Post on 06-May-2015
The Water CycleReporter: Fatima Ellaine M. Sisracon
Water Cycle
Also known as the hydrologic cycle or H2O Cycle.
Describes the movement of water on, above and below the surface of the Earth.
Major Physical Processes Involved
Evaporation Condensation Precipitation Transpiration Sublimation Deposition Infiltration
Evaporation
The physical state of water is changed from liquid to gas.
Condensation
A process by which a water vapor changes its physical state from gas to liquid.
Precipitation
Precipitation is the process that occurs when any and all forms of water particles fall from the atmosphere and reach the ground.
Transpiration
Water inside of plants is transferred from the plant to the atmosphere as water vapor .
Sublimation
The state change directly from solid water (snow or ice) to water vapor.
Deposition
Changing of water vapor directly to ice.
Infiltration
The physical process involving movement of water through the boundary area where the atmosphere interfaces with the soil.
Other Processes Involved
Interception Percolation Snowmelt Advection Runoff Storage
Interception
The process of interrupting the movement of water in the chain of transportation procedures leading to streams.
Percolation
The movement of water though the soil, and it's layers, by gravity and capillary forces.
Snowmelt
The runoff produced by melting snow.
Advection
The movement of water vapor through the atmosphere.
Runoff
The flow of water from a drainage basin or watershed that appears in surface streams.
Storage
Water is stored in the atmosphere; water is stored on the surface of the earth, and water stored in the ground.
Residence Time
Groundwater can spend over 10,000 years beneath the Earth’s surface before leaving.
Old groundwater is called fossil water.
The residence time in the atmosphere is about 9 days before falling to the Earth as precipitation.
Antarctica and Greenland store ice for very long periods. Ice from Antarctica has been reliably dated to 800,000 years before present, though the average residence time is shorter.
Two Ways of Estimating R.T.
Conservation of Mass- considers the amount of
water.
Isotopic Techniques- dating groundwater.
Changes Over Time
Much more water is “in storage” compared to the amount of water involved in the cycle.
Human Activities that alter the Water Cycle
Agriculture Industry Alteration of the chemical composition of the
atmosphere Construction of dams Deforestation and Forestation Removal of groundwater from wells Water abstraction from rivers Urbanization
Effects on Climate
The water cycle is dependent on solar energy. Eighty-six (86) percent of the global evaporation occurs from oceans. They help lower the temperature by evaporative cooling.
Biogeochemical Cycling
Water cycle is a biogeochemical process. Chemicals may be included in water cycle whether wanted or unwanted.
History of Hydrologic Cycle Theory
Ancient theories and beliefs about the origin of water.
Floating Land Mass
Land mass floated on bodies of water.
e.g.
Biblical Books of Moses,Works of Homer
Precipitation and Percolation
Greek scholars speculated that much of the water in rivers can be attributed to rain.
e.g.Anaximander, Xenophanes of
Colophon, Chi Ni Tzu, Lu Shih Ch’un Ch’iu, Anaxagoras of Clazomenae, Diogenes of Apollonia, Plato, Aristotle
Precipitation Alone
Rainfall alone is sufficient for the maintenance of Rivers, as mentioned by Bernard Palissy and a study attributed to Pierre Perrault.
End of Discussion about Water CycleThank you for your participation.