Key Definitions Flashcards
Anticyclone
A system of high pressure, causing high temperatures and unseasonably high evaporation rates
Aquifer
A permeable or porous rock that stores water
Channel flow
Water flowing in a stream or river
Conventional precipitation
Solar radiation heat the air above the ground, causing it to rise, cool and condense forming precipitation
Cryosphere
The global water volume locked up within a frozen state
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
Desublimation
The change of state of water from gas to solid without being a liquid
Drainage basin
The area of land drained by a river and its tributaries
Drainage density
The total length of all rivers and streams divided by the area of the drainage basin
Drought
An extended period of deficient rainfall relative to the statistical average for the region
Economic water scarcity
When water resources are available but insufficient economic wealth limits access to it
ENSO cycles
El Niño 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 the soil
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 subtropical areas, caused by a changed prevailing wind. Can lead to annual flooding
Open system
A system affected by external flows and inputs e.g. drainage basin
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 morphology of the land
River regime
The pattern of river discharge over a year
Runoff
Water flowing over the surface of the ground e.g. after precipitation or snowmelt
Salinisation
Where salt water contaminates freshwater stores or soils, creating saline conditions and reducing human consumption
Saltwater encroachment
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 shortage supply less than optimal, to make crops resistant to water shortages
Storm hydrographs
Variation of river discharge over a short period of time (days)
Sublimation
The change of state of water from a solid to a gas, without being a liquid
Thermohaline circulation
The movement of volumes of seawater from cold deep water to warm water surface water
Throughflow
Water moving horizontally through the soil, due to gravity
Transpiration
The process through which water evaporates through the stomata in a leaf
Water budget
The annual balance between inputs and outputs in 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
Water security
The ability to protect and access a sustainable source to adequately meet demand
Water sharing treaty
International agreements for trans boundary 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
