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.