water (hydrologic) cycle

The continuous process of surface water (puddles, lakes, oceans) evaporation from the sun's heat to become water vapor (gas) in the atmosphere. Water condenses into clouds and then falls back to earth as rain or snow (precipitation). Some precipitation soaks into the ground (percolation) to replenish groundwater supplies in underground aquifers.

Last modifed Monday, December 18, 2006.