Búsqueda alfabética
Search by Word

Search by Topic

Glossary of Terms >


Term Hydrologic cycle

The process of water circulation on Earth through which it is concentrated, purified and distributed. The successive phases of the hydrological cycle relate to different natural physical states of water: evaporation, condensation, precipitation, surface runoff, groundwater infiltration, accumulation in artificial bodies and evaporation once again.  

1)    Precipitation: The falling of solid or liquid water on Earth’s surface from clouds as the result of the condensation of steam. Also called rain.  
2)    Infiltration: The process by which water penetrates the ground from the surface. In the first stage it satisfies the need for moisture in the area close to the surface, then, after a certain level of moisture is achieved it becomes part of a water body below. Upon infiltrating the soil, the water becomes groundwater and slowly moves from high pressure and elevation areas to low pressure and elevation areas. It moves from the place of infiltration through an aquifer toward a discharge area, which can be the sea or ocean.
3)    Transpiration: The process by which a portion of water absorbed by plant roots is released in the form of vapor. About 10% of the precipitation that falls to Earth vaporizes through plant transpiration; the rest evaporates from the seas and oceans.
4)    Surface runoff: The process by which rainwater that does not infiltrate the soil reaches the surface directly and flows into rivers and lakes. This water is then transported to seas and oceans. It is known as surface runoff water.
5)    Evaporation: The process by which water is transferred from the Earth’s surface back to the atmosphere due to the influence of sunlight, which heats the water in oceans and lakes. In the atmosphere, the evaporated water forms clouds that eventually cause precipitation, returning the water once again to the Earth. Oceanic evaporation is the most important form of evaporation.
6)    Condensation: The process of the change of water from a gaseous to a liquid form so it becomes visible in the air. The accumulation of water in the air forms clouds.


Additional Information
LinkRepresentación esquemática del ciclo hidrológico
Topic  Protected areasResources coastal / marineBiodiversityEnvironmental education