The continuous circulation of water between oceans, the atmosphere and land. The sun is the energy source that raises water by evapotranspiration from the oceans and land into the atmosphere, while the forces of gravity influence the movement of both surface and subsurface water.
The hydrological cycle is the circulation of water within the earth's hydrosphere, involving changes in the physical state of water between liquid, solid, and gas phases and the exchange of water between atmosphere, land, surface and subsurface waters.
Why is the hydrological cycle important?
It is important to understand the interaction between different components of the hydrological system and water movement and storage.