C Flashcards
Calcification
Deposition of calcium carbonate in a soil in low precipitation areas having high rates of evaporation and thus water deficit.
Calcareous soils
Soils controlled by a calcium-based parent-material such as limestone or chalk.
Calcium carbonate
A compound with the formula CaCO3.
Caldera
A volcanic cone where the original top and centre have been removed either through a massive eruption or through collapse leaving the base of the cone as a large ring-shaped ridge.
Caliche
An alkaline salt deposit (crust) created by salinisation.
Calorie intake
A measure of the amount of energy derived from food. Requirements vary with sex, age, size and environmental factors. One of the measures having a bearing on health.
Calving
A form of ablation whereby a mass of ice breaks away from a glacier or sheet. After reaching a body of water the tip of the glacial mass is floated creating stresses with the main body remaining on land that cause it to snap free and float away as an iceberg.
Cambrian
In geologic time, a period lasting from 570m to 505m years ago.
Canopy
When the trees in a woodland or forest area are close enough together that the upper leaf layer of the trees form a more or less consistent cover.
Canyon
A large-scale, steep-sided valley which is deeper than it is wide.
CAP
See common agricultural policy.
Capillary action
The upward movement of water through a channels in a substance. In geography, most commonly the upward movement of water through a soil. Caused by adhesion of the water to the channel surface and cohesion of water molecules to one another.
Capillary water
The water that moves around the soil and is available for plant use.
Capital
Three forms can be identified:
- Money capital is the finance to start or expand a business that comes either from shareholders or from loans.
- Fixed capital is the investment of existing buildings or equipment to a business
- Social capital is the social amenity infrastructure of an area that may attract a business to set up there.
Capitalism
A social and economic system relying on market mechanisms to allocate factors of production which are privately rather than state owned.
Carbonation
A form of chemical weathering where natural rainwater, a weak carbonic acid, reacts with calcium carbonate in rock to produce calcium bicarbonate.
Carbon dating
A means of dating organic material based on the fact that carbon-14, a radioactive component of all living things, decays at a known rate over time from death.
Carbon dioxide (CO2)
An atmospheric gas which has in modern times made up approximately 0.03% of the atmosphere by volume. It is vital for photosynthesis and for its contribution to the Greenhouse Effect which allows life to exist on earth by absorbing long-wave radiation from the earth’s surface and holding the energy in what we know as air temperature.
Carboniferous limestone
A sedimentary rock laid down in the geological period 280-345 million years BP (the Carboniferous period). Has a calcium carbonate content of at least 80% meaning it was laid down in highly productive, warm, shallow seas which provided the necessary skeletal remains. Characterized by thick, well-jointed beds which are pervious and allow rapid carbonation leading to karst scenery.
Carbon monoxide (CO)
A gas produced through inefficient and therefore incomplete combustion of fossil fuels.
Carbon tax
Taxes levied on fossil fuel products as a disincentive to consume them as a strategy to slow global warming.
Cardinal points
North, South, East, West.
Carnivore
An animal that consumes other animals for food.
Carr
An area of swamp whose dominant flora is a mixture of trees, bushes and shrubs.
Carrying capacity
The idea that any given environment can only support a finite population. Originating in ecology for plant communities, social geographers have tried to apply the idea to human populations.
Cartel
A group of producers within a single industry who agree to limit supply to keep prices high. To be effective they must control most of the productive capacity of the industry and every member must abide by the agreement. Not appropriate to all industries. Most countries legislate against cartels as they exploit the consumer to too great a degree. One famous, and legal, cartel is OPEC.
Cartography
Map and chart making.
Cash cropping
The growing of crops for sale as opposed to consumption.
Catastrophism
The belief that landscape is the result of sudden, catastrophic events, rather than slow, day-to-day processes. Outmoded, but recognized as a contributory factor.
Catchment area
The area of land from which precipitation makes its way to a particular river channel.
Catena
Sequence of soils on a slope where the differences between them are a direct function of the change in slope.
Cation exchange capacity
Ability of the soil to retain cations and thus be fertile.
Catotelm
The lower level or layer of a peat deposit.
Cave
A R ecess in the ground.
Cavern
A large cave.
Cavitation
Creation of pot holes in a stream bed due to the blasting effect of particles thrown against it by the formation and collapse of air bubbles. The bubbles form in streams flowing at high speed or under high pressure.
CBD
See central business district.
Census
The collection of data about a population. At its simplest, a count of the number of people in an area. EMDC governments collect much more data to do with demographics, housing, social patterns and economic factors. These are usually carried out every ten years and participation is compulsory.
Central business district (CBD)
Centrally-located (in space and/or time) zone of an urban area, containing the principal commercial, professional, retail and governmental functions.
Centrally planned economy
See command economy.
Central place theory
The idea that all settlements influence the area surrounding them in the provision of goods and services - the sphere of influence. This leads to a regular spacing of settlements of a similar size and function across a landscape. Larger settlements-spheres of influence overlay those of smaller ones.
CFC
See chloroflurocarbon.
Chalk
A porous, sedimentary rock formed mostly from the skeletal remains of marine organisms. Bedding planes and joints increase the permeability. It is relatively soft but, when uplifted, can maintain an upland landscape as the permeability allows the rapid removal of water which slows weathering and erosional degradation.
Channel efficiency
The ability of the channel to conserve energy that may otherwise be lost to friction. Measured by hydraulic radius.
Channel flow
Run off of surface water in a defined channel as in a river or stream.
Channelization
Straightening and / or deepening of river channels to improve / maintain navigability and for flood control.
Channel morphology
Shape and dimensions of the cross-section of a channel.
Chaparral
A biome of scrub vegetation i.e. one dominated by short, woody dense bushes, found in California. Related to maquis of the Mediterranean. Adapted for hot, dry summers and mild winters which may include periods of drought.
Chelation
A form of chemical weathering. Organic acids released during decomposition release iron and aluminium from the A horizon and combine with them to form chelates.
Chemical Oxygen Demand (COD)
A measurement of the organic content of waste material related to the amount of oxygen required for it to be stabilized.
Chemical weathering
A weathering process in which the resultant material is chemically different to the original rock. Usually carried out by dilute acids. Rates will therefore increase with the increased presence of water and increased temperature except for carbonation in which weathering rates increase at lower temperature. Other types include hydration, hydrolysis and oxidation.
Chernozem
Soil type often found in continental interiors with a temperate grassland biome type. Thick grass provides for rich black humus which is extended into the A horizon by fauna during warm summers. Wet spring and early summer leads to leaching. Hot late summer causes capillary action. Up and down movement of water leads to formation of calcium carbonate nodules at about 1m depth.
Chinook
The N. American name for a warm dry wind sinking on the leeward side of a mountain range.
Chi-squared test
The comparison of an actual distribution of points with a random distribution of the same number of points to establish whether or not there is a significant enough difference to say that the actual distribution has occurred for a particular reason.
Χ^2 = Σ{(O-E)^2}/E
where O is the observed frequency and E is the expected frequency.
Chloroflurocarbons (CFCs)
Chemicals which were used in foam, refrigeration units, and aerosols for many years. Their release into the atmosphere was held responsible for the depletion of helpful ozone in the stratosphere and they also act as a greenhouse gas. Many countries have now banned their use.
Choropleth map
A map using different densities of shading to indicate the distribution of different classes of data by administrative unit across an area.
Chott
The name given to depressions found along and within the northern border zone of the Sahara which fill with water from the overland flow during flash floods. The water may remain for several weeks afterwards allowing a flourishing of vegetation although fauna is limited.
Christaller, Walter
One of the main architects of central place theory.
Cirque
See corrie.
CITES
Convention on International Trade in Endangered Species of Wild Flora and Fauna - an international agreement designed to limit the harmful impacts of removal of plants and animals from their natural habitats, especially those whose population numbers decline to critical levels.
City Action team
Group of civil servants charged by 1980s and 1990s UK government with formulating solutions to inner city decay, particularly problems of unemployment and derelict land.
Clapotis
Phenomenon where pattern of incoming sea waves exactly matches waves reflected by a sea wall or a sea cliff resulting in a static pattern of crests and troughs just offshore.
Clarke-Fisher model
Theoretical change in the relative importance of primary, secondary, tertiary and quaternary employment sectors over time as an economy develops from pre-industrial, through industrial to post-industrial stages.
Clay
A particle size classification for rock. Clay should be a rock particle with a diameter of less than 0.002mm.
Clay-humus complex
A soil particle made up of clay and some humus.
Clean Air Act, 1956
UK legislation to control the amount of smoke produced in urban areas in response to the smog that commonly afflicted them, often for days on end.
Cleavage
The line of weakness in a rock along which it will break when put under stress.
