Water is essential to all organisms. Liquid water is the primary physical phase
in which water is used.
Water moves by the processes of evaporation, transpiration, condensation,
precipitation, and movement through surface and groundwater (see picture
below).
84% of water vapour comes from the oceans through the process of
evaporation.
Over land, 90% of water in the atmosphere comes from plant transpiration
WATER RESERVOIRS
The oceans contain 97% of the biosphere’s water 2% is in glaciers and polar ice
caps, and 1% in lakes, rivers and groundwater
Only 0.024% of water on Earth is accessible and available.
The rest: too salty, too deep, ice.
, HUMAN INFLUENCE
We change the water cycle through (in pink/orange in the picture below):
Extraction
Land cover change – run-off effects, local weather
Increased flooding – drain wetlands, more impervious surfaces