The Water Cycle

WATER CYCLE(AKA HYDROLOGIC

CYCLE)•Continuous movement of water from the atmosphere to the earth’s surface and back to the atmosphere again.

3 MAIN PROCESSES INVOLVED IN THE WATER CYCLE:•Evapotranspiration: the process of evaporation (liquid water changing into water vapor) and transpiration (plants giving off water vapor into the atmosphere).

•Condensation: water vapor (gas) changes into liquid water.

•Precipitation: water falls from clouds to the ground.

GROUNDWATER•The underground water that fills almost all the pores in rock and sediment.

•Makes up 90% of the earth’s unfrozen freshwater supply.

•Aquifer: a body of rock in which large amounts of water can flow and be stored.

•Aquitard: a body of rock in which water cannot flow or be stored.

ROCK PROPERTIES THAT AFFECT GROUNDWATER•Porosity: percentage of open spaces in rock.

•Determined by :•Sorting: well-sorted- equal sized = more porous•Poorly sorted-unequal sized = less porous

•Permeability: how easily water flows through open spaces.•For a rock to be permeable, open spaces must be connected.

•Think about the school…•All the doors open = Permeable•All the doors closed = Impermeable

ZONES OF GROUNDWATER•Zone of Saturation: the layer of ground where all the pores are filled with water.

•The upper surface of the zone of saturation is called the water table.

•Zone of Aeration: the area between the water table and the earth’s surface.

•Capillary fringe: the area just above the water table where water is drawn up into this area by “capillary action”