Saturday, January 8, 2011

The Hydrological cycle

                The world’s water is forever going to round in circles not just I ocean currents, but between atmosphere and ocean by evaporation from lakes, rivers and seas, transport in clouds precipitation as rain or snow , seepage from ground water and lakes, and flow of rivers. This is the hydrological cycle. Ninety seven percent of the world’s water is contained in oceans and saline lakes; the remaining three percent is fresh water. Three quarters of fresh water is stored as ice and nearly one quarter is in underground aquifers. All rivers, lakes and clouds contain less than one percent of the world’s fresh water, or 0.03 percent of the total