Lesson 1 - The Global Hydrological Cycle - Key definitions Flashcards
Define the term systems approach?
A way of studying natural processes by looking at the balance of inputs and outputs, and how water is moved between stores by flows.
`Define the term stores?
Reservoirs where water is held, such as the oceans.
Define the term fluxes?
The rate of flow between the stores.
Define the term processes?
The physical mechanisms that drive the fluxes of water between the stores.
Define the term cryosphere?
Areas of the Earth where water is frozen into snow and ice.
Define the term blue water?
Water is stored in rivers, streams, lakes and groundwater in liquid form (the visible part of the hydrological cycle).
Define the term green water?
Water stored in the soil and vegetation (the invisible part of the hydrological cycle).
Define the term residence time?
The average amount of time a water molecule will spend in a reservoir or store.
Define the term fossil water?
Ancient, deep groundwater from former pluvial (wetter) periods.
Define the term transpiration?
The diffusion of water from vegetation into the atmosphere, involving a change from a liquid to a gas.
Define the term groundwater flow?
The slow transfer of percolated water underground through pervious or porous rocks.
Define the term throughfall?
When rainfall persists or is relatively intense, and the water drops from leaves, twigs, needles etc.
Define the term percolation?
The deep transfer of water from the surface or soil into the rocks below. Permeable rocks, those with joints (previous rocks e.g. carboniferous limestone) or those with pores (porous rocks e.g. chalk and sandstone).
Define the term evapotranspiration?
The combined effect of evaporation and transpiration.
Define the term river regime?
The annual variation in discharge or flow of a river at a particular point or gauging station, usually measured in cumecs.
