The Water Cycle is also known as the Hydrological cycle. The world’s water is recycled over and over again through the continuous movement of water between the atmosphere, the land and the sea.
Water vapor stored in the atmosphere falls as precipitation on the oceans and the land. Most of it falls as rain, but some as snow, sleet and hail.
On land a variety of processes see the transfer and storage of water. Precipitation on land in the form of snow can be stored as glacial ice. Water that falls on land becomes surface runoff.
Some run-off from rain and melting snow finds its way to rivers and streams, which eventually make its way to the sea. Some also gets stored as freshwater in lakes. But on its journey some runoff may percolate porous rocks such as limestone or infiltrate the soil and be stored as groundwater. Subsurface water may slowly make its way back to the surface through a spring.
Precipitation on land can also get intercepted and stored by vegetation. Plants in turn release water vapor back into the air through the process of transpiration, which accounts for 10% of water being returned to the atmosphere.
Approximately 90% of water vapor is returned to the atmosphere through the process of evaporation. This is where solar radiation transforms water from a liquid to a gas. We call the combined evaporation and transpiration evapotranspiration.
As the water vapor rises in the atmosphere, it cools and the process of condensation occurs. This is the process by which water vapor in the air is changed into liquid water and results in the formation of clouds.
As the water vapor rises in the atmosphere, it cools and the process of condensation occurs. This is the process by which water vapor in the air is changed into liquid water and results in the formation of clouds.
