As it moves through the environment it picks up gasses and elements, flows to the sea and through the ground, in an endless process known as the hydrologic cycle . Studying the concept of the hydrologic cycle is perhaps the most useful way to understand how precious fresh water is, and how important the health of the oceans are to sustain life on the planet. The cycle may be viewed as a description of the ways in which water moves around the earth. It is important because it accounts for the circulation of water in all the different states. Planners may use the hydrologic cycle as a conceptual tool in order to anticipate problems and consequences which may arise from development.
Students typically study the hydrologic cycle in high school.
The distribution of water is the key to understanding the hydrologic cycle as well as the availability of water for human use or consumption. As seen in the schematic above, the hydrologic cycle is the continuous circulation of water from the ocean to the atmosphere to the earth and back to the ocean. This cycle is solar powered as the water from the ocean and the land surface evaporates to the atmosphere. Throughout the cycle, water may be temporarily stored in lakes, streams, the soil, as groundwater, etc. The amount of storage is calculated by using the hydrologic equation.