S Flashcards
Salinisation
The deposition of salts at the surface of a soil in areas where evapotranspiration exceeds precipitation so drawing water up through the soil and with it salts that had been dissolved in it.
Sahel
A region in the centre of West Africa on the margins of the Sahara and prone to drought.
Saltation
The transport of load by bouncing along the bed of a river channel.
Salt marsh
An area of semi-vegetated tidal mudflat that becomes increasingly vegetated as sediments accumulate in sheltered waters allowing salt-tolerant plants to colonise them.
SALR
See saturated adiabatic lapse rate.
Saline
Of, containing, or concerned with salt (NaCl).
Salinity
Amount of salt in solution.
Salt lake
Inland body of water with a high salinity.
Salt pan
The dried out bed of a salt lake.
Sand
A particle of rock / mineral that has a diameter between 0.1 and 1.0mm.
Sand bar
A long strip of deposited sand lying offshore, usually only exposed at low tide, if at all.
Sand dune
A mound of sand deposited by wind in desert areas and along shore lines.
Sandur
See outwash plain.
Saprophyte
An organism which lives off other dead or dying organisms.
Satisficing
Accepting what is satisfactory rather than chasing the maximum possible outcome.
Saturated
Literally full of water - no more can be held.
Saturated adiabatic lapse rate
The rate of fall in air temperature by adiabatic change as saturated air gains altitude.
Varies between 4° and 9°C per 1000m - slower than the DALR as latent heat is released during condensation.
Savanna
The biome found in tropical areas either side of the equatorial zone between 10˚ and 20˚.
Scale
In general use refers to the size of an area or time period.
On maps, the scale indicates how many centimetres in the real world are represented by a centimetre on the map.
Scarp
The steep slope of an escarpment.
Scatter-graph
A graph which plots values by the use of dots.
The dependent variable usually goes on the y-axis and the independent variable on the x-axis.
The values are plotted as coordinates.
Scattering
The diffusion of insolation by particles in the atmosphere.
This radiation does not reach the surface as a result.
Science park
An industrial estate near a university or other research establishment where it is hoped cooperation between business and research can lead to the commercialization of technological advances.
Schengen agreement
An agreement by some members of the EU to remove all travel restrictions for their nationals across the borders of the members.
Scouring
See abrasion.
Scree
Highly angular rock pieces produced by freeze-thaw weathering and found at the base of a steep or vertical cliff face.
Sea breeze
A wind blowing from the sea to the land.
Sea-floor spreading
The widening of an ocean basin by the creation of new crust at a divergent margin.
Sea-level
Average elevation of the surface of the oceans.
Sea-level change
Two types:
- Eustatic - a change in the volume of water held in the oceans as climate variations change the amount stored as snow and ice.
- Isostatic - a change in the vertical position of the land due to the on-loading or off-loading of vast quantities of ice.
Seamount
An undersea volcano in a shield area.
Sea-wall
A steel and concrete wall built at the back of a beach, usually to protect a high value land area such as a town.
Sea-wave
At sea, waves represent a horizontal movement of energy but a vertical elliptical movement of water.
Secondary consumer
Any animal which feeds on primary consumers or other secondary consumers.
Secondary forest
Forest which is regrowing after the original vegetation was cleared.
Secondary sector
Manufacturing industry.
Secondary succession
The process of revegetation of an area that has been cleared for some reason.
Second world
Outdated term for the old communist bloc of the USSR and Eastern Europe.
Sectoral change
The general trend for the percentage of a workforce in agriculture to decline over time and for the secondary and then tertiary sectors to become increasingly important.
Sector model
Based on 149 US cities, an urban land-use model which accounts for transport routes within the city.
Suggests that industry and the wealthy make the first land-use decisions and the poor get whatever is left.
Sediment
Any material, of any size, which has been eroded / weathered and then transported and deposited by water, wind or ice.
Sedimentary rock
Any rock formed from sediments under pressure from other overlying sediments.
Sedimentation
The accumulation of sediment.
Sediment yield
Total amount of sediment moved by a river over time, usually in m³/km²/yr.
Seed dispersal
Movement of seeds away from parent plants.
Segregation
The location of particular groups of people into distinct areas separate from the general population, usually based on race, religion or economic circumstances.
Seif
A sand dune found in desert areas where the alignment is with the prevailing wind direction.
Seismic
Literally of an earthquake.
Self-employment
Work as a freelancer or owner operator.
Self-sufficiency
The ability to survive without outside help.
Separatism
The efforts of certain groups to create autonomous regions, or even achieve national independence, for a particular area within an existing nation-state.
Sere
A particular type of plant succession.
Sesquioxide
The oxides of iron and aluminium that occur in soils.
Set-aside
The policy within the EU, begun in the late 1980s, in which farmers are paid for keeping land out of production. Introduced to address the overproduction of food in these countries.
Settlement
A location where people have built structures to use as a base for their existence.
Settlement morphology
The pattern and / or shape of a settlement.
Shanty town
An area of informal housing built by its residents on the edge of a city.
The building materials are often waste from other sources and the land is occupied illegally.
There are no services and all quality of life indicators are very low.
Share-cropping
A system of land rent where the farmer pays with a percentage of his yield rather than cash.
Shield area
Ancient, stable area of crust away from plate margins and therefore unaffected by volcanic or earthquake activity.
Shield volcano
A volcanic cone made up of multiple layers of basaltic lava.
Shifting cultivation
A farming system in which a small tribal group cuts and burns the natural vegetation before cultivating the land.
After a number of years the land becomes depleted and the group moves to a new area.
The original land will recover after a period and the group usually rotates through three or four locations.
Shingle
The mixture of gravels, pebbles and shell fragments that accumulate on some beaches.
Shrub
A plant which has a thick woody stem but not thick or sturdy enough to be described as a trunk - smaller than trees.
Sial
Crustal material made mainly of silica and aluminium.
Silica (SiO2)
Most common mineral component of rock.
Sill
A sheet-like intrusion of magma between bedding planes.