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.