated depression on the
ocean floor along a transform fault.
Françafrique The economic interdependence of
France and its former African colonies. The
currency of many was tied to the French franc
and, since 1999, to the Euro.
Free trade Free movement of goods between
countries without tariffs etc.
Free Trade Zones (FTZs) FTZs were formerly called
free ports. They are areas where goods may be
imported, handled, manufactured and re-exported
without the going through customs. Only when
goods enter the country are tariffs paid.
Freeze-thaw/frost shattering The process of
physical weathering where water seeps into
cracks and freezes.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
11
Freezing The process by which a liquid changes to
a solid, such as from water to ice.
Fringing reef A coral platform attached to and close
to the land. It may have a narrow and shallow
lagoon between the reef and the mainland.
Front The surface separating two different air
masses.
Frontal uplift The rising of the warmer and lighter of
the two air masses that meet in a depression. It
rises over the denser colder air mass along the
warm front and is also forced to rise along the
cold front as it is undercut by colder air moving in
at the rear.
Frontal zone Where two air masses meet and mix
to a small extent as they are similar, creating a
zone rather than a sharp front between them.
Fujita-Pearson Scale A measurement of tornadoes
that includes wind speed, path length, path width
and damage done.
Functional linkages Where manufacturing or
services have features that allow them to benefit
from each other.
Functional zonation The way that zones of
distinctive land-use develop in towns and cities.
Gabbro A dark coloured, coarsely crystalline rock
found deep in the oceanic crust.
Gabions Wire cages (1m3) infilled with stones.
They can be wired together to make any shape
or structure, e.g. Groynes or sea walls. They are
used to support slopes or stabilise river banks.
Gated community Residential area of an urban
area where access is controlled by security
measures, designed to protect the relatively
wealthy residents.
GDP/person A country’s gross domestic product
(GDP) divided by its population. GDP is the total
value of the goods and services produced by a
country in one year.
Genetically modified (GM) crop/varieties Plants
used in agriculture where the DNA has been
modified using genetic engineering techniques.
The aim is to produce a variety of the crop which
has an improved trait, e.g. resistance to pests
and diseases.
Gentrification The buying and renovating of houses
and stores in run down urban areas by wealthier
individuals. This improves the properties and
stimulates retailing and entertainment in the
area.
Geomagnetic reversals The periodic reversals
that have occurred in the dipoles of the Earth’s
magnetic field - as though a bar magnet has
‘flipped’. The magnetic north pole becomes a
south pole and vice versa.
Geostrophic wind A wind that blows parallel to
the isobars as the Coriolis force balances the
pressure gradient force..
Gersmehl diagram A scaled diagrammatic
representation of the amount of nutrients stored
in the biomass, litter and soil of an ecosystem
(shown by proportional circles) and the amount of
nutrients transferred between the stores (shown
by lines of proportional thickness).
Ghetto Part of a city in which members of a ethnic
or religious minority group live. Very often found
in the inner city zone of a settlement.
Gini coefficient A measure of the equality of
distribution of a country’s income developed by
the Italian statistician and sociologist Corrado
Gini in 1912. A Gini coefficient of 0 is perfect
equality, where everyone has the same income. A
Gini coefficient of 1 would be where one person
has all the income.
Glacials Cold phases of climate when glaciers
expanded.
Gleying A soil forming process in which
waterlogging reduces red ferric oxides to bluegrey ferrous oxides. Gleyed horizons can be
mottled as a result of periods of drying out.
Global distribution Locations in the world where the
subject of a study is found.
Global energy budget Incoming solar radiation
balanced against losses from the earthatmosphere system.
Global peak oil production The point in time when
the greatest global oil production occurs.
Global warming An increase in the world’s average
temperature. Usually used in connection with
human activity adding greenhouse gases to the
atmosphere.
Globalisation The growth of international
integration, in other words the increase in
links between different parts of the globe.
This includes the growth in trans-national
corporations (TNCs), advances in transportation
allowing the movement of people, advances
in communications infrastructure such as the
internet and cell phones allowing the movement
of knowledge, the growth of international political
alliances such as the European Union.
Gorge A deep, steep sided valley.
Gradient analysis Measuring changes in land
values and population density from the city
centre outwards.
Grading Making slope angles gentle to make them
stable.
Granite A light coloured coarsely crystalline rock
found in the continents.
Granular disintegration When weathering causes
rocks to disintegrate into mineral grains.
Great Ocean Conveyor Belt A continuously
circulating current that moves along the ocean
floor due to differences in temperature and
salinity.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
12
Green belt An area around major cities where
development is prohibited, particularly in the UK,
designed to limit urban sprawl.
Green Revolution The huge increase in global food
supply between 1960 and the present day. It is
the main reason why food supply has kept up
with population growth.
Greenfield site A site not previously built on.
Greenhouse effect The process by which
atmospheric gases, such as water vapour and
carbon dioxide, absorb long-wave radiation from
the Earth and re-radiate it back to Earth, keeping
heat in the Earth-atmosphere system.
Greenhouse gas A gas, such as carbon dioxide and
methane, which absorbs radiation (especially
infra-red from the land) and adds to the
enhanced greenhouse effect (climate change).
Grey sector Retired people, often with free time
and spending power.
Gross primary productivity (GPP) The total of
all energy produced by photosynthesis in an
ecosystem, including respiration.
Groundwater Water that percolates into the
bedrock and is stored there. Most groundwater
eventually flows down through the rocks towards
the nearest river.
Grouting Injecting permeable rocks with cement to
reduce pore water and increase strength.
Groyne A barrier, usually made of wood, built
at right angles to the trend of a beach. Their
purpose is to reduce sediment transport along
the coast by longshore drift.
Gulley (or gully) V-shaped valley as a result of
recent vertical erosion.
Gully erosion Erosion of the land surface into a
series of V shaped valleys.
Hadley Cell A circulation of air in the tropics and
sub-tropics. Air rises in the Equatorial Low
Pressure Belt and then blows pole-wards just
below the tropopause, before sinking in the subtropical high pressure belt at about 30° N and
30° S and blowing back to the Equator as surface
trade winds.
Hail A form of precipitation in the shape of a small
ball and made of alternate layers of frozen water
(ice glaze) and rime.
Halophytes Salt tolerant plants.
Hamada Bare rock desert.
Hard engineering Protecting vulnerable coastlines
by building large, solid structures (often of
concrete or stone) to absorb or reflect the energy
of the waves.
Harmonic tremor Continuous rhythmic
earthquakes.
Hawaiian eruption The emission of fluid basalts
from volcanic vents with occasional lava
fountains as gases escape.
Hazard A threat that could injure people and
damage the built environment.
Head of water The vertical distance down which
water flows before turning the turbines in a HEP
station. The greater the head of water, the more
power can be generated.
Headland An area of land, usually composed of sea
cliffs, which sticks out into the sea.
Headwaters The streams in the upper part of a
drainage basin near the source of the main river.
Heat island An urban area with higher temperatures
than the surrounding rural area.
Heave The downslope movement of material due to
freezing and thawing.
Heavily Indebted Poor Countries (HIPC) A joint
IMF-World Bank approach to debt reduction in
countries with weak economies.
Helicoidal flow The line of fastest flow in a
river channel (thalweg) follows a corkscrew or
spiralling path as the river moves downstream.
Herbaceous plants A plant that is not woody and
which dies down after flowering. Grass is an
example.
Herbivore Plant eater.
Hi-tech industries Meaning high technology, there
is no strict definition of what this includes.
It is generally the most advanced technology
available at the time and includes aerospace,
automotive, artificial intelligence, biotechnology,
computer engineering, computer science,
information technology, nanotechnology, nuclear
physics, photonics, robotics, semiconductors and
telecommunications.
Hidden borrowing System used by banks to make
borrowing appear less than the true amount
Hierarchy of world cities Cities ranked according to
their international influence.
Higher order goods and services Goods and
services with a large threshold population and
range. They are bought or used infrequently and
only available in larger settlements.
Hinterland The land area served by a port.
Hoar frost Ice crystals with temperatures below
freezing point deposited in still conditions on
grass and other surfaces.
Hold the line Maintaining and repairing the
current coastal defences so that the coastline
is protected from further coastal erosion and
so that the risk of future coastal flooding is not
increased.
Homer Hoyt’s sector model A model of urban landuse developed in 1939 where zones radiate from
the centre.
Honeypot Congested tourist locations dominated by
crowded roads and pavements, tourist shops and
food outlets.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
13
Horizontal integration Where each production
branch of a company produces one model for a
regional or even global market.
Horse latitudes The areas of the subtropical high
pressure systems roughly 30 to 35° north and
south of the Equator.
Hot spots Isolated areas of high heat flow in the
Earth which can be away from plate margins.
Human development index (HDI) A broad index
used by the UN which is calculated by based on
a country’s GDP per person (PPP), adult literacy
and other aspects of a country’s educational
provision and life expectancy at birth.
Humic acids Acids produced by the decay of
organic matter.
Humidity Moisture in the form of water vapour in
the air.
Humification The soil forming process by which
dead organic matter is converted to humus by
decomposers.
Humus A complex organic matter formed by the
breakdown of raw organic matter.
Hurricane A hazardous tropical storm with wind
speeds of 119 km/h and above, that occurs
in the Caribbean Sea, Gulf of Mexico and west
coast of Mexico.
Hybrids Selectively bred varieties of crops and
animals which are noted for their consistency.
Hydration and dehydration Processes of chemical
weathering where wetting and drying can cause
the addition or removal of water from the
molecules of some minerals, causing expansion
or contraction which assist disintegration.
Hydraulic action Erosion produced by the energy
of the moving water in the waves as they hit the
coastline.
Hydraulic radius This is a measure of the efficiency
of the river. Hydraulic radius = channel cross
sectional area divided by wetted perimeter.
Hydro-electric power (HEP) Making electricity from
the power of flowing water.
Hydrograph A graph showing how a river’s
discharge (on the vertical axis) changes over
time (on the horizontal axis).
Hydrological cycle The way that water moves from
the sea, through the air, onto (and into) the land,
and back into the sea. It is driven by the sun’s
heat and by gravity. It is often known simply as
the water cycle.
Hydrological regime The annual hydrograph of a
river.
Hydrolysis A process of chemical weathering when
a mineral is broken down by a reaction with water.
It is important in the silicate minerals which form
most rocks, especially the mineral feldspar.
Hygrophytic plant A water loving plant with
adaptations that allow it to exist in very wet
areas.
HYV crops High Yielding Varieties of crops. Crops
such as Rockefeller Rice which have been
selectively bred to produce more food per
hectare.
Icelandic eruption The emission of fluid basalt lave
quietly from fissures at mid-ocean ridges.
Illegal immigrants People who migrate without
permission. They do not have a visa or other
papers allowing them to enter the destination
country.
Illuviation A soil forming process in which material
is deposited in a horizon after being moved in
solution or in suspension, usually from above,
as in tropical red soils. In the seasonally humid
areas illuviation takes place in the upper
horizons during the dry season.
Immigrant Someone who moves into a country.
Immigration People moving into a country as
part of an international migration; see also
international migration.
In-migration People moving into a region of a
country as part of an internal migration within
that country; see also internal migration.
Incidental pollution A one-off event, e.g. the
Chernobyl radiation leak or the Exxon Valdez oil
spill.
Incoming solar radiation Short-wave solar radiation
received by the earth-atmosphere system. Also
known as insolation.
Industrial agglomeration The clustering of
industries or services of a particular type at a
particular location.
Industrial estates Areas set aside for industry and
usually have a variety of industries on site. They
tend to deal with light industries but not always.
Industrial Revolution The developments in heavy
manufacturing industry and the factory system
which started over 200 years ago in MEDCs
when people left their jobs in agriculture in rural
areas and migrated to the growing towns and
cities to work in factories.
Inertia Used to describe geographical patterns,
such as industrial location, which owe their origin
to factors which no longer apply.
Infant mortality rate The number of children
who die, under the age of one, expressed per
thousand live births per year.
Infanticide The intentional killing of children in their
first year of life.
Infilling Process seen in urban areas in the UK
where a large old house with a large garden is
bought by a developer. Housing is built in the
garden then the old house is done-up and sold
on with a much reduced garden.
Infiltration capacity The speed at which rainwater
can infiltrate into the soil.
Infiltration rate The amount of water sinking into
the ground surface in a given unit of time.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
14
Informal economy When people work for themselves
without the authorities knowing about them. This
means they do not have to pay tax.
Informal economy When people have an unofficial
job or set up their own unofficial business and do
not pay taxes.
Informal sector When people work unofficially
without employment rights and without paying
taxes.
Infrastructure The basic physical systems of a
business or nation including roads and railways,
telephone and broadband, sewerage, water and
electricity systems, schools, hospitals. These
systems tend to be high-cost investments,
however, they are vital to a country’s economic
development and prosperity.
Inland drainage basin Drainage basin of a river
with its mouth inland where water is lost through
evaporation
Inner-city The inner city is typically found in a ring
around the CBD in HIC cities. It is a mixed zone
of old housing and old factories. Unemployment
and other socioeconomic problems are typical of
this urban zone.
Inselbergs An isolated mountain that rises
from a flat plain in arid and seasonally humid
landscapes; an isolated upland.
Insolation Incoming short-wave solar radiation
received by the earth-atmosphere system.
Integrated coastal management A form of coastal
management which takes into consideration all
aspects of the coastal zone in an attempt to
achieve sustainability.
Integrated transport policies Different forms
of transport such as bus, overground rail,
underground rail are planned so that they link
together for the benefit of the customer.
Intensification Increasing inputs to increase
output.
Intensity The destructiveness of an earthquake. It
is measured on the Mercalli Scale.
Intensive production System based on high inputs
and outputs per unit.
Inter-tidal zone The zone on the beach between the
mean low tide and the mean high tide level.
Inter-tropical convergence zone (ITCZ) Belt close
to the Equator where the Trade Winds meet and
air rises with low pressure at the surface.
Interglacials Warm phases of climate when glaciers
shrank.
Intermittent river A river that only flows
occasionally.
Internal market A way that a business can organise
its activities where parts of the company are set
up as different businesses which sell goods and
services to each other, e.g. a components plant
selling components to an assembly plant.
Internal migration When people move from one
place to another within a country.
Internally displaced persons (IDPs) Refugees that
have moved to a safer part of their own country.
International migration The movement of people
across international frontiers, i.e. from one
country to another.
Intra-urban migration When people move house
within one urban area, i.e. from one part of a town
or city to another part of the same town or city.
Invisible imports/exports/trade Services which
are sold to other nations.
Inward investment When an area attracts money
from outside which is used to develop the area in
some way.
Irish potato famine The time from 1845 onwards
when the fungus Phytophthora infestans started
to destroy the potato crop. This led to famine,
and of the 8 million people living in Ireland, about
a million people died and another million left the
country, mainly for England, Scotland and the USA.
Irrigation Providing water for crops by artificial
means.
Island arc A curved, volcanic, island archipelago
found on the landward side of an ocean trench.
Isobar A line on a map joining places with the same
air pressure.
Isohyet A line on a map joining places with the
same amount of rainfall.
Isostatic A local change in sea level, usually
produced by movements of the land relative to
the sea.
Isostatic rebound During a glacial period the land is
pushed down by the weight of the ice sheets. At
the end of the glacial period the ice sheets melt
and the land slowly rises back to its former level.
Isotherm A line on a map joining places having with
the same temperature.
Isthmus A narrow stretch of land between two seas
that connects two land masses.
Jet stream An extremely fast current of air near
the tropopause. The Polar Front jet streams
move through the centre of the Rossby waves.
There is also a sub-tropical jet stream in each
hemisphere.
Juvenility index Shows the proportion of younger
people in a population.
Kaolinite Clay produced by the decay of minerals in
igneous rocks.
Key word/phrase Definition
Kopje Low, irregular hills, often of granite, formed
by the disintegration at the surface of domes
with rectangular jointing. The term is also
sometimes used to include tors. Or mounds
of boulders and weathered bedrock found on
hilltops in the tropics particularly in granite.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
15
Kyoto treaty The Kyoto treaty (or protocol) is an
international treaty, which commits the countries
that sign it to reduce their greenhouse gas
emissions. It is based on the assumptions
that global warming exists and man-made CO2
emissions have caused it.
La Niña A strong movement of warm water from
east to west that sometimes flows just south of
the Equator in the Pacific Ocean, leading to very
heavy rains in north east Australia and cooler
than average conditions in Peru.
Labour-intensive industries Industries such as
clothing and shoe manufacture which have large
inputs of labour per unit of output.
Lagoon An area of shallow water separated from
the sea by a bar or a coral reef. It can also be a
shallow lake in a delta.
Lahar A mudflow on the slopes of active volcanoes
when ash mixes with water from torrential
rainstorms.
Laminar flow Water flowing downwards, over a
smooth surface, in a simple sheet, with no
eddies or meanders.
Land breeze A surface wind in a coastal area that
blows at night from land to sea due to pressure
differences over the two surfaces.
Land degradation The reduction or loss of potential
productivity and biological potential by adverse
changes in soil characteristics and/or soil loss
by water and wind erosion.
Land tenure The set of rules which govern how land
is owned and held by individuals, governments
and companies.
Landfill Domestic rubbish and other waste which is
buried in a large hole in the ground.
Lapilli Pebble-sized particles resulting from a
volcanic eruption.
Latent heat of condensation Heat stored in water
vapour during melting or evaporation processes
which is released back into the atmosphere when
the water vapour condenses.
Latent heat transfer Heat that is stored in water
vapour after being taken from the air and used in
melting and evaporation processes.
Lateral erosion When a river erodes sideways.
Rivers close to base level cannot erode vertically
so erosion is concentrated on the river banks
rather than the river bed.
Laterite A hard red mass of oxides of iron and
aluminium in the subsoil of tropical soils that
hardens when exposed by erosion.
Latitude An imaginary line circling the Earth, the
degree of which shows how far north or south it
is from the Equator.
Latosol See oxisol
Latosolisation The accumulation of iron and
aluminium oxides (sesquioxides) in the B horizon
of a tropical soil.
Lava Flows of molten rock emitted on to the
surface through a volcanic vent or fissure.
Lava dome A small, steep-sided, round-topped
mound of silicic lava formed on the slopes of, or
in the crater of, a volcano.
Law of diminishing returns Where increased capital
inputs do not produce a proportional increase in
outputs.
Leaching A soil forming process in which
substances are removed from a horizon and
taken down in solution.
Legislation Passing laws.
Levées Raised banks on either side of a river
flowing across a flood plain. They might cause
the river to flow above the level of the flood plain.
Liana A thin woody plant that twists and climbs
round tree trunks in tropical rainforests.
Liberalisation of trade Reducing restrictions on
trade such as tariffs.
Licence Issued by a government to an importer to
control imports.
Lichens The first stage in a lithosere, algae
living with fungus colonise newly available rock
surfaces and obtain their nutrients from the
atmosphere. They lack roots and exist without
soil.
Life expectancy The average number of years,
from birth, that a person can expect to live. This
means the age at which 50% of the children,
born in a particular year, have died.
Limestone A sedimentary rock with a high
carbonate content, often formed from fragments
of shell material.
Linear settlement Dwellings in a line, often along a
road.
Liquefaction Unconsolidated materials act as a
liquid and flow when affected by earthquake
shockwaves.
Lithosere Vegetation succession that develops on
an original rock surface.
Lithosphere/plates The upper, colder, rigid part
of the Earth including the Earth’s crust and
part of the upper mantle. The thickness of the
lithosphere varies greatly, ranging from less
than 15 km for young oceanic lithosphere to
about 200 km or more for ancient continental
lithosphere (for example, the interior parts of
North and South America).
Litter Undecomposed leaves and parts of plants
that lie on the ground surface.
Loam A soil with a good structure formed by a high
humus content and a good range of particle sizes
not only have a good balance of water retention
and drainage.
Loess Fine-grained, wind-blown deposits blown out
from deserts to adjacent areas, e.g. in northwest China.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
16
Log-normal graph paper Graph paper with one
linear scale and one log scale.
Log/log graph A graph which uses logarithmic
scales on both the horizontal and vertical axes.
Long profile A line drawn from the source of the
river (where it starts) to the mouth of the river
(where it meets the sea). It shows how the
gradient of the river channel changes as it flows
downhill. The typical long profile is concave –
steeper in the hills and gentler in the lowlands.
Longevity Longevity is best thought of as meaning
‘typical length of life’ but it is also used to mean
‘long lifespan’ or ‘living until you are very old’.
Longitude An imaginary line circling the Earth, the
degree of which shows how far east or west it is
from the Prime Meridian.
Longshore bar Long thin ridges of sediment on the
sea bed, running parallel to the coastline, at or
below the level of the lowest spring tide.
Longshore currents Wave refraction sets up
longshore currents that operate in the sea below
low tide level and run parallel to the coastline.
They move sediment from the headlands into the
bays, forming bay beaches.
Longshore drift When waves arrive at an angle to
the beach, swash carries material up the beach
at an angle and backwash carries it straight
back down the beach. The overall effect of this
zigzagging is to move material along the beach.
Lorenz curve A graphical representation of the
cumulative distribution of wealth or income,
developed by Max O. Lorenz in 1905 for
representing inequality of the wealth distribution.
Loss of sovereignty Where a country or a
government loses control of activities which take
place within its boundaries.
Low water mark The mean of the lowest levels of
the sea at low tides.
Lysimeter Container of soil and vegetation used to
measure evapotranspiration.
Mafic (basic) lava Lava containing less than 50%
silica. It is very fluid and solidifies slowly.
Magma Molten rock beneath the Earth’s surface.
Magma chamber An area beneath a volcano that is
the source of its magma.
Magnetic stripes Stripes of rock on the ocean
floor parallel to an ocean ridge crest, alternate in
magnetic polarity (normal-reversed-normal, etc.),
showing a symmetrical pattern on either side of
the ridge. The youngest rocks at the ridge crest
always have present-day (normal) polarity.
Magnitude This term has two meanings:
1. The size of a river flood, measured in terms of
the maximum discharge.
2. The amount of energy released during an
earthquake. It is measured on the Richter Scale.
Managed realignment Allowing the shoreline to
move backwards or forwards but with the use
of management strategies that will control this
movement.
Managed retreat Allowing the shoreline to move
backwards but with the use of management
strategies that will control this movement.
Mantle The middle layer of the Earth between the
crust and the core.
Mantle plume A stationary area of high heat flow
in the mantle. It rises from great depths and
generates magma; see hot spots.
Marine process The landscape processes of
erosion, transportation and deposition that
operate along the coastline because of wave
action.
Marine Protected Areas (mpas) Areas of
the oceans or seas that are protected for
conservation purposes.
Maritime climate A climate with temperatures
moderated by the proximity to the sea, resulting
in a small annual range, with cooler summers
and warmer winters than the inland.
Mass movement Also known as mass wasting,
this is the downslope movement of rock and
weathered debris by gravity alone. It does not
include erosion.
Mass tourism Tourism for people other than a rich
elite and catering for large numbers.
Meander belt A zone along a flood plain defined by
the outside of the river’s meanders.
Mega-cities A city with a population of over ten
million.
Megalopolis Term used in the USA for the
conurbations created by suburbanisation and
urban sprawl.
Melting The process by which solid ice changes to
liquid water.
Mercalli Scale A twelve point scale which indicates
the amount of physical damage done by an
earthquake.
Mesa A flat-topped inselberg.
Mesocyclone Rotating up-currents up to 16 km in
diameter in a tornado.
Micelle A soil particle of combined clay and humus
which enables cation exchange because it
attracts, and temporarily holds, cations to its
surface by its strong negative charge.
Midden A dump for domestic waste, usually not
too far from the house. Common in pre-industrial
societies and LICs.
Migration The permanent change of residence of
an individual or group of people. ‘Permanent’
means a change of residence that lasts for more
than one year.
Migration stream Migrants sharing a common
source area and destination.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
17
Millennium Development Goals The UN Millennium
Summit in 2000 established 8 targets. All UN
member states at the time committed to help
achieve these targets by 2015.
Millionaire city A city with a population of over one
million.
MINT Term used in 2014 to describe the next
countries likely to develop their economies
significantly – Mexico, Indonesia, Nigeria and
Turkey.
Miocene A subdivision of the Tertiary Period of
geological time.
Mist Tiny droplets of water that hang in the air
near the ground surface and reduce visibility to
between one and two kilometres.
Mixed woodland Woodland that contains both
deciduous and coniferous species of trees.
Mobile yellow dunes High ridges of mobile sand
dunes inland of the fore-dunes.
Moment magnitude scale A scale now used for
measuring earthquake magnitude in terms of the
total amounts of energy released. It is calculated
by multiplying the rigidity of the Earth by the
amount of slip along the fault and the size of the
area that slipped.
Monitoring The undertaking of regular checks at
potentially dangerous sites.
Monoculture Where the same crop is grown on the
same land, year after year.
Monsoon winds Summer winds blowing towards
continental low pressure systems which develop
over the warm land.
Montane rainforest Rainforest that grows on
highlands.
Montmorillonite A clay produced by the decay of
minerals in igneous rocks and highly prone to
expansion and contraction resulting in slope
failures.
Moratorium Stop or pause.
Mortality The rate at which people die. It is related
to infant mortality, life expectancy and longevity
as well as to the crude death rate.
Mosses Small plants that grow in clumps and
are early pioneer plants in the vegetation
succession. They have small roots and low
nutrient demands.
Mudflats Flat areas of alluvial sediment, usually
deposited in an estuary, exposed at low tide.
Multi-national corporation (MNC) A company which
owns manufacturing or services industries in one
or more countries other than the home country.
Multilateral aid Aid involving more than two countries,
e.g. UK, France and USA give money to the UN or
the World Bank, which passes it on to an LIC.
Multilateral Debt Relief Initiative (MDRI) A system
to allow 100% relief on certain debts by the IMF,
the World Bank, and the African Development
Fund (AFD) for countries completing the HIPC
Initiative process.
Multiple line graph Several line graphs plotted
against the same axes on one graph.
Multiplier effect Where an area has an initial
advantage which leads to other economic
developments and an upward spiral of
development.
Municipal housing Housing owned or controlled by
local government.
Nagana Animal disease transmitted by the tsetse
fly.
Native species Flora and fauna originating in an
area.
Natural change The change in the size of a
population caused by the difference between
the birth rate and the death rate. If birth rate
exceeds death rate, the population will grow. If
death rate exceeds birth rate the population will
decline.
Natural disaster A natural occurrence which
produces death, damage to property, and
disruption to people’s lives.
Natural resources Useful materials that have not
been created by humans. This includes minerals
dug from the Earth, materials from the natural
vegetation such as timber and also water.
Naturbanisation A trend whereby urban-rural
migrants have tended to move into the most
scenic areas of the countryside, such as the
national parks.
Nearshore zone Sometimes called the breaker
zone. The lower part of the beach below the
mean low tide level but uncovered by spring
tides.
Negative deindustrialisation The decline in
manufacturing employment in HICs where the
economy is not growing and new industries do
not emerge to replace the old ones.
Neocolonial When colonial links have been broken
but the colonial power still has economic
influence in the former colony.
Net migration The balance between people moving
into a region or country and the people moving
out of that region or country.
Net primary productivity (NPP) The amount of
biomass produced per unit area in a given time
by the photosynthesis of plants.
Net radiation balance The difference between
incoming and outgoing radiation, which varies
from time to time and place to place (but has
to be in balance overall if the world is not to get
hotter or colder).
Niche market tourism Tourism designed to cater
for special-interest groups.
NICs Newly Industrialised Countries.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
18
Nimbostratus A very thick, dark grey layer cloud
with sufficient vertical height to produce steady
rain.
No active intervention This is also known as the
‘do nothing’ strategy because there will be no
further investment in coastal defence.
Nodal points Route intersections which have great
accessibility.
Non-critical renewable resources Have unlimited
availability. They are everlasting and we do not
need to worry about the rate at which they are
used, e.g. solar power, tidal power and wave
power.
Non-governmental organisations (NGO) Charities
and other organisations not controlled by
governments.
Non-point source pollution Pollution which
emanates from an area, e.g. exhaust emissions
from all the vehicles in a city.
Non-renewable energy resources Have been built
up over a very long period of time. They can run
out and can’t be replaced in the foreseeable
future.
Normal relief Anticlinal ridges and synclinal valleys.
North Atlantic Drift Name given to the warm ocean
current that begins as the Gulf Stream in the
Caribbean and flows north eastwards across the
North Atlantic Ocean.
Nucleated settlement Dwellings are clustered
together.
Nuée ardente A very hot, dense cloud of
incandescent gas and tiny fragments of solid
material that moves in contact with the ground
rapidly down slope from the vent of a volcano.
Nutrient stores The biomass, litter and soil in
an ecosystem where nutrients are found in
considerable quantities and between which
nutrients are transferred.
Oases Any location in a desert where water occurs
at the surface.
Objective Impartial and unbiased, not influenced
by personal feelings or opinions. A statement of
fact.
Occluded front The front formed when the warm
front is caught up by the cold front so the two
merge and are lifted above the ground surface as
the depression nears the end of its life cycle.
Ocean current A body of water moving through the
ocean, driven by surface winds.
Ocean trenches Long, narrow areas of the ocean
floor about 10 km deep. The ocean floor is
generally 2–5 km deep. The surface is dragged
down by subduction.
Oceanic ridges Raised areas of the ocean floor
which encircle the Earth, they are more than
50 000 km long in some places and more than
800 km across. They rise an average of about
4500m above the sea floor. They are generally
hidden beneath the ocean surface, but there are
exceptions like Iceland.
OECD The Organisation for Economic Co-operation
and Development is an international economic
organisation of 34 countries, founded in 1961 to
stimulate economic progress and world trade.
Official development assistance (ODA) System
used to measure amounts of development aid.
Offshore bar Long thin ridges on the sea bed,
running parallel to the coastline below the level
of the lowest spring tide. They are produced
when the circular movement of water in the
waves starts to touch the sea bed.
Offshore zone The zone below the level of the
lowest spring tides, never uncovered.
Offshoring Relocating a business function to
another country, e.g. call centres.
Okta An okta is used as a measurement of cloud
amount. Full cloud is 8 oktas or eighths.
Old-age index Shows the proportion of old people
in a population.
Opening-up cost The cost of purchasing or building
a house at the point of destination and the
cost of purchasing the everyday items needed
for the new home, e.g. furniture and domestic
appliances.
Optimum population Occurs when the population
is in balance with the available resources of an
area, given the current level of technology.
Orogenesis (orogenic belt) All the processes
involved in mountain building including folding,
faulting and uplift.
Orographic (relief) rainfall Rainfall forming over
hills due to the expansion and cooling of rising
air.
Orographic uplift Air forced to rise by high ground.
Orthogonals Lines drawn at right angles to the
wave crests as they approach the shore. They
show how wave energy is concentrated or
dispersed.
Out-migration People moving out of a region of a
country as part of an internal migration within
that country.
Outsourcing The contracting out of a business
process to another party. For example a private
school may have its catering outsourced to
separate company and its cleaning outsourced to
another.
Outwash (glacial outwash streams) Seasonal flow
of summer meltwater from a glacier or ice-sheet.
Overcropping Growing too many crops on a plot.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
19
Overland flow One of the three main ways that
water reaches a river. On a slope, surface water
flows downhill towards the river, producing
overland flow (sometimes called surface runoff).
Overpopulation Occurs in an area where the
available resources are unable to sustain the
population at a good standard of living.
Ox-bow lake An old meander which has become
cut off from the river. It is often filled with marshy
vegetation.
Oxic horizon A layer in soil that contains a lot of
redeposited iron and aluminium (sesquioxides).
Oxidation Process of chemical weathering,
particularly affecting iron minerals where there is
addition of oxygen to a mineral or the removal of
an electron. The reaction is associated with welloxygenated environments.
Oxisol (latosol) A red soil formed in tropical humid
forests. It is characterised by an oxic horizon of
accumulated sesquioxides in the B horizon.
Pahoehoe lava Relatively slow flowing, thin lava
with a smooth surface of curved flow lines.
Palaeoclimate An ancient climate.
Palaeomagnetism This is the ancient, fossil
magnetism contained in iron bearing rocks. It
can be measured to give information about the
Earth’s magnetic field in the past and about the
position on Earth where the rock formed.
Pandemic An epidemic of an infectious disease
that has spread through the human population
across a very large region or even worldwide.
Parabolic dunes Barchan dunes where the horns
have become fixed by vegetation. The central
part of the dune moves forwards but the horns
are fixed, so that unlike barchans, the horns face
up wind
Parasitic cone A small cone which forms on the
flanks of a stratovolcano.
Park and ride An urban transport scheme which
allows people to park their cars outside an urban
area and catch a bus to the centre.
Partial melting The process where fractions of a
rock become liquid. The magma produced may
collect to form larger bodies.
Peak land value intersection The point where
roads from the outskirts of an urban area
converge and land prices are highest.
Peaky (in describing hydrograph) A hydrograph
with a very uneven flow with many sharp and high
flood peaks.
Pediments A gently sloping (maximum 6° or 7°)
rock platform, either bare or with a thin covering
of rocks which stretches away from the foot of a
mountain range.
Pediplanation A theory that large erosion surfaces
have been formed by back-wearing of slopes after
uplift.
Pedocals Soils where the calcium has not been
leached. In semi-arid areas it is possible for
potassium and sodium to be leached and
calcium to remain.
Peds Soil particles held together in small units that
give the soil structure.
Peléan eruption A very violent emission that results
in a nueé ardente issuing from the side of a
volcano.
Perception of risk The degree to which people
recognise that they are in a hazardous situation.
Percolation Water that flows down from the soil
into the bedrock.
Perennial A plant that lives for more than two
years.
Perennial river A river that always flows.
Peridotite A very dark coloured dense crystalline
rock, at least 70% of which is the mineral olivine,
and forms much of the Earth’s mantle.
Permafrost Permanently frozen ground.
Permeability This term has two meanings:
1. The ability of material such as soil and rock to
allow water to pass through it.
2. The rate at which water can pass through a
rock.
Permo-Carboniferous A period of geological time
combining the Permian and Carboniferous
Periods between 248–354 million years ago.
Petroleum Crude oil. A mixture of hydrocarbons
found in the pore spaces of some rocks.
Phase (of water) The different forms or states in
which water can occur (gas, liquid and solid).
Photochemical smog Smog produced by the effect
of sunlight on nitrogen oxides and hydrocarbons
from vehicle exhausts. It includes ground-level
ozone.
Photosynthesis The process by which green plants
use light energy from the sun to change carbon
dioxide and water into carbohydrates(glucose), so
storing that energy. The process occurs only in
daylight and releases oxygen, essential for life.
Physical drought The balance between precipitation
and potential evapotranspiration.
Physiological drought When plants suffer from
excess concentration of salt in the soil and water
is drawn out from the roots by osmosis.
Piedmont zone Literally meaning ‘mountain foot’,
this is the zone that includes the pediment,
peripediment, bahada and alluvial fans.
Pioneer community The first plants to colonise a
new surface.
Plagioclimax A climax community of plants that is
maintained by human activity
Plagiosere A series of stages in vegetation
succession that develop after the climatic climax
vegetation is removed by human activity.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
20
Planetary/global albedo The total amount of solar
radiation reflected back to space by the Earth’s
surface and atmosphere.
Plant community The total of all the plant species
living in the ecosystem.
Plant succession Where hardy plants grow in
a harsh environment such as bare sand or
tidal mud flats. As they grow, they make the
environment better so that less hardy plants can
grow. This process continues over time until the
climatic climax vegetation becomes established.
Plastic flow The way solids can deform in a ductile
manner under stresses such as gravity.
Plate tectonics The concept that the lithospheric
plates are in motion and that the movement is
responsible for the formation of major landforms,
developed in the 1960s and 1970s.
Platy Describes a soil horizon with flat and thin
peds, which can lead to poor drainage.
Playa Term playa sometime used to refer to a
basin of inland drainage containing a shallow,
fluctuating, saline lake. However, it is sometimes
used to refer to the lake itself.
Pleistocene pluvials Wet phases of climate in the
past 2 million years.
Plinean eruption A violent emission of gas, ash and
pumice, resulting in a very high ash cloud that
reaches into the stratosphere.
Plunge line The point at which the wave breaks.
Plunge pool The deep hollow in a river bed at the
foot of a waterfall.
Plunging breaker When storm waves break, they
become vertical and plunge down onto the beach.
Pluton Any large mass of igneous rock which
crystallised deep below the surface and revealed
by later erosion.
Pluvial lakes Lakes which have experienced large
fluctuations in volume due to changes in rainfall
and evaporation.
Point bar The material deposited on the gentle
inner bank of a river meander.
Point source pollution This occurs when the
pollutant is issued at one point, e.g. a pipe
pouring untreated sewage into a river.
Polar cell A theoretical circulation of air from the
poles to the Polar Front and back to the poles
at a higher level. In fact, cold air from the poles
does not rise at the Polar Front.
Polar front The surface along which warmer tropical
maritime air meets colder polar air.
Polder An area of land reclaimed from the sea. It
is usually below sea level and has to be drained
artificially using pumps.
Population The total number of individuals of the
same species in an ecosystem.
Population change The annual population change
of an area is the cumulative change in the size
of its population after both natural change and
migration have been taken into account.
Population density The number of people in a given
area, usually measured as the number of people
per square kilometre.
Population distribution Usually shown on a map,
it uses variations in population density to show
how people are spread out across an area.
Population momentum The fact that there are so
many young people in the population who still
have to produce their own children. Even if fertility
rates fall below replacement level, the population
will still grow because so much of the population
is moving into the child bearing age group.
Population policies Those actions of a government
that try to control, manage or influence the size,
nature or distribution of the population.
Population pressure This is closely linked to the
idea of overpopulation, with more people in a
country than the resources can support. It is a
strong push factor for migration.
Population projections Predicting the nature of
future populations. These predictions are based
on theories such as the DTM and are usually
shown using age/sex structure diagrams.
Population structure The number of males and
females within different age groups in the
population. It divides a population into groups
depending on gender and on age.
Pore water pressure The pressure of groundwater
held within a soil or rock, in gaps between
particles.
Porosity The percentage of void space in a rock.
Porous Rock which allows water to pass through
it because of the pore spaces (holes) that it
contains.
Positive deindustrialisation The decline in
manufacturing employment in hics where the
economy is growing and increased demand may
allow industries to continue to manufacture in
HICs or it may be possible for the workers to be
absorbed by the growing service sector.
Post-industrial city A city affected by deindustrialisation.
Potential evapotranspiration The amount of water
that could go back to the atmosphere if an
unlimited supply of soil moisture was available. It
is usually more than actual evaporation.
Poverty trap Where people are poor and have no
way of escaping this situation.
Power station A ‘factory’ which produces electricity.
Prairies The temperate grasslands of North America.
Precipitation Liquid and solid ice particles that fall
from the atmosphere to the Earth’s surface. Rain
and drizzle fall in liquid form, while snow and hail
are solid ice.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
21
Predator An animal which kills other animals for
food.
Prediction A relatively precise statement of time,
place and size of a future event.
Pressure The force exerted by the column of air
that extends from a location to the tropopause,
measured in millibars.
Pressure gradient The rate at which pressure
changes between two points.
Pressure gradient force The force exerted by the
rate at which pressure changes between two
points. The greater the pressure gradient force,
the stronger the wind.
Pressure group An organisation that seeks to
influence government policy and/or public opinion.
They promote a particular cause or interest.
Pressure release/unloading Process involved in
weathering when the ground surface is lowered
by erosion and the reduction in pressure on
the rocks below allows them to expand a split
parallel to the surface.
Prevailing wind The most frequently occurring wind
(direction) in an area.
Primary Activities which involve the collection or
production of natural resources, food and raw
materials directly from the land or sea, e.g.
farming, fishing, forestry, mining and quarrying.
Primary energy mix This is a percentage
breakdown of the sources of primary energy that
a country uses.
Primary produce dependent Obtaining foreign
currency by exporting a small range of primary
products, often at low prices compared with the
prices of manufactured goods or services.
Primary products The products of primary industry.
Primary industries produce goods directly from
the earth, e.g. farming, fishing, forestry and
mining.
Primary succession The original vegetation
succession that develops naturally in an area. It
begins with pioneer plants on a newly available
surface and ends with the climatic climax
vegetation.
Primary wave A type of earthquake wave which
travels fastest and arrives at a place first, before
the secondary and surface waves.
Prisere The sequence of communities from the
pioneer species on the original bare surface to,
but not including, the climax community.
Privatisation The selling of publicly owned assets.
Pro-natalist policies A policy refers to those
actions of a government that try to control,
manage or influence something. Pro-natalist
policies encourage people to have children and
are designed to stimulate the birth rate.
Product chain The sequence of production of an
item involving primary, secondary, tertiary and
quaternary activities.
Proportional circles Circles used on a diagram to
show the relative sizes of the values represented
by using the square root of the values, or
multiples of them, to determine the radius of
each circle.
Proportional symbols Any type of symbol can
be drawn in proportion to the values being
represented. This can include the relative
thickness of bars, size of rectangles and whole
or part ‘people’.
Protectionism Economic policies which restrict
trade between countries through methods such
as taxes on imported goods. It is designed to
protect the industries in the importing country.
Protectionist Policies aimed at giving the home
country or companies within the home country
advantages over other countries.
Pseudo-bedding planes Cracks parallel to the
Earth’s surface formed by pressure release.
Pull factors The good things about the destination
area that attract the migrant to move there.
Purchasing power How much a person’s money will
buy in their country of residence.
Purchasing power parity (PPP) The way that
measures such as GDP are adjusted to take
account of the purchasing power of money in the
country. It is expressed as $US per person so
that countries can be compared.
Push factors The bad things about the source area
that the migrant wants to escape from.
Pyroclastic flow A very hot, dense mass of
shattered rock fragments and gases that moves
very quickly down slope from the vent of a
volcano.
Pyroclastic material Solid material of shattered
rock thrown out from a volcano.
Qualitative Something that has to be estimated
or described because it is difficult to measure.
Based on a person’s opinion or judgement.
Quality of life Quality of life is related to wealth but
is also determined by social and environmental
factors, it sums up everything that affect a
person’s well-being and happiness.
Quantitative Something that can be measured or
counted and expressed as a numerical quantity.
Quaternary Activities including modern, hi-tech
manufacturing and service industries and
activities involving research and providing
information, expertise and advice.
Quota A limit on the quantity of a commodity or
service that can be produced abroad and sold
domestically.
Radiation Energy emitted by a body in the form of
electro-magnetic waves.
Radiation cooling Cooling produced by long-wave
heat radiation from the Earth’s surface,from
clouds and gases in the atmosphere.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
22
Radiation fog Fog caused by the loss of the Earth’s
heat into space at night. Contact with the cold
land results in enough condensation of water
vapour to reduce visibility to less than 1 km.
Radiation window Dry air without clousd through
which the Earth’s long-wave radiation is able to
escape into space.
Radiative forcing The warming effect of greenhouse
gases.
Radioactivity The change (‘decay’) of unstable
nuclei of certain atoms to produce stable forms,
giving out energy and heat.
Radiometric dating A method of measuring the
absolute age (a number of years) of a rock using
its naturally occurring radioisotopes.
Rain Water droplets, about 2 mm in diameter, which
fall to the surface of the Earth.
Rainfall intensity Amount of rain falling in a given
unit of time.
Rainshadow Dry areas to the lee of hills where
descending air is heated by compression.
Raised beach An old beach which is now above the
current sea level. Relict features such as wavecut platforms, cliffs, caves, arches and stacks
can found well above present day sea level. They
are produced by a fall in sea level relative to the
land.
Rationalisation Changing a business to make
it more efficient. And increase profitability. In
practice it usually involves closure of plants.
Raw materials The resources which are used to
make manufactured goods. Iron ore is a raw
material in the steel industry but, in turn, steel is
a raw material in the car industry.
Re-urbanisation The movement of people and
economic activities back into the central areas
of cities, including the CBD, and inner city
residential and industrial areas. It is designed
to counter the impact of edge cities and retail
parks.
Recharge Water moving from the surface into the
rocks, replacing water that flows out of the rocks
as baseflow/groundwater flow.
Reclamation Land reclamation involves returning
polluted or degraded land back to a useful state.
Recurrence interval How often, on average, a
particular size (magnitude) of flood is likely to
occur.
Reduction Process of chemical weathering
occurring in oxygen-deficient environments where
oxygen is removed from a mineral or an electron
is added.
Reflected solar radiation Solar radiation bounced
back into space from the upper surfaces of
clouds, water droplets within them or from the
Earth’s surface.
Refracted When the wave front is bent as it
approaches a coastline and they increasingly
take on the shape of the coastline.
Refugees People who are forced to migrate. They
move to seek refuge from a life-threatening
situation.
Reg Stony areas in deserts.
Regeneration The rescue and improvement of
redundant and rundown buildings and derelict
areas within a town or city.
Regional Development Agencies Organisations set
up by the UK government and abolished in 2011,
aimed at stimulating economic development in
the regions.
Regional Growth Fund UK Government fund to
encourage private sector growth and new jobs,
particularly in areas and communities currently
dependent on the public sector. The aim of the
policy is to reduce the size of the public sector
rather than to develop peripheral regions.
Regolith The surface cover of loose,
unconsolidated material including alluvium,
glacial deposits, wind-blown sand, peat, scree
and soil.
Relative humidity The amount of water vapour
the air is holding, expressed as a percentage of
the maximum amount it could hold at the same
temperature.
Relay migration When family members taketurns
to migrate to the city, often when they are young
adults and before they marry. This produces a
steady stream of remittances from which the
family benefits.
Relief aid See emergency aid.
Remittances Money sent home by migrant workers.
Renewable energy resources Either have
unlimited availability (e.g. solar power) or can be
replenished relatively quickly (e.g. wood).
Reorganisation Changing a company or an industry
to increase efficiency. This can be achieved
naturally, through mergers and acquisitions or by
changing the structure of management.
Repatriate The process of returning a person
to their place of origin. This often applies to
illegal immigrants who are deported from the
destination area.
Residential segregation/residential
zonation Where different socioeconomic groups
reside in different areas of an urban area.
Resilience How well a population recovers from a
disaster.
Resource Any part of the environment that can be
used to meet human needs.
Resource endowment The amount of mineral
wealth, agricultural and industrial production of
an area or country.
Resource-frontier regions Areas on the edge of
zones of economic development.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
23
Respiration The process by which plants use
oxygen to break glucose and carbohydrates
down to carbon dioxide and water. Some heat
energy and carbon dioxide is released to the
atmosphere
Retailing Shopping.
Revetment A sloping wall running along the coast
parallel to the sea. Can be made of concrete,
masonry, rip-rap or wood.
Ria A drowned river valley.
Ribbon development Urban sprawl which took place
alongside main roads.
Richter Scale A log scale which measures the
magnitude of earthquakes.
Ridge of high pressure An elongated area of high
air pressure, that extends into an area with lower
air pressure.
Ridge push Intrusion of magma into the spreading
ocean ridges such as the Mid-Atlantic Ridge
pushing the plates apart
Riffles Areas of shallow water along the course of
a river, often spaced regularly between deeper
areas known as pools.
Rift valley A valley formed when a central block has
dropped beneath parallel fault systems.
Rills A fine network of channels in the land surface,
an intermediate stage between gully and sheet
erosion.
Rime Ice crystals formed when super-cooled water
droplets in slow moving fog come into contact
with a cold surface and build up.
Ring road A road which circles an urban area, either
inside or outside the built-up area.
Rip-rap Large blocks of rock or concrete placed as
a ramp in front of a cliff or a sea wall.
Risk The exposure of populations to danger or
damage from a hazard event
River channel The trench in which the river flows. It
is defined by the river bed and the river banks.
River cliff The steep outer bank of a river meander.
Rock avalanche Many pieces of loose rock moving
en masse down a slope.
Rock fall When a vertical rocky cliff is undermined
by marine erosion and a large section of the cliff
face falls onto the beach.
Rock pedestals Mushroom-shaped rocks, the result
of wind erosion in deserts.
Rossby waves Large curves that sometimes
develop in the paths of the upper westerlies.
Rotation of stock The movement of farm animals
from one field to another, usually done to allow
regrowth of pasture and prevent overgrazing.
Rural Area which is mainly countryside.
Rural Development Policy Part of the European
Union’s Common Agricultural Policy (CAP) which
focusses on the broad regional development
of rural areas, many of which are in peripheral
locations.
Rural-urban fringe The transition zone where urban
and rural land-uses are mixed.
Rural–urban migration The movement of people
from the countryside to urban settlements (towns
and cities).
Ruware A low, dome-shaped rocky hill.
Saffir-Simpson Scale A scale of the potential
damage to structures caused by sustained wind
speeds in hurricanes.
Sahel The southern edge of the Sahara Desert,
transitional with the savannas.
Salinisation There are two meanings for this term:
1. A soil forming process in which sodium and
potassium salts move up in solution from saline
groundwater and build up at or near the surface
as they are precipitated during evaporation of the
water.
2. The build-up of salts in the soil as a result of
over-irrigation.
Salt crystal growth A weathering process when
salt solutions within the pores or joints of a rock
crystallise. The crystals then expand and force
the rock apart.
Saltation Process of transport when particles ‘hop’
across the surface. It is the main process by
which sand is moved from place to place.
Saltmarsh A flat, sheltered area of lowland coast
where fine sediment has been colonised by salt
tolerant plants. It is usually covered by the sea at
high tide.
Sand dunes Hills of sand above the high tide level.
They are formed by sand blown from the beach
by onshore winds.
Sanitation Promoting good health by the treatment
and proper disposal of sewage.
Sapling layer/under-storey A layer of the crowns of
young trees that lies beneath the canopy layer in
tropical rainforests.
Saprolite Weathered rock which retains the
features of the original rock but crumbles
immediately if exposed and disturbed.
Saprophytes Plants that live on dead organic
matter,
Saturation The state of air when it is holding
the maximum amount of water vapour for its
temperature.
Savanna grasses Grasses that grow in tropical
seasonally humid climates. They grow very tall in
the wet season and die down in the dry season.
Savanna/savannah The tropical grasslands with
trees, associated with a tropical continental
climate.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
24
Scattered rays Solar radiation deflected back to
space by contact with small particles in the air,
such as dust and smoke.
Schengen Agreement 26 European countries have
abolished passport and other border controls
at their common borders. It has led to free
movement of people within most of the EU.
Scree (talus) Angular rock fragments.
Sea breeze A surface, coastal area wind that blows
during the day from sea to land due to pressure
differences over the two surfaces.
Sea-floor spreading The process of creation of new
oceanic lithosphere at the ocean ridges and the
divergence of the new lithosphere on either side
of the ridge
Seamounts A submarine volcano which originated
over a hot spot.
Seasonal river A river that only flows in the wet
season.
Secondary Industries are those which process,
manufacture and assemble the products we
need.
Secondary wave A type of earthquake wave with
intermediate speed that arrives at a place after
the primary wave but before the surface wave.
Sediment Soil and rock particles carried along by a
river.
Sedimentation When river sediment is deposited
from still water. This process is common on flood
plains and on the sea bed.
Seifs Linear dunes which lie parallel to the main
wind direction
Seismic gap theory A method of working out
where a strong earthquake is likely to occur by
comparing a section of an active fault that has
not experienced earthquakes for a considerable
time with other segments along that fault.
Seismic wave Vibrations that originate where
displacement occurs in rocks below ground and
move round the world, causing shaking.
Seismograph An instrument that records seismic
waves.
Selective logging The removal of certain trees in
a logging operation, leaving others standing to
reduce soil erosion.
Semi-detached house A house joined to another
one.
Semi-fixed grey dunes High dune ridges that are
found inland of the mobile yellow dunes. They
are mostly covered in vegetation and relatively
stable.
Semi-logarithmic graph paper See log-normal graph
paper.
Sensible heat transfer The transfer of heat energy
by conduction or convection.
Seral community The plants that grow together in
one stage of vegetation succession.
Seral stages A series of plant communities during
vegetation succession, each of which differs from
the one that preceded it and from the one that
replaces it.
Sere A plant community that forms one stage in the
vegetation succession.
Serir Stony desert.
Service industry Activities including the tertiary and
quaternary sectors. Physical or tangible products
are not produced and services include attention,
advice, access, information, experience, and
discussion. Examples include retail, medicine,
education and distribution.
Services Sometimes referred to as functions, it
includes any outlet that carries out trade or work
in a settlement including shops and outlets such
as hairdressers, airports or schools.
Servitude The condition of being a slave or of
having to obey another person, an individual
lacking the freedom to determine their way of life.
Sesquioxides Hydrated oxides and hydroxides of
iron and aluminium.
Sex ratio The number of males per 100 females in
a population.
Shaking The movement of ground that occurs when
an earthquake shockwave passes through.
Shale rock A type of sedimentary rock derived from
clay and mud. It has very small pore spaces.
Shanty town An area of a city where houses are
very poor quality, often built by the people living
in them and where service provision (water,
sewers, etc) is inadequate and the land usually
does not belong to the householder.
Shearing Stresses which slide past each other.
Sheet erosion Removal of soil or sediment from the
ground surface in a roughly uniform layer.
Sheet flood Where overland flow occurs on
relatively gentle slopes, the water does not
become concentrated in channels
Sheet-wash The removal of soil from a wide area by
a thin sheet of water moving over a gentle slope.
Shelter belts Bands or rows of trees planted to
reduce wind speed.
Shield volcano A tall volcano with gently sloping
sides and a very wide base, composed of mafic
lava and which forms at constructive plate
margins and hot spots.
Shifting cultivators Groups of people who make
clearings in the tropical rainforest and grow
subsistence crops for a few years until the soil
is exhausted of nutrients. They then abandon the
plot and repeat the process in another location.
Shockwave See seismic wave.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
25
Shoreline management plan (SMP) Coastal
management based on the movement of
sediment within a sediment cell so that the
overall impact of any new management strategy
can be considered, rather than just the impact at
the place it is constructed.
Shotcrete Spraying rock surfaces with concrete to
help stabilise loose fragments.
Shrub layer The layer in a vegetation structure
which lies between the herbaceous and sapling
layers.
Shrubs Bushes. They are lower growing than trees
and branch from near the ground.
Silicic (acidic) lava Lava that contains more than
60% silica. It is very viscous and solidifies
quickly.
Simple spit Spits occur when longshore drift
extends the beach part of the way across an
estuary, bay, or inlet. Simple spits are sometimes
straight but more usually have curved ends
Sinkholes (dolines) Openings in limestone rock
through which streams disappear underground.
Over time they are enlarged by solution.
Sinuosity (of a river) The sinuosity of a river channel
is a measure of how bendy it is. It is calculated
by dividing the length of the river channel by the
length of the valley in which it flows.
Site The land a settlement is built on, including
altitude, gradient, aspect, water supply, bridge
points and fords, and the location of natural
resources such as minerals.
Situation The position of a settlement in relation to
the surrounding area. Including transport routes,
agricultural productivity of the area and position
in relation to other towns.
Slab pull Cold, denser oceanic lithosphere sinking
due to gravity into the subduction zone. This
drags the rest of the plate with it.
Sleeping sickness Human disease transmitted by
the tsetse fly.
Slide Type of mass movement when a section of
a hillside becomes unstable, shears away and
moves downhill in a sudden, rapid movement.
Slump (slip/rotational slump/rotational slip) A
type of mass movement in which material moves
in a rotational way downslope under gravity along
an inclined slip plane. For example, when a cliff
of unconsolidated material is undermined by
marine erosion and a large section of the cliff
face slips downwards towards the beach. The
slip plane is usually curved, hence the phrase
‘rotational slip’.
Smog Urban fog with added pollutants, such as
smoke, soot, dust and sulfur dioxide.
Snow A type of precipitation formed from ice
crystals joined together in hexagonal patterns.
Soft engineering Involves working with nature
to protect the coast by enhancing the natural,
protective, coastal processes.
Soil exhaustion When the nutrients in a soil have
been over-used so that there is insufficient to
support adequate crop growth.
Soil horizon A distinctive layer of soil, usually more
or less horizontal.
Soil liquefaction Weak unconsolidated rocks act as
a liquid and flow when shaken by an earthquake
shockwave.
Soil moisture deficit When all the water in the soil
has evaporated into the atmosphere. Crops will
not be able to grow unless irrigation water is
available from reservoirs or deep wells. Streams
dry up.
Soil moisture surplus The state in a soil in which
there is more soil moisture than is required by
the vegetation.
Soil moisture utilisation A period during
which potential evapotranspiration exceeds
precipitation and plants are using water that
remains in the soil.
Soil structure The way in which soil particles are
held together.
Soil water budget The balance between inputs of
water into the soil and outputs by evaporation
and transpiration
Solid waste Rubbish in a solid form. It includes
domestic rubbish and human and animal
manure.
Solifluction Accelerated soil creep that occurs in
permafrost areas, even on gentle slopes.
Solonchaks Soils with a high concentration of salts
Solstice An astronomical event when the noonday
sun is overhead at one of the tropics, its furthest
from the Equator. June 21 is the summer
solstice in the Northern Hemisphere and the
winter solstice in the Southern Hemisphere. The
solstices are reversed on 22 December.
Solution The chemicals in sea water can dissolve
rocks such as Chalk and Limestone.
Solution notches Indentations resulting from
solution at the base of slopes where the water
table is at the surface in tower karst.
Source area The area of origin of the migrant. The
place that the migrant has moved from.
Special Areas Areas established in 1934 by the
UK government under the Special Areas Act.
This was the first of a long series of measures
which aimed to bring regeneration to severely
depressed areas through strategies of financial
aid to new firms willing to relocate to them.
Specific heat The amount of heat energy needed
to increase the temperature of one gram of a
substance by one degree Celsius.
Speeding limb A part of a Rossby wave that is
flowing pole-wards.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
26
Spheroidal weathering Process of chemical
weathering occurring in rocks such as basalt,
dolerite and granite where layers peel off and
rounded boulders are produced.
Spit A long, narrow ridge of sand or shingle
extending from a bend on the coastline, partly
across a bay or inlet.
Spray zone The zone above the high tide level
which salty spray can reach on a cliffed coastline.
The spray is caused by waves smashing into the
base of the cliff.
Spread effects As costs rise in the economic
core regions, development is encouraged in
adjacent areas which can enjoy some of the core
benefits such as contact with other innovative
businesses, contact with financial and political
institutions, good entertainment and recreational
facilities, social contact with similar people,
without the very high costs of property and
labour.
Spring tide Once a fortnight, when the Sun and
Moon are aligned, there is an unusually high tidal
range. The high tide is higher than usual and the
low tide is lower than usual.
Stack An isolated coastal rock column, often
accessible at low tide but not at high tide.
Stakeholder A person, group or organization
that has an interest or concern in an issue,
development or proposal.
Standard of living The way people are able to live
their lives based on the wealth that they have.
Star dunes (mega-dunes) Very large dunes develop
where there are complex winds and a large
supply of sand. There is a central peak with
radiating arms, each arm corresponding to a
different wind direction.
Step migration When the move is done in stages or
steps. At first people move to a local town, then
to a regional city and finally to a major city such
as the capital.
Steppe The temperate grasslands of Eurasia.
Sterilisation An operation which restricts an
individual’s ability to reproduce. A person who
has been sterilised can no longer have children.
Stomata Pores in the leaves of plants through
which transpiration occurs.
Storm beach The top of the beach, formed by
stones and pebbles thrown up by strong waves
during a storm.
Storm hydrograph A graph showing how a river’s
discharge changes over a short period of time,
responding to a single input of rainfall.
Storm surge A rush of sea water driven onto land
by strong winds when the sea surface is raised,
either because of expansion caused by heating or
because a low pressure system with its rising air
takes weight off the sea surface, allowing it to rise.
Storm wave Large waves, produced by strong
winds, blowing from the ocean directly onto the
coastline.
Stovepipe tornadoes Narrow cylindrical tornadoes.
Strato-volcano (composite cone) A conical volcano
made up of alternating layers of lava and ash.
Stratocumulus A layer or line of mainly attached
cumulus clouds.
Stratosphere The layer of the atmosphere above
the troposphere in which temperature increases
with increasing height.
Stratovolcano A steeper-sided, narrower based
volcano than a shield volcano,that is formed
of alternate layers of intermediate lava and
pyroclastic material.
Stratus Low level layer cloud.
Strip cultivation and inter-cropping Planting
different crops in alternating bands.
Strombolian eruption Frequent emissions of lava
with sufficient gas content to throw out some
volcanic bombs.
Structural funds Regional funds of the European
Union including the European Social Fund,
European Regional Development Fund and the
Common Agricultural Policy.
Structure (of vegetation) The layering in a plant
community that results from plants with different
life-forms growing to certain heights.
Stump A low lump of bedrock, exposed at low
tide, formed from the base of a stack which has
collapsed.
Sub-aerial process The landscape processes of
weathering and mass movement that operate on
the cliff face above the reach of the waves.
Subclimax community A group of plants that
populate a sere in a vegetation succession that
is not the climatic climax.
Subduction When an oceanic plate is forced
beneath another plate and destroyed by being
re-absorbed into the mantle.
Subjective An opinion based on a personal
perspective.
Sublimation The process by which solid ice
changes directly into the gas, i.e. water vapour.
Subsere A stage in a vegetation succession that is
not the climatic climax.
Suburbanisation The movement of people from
homes in central areas of a city (CBD and innercity) to homes on the outer edges. It was a major
feature of European cities during the first half of
the 20th century.
Succulents Plants that store water in their leaves
or stems.
Supercell thunderstorm An extremely violent
thunderstorm in a tornado.
Supply chains The network created amongst
different companies producing, handling and/or
distributing a specific product.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
27
Supply management Ensuring that energy supplies
are sufficient to match demand.
Support ratio The inverse of the dependency ratio.
It shows the proportion of the population which is
dependent on the working population.
Surface wave A type of seismic wave that travels
more slowly than the primary and secondary
waves and arrives at a place last.
Surging breaker A breaking wave that slides or
surges up the beach.
Sustainable coastal management Coastal
management where the strategies involved
do not just work in the present but also in the
future, ideally with minimum maintenance costs.
Sustainable development Development which
meets the needs of today’s population without
compromising the ability of future generations to
meet their needs.
Sustainable farming Rather vague term which
includes measures which allow agriculture to
continue in difficult areas. It includes various
measures described in the book.
Sustainable urban community Rather vague term
used to describe modern urban developments
built to high environmental standards.
Sustained pollution Long-term pollution caused
by ongoing human activities, e.g. the release
of carbon dioxide into the atmosphere from the
burning of fossil fuels.
Sward zone A zone of saltmarsh where grasses
dominate the ecosystem. It may only be covered
by the sea for an hour a day.
Swash The body of foaming water that rushes up
the beach when a wave breaks.
Swash-aligned Beaches that are aligned parallel to
the crests of the prevailing waves.
Swell wave If the wind that created the waves dies
down over the ocean, the waves will continue to
move in the same direction until they reach the
coastline. When they reach the shore they will
break gently.
Syncline An area of downfolded rock (more
technically a fold where the core of the fold is
younger than the outside).
System A group of interacting components which
react as a whole to external stimuli known as
inputs.
Tar sands Unconsolidated material, e.g. clay and
sand, which contains crude oil. Tar sands can be
mined and processed to extract the oil, which is
then refined into petroleum products.
Tariff A tax on imports or exports.
Tarns Small lake in the north of England.
Tax evasion When individuals and corporations fail
to pay tax by illegal means.
Tectonic process An action causing change that
results from the movement of plates.
Teleworking Work carried out remotely, generally by
telephone, including call centres.
Temperate The middle zone of latitudes, lying
between the polar and tropical zones.
Temperature inversion An altitude in the
atmosphere, above which the temperature is
warmer than the air below it. This is the opposite
of the normal situation.
Tension Diverging stresses which stretch the
Earth’s crust
Tephra Airborne solid rock material ejected from a
volcano.
Terracettes Small ridges, caused by soil creep,
running across slopes
Terracing Converting a uniform slope into a series
of steps to assist agriculture and prevent
erosion.
Tertiary Industries which produce no goods but
provide a service. Jobs in health, education,
retailing and transport are examples.
Tertiary Period Period of geological time between 2
and 65 million years ago.
Texture The average grain size of a soil. If large the
soil has a coarse texture and if small it has a
fine texture.
Thalweg The line of fastest flow of water in the river
channel. It follows a corkscrew or spiralling path
as the river moves downstream.
The Great Green Wall Project proposed 1980s to
stop the growing of the Sahara. The idea was to
fight desertification by planting a ‘wall of trees’
across the continent from Senegal in the west to
Djibouti in the east.
The Harris and Ullman multiple nuclei model A
model of urban land-use developed in 1945 for
cities with more than one growth point.
The tropics The latitudinal zone that extends from
the Tropic of Cancer (23½° N) to the Tropic of
Capricorn (23½° S).
Thermal Equator An imaginary line around the
world joining the hottest places at any time.
Thermal fracturing Disintegration of rocks due
to heating a cooling – a form of mechanical
weathering.
Throughflow One of the three main ways that water
reaches a river. Water that flows downhill through
the soil, parallel to the surface.
Thrust fault A low angle fracture of rocks along
which the upper beds have been moved over the
lower beds by a compressional force.
Tidal flow An urban transport system where more
lanes are available for traffic travelling inwards
in the morning and more lanes are available to
traffic travelling outwards in the evening.
Tidal range The difference in height between the
low and high tide levels.
Tied aid Aid that must be spent in the donor
country or countries on goods or services.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
28
Tombolo Outwards beach extention that joins an
offshore island.
Top-down Aid given where governments implement
central programmes and held to account by the
donors.
Tor Small hills consisting of corestones produced
by spheroidal weathering below the surface,
resting on solid well-jointed bedrock. Usually
formed of granite.
Tornado A violent, rapidly rotating and fast moving,
funnel-shaped column of cloud that extends
down to the ground.
Tower karst A limestone landscape in which very
steep sided, narrow limestone hills rise abruptly
from an alluvial plain where the water table is at
the surface.
Trade agreements Deals between governments to
control the trade between the countries, usually
by licenses, tariffs and quotas.
Trade balance (balance of payments) The
difference between the monetary value of the
exports and imports of output of a country,
measured in the currency of that country.
Trade bloc A group of countries who have joined
together to stimulate trade between them, often
to the disadvantage of other countries.
Trade deficit Negative trade balance – imports are
worth more than exports.
Trade surplus Positive trade balance – exports are
worth more than imports.
Trade trap When a poor country produces goods
for sale abroad but where the price of those
goods is determined by the rich countries. When
the price of the poor country’s exports drops,
they have to keep producing the goods in order
to make money to pay the interest on the debts
they incurred when developing the ability to
produce the goods for export.
Trade Winds Winds that blow from the subtropical high pressure cells to the Inter-tropical
Convergence Zone; they blow from the north east
in the Northern Hemisphere and from the south
east in the Southern Hemisphere.
Traditional society A society which is characterised
by high levels of primary production, especially
subsistence agriculture. Technology is basic
and education is only for the ruling classes,
typified by land owners and priests. The money
economy is poorly developed and barter is still
common. Infrastructure, especially transport, is
poorly developed and mobility, both social and
physical, is very limited. Most people are poor
peasant farmers, living in the countryside, with
no prospect of improving their conditions or of
moving away from their village.
Trans-national corporation (TNC) A company which
owns manufacturing or services industries in one
or more countries and does not identify itself
with one national home.
Transform fault A fault with lateral displacement at
right angles to a spreading ridge system.
Transpiration When plants draw water from the soil
through their roots and allow it to evaporate into
the air through their leaves.
Trophic level Position on the hierarchy of
consumption in the food chain.
Tropical karst Limestone landscapes within the
tropical latitudes having residual limestone hills
shaped as cones or towers between depressions
or plains.
Tropical storm A low pressure system in the tropics
with wind speeds of 63–118 km/h.
Tropopause Level at the top of the troposphere
separating it from the stratosphere. At this height
temperature stops decreasing with increased
height.
Troposphere The lowest layer of the atmosphere,
where changes are caused by weather. Here
temperature decreases with increased height.
Trough of low pressure An elongated area of low air
pressure that extends into an area with higher air
pressure.
Trypanosomiasis Disease transmitted by the tsetse
fly.
Tsetse fly Insect found in humid tropical areas
associated with animal and human disease.
Tsunami A very high wave with a long wave-length
resulting from a displacement of the sea bed.
The wave quickly steepens and increases greatly
in height in shallow water.
Turbulence Water flowing in a chaotic way with
much swirling and eddying.
Turbulent flow Water flowing in a river channel is
subject to friction, both with the river bed and the
banks. This leads to chaotic, swirling, turbulent
flow.
Typhoon A tropical cyclone with wind speeds of at
least 119 km/h that occurs in the western part
of the North Pacific Ocean.
Underemployment When people have some
employment but insufficient to occupy them fully.
Underpopulation Occurs in areas with not enough
people to use all the resources efficiently for the
current level of technology.
Unemployment When people have no work.
UNESCO The United Nations Educational, Scientific
and Cultural Organization, a specialized agency
of the United Nations (UN). Its purpose is to
contribute to peace and security by promoting
international collaboration through education,
science, and culture.
Unicef The United Nations Children’s Fund has
its headquarters in New York. It provides
humanitarian and developmental assistance to
children and mothers in developing countries.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
29
Unstable equilibrium A state of balance that is
unlikely to last. A pencil can be balanced on its
point but any small change in its environment,
e.g. a movement in the air, will make it fall over.
A country can achieve optimum population, but
any change in the size of the population or the
availability of resources will move it away from
the optimum point.
Upper westerlies Fast winds with general west to
east paths at high altitude between 30° and 50°
lat. in each hemisphere.
Upward transition regions Areas of economic
growth outside of the main metropolitan area.
Urban Mainly towns and cities or built-up areas.
Urban model A simplified theory which attempts to
explain the patterns of urban land-use and the
reasons for them.
Urban renewal The re-development of rundown
urban areas which brings about improvements.
Urban sprawl The outward growth of urban areas
into areas of rural open space.
Urban–rural migration When people move from
the cities to live in villages or small towns in the
countryside.
Urban–urban migration When people move from
one urban settlement to another, e.g. from a
town to a city.
Urbanisation Urbanisation is the increase in the
proportion of a country’s population that live in
towns and cities.
Van t’Hoft’s Law The speed of chemical reactions
double for every 10 °C increase in temperature.
Vegetation succession A series of plant
communities that develop on a surface that was
originally unsuited to vegetation, ending with the
climatic climax community.
Vent A vertical pipe in a volcano through which
magma moves to the surface.
Ventifacts (dreikanter) Pebbles and boulders often
in deserts with a series of two, three or four
surfaces (facets) which are worn and polished by
wind.
Vernacular architecture The style of the domestic
and functional buildings rather than the public or
monumental buildings.
Vertical integration Where each branch of a
company carries out a separate part of the
production process and the products are
transferred to the final assembly plant.
Vesuvian eruption A violent ejection of shattered
materials from the solid plug of a volcano after
a long period of inactivity, resulting in a wide ash
cloud.
Vicious circle A situation where someone’s current
circumstances are such that they lead to factors
which reinforce the current situation. An example
is poverty – a poor farmer cannot purchase
materials to improve their farm so their crop
yields stay low, there is no surplus to sell, so the
farmer has no money and remains in poverty.
Virtuous spiral A situation where a positive change
leads to further positive changes which in turn
reinforce the original change. For example, land
reform exempts a farmer from paying rent so the
farmer can use the money to improve the farm,
increasing crop yields, producing more money to
improve the farm and so on.
Visa An international travel document, giving a
person permission to enter a foreign country.
Visible imports/exports/trade Actual goods which
are sold to other nations.
Visual pollution Things which people find ugly to
look at.
Vital rates The factors that affect population
change such as birth rate and death rate. They
are usually expressed as the rate of change per
thousand people, per year.
Volcanic blocks Large angular fragments resulting
from the shattering of solid lava during an
eruption.
Volcanic bombs Rounded fragments formed as
molten lava cools while spinning through the air.
Volcanic explosivity index An eight point
logarithmic scale which measures the magnitude
of volcanic eruptions.
Volcanic landslide The movement of loose material
under gravity down the slopes of a volcano as a
result of earthquakes or the bulging of a side of
the volcano.
Volcano A conical hill composed of material ejected
on to the earth’s surface from a vent.
Voluntary aid Aid provided by NGOs.
Voluntary migration When migrants choose to
move. They are affected by push and pull factors
but the final decision to move is their own.
Von Thünen’s model A model of agricultural landuse patterns based on an economic ideal.
Vulcanian eruption Emissions of ash and cinders in
fairly violent eruptions, resulting in a cauliflowershaped ash cloud.
Vulnerability Conditions that make a population
more likely to experience a hazard event.
Wadi (Arabic) A steep-sided, rocky ravine or valley in
a desert or semi desert which is usually dry.
Wall cloud An isolated cloud that projects below
the other clouds in the rain-free part of a
tornado.
Warm front The surface between warmer tropical
air and cooler polar air that forms when the less
dense tropical air mass moves over the denser
polar air.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
30
Water budget The balance of the inputs and
outputs of water in a drainage basin. It is
determined by calculating the inputs, outputs,
and storage changes of water in the drainage
basin. Sometimes called the water balance.
Water deficit When demand for water exceeds the
supply.
Water surplus When water supply exceeds the
demand.
Water table The level of saturation in the bedrock.
The upper surface of groundwater in the rocks.
Water vapour The invisible gaseous form of water
that is present in all air in varying quantities.
Waterspout A tornado formed over a warm sea.
Wave crest The top of a wave.
Wave energy In deep water, the energy of a wave is
proportional to the wave length multiplied by the
wave height squared.
Wave form The shape of a wave caused by the
rising and falling of the water as the wave energy
moves.
Wave frequency The number of waves that break
on the beach in a given period of time.
Wave height The difference in height between a
wave crest and a wave trough.
Wave length The distance between two wave
crests.
Wave period The time taken for a wave to travel
through one wave length.
Wave steepness This is calculated using the
formula ‘wave height ÷ wave length’.
Wave trough The bottom of a wave - the low point
between two wave crests.
Wave velocity The speed of movement of the wave
crest.
Wave-cut notch Where a cliff has been eroded,
causing an indentation near the high tide level.
Wave-cut platform A flat or gently sloping area of
rock between the high-tide and low-tide levels,
often at the base of a cliff.
Weathering The decay and disintegration of rocks
in situ, involving physical, chemical and biological
processes. It excludes the erosional effects of
running water, rivers, the sea, glaciers and the
wind. The weathering processes do not transport
the products away.
Wedge tornado A very wide tornado.
Welfare benefits Provision of a minimal level of
well-being and social support for people living in
a country. The benefits usually take the form of
money given by the government to people who
would otherwise be suffering extreme hardship.
Wetted perimeter The length of the bed and banks
in direct contact with the water in the river
channel.
Work permit A legal authorization from a country’s
government which allows an immigrant to take a
job within that country.
Working population People in a population (roughly)
between the ages of 16 and 64. These are
the people who could be ‘economically active’
even though some of them may not actually be
workers.
World city/global city A city that has an economic,
cultural and political significance beyond the
boundaries of its own country.
World Health Organization An agency of the United
Nations that is concerned with international
public health. It was established on 7 April 1948
and has its headquarters in Geneva, Switzerland.
Xerophytic Describes plants with adaptations that
enable them to withstand drought.
Yardangs Sharp keel-like ridges of rock in deserts
separated from a parallel neighbour by a furrow.
The ridges may be up to 6 m high and 35 m wide.
Zero population growth (ZPG) When a population
has stabilised and is no longer growing. This is
typical of Stage 4 of the DTM.
Zeugen (sg. zeuge) Tabular, under-cut hills in
deserts.
© OUP 2015: this may be reproduced for class use solely for the purchaser’s institute
31