Dam
A barrier that holds back water within an aquatic system, often for the purpose of hydroelectric power generation and flood control.
Death Rate
The number of deaths per 1,000 people in a given year.
Decentralisation
The redistribution of administrative power from central government to local control.
Deciduous
Plants that drop their foliage at various times of the year, or continuously.
Deforestation
The removal of trees from a forested area.
Deindustrialisation
The process by which heavy and manufacturing industry closes across a region, usually due to economic hardship.
Delta
An area of sediment and silt deposit at the mouth of a river.
Democracy
A political system whereby representatives are elected by a country's people.
Demographic Transition Model
A model illustrating population change over time, reflecting how birth rate and death rate affect the total population of a country.
Demography
The study of population structures.
Dependency Ratio
A ratio of economically active and non-economically active people in a population (Population under 16 + Population over 65)/(Population aged 17-64)*100.
Dependency Theory
A concept that suggests that the workings of developed countries cause the developing nations to remain poor as a result of their reliance on them for trade and aid.
Dependents
Typically non-economically active person requiring someone or something for financial or other support, such as those younger than working age and retirees.
Deportation
The forced removal of a person from a country or region.
Deposition
The process in which eroded material such as sediments, soil and rocks are dropped when the means of transportation loses energy.
Depression
An area of low atmospheric pressure typically characterised by cloudy, rainy, windy and generally unstable weather.
Desalination
The process that removes salts from saline water in order to make it potable
Desalination
The removal of salt, usually from sea water.
Desert
A dry, barren area of land with little precipitation and consequently little or no vegetation.
Desertification
The process by which land becomes increasingly arid and the desert grows in size and depth.
Destructive Plate Boundary
A plate boundary where tectonic plates move together or towards each other, forcing the denser plate to be subducted under the other and destroyed.
Destructive Wave
A steep, high frequency wave formed by strong winds over large fetch areas which typically cause a net loss of material from beaches.
Desulphurisation
A vital process to remove sulphur from emissions, subsequently reducing acid rain caused by power station discharges.
Developed Country
A country with a high GDP per capita and one that exists in relative economic security.
Developing Country
A country with a low GDP per capita and one that exists with a degree of economic insecurity.
Development
A concept that refers to standard of living or the quality of life of a human population.
Development Gap
The widening difference in levels of development between the world's richest and poorest people.
Dew Point
The atmospheric temperature below which water droplets condense and dew can form.
Diaspora
A scattered or dispersed population.
Diplomacy
The process of negotiating between different countries.
Discordant Coastline
A coastline comprised of alternating strata of hard and soft rock, characterised by headlands and bays along its length.
Dispersed Settlement
Settlements where buildings are spread out or scattered in a locality.
Displaced People
Those removed from their land, sometimes by force to make way for new developments.
Distributary
A branch of a river that branches off and flows away from a main stream channel such as in a delta.
Division of Labour
The separation of a process, with each task performed by a separate person or group of people, thus improving efficiency.
Dome Volcano
A roughly circular dome over the vent or protruding from of a volcano formed by the slow extrusion and cooling of lava from a volcano.
Domestic Demand
The demand for a resource which comes from the locality in which it is naturally found.
Domestic Supply
The supply of a resource into the same locality where it is naturally found.
Downs
An expanse of rolling, grassy and treeless upland.
Drainage Basin
The area of land drained by a river and its tributaries.
Dredging
The scraping of the ocean floor by commercial fishermen to collect up sea bed dwelling sea life.
Dredging
The removal of sediment from the bottom of a river or sea, often undertaken to improve navigation or to obtain material to use elsewhere.
Drip Tip
Specially adapted leaves that are usually found on plants in a rainforest that allow water to run off them quickly without causing damage.
Drone
A small aircraft without a human pilot on board used for field research, such as by attaching cameras that are able to take aerial photographs.
Drought
A period of time over which an area of land experiences a much reduced water supply.
Drought Resistant
Plants that are able to survive in very arid conditions due to a series of adaptations.
Drumlin
A low oval mount or small hill, typically found in clusters, consisting of compacted boulder clay moulded by past glacial action.
Dust storm
A weather event where a strong wind blows dust and sand off the surface of the soil or desert.
Earthquake
The sudden release of energy through the Earth's crust caused by plate movement which causes seismic waves of different magnitudes.
Ecological Footprint
A calculation of the area of biologically productive land and water required for a given population to exist at a given consumption level.
Ecological Good
A product that can be naturally harvested from an ecosystem, for example fruits and timber.
Ecological Niche
The place within an ecosystem that a particular species occupies in terms of space and nutritional requirements.
Ecological Resilience
The ability of an ecosystem to recover back to its original state once it has been damaged by outside forces.
Ecological Service
A way in which an ecosystem helps human beings to live, for example through removing harmful gases from the atmosphere.
Economic Crash
A collapse in the economic status of a country due to, for example, a sudden decline in trade or rise in unemployment.
Economic Migration
A form of voluntary migration where the main purpose of moving is to benefit financially either in the short or long term.
Economic Water Scarcity
Where a population does not have the necessary monetary means to utilise an adequate source of water, primarily caused by a lack of investment in water or unequal distribution of resources.
Economy
The organisation of money and resources within a nation, especially in terms of production, distribution and consumption of goods and services.
Economy of Scale
The proportionate saving in costs gained by increased levels of production.
Ecosystem
A set of living organisms that interact with non-living components to create a system of inputs, processes and outputs.
Ecosystem Engineers
Organisms that change their habitat and ecosystem to make it more diverse or susceptible to different species.
Ecotourism
Responsible travel to natural areas where active steps are taken to conserve the environment and improve the well-being of local people.
Ecotown
A newly-built urban area designed to facilitate a lifestyle that promotes sustainability and has as little negative impact on the environment as possible.
Eddy
A current of water or air moving contrary to the main current, especially in a circular movement, causing a small whirlpool.
Edge cities
A relatively large urban area situated on the outskirts of a city, typically near a major road and with its own concentration of office and retailing activities.
Education
The process of facilitating learning, transferring knowledge, skills, values and beliefs through teaching, discussion, training or research.
Egan Wheel
A representation of the characteristics expected of sustainable communities.
El Niño Southern Oscillation
The movement between one form of localised climate conditions to another, normally creating extreme weather conditions for those living in coastal regions.
Emigration
The movement of people out of a country or region.
Emissions
Trading A market-based approach using tradable pollution permits, used to control pollution by providing economic incentives for achieving reductions in emissions.
Encroachment
The slow change of one land use to another by external factors.
Endangered
A species that according to the IUCN Red List is likely to become extinct.
Endemic
A plant or animal that is only found in one particular place.
Energy Balance
The ratio between the energy a country or population demands against how much it produces.
Energy Budget
The net balance between solar insolation and outgoing radiation from the Earth.
Energy Pathways
The flows of energy from producer to consumer.
Energy Security
The state of being able to access affordable energy supplies readily and able to provide a reliable source of power.
Enhanced Greenhouse Effect
The impact on the climate from the additional heat retained due to increased amounts of greenhouse gases that humans have released into the atmosphere.
Environmental Impact Assessment
A survey that tries to predict the positive and negative environmental consequences of a project going ahead.
Environmental Stewardship
Protecting the environment through processes such as recycling, conservation, regeneration, and restoration.
Epicentre
The point on the Earth's surface directly above the focus of an earthquake.
Epidemic
The rapid spread of an infectious disease through a population, the speed of which makes treatment and containment difficult.
Equality
The status of being equal amongst a society.
Erosion
The removal and subsequent transportation of part of the land surface, often first broken up by weathering, by an agent of erosion such as wind, water, gravity or ice.
Erratic
A large, heavy boulder found in an area of different geology to surrounding rock, believed to have been brought from a distance by glacial action.
Eruption
The escape of gases, steam and lava from within the crust to the above the Earth's surface.
Escarpment
A geomorphological feature of a hill with one steep slope and one shallow slope.
Estuary
The tidal mouth of one or more rivers, forming a transitional zone between river and maritime environments,
Eurocentric
A map projection which has Europe, and particularly the UK in the centre.
Eustatic Sea Level Change
Global sea level change that may reflect a change in the quantity of water in the ocean, or change in the shape and capacity of the ocean.
Eutrophication
An excessive increase in the chemical nutrients found in an ecosystem, primarily associated with fertiliser run-off and often resulting an ecosystem being left lifeless.
Evaporation
The process by which water is converted from a liquid state to a gaseous one.
Evapotranspiration
The release of water vapour from plant stoma.
Exponential
A phenomenon that is increasing at an increasing rate.
Export
The movement of goods out of a country for trade.
Extremophile
A microorganism that thrives in physically or geochemically extreme conditions of temperature, acidity, alkalinity, chemical concentration or pressure.
Fair Trade
A global movement where local producers of goods and services receive fairer prices.
Fallow
Agricultural land which is not used for crops but is left unused in order to restore its natural fertility.
Famine
A period of time over which an area of land experiences a much reduced food supply.
Farm Diversification
When a farm branches out from traditional practices to include other money making activities, that usually do not involve food production.
Fauna
Referring to animal life.
Feral
Animals that are of domesticated breeds but which have since evolved into wild animals.
Fertility Rate
A measurement showing the number of births in a year per 1000 women of reproductive age.
Fetch
The distance that a sea wave has travelled from its initiation to the coast where it breaks.
Financial
To do with the management and study of money, economics and finance.
Firn
Granular, partially consolidated snow that has passed through one summer melt season, but is not yet glacial ice.
Flash Flood
Sudden, rapid and high volume flooding caused by heavy or excessive rainfall or snow melt in a short period of time.
Floodplain
The area of low-lying ground adjacent to a river, formed mainly of river sediments and prone to flooding.
Floodplain Zoning
A soft engineering flood defence strategy ensuring land on a flood plain is not urbanised or that most important buildings (such as hospitals) are not in the direct path of potential flood water.
Flora
Referring to plant and vegetation life.
Foehn (Fohn) Wind
A type of dry, warm, down-slope wind that occurs in the lee (downwind) side of a mountain range.
Fold Mountains
Mountain ranges formed when two tectonic plates push together at their border, forcing the edges of the plates upwards into a series of folds.
Food Chain
A linear sequence representing the direct pathway and nutrition of various species from primary producers (plants) to consumers (top carnivores).
Food Miles
A measure of the energy it takes to transport food from the grower to its final consumer.
Food Processing
The actions needed to turn a raw agricultural product into one more suitable for the next stage of trade.
Food Web
A representation of the ways in which food chains overlap and intertwine with each other such as within and between ecosystems.
Footloose
An industry which by the nature of the raw material used and its labour, market and transport needs is not tied to a particular location.
Forced Migration
The coerced movement of a person or persons away from their home or home region, often caused by persecution, development, exploitation or natural phenomena.
Foreign Direct Investment (FDI)
Investment from one company or country into another country.
Formal Economy
Businesses, enterprises and economic activities that are monitored, protected and taxed by the government.
Fossil Fuel
A type of resource which comes from the fossilised remains of dead plants and animals and which when burnt in combustion releases energy.
Four Figure Grid Reference
Used to pinpoint a location to within a square measuring 1km2 on an Ordnance Survey map.
Fracking
The process of injecting liquid at a high pressure into subterranean rock to force open existing fissures and extract oil or gas.
Free Trade
In reference to a free market economy, by which competition is set up between private industries and the price of goods and services is controlled by the levels of supply and demand.
Freeze-Thaw Action
Weathering of rock which occurs when water, which has penetrated the joints and cracks, freezes and expands causing the rock to shatter.
Freight
Goods that are packaged in large quantities and shipped overseas for export and import.
Frontal Rainfall
Rain occurring when two air masses meet, the warmer of which is pushed up over the cold (more dense) air creating the front.