Thursday, 30 May 2013

A - list of geographical terms and definitions

Abiotic: All the non-living things, which comprise the environment are known as abiotic factors. Rock, water, mountains are all examples of abiotic elements of environment.
Ablation: The geographical term, ablation is defined as the net loss of water from the glacier due to melting, evaporation, sublimation, and calving.
Abrasion: Abrasion is the degeneration of land due to 'scouring action of materials'.
Abrasion: erosion caused by rocks and boulders in the base of the glacier acting like a giant file scratching and scraping the rocks below.
Abrasion: the pebbles being transported wear away the bed and banks of the river channel.
Abrasion: wearing away of cliffs by sediment flung by breaking waves. See Corrasion.
Absentee Landlords: land owners who live away from their estate, often in an urban area. They take rent from their tenant farmers but may make little contribution in return. (See Tenant Farmer).
Absolute Humidity: Absolute humidity is determined by content of water vapor in the air (grams) per cubic meter.
Absolute Location: An absolute location of a place is defined by longitude and latitude on the earth's surface.
Absorption: Absorption is defined as the permeation of one substance into another. For example, the land absorbs the rain and increases the ground water level.
Abyssal Plain: Abyssal plain is a large flat area of the ocean, generally 5,000-6,000 m below sea level.
Accessibility: A locational characteristic that permits a place to be reached by the efforts of those at other places.
Accessibility: How easy a place is to get to.
Accessibility: The ease or difficulty associated with reaching a location or a destination is known as accessibility.
Accessible: A place which is easy to reach.
Acculturation: A change or a modification in a culture due to adoption of new principles, customs, trends and traits is known by the term acculturation.
Acid Lava: Lava which contains high levels of silica is known as acid lava. Acid lava has high viscosity and high melting points.
Acid Rain: A commonly used geography term, acid rain is highly acidic due to sulfuric and nitric acids created by human pollution and burning of fossil fuels.
Acid rain: Rain that has become more acidic than normal (a pH below 5.0) as certain oxides present as airborne pollutants are absorbed by the water droplets. The term is often applied generically to all acidic precipitation.
Active volcano: A volcano that is currently erupting, or has erupted during recorded history.
Active Volcano: A volcano that has erupted recently and is likely to erupt again.
Adiabatic cooling/heating The rate of cooling (by expansion) as an air parcel rises. It is approximately 1 degrees Celsius per 100 metres. It is also the rate of heating (by compression) as an air parcel descends.
Aeolian: This geography term is derived from the Greek God of Winds, Aeolus. Aeolian refers to the erosion caused by winds or that is related to winds.
Aerial Photograph: Aerial photograph is photography done from above the surface of the earth. These photographs help in providing an aerial (birdlike) view of a geographical terrain.
Aerosol: Fine liquid or solid particles suspended in the atmosphere. Aerosols resulting from volcanic eruptions are tiny droplets of sulfuric acid—sulfur dioxide that has picked up oxygen and water.
Afforestation: Afforestation refers to planting trees on barren lands and also in other deforested areas.
Aftershock: Aftershock is defined as the tremors that are felt after a major earthquake, from the epicenter.
Ageing Population Structure: a population pyramid with a narrower shape, broad at the top, found in MEDCs. This reflects their low birth rates and the greater proportion of elderly people.
Ageing Population: In the population structure of many MEDCs there is often a high proportion of elderly people who have survived due to advances in nutrition and medical care. This creates problems since these people do not work and have to be provided with pensions, medical care, social support, sheltered housing etc. from the taxes paid by a proportionally smaller number of workers. In addition, an increasing number of young people are employed as care workers for the elderly. This removes them from more productive jobs within the economy and harms a country's competitiveness.
Age-Sex Pyramid (Population Pyramid): a series of horizontal bars that illustrate the structure of a population. The horizontal bars represent different age categories, which are placed on either side of a central vertical axis. Males are to the left of the axis, females to the right.
Age-sex Pyramid: Age-sex pyramid is also known as the population pyramid. This geographical term is a graph, which gives the age and sex distribution of a population.
Agglomeration Economies: savings which arise from the concentration of industries in urban areas and their location close to linked activities. e.g. A car factory attracts component suppliers to locate close by, saving on transport costs. Other savings are made in labour and training costs, and the use of the services found in urban areas, e.g. housing, banking, roads, electricity, etc.
Agglomeration: a group of industries in the same location.
Agribusiness: large-scale capital-intensive, commercial farming.
Agricultural: to do with farming. The work of growing crops or rearing animals.
Agriculture: Agriculture is the science and business of growing crops, breeding livestock and cultivating soil.
Agriculture: The growing of crops and rearing of animals.
Aid: the giving of resources by one country or organisation, to another country.
Air mass A large body of air that has similar temperature, pressure and moisture properties.
Air mass: A very large body of atmosphere defined by essentially similar horizontal air temperatures. Moisture conditions are also usually similar throughout the mass. (IIP 2008)
Air Pressure: Air pressure is the force that the air exerts on the surface.
Albedo: The amount of sun's rays that is reflected by an earthly body is called albedo. It is the reflection of a certain area of earth, like snow and mountains, on the surface. For example, the albedo of snow covered mountains hurts the eyes.
Alluvia: Clay, silt, gravel, or similar detrital material deposited by running water.
Alluvial Fan: Alluvial Fan is a fan-shaped soil deposit formed due to sediments. This is usually found at the foot of the valley, where a stream fans out and deposits the sediments of the stream.
Alluvial soils: Soils deposited through the action of moving water. These soils lack horizons and are usually highly fertile.
Alluvium: Alluvium are deposits made by rivers. These are found near floodplains or at point-bars.
Alluvium: rock particles (clay, silt, sand and gravel) deposited by a river.
Altitude: Altitude is the vertical height above the sea level.
Altitude: Height of an object in the atmosphere above sea level.
Amalgamated Farms: small farms joined together to form one large agricultural unit. (See Economies of Scale).
Amenities: services that people find very useful, but are not essential, like swimming pools, libraries, parks, etc..
Amenities: These may be within the home, in which case they refer to baths, toilets (w.c.'s), hot water etc., or outside people's homes in which case they would include parks, shops, public transport provision, etc..
Angle of Dip: the angle of the bedding planes which affects the shape of the cliff. If the rock layers are horizontal, small overhangs of more resistant rock form in the cliff face. If the bedding planes dip towards the sea, a gently sloping cliff face is formed with few overhangs. If the bedding planes dip away from the sea, a steep cliff face with many large overhangs of more resistant rock is formed.
Angle of Response: Angle of response is the maximum angle that a slope attains and at which it remains stable. It may be a pile of rocks or any granular pile. It is caused due to friction and cohesion.
Angular Rock: a rock with sharp edges.
Anticyclone High pressure system in which air descends to give calm conditions and clear skies. Associated with summer heatwaves and winter frosts and fogs.
Anticyclone: As per geography definitions, anticyclone is a stable air mass, which produces high pressure and warm conditions.
Anticyclones: A region of high atmospheric pressure surrounded by low atmospheric pressure.
Antipode: The exact opposite point on the surface of the earth to any other given point is known as antipode. For example, south and north poles are considered as antipodes of each other.
Aphelion: Aphelion is the point of time when the earth is farthest from the Sun, while it is revolving in the orbit. This occurs around July 3, when the earth is approximately 94,555,000 miles away from the Sun.
Appropriate Technology: technology suited to the area where it is used. It usually refers to simple, low-cost machinery. (See Intermediate Technology).
Aquatic Fauna: In the geography glossary, aquatic fauna is defined as the animal species living under and in water.
Aquatic Plants: In the geography glossary, aquatic plants are defined as all the plants living and reproducing in the water.
Aquifer: Aquifer is a water reserve in the Earth's belly. In other words, it is an underground water reserve which is extracted for surface applications.
Arable Farm: one which specialises in producing crops e.g. wheat farming in East Anglia.
Arable Farming: A farm or area that only grows crops.
Arch: wave-eroded passage through a small headland. This begins as a cave formed in the headland, which is gradually widened and deepened until it cuts through.
Archipelago: Archipelago is a group of islands. For instance Hawaii, is an archipelago.
Arête: sharp, knife-like ridge formed between two cirques cutting back.
Arid: Arid is a climatic condition characterized by extreme dryness.
Arroyo: Arroyo is defined as a dry creek, which fills up only after a heavy spell of rain.
Aspect: the direction in which a slope faces, which often affects the amount of solar energy received. South-facing slopes in Europe receive more solar radiation than north-facing slopes and are better suited to crop production.
Aspect: the direction a cirque faces; south-facing cirques tend to be larger and more eroded due to greater ice movement.
Aspect: the direction a cliff faces; facing the direction of the prevailing wind can lead to high rates of cliff erosion.
Assembly Industries: see Screw Driver Industries.
Assisted Areas: see Development Areas.
Asteroids: Small star shaped planetary bodies, moving between Mars and Jupiter.
Atlas: A bound collection of maps.
Atmosphere The envelope of air surrounding the Earth and bound to it by gravity.
Atmosphere: Atmosphere is a very popular geography term. Geography glossary at defines it as, an envelope of air, gases and suspended particles which surrounds the earth. It has 78.09% of nitrogen, 20.95% of oxygen and remainder 0.96% consists of 19 gases. The layers of the earth's atmosphere is divided into troposphere, stratosphere, and tropopause. The atmosphere stretches 1000 km above the sea level, but 99% of gases are trapped within the limit of 40 km.
Atmosphere: Cover of air that stretches up to six hundred miles above the earth. If an aero planes passes out of this cover, it will be able to reach any planet without any difficulty, because gravitation does not exert its pull beyond this hemisphere.
Atmosphere: The mixture of gases, aerosols, solid particles, and water vapor that envelops the Earth.
Atmospheric pressure Pressure (force per unit area) exerted by the atmosphere on any surface by virtue of its weight.
Atoll: Atoll is a ring shaped coral reef, which encloses a shallow lagoon.
Attitudes to Change: farmers usually operate on the basis of their view of the world, which may be very different from the farming expert's view. Farmers' attitudes are affected by their individual culture or background (e.g. 'backward' rural areas tend to have cautious farmers who are unwilling to change; urban fringe areas tend to have farmers who are used to change and are willing to try new ideas), their own individual background (e.g. risk takers or cautious), and by the amount of information that is available to them.
Attractive Countryside: Areas of pleasant scenery such as mountains rivers, lakes and coasts.
Attrition: erosion caused when rocks and boulders transported by waves bump into each other and break up into smaller pieces.
Attrition: The particles are knocked about as they are transported, and they gradually become more rounded and reduced in size.
Aurora Australis: Aurora Australis is a hypnotic band of lights that cascades in the Southern Hemisphere in the night sky. They are also known as the Southern Lights and commonly appear in shades of electric greenish-blue.
Aurora Borealis: Aurora Borealis is a magnificent band of lights that appears in the far Northern Hemisphere. It appears at night and is also known as the Northern Lights.
Aurora Borealis: Beautiful light of the sunset seen late all night in the North hemisphere.
Autumnal Equinox: Autumnal Equinox is the day of the year, when the day is equal to night. In the Northern Hemisphere, the autumnal equinox occurs on 22 or 23 September and in Southern Hemisphere it occurs on 20 or 21 March.
Avalanche: When snow, debris or rocks slide down rapidly from a hill or a mountain, it is called an avalanche.
Axis: Imaginary line passing through the centre of the earth from North and South Pole.
Axis: In geography terminology, axis is an imaginary line, which run through the North and South pole. The earth rotates around this axis every 24 hours, which is how the phenomenon of day and night occurs.