The hydrologic cycle is the natural circulation of water near the surface of the Earth. Driving force is from the radiant energy received from the sun. The sun heats the sea surface causing evaporation, transfer of water from the liquid to the gaseous state, to form part of the atmosphere. Water vapor remains in the atmosphere for several days and through combination of circumstances, changes back to the liquid state through a process called condensation to form clouds.
Snow can become ice and remain stored on the mountains for long periods.
Rainfall falling on the land may be intercepted by vegetation and return through evaporation to the atmosphere. Rainfall reaching the ground partially infiltrates and partially forms surface runoff. Infiltrated water may percolate deep into the ground to reach the groundwater table or may be taken up by vegetation and return to the atmosphere through transpiration. Groundwater flow and surface runoff meet and recharge lakes and rivers. Evaporation takes place from all open water bodies.