HydrionisGlobal Water Intelligence
Diagram

The water cycle

Water moves continuously between ocean, atmosphere, land and ground. Nothing is created or destroyed — the cycle redistributes a fixed global stock.

The water cycle

Water moves continuously between ocean, atmosphere, land and ground. Nothing is created or destroyed — the cycle redistributes a fixed global stock.

The water cycleA cycle diagram. Evaporation from the ocean and transpiration from vegetation lift water into the atmosphere, where it condenses into cloud and falls as precipitation. On land, precipitation either runs off into rivers, infiltrates into groundwater, or is intercepted and evaporated. Rivers and groundwater flow return water to the ocean, closing the loop.Land and subsurfaceOceanvapour risesvapourfallspercolationbaseflowdischargeCondensationcloud formationCondensation: Water vapour cools and condenses onto aerosol particles to form cloud droplets.Precipitationrain, snow, hailPrecipitation: The only input of fresh water to the land surface.Evaporationfrom oceanEvaporation: The ocean supplies roughly 86% of all evaporation on Earth.Transpirationfrom plantsTranspiration: Plants draw soil water up and release it as vapour through their leaves.Runoffto riversInfiltrationto soilGroundwaterslow flowGroundwater: Residence times range from months in shallow gravels to tens of thousands of years in deep aquifers.River dischargeOcean96.5% of all water
Evapotranspiration
Evaporation and transpiration together. Over land it returns roughly two thirds of precipitation to the atmosphere before it ever reaches a river.
Baseflow
The groundwater contribution to river flow. It is what keeps rivers running weeks after the last rain.
Residence time
Atmospheric water turns over in about nine days; deep groundwater can take tens of thousands of years.

The diagram shows pathways, not proportions. Ocean evaporation dwarfs every land flux shown, and the arrows are not drawn to scale.

Text description

A cycle diagram. Evaporation from the ocean and transpiration from vegetation lift water into the atmosphere, where it condenses into cloud and falls as precipitation. On land, precipitation either runs off into rivers, infiltrates into groundwater, or is intercepted and evaporated. Rivers and groundwater flow return water to the ocean, closing the loop.

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