WATER CYCLES definitions Flashcards
Anticyclone
- A system of high pressure, causing high temperatures and unseasonably high evaporation rates.
Aquifer
- A permeable or porous rock which stores water
Antecedent
Moisture already present
Channel flow
Water flowing in a rivulet, stream or river
Convectional precipitation
Solar radiation heats the air above the ground, causing it to rise, cool & condense forming precipitation (often as thunderstorms)
Cryosphere
The global water volume locked up within a frozen state (i.e. snow and ice)
Depression
A system of low pressure, with fronts of precipitation where low and high pressure air masses meet.
Desalination plant
The conversion of seawater to freshwater, suitable for Human consumption
De sublimation
The change of state of water from gas to solid, without being a liquid (the opposite process to sublimation)
Drainage basin
The area of land drained by a river and its tributaries
Drainage density
The total length of all rivers & streams divided by the area of the drainage basin.
Drought
An extended period of deficient rainfall relative to the statistical average for the region (UN)
Economic water scarcity
When water resources are available but insufficient economic wealth limits access to it.
ENSO cycles
El Nino Southern Oscillations - naturally occurring phenomena that involves the movement of warm water in the Equatorial Pacific.
Evapotranspiration
The combined total moisture transferred from the Earth to the atmosphere, through evaporation and transpiration
Frontal precipitation
Where air masses of different temperatures meet at a front, one mass will be forced over another, causing precipitation beneath the front
Global hydrological cycle
The continuous transfer of water between land, atmosphere and oceans. The Earth is a closed system.
Groundwater flow
Water moving horizontally through permeable or porous Rock due to gravity.
Hydrological drought
Insufficient soil moisture to meet the needs of vegetation at a particular time
Infiltration
The movement of water vertically through the pores in soil.
Integrated drainage basin management
Establishing a frame of coordinated efforts between administrations (e.g. local government) and stakeholders (e.g businesses) to achieve balanced management of a basin (World Bank))
Interception
Raindrops are prevented from falling directly onto the ground, instead hitting the leaves of a tree.
Meteorological drought
When long-term precipitation trends are below average
Monsoon
The drastic variation between wet and dry seasons for sub-tropical
areas, caused by a changed prevailing wind. Can lead to annual flooding.
Open system
- A system affected by external flows and inputs (such as a drainage basin, or a sediment cell)
Percolation
Water moving vertically from soil into permeable rock
Physical water scarcity
A physical lack of available freshwater which cannot
meet demand
Relief precipitation
Precipitation caused when air masses are forced to rise over high land, determined by the relief/ morphology of the Land
River regime
The pattern of river discharge over a year.
Runoff
Water flowing over the surface of the ground eg. after precipitation or
snowmelt.
Salinisation
Where salt water contaminates freshwater stores or soils, creating saline conditions and reducing human use/ consumption.
Saltwater enrochement
The movement of saltwater into freshwater aquifers or soils. This may be caused by sea level rise, storm surges or over-extraction
Smart irrigation
- Providing crops with a water supply less than optimal, to make crops resistant to water shortages.
Storm hydrograph
Variation of river discharge over a short period of time (days)
Sublimation
The change of state of water from solid to a gas, without being a
liquid.
Through flow
Water moving horizontally through the soil, due to gravity
Transpiration
The process through which water evaporates through the stomata in plants’ leaves
Water budget
The annual balance between inputs and outputs within a system
Water conservation
Strategies to reduce water usage and demand
Water recycling
The treatment and purification of waste water, to increase supply
Water scarcity
There are limited renewable water sources (between 500 and 1000 cubic metres per capita per year)
Water security
The ability to protect and access a sustainable source to adequately meet demand
Water sharing treaty
International agreements for transboundary sources
Water transfer
Hard engineering projects, such as pipelines or aqueducts, that
divert water between basins to meet demand
Watershed
The boundary between neighbouring drainage basins
Confluence
Where rivers meet
Tributary
Veins of rivers flowing though other parts
Mouth
Where river meets sea
Source
Where river starts
Water table
Layer under the surface that is always wet/point at which underground is always wet
Flashy
A flood caused by excessive rainfall in a short amount of time
