Gabion
A container filled with rocks, concrete, sand, soil or other materials that is commonly used as a defence against erosion.
Garden City
A whole or part development of a city with green space and sustainability central to its design principles.
Gender Gap
The difference in social status, wage levels or rights and freedoms available between men and women.
General Agreement on Trade and Tariffs (GATT)
An international agreement to promote trade and economic benefits. It aimed to encourage free trade by imposing trade rules and reducing tariffs among its member nations.
Genetic Modification (GM)
A process of transferring genetic material from the cells of one organism to those of another for the purpose of producing stronger or more resilient strains.
Gentrification
The restoration and upgrading of deteriorated urban property by middle-class or affluent people, often resulting in displacement of those of a lower income level.
Geoengineering
The large-scale, deliberate manipulation of an environmental process that affects the Earth's climate in an attempt to counteract the effects of climate change.
Geology
A study of the physical structure and substance of the Earth, in particular the rocks that compose it and processes which act on them.
Geomorphological
The physical features on the Earth's surface and their formation.
Geophysical Hazard
Hazards where the principal cause is climatic, meteorological, geological or geomorphological.
Geopolitical Independence
Freedom experienced within a country following colonial rule.
Geopolitics
The study of the effects of geography on international politics and international relations.
Geothermal Energy
A source of power whereby the heat of the Earth's subsurface is utilised, often by using water to create steam which in turn powers turbines.
Geothermal Power
Power generated by using the warmth of the subsurface layers to heat water which in turn spins a turbine.
Geyser
A hot spring characterised by water that intermittently boils, ejecting a column of water and steam into the air.
Ghettoisation
The process by which people of a similar background (such as ethnically, by age nationally, or socio-economically) start to residentially cluster in one place.
Gini Coefficient
The measurement between 0 and 1 of the inequality among values of a frequency distribution such as levels of income.
Glacial Accumulation
Processes that add snow or ice to a glacier, including snowfall, avalanching or wind transport.
Glacial Retreat
Net loss of ice from a glacier as a result of ablation exceeding accumulation.
Glacier
A river of ice that moves down a gradient towards the sea.
Global Brightening
An increase in the amount of sunlight reaching the Earth's surface, caused by decrease in light-absorbing compounds in the atmosphere.
Global Dimming
The gradual and widespread reduction in sunlight at the surface of the Earth, caused by the blocking and scattering of insolation by particulate matter in the atmosphere.
Global Positioning System (GPS)
A satellite navigation system that provides the user with data about their location.
Globalisation
Increasing interconnectedness between people and processes in different countries.
Glocalisation
The process by which concepts which are inherently global are represented or reinterpreted to reflect local nuances.
Gondwanaland
A super continent of the Southern Hemisphere that, according to the theory of plate tectonics, broke up into India, Australia, Antarctica, Africa, and South America.
Gorge
A deep and narrow opening between upland areas, usually containing a river and caused by the ongoing erosion by a waterfall.
Governance
The system by which a person, state or situation is controlled.
Grassroots Development
A project that involves the organisation and cooperation of local people to solve a locality specific issue.
Green Belt
An area of land surrounding a city that offers partial protection against further development and urban sprawl.
Green Employment
Work, employment or activity that contributes substantially to preserving or restoring natural environmental quality, contributing to a more sustainable world.
Green Revolution
A wave of agricultural technological developments that encouraged greater productivity in agriculture, particularly in developing nations.
Green Technology
Technology that promotes environmental sustainability through its use, mitigating or reversing the effects of human activity on the environment.
Green Washing
The process by which companies who are known to cause environmental problems claim to be improving their record through positive press releases and public media spin.
Greenbelt
An area of land surrounding an urban area in which planning restrictions are enforced to curb new house, commercial or industrial developments, preventing urban sprawl.
Greenfield
An undeveloped, often agricultural, tract of land that is a potential site for industrial or urban development.
Greenhouse Effect
The natural process by which the atmosphere traps the Sun's energy, warming the Earth enough to support life.
Greenhouse Gases
Gases that are released by the burning of fossil fuels, such as carbon dioxide, methane and ozone.
Grey Water Recycling
The use of rainwater or semi-filtered waste water to flush toilets or water gardens.
Grid Line
Any of a series of numbered horizontal and perpendicular lines that divide a map into squares to form a grid, subsequently allowing any point to be located by a system of coordinates.
Grid Square
The squares of a map denoted by a grid formed by a series of numbered horizontal (Northing) and vertical (Easting) lines
Gross Domestic Product (GDP)
The total value of goods and services produced in a country in one year.
Gross National Income (GNI)
The total income for a country comprising the total value of goods and services produced within the country (GDP) together with its income received from other countries, excluding net taxes.
Gross National Product (GNP)
The total value of good produced and services provided by a country, but not within its borders, during one year.
Groundwater
All sub-surface water which is not chemically combined with any minerals present.
Groundwater Flow
The movement of water beneath the surface of the ground, consisting largely of surface water than has infiltrated down;.
Groyne
A breakwater running seawards from the land, constructed to stop the flow of beach material transported by longshore drift.
Guerrilla
A member of a small independent group taking part in irregular warfare.
Habitat
An environmental setting that is occupied specifically by a particular species or set of related species.
Halophytic
A plant that is adapted to living in a saline environment.
Halosere
Plant succession in a saline environment, such as a salt marsh or estuary.
Hamlet
A small settlement with fewer than one hundred inhabitants and limited services.
Hanging Valley
A high-level tributary valley in glacial areas from which the ground falls sharply to the level of the lower.
Hard Engineering
Measures taken to prevent the impact of a natural hazard or phenomenon by means of physical structures and changes to the landscape.
Headland
A narrow piece of land that projects from the coastline into the sea, separating bays.
Heat Wave
A prolonged period of abnormally hot weather.
Heavy Industry
Industries that involve the manufacture of large and heavy, sometimes one-off goods such as boat building and metal works.
Heterogeneous Culture
A culture where difference is present within a population, including individuals of different cultural backgrounds, ethnicities, sexes or ages.
High Order Goods and Services
A good or service, usually costly, that people only occasionally buy, such as computers, furniture or jewellery.
High Tech Industry
An industry that develops or uses the most advanced methods and most modern equipment.
Hjulstrom Curve
The relationship between the velocity of a river and the particle sizes that may be transported which is used to determine whether a river will erode, transport or deposit sediment.
Homogeneous Culture
A society comprised of people of the same cultural backgrounds.
Hot Spot
A volcanic region fed by underlying mantle that is anomalously hot compared to the surrounding mantle.
Hot Spot Volcano
A volcano formed above a hot spot or plume of magma.
Hotspot
A place that is particularly diverse in ecology but which is also under significant threat.
Hub
A place that displays multiple real and conceptual connections to other places.
Human Development Index
A compound indicator of economic development, combining GNP per capita with life expectancy and literacy in a weighted average.
Human Rights
The rights such as freedom of speech, freedom of movement, certain standards of life or treatment which are believed to belong to every individual.
Humanitarian Aid
A description for those organisations acting with the needs of the person at the core of their work, such as providing materials or logistical assistance to those in need.
Hurricane
An alternative name for a tropical storm, usually used by people of North and Central America.
Hydraulic Action
The sheer erosive force of water within a stream or river.
Hydroelectric Power
Energy that is produced by the gravitational force of water falling through a gradient for example through a turbine system in a dam.
Hydrogen Economy
A proposed system in which energy needs are predominantly met by hydrogen instead of fossil fuels, bringing major environmental benefits.
Hydrogen Fuel Cell
A fuel cell in which hydrogen reacts with oxygen creating a current that is used to generate electricity.
Hydrograph A
graph of a particular weather event, catchment area and river channel which combines a bar chart of precipitation with a line graph of river discharge.
Hydrological Cycle
The continuous circulation of water around the world and between stores, facilitated by hydrological processes such as evaporation, transpiration, condensation, precipitation and percolation.
Hydrological Hazard
Hazards driven by hydrological processes, such as river and coastal flooding, drought, tsunamis, tropical cyclones and monsoons.
Hydroponic Farming
A form of agriculture which produces crop through highly-managed nutrient rich water rather than through soil contact.
Hydrosphere
The combined mass of water found on, under and over the surface of the planet - including oceans, seas, lakes, rivers, ice and water underground.
Hypermarket
A very large supermarket that is usually built on the outskirts of a town.
Ice Sheet
A mass of ice covering surrounding terrain greater than 50,000km2 for a long period of time.
Idyll
An idealised view of a place or a sense of extreme peace and comfort with one's surroundings.
Igneous Rock
Rock formed through the cooling of magma or lava.
Immigration
The movement of people into a country or region.
Import
The movement of goods into a country for trade.
Import Substitution
The process by which countries start to manufacture goods for which they had previously relied on imports.
Improved Water
Supply A water supply that, by the nature of its construction or through active intervention, is protected from outside contamination.
Incineration
Waste destruction which involves burning rubbish at high temperatures in a furnace.
Independence
A state whereby a country and its inhabitants are able to self-govern.
Independents
Those people within a population (aged 16 to 65) who theoretically do not financially rely on the state or another person to provide for them.
Indigenous Population
The original inhabitants of a place.
Industrialisation
The growth of industry, usually referring to manufacturing industries.
Industry
A business, usually privately owned, which aims to make goods or provide a service for the making of a profit.
Inequality
A state in which some people obtain all the economic, environmental and social wealth while the majority have little.
Infant Mortality Rate
The number of deaths in the first year of life per 1000 children born.
Infiltration
The downward movement of water into the soil.
Informal Economy
A section of employment where workers work independently and without security such as home weaving or shoe shine stalls.
Informal Settlement
An area where groups of housing units have been constructed on land that the occupants have no legal claim to, or occupy illegally.
Infrastructure
The services and facilities needed for an economy to function, for example transport networks, energy supply and health care.
Insolation
The solar radiation received at the Earth's surface.
Instant Cities
Cities that come into existence suddenly and flourish as a result of the unique economic opportunities at the time.
Interception
The holding of raindrops by plants as the water falls onto leaves, stems and branches.
Interlocking Spurs
Tapering ridges which alternately project into a river valley, around which the river winds its course.
Internal Deformation
The process by which ice crystals deform at the base of a glacier due to the sheer weight of ice on them, creating as slip plane.
Internal Migration
The movement of people within a named country or region.
Internally Displaced People
People who are forced to flee their homes but remain within their country's borders.
International Aid
Money and assistance that is given from one country to another.
International Elite
A group of people who due to their high level of wealth and status can live anywhere in the world without negatively affecting their lifestyle and work practices.
International Monetary Fund (IMF)
An international financial organisation set up to promote trade by keeping currencies stable and having a fund of money from which member states may borrow.
Intrusive Landform
New, usually igneous rock material that is emplaced into pre-existing rock after being forced to the Earth's surface.
Invasive Species
Species that are not native to a particular place and that once found in a new place tend to spread very quickly through it.
Investment
Money put into financial schemes with the expectation of material results in the future.
Inward Investment
The transfer of money from a source into a region or sector with the aim of gaining capital or developing its presence.
Irrigation
The artificial provision of a water supply to land or crops.
Isolation (Geographical Isolation)
The state of being cut off from other people and places due to a lack of communication and connection infrastructure.
Isostatic
A condition in which there is equal pressure on every side of a geomorphological feature or process.
Isotherm
Line on a climate map or chart connecting points of equal average temperature.
IUCN Red List
An information source compiled by the International Union for the Conservation of Nature listing the conservation status of the world's species.