Key words Flashcards
A cycle
an example of a continuous system e.g. water cycle or carbon cycle.
A system
a model which helps to explain relationships within a unit. It consists of a number of components which are linked together.
Is a set of interrelated components working together towards some kind of process.
A model
a way of simplifying or representing a complex reality.
Elements
the parts or substances that make up the system
Attributes
characteristics of the elements that may be perceived and measured
Relationships
associations that occur between elements and attributes
Boundary
the edge of a system
inputs
elements entering the system
the addition of matter and/or energy into a system
Stores/components
elements being stored in the system
A part of the system where energy/mass is stored or transformed
Flows/transfers
elements moving around the system
A form of linkage between one store/component and another that involves movement of energy or mass
Outputs
elements leaving the system
Dynamic equilibrium
there is a balance between both inputs and outputs
Open system
when there are both inputs and outputs transfers energy and matter (or mass) across its boundary
Closed system
when there are no inputs or outputs matter (or mass) is confined to the system but energy may enter and exit
Positive feedback
when the effects of an action are amplified by other knock-on effects
Negative feedback
when the effects of an action are nullified by its knock-on effects
Isolated system
no interactions beyond its boundary
Cascading system
made up of a chain of open systems where the output from one system forms the input into another
Atmosphere
Is the layer of gas between the earth’s surface and space, held in place by gravity
Lithosphere
Is the outermost part of the earth. It includes the crust and the upper parts of the mantle.
Hydrosphere
The hydrosphere includes all of the water on earth. It may be in liquid from, solid form or gas from. It can also be saline or fresh.
Biosphere
The biosphere is the part of the earth’s system where living things are found. It includes all living parts of earth plants , animals, birds, fungi, insects, bacteria etc.
Cryosphere
Includes all the parts of the earth system where its cold enough for water to freeze eg. Glacial landscapes
Magnitude
the strength or amount of something
Precipitation
water falling in its many forms such as rain, hail, sleet or snow
Evaporation
The process by which liquid water changes to a gas. This requires energy, which is provided by the sun and aided by wind
Condensation
The process by which water vapour changes to liquid water
Troposphere
the lower part of the atmosphere where all our weather occurs
ITCZ
Inter-tropical convergence zone - where warm air from the tropics meet at the Equator creating an area of low pressure
Dew point
the temperature at which water vapour turns into a liquid creating a cloud
High pressure
when the air is descending and warming therefore no condensation
Low pressure
when the warm air is rising creating clouds and precipitation
Orographic
the movement of water vapour over a mountain
Prevailing
the most common wind direction
Rain shadow
the side of the mountain that is dry due to the windward side receiving precipitation
Ablation
when the ice melts into water
Accumulation
when liquid water freezes into ice
Sublimation
when a solid (e.g. ice) turns immediately into a gas without melting
Deposition
when water vapour immediately freezes without turning into a liquid first
Calving
when part of an ice sheet breaks off, creating an iceberg
Ice sheets
a mass of glacial ice extending over 50,000 Km2
Ice caps
thick layers of ice on land that are smaller than 50,000 Km2
Glaciers
thick masses of ice found in deep valleys or upland hollows
Permafrost
ground that remains at or below 0c for at least 2 years
Sea ice
that part of the Arctic and Antarctic that freezes in the winter
Latent heat
is the amount of heat that is given out or taken in from the surroundings.
Water scarcity
is when the annual supply of water per person is below 1,000m3
Water stress
is when the annual supply of water per person is less than 1,700m3
Economic scarcity
human and financial factors limit water use to less than 25% of river flows
Physical scarcity
more than 75% of river flows being used
Precipitation
water falling from the sky as rain, hail, sleet or snow
Throughfall
rainwater dripping off the tips of leaves
Stemflow
water flowing down the branches, trunk of a tree
Infiltration
water absorbing into the ground
Evapotranspiration
water being evaporated or transpired
Overland flow/sheet flow
water running off the surface of the ground
Throughflow
water flowing through the ground
Percolation
water soaking its way down through the underlying rock
Groundwater store and flow
water stored under the ground
Channel flow
the water that is flowing in a river
Run off
water flowing in channels across the ground
Water table
this marks the top of the groundwater
