Definitions Flashcards
systems approach
These approaches study the hydrological phenomena by looking at the balance of inputs and outputs, and how water is moved by stores and flows.
stores
stocks where the water is held, such as in the ocean, lakes etc.
fluxes
the rate of flow between stores
processes
the physical mechanisms that drive the fluxes of water between the systems
cryosphere
Areas of the earth where water is frozen into snow or ice.
blue water
water is stored in rivers, lakes, and groundwater in liquid form.
green water
Water is stored in vegetation and soil
precipitation
the movement of water in any form from the atmosphere to the earth.
evaporation
the change in state of water from a liquid to a gas.
residence time
the average time a water molecule will spend in a reservoir or a store.
fossil water
ancient, deep groundwater from, former pluvial periods.
transpiration
the diffusion of water from a gas to a liquid from vegetation to the atmosphere.
groundwater flow
the slow transfer of percolated water underground through pervious or porous rocks.
convection rainfall
often associated with intense thunder storms, which occur widely in areas with ground heating such as the tropics with continental interiors.
cyclonic rainfall
A period of sustained, moderately intense rain, it is associated with the passage of depressions.
orographic rainfall
concentrated on the windward slopes and summit of mountains.
rain shadow
the dry area of the leeward side of a mountainous area. The mountains block the passage of rain-producing weather systems, and cast a ‘shadow’ of dryness behind them.
catchment
an area of land drained by a river and its tributaries.
watershed
the high land which divides and separates waters flowing to different rivers.
interception
where water is captured by vegetation, or buildings and hard surfaces, before reaching the soil.
vegetation storage
any moisture taken up by vegetation and held within plants
surface storage
any surface water in lakes, puddles, ponds etc.
soil moisture storage
water held within soil
groundwater storage
water held within permeable rocks (ie an aquifer)
channel storage
the storage of water within streams or rivers
interception loss
water retained by plant surfaces and later evaporates or absorbed by vegetation and transpired
infiltration
the movement of water from the ground surface into the soil.
infiltration capacity
the maximum rate in which rain can be absorbed by soil.
throughfall
when the rainfall persists or is relatively intense and the water drops from leaves, twigs, needles etc.
stem flow
this is when water trickles along twigs and branches, and then down the trunk.
surface run-off
the movement of water that is unconfined by a channel across the surface of the ground. Also known as overland flow.
throughflow
the lateral transfer of water down slope through the soil via natural pipes and percolines
percolines
lines of concentrated water flow between soil horizons to the river channel.
percolation
the transfer of water to soil into the bedrock beneath.
saturated overland flow
the upward movement of the water table into the evaporation zone.
channel flow
the flow of water in streams or rivers.
condensation
the change from a gas to a liquid.
dew point
the temperature in which dew forms. It is a measure of atmospheric moisture.
evapotranspiration
the combined affect of evaporation and transpiration.
potential evapotranspiration
the water loss that would occur if there was an unlimited supply of water in the soil or for use by vegetation.
albedo
a measure of the proportion of the incoming solar radiation that is reflected by the back into the atmosphere and space.
Agricultural drought
Rainfall deficiency from meteorological dorught causes soil moisture deficiency and has a knock-on affect to plant growth.
Desertification
The land degredation in arid, semi-arid, and sub-humid locations.
Ecosystem service
The inputs of an ecosystem into human wellbeing.
El Nino.
A system which causes the reverse warming of the ocean in the Pacific, which occurs every 3-8 years. It lasts from 12-22 months.
Eutrophication
The intense nutrients wihtin lakes or bodies of water caused by land runoff from farming causes large algae growth on the surface, causing animals and plants to die from lack of oxygen.
Famine drought
A widespread humnitarian crisis caused by the lack of food causd by failing agricultural systems.
flash flooding
flooding with an exceptionlly short lag-time.
flood return period
The time a flood of a specific magnitude is likely to occur again based on past flood events
groundwater flooding
flooding that is caused by prolongued rain saturating soil and rock.
hydrological drought
reduced precipitation causes a deficit of streamflow and throughflow.
Jokullhlaup
A type of glacial outburst flood caused by the sudden failure of a dam, usually caused by heating from magma.
meteorological drought
the shortfall of precipitation due to short-term variability within a loinger-term trend, compared to normal conditions.
morbidity
a state of ill health.
surface water flooding
Heavy rainfall has insufficient time to infiltrate into the ground, therefore causing water to run off overland.
teleconnections
climate anomolies which relate to each other over large distnaces.
tipping point
where a system changes from one state to another
urbanisation
The increased number of people living in towns and cities comapred to living in the countryside.
wetland
an area of marsh, peatland, fen, or water.
economic water scarcity
Where people cannot afford water, even when it is available. (Bolivia)
fracking
where fracturing occurs through hydraulic pressure from liquid.
Grey water
recycled water, usually from bath, sink, or washing water.
hard engineering
a large-scale technological fix.
hydroponics
a method of growing plants without the need for soil, and substituting with nutrient solutions.
irrigation
artificial watering of crops.
IWRM
Integrated Water Resource Management a way of promoting water management on an equitible and coordinated scale.
physical water scarcity
the insufficient supply of water in a region. More than 75% of blue water is being used.
privatisation
Where governments give ownership of national water schemes to private individuals or companies.
sustainable water
clean, affordable water should be available to all in future generations.
virtual water
the exchange of hidden water when commodities such as food or products ar traded.
water insecurity
where future water supplies cannot be guaranteed.
Water poverty index
a measure of 5 components which assess the degree of shortage and stress of water supply on a region.
water scarcity
less than 1000m3 per capita of water available.
water stress
Where there is less than 1700m3 of water available per capita.
