USGS Water Cycle Diagram

This detailed diagram from the U.S. Geological Survey illustrates how water circulates through various systems on Earth, including the atmosphere, oceans, glaciers, groundwater, and human infrastructure.

Pools (water storage locations) include:

• Oceans (mixed and deep water zones)
• Lakes (fresh and saline)
• Wetlands (fresh and brackish)
• Rivers
• Reservoirs
• Snowpack
• Ice sheets and glaciers
• Soil moisture
• Groundwater
• Atmospheric moisture over ocean and land

Fluxes (ways water moves between pools) include:

• Ocean evaporation
• Precipitation over land and ocean
• Runoff and streamflow (to oceans or closed basins)
• Snowmelt
• Groundwater recharge and discharge
• Evapotranspiration (from plants and soil)
• Ocean circulation
• Human water use (municipal, industrial, agricultural, and domestic)

Directional arrows in the image indicate how water flows between these components. Additional features include permafrost zones, urban runoff, grazing lands, and infrastructure for water withdrawal and use.