Hydrological cycle is the process that involves the continuous circulation of water in the Earth-atmosphere system. The hydrologic cycle is a conceptual model that describes the storage and movement of water between the biosphere, atmosphere, lithosphere, and the hydrosphere. Water on our planet can be stored in any one of the following major reservoirs: atmosphere, oceans, lakes, rivers, soils, glaciers, snowfields, and groundwater. Water moves from one reservoir to another by way of processes like evaporation, condensation, precipitation, deposition, runoff, infiltration, sublimation, transpiration, melting, and groundwater flow. The oceans supply most of the evaporated water found in the atmosphere (“The Water Cycle.”). Of this evaporated water, only 91% of it is returned to the ocean basins by way of precipitation. The remaining 9% is transported to areas over landmasses where climatological factors induce the formation of precipitation (Hubbart). The resulting imbalance between rates of evaporation and precipitation over land and ocean is corrected by runoff and groundwater flow to the oceans. Water is more or less constantly moving and changing from one state to another (solid, liquid, or vapor/gas) while interacting with the physical processes present in the atmosphere, lithosphere, and biosphere. These changes and movements of water are linked together in the hydrologic cycle. Components of the hydrologic cycle include water vapor and clouds in the atmosphere, but also include liquid surface waters (oceans, lakes and streams) on continents as well as groundwater. Other important components of the hydrologic cycle include glacial ice held on continents, and water contained in biomass. Plants and animals are about 70% water, by volume (“Hydrologic Cycle”). Water evaporates in enormous quantities from the oceans and then falls as precipitation either on land or ocean. That portion which falls on land evaporates, is transpired by plants,
Cited: “How the Hydrologic Cycle Works.” FWEE. 14 May 2005. The Foundation for Water and Energy Education. 23 Mar. 2008 <http://www.fwee.org/ Hlogic.html>. Hubbart, Jason. “Hydrologic Cycle.” The Encyclopedia of Earth. 31 May 2007. 23 Mar. 2008 <http://www.eoearth.org/article/HydrologicCycle>. “Hydrologic Cycle.” Earthscape. 26 Jan. 1998. 23 Mar. 2008 <http://www. Und.nodac. Edu/instruct/eng/fkarner/pages/cycle.htm>. “The Water Cycle: Ground Water Storage.” USGS: science for changing world. 02 Jul. 2007. United States Geological Survey/ U.S. Department of the Interior 23 Mar. 2008 <http://ga.water.usgs.gov/edu/watercyclegwstorage.html>.