Water Cycle Diagram — free printable diagram

The stages of the water cycle

The water cycle, or hydrological cycle, is the continuous movement of water between the oceans, the air and the land. It is drawn as a loop because it has no beginning and no end, and it is driven by just two things: energy from the sun, which lifts water into the air, and gravity, which brings it back down. The stages below are the ones normally labelled.

Evaporation

The sun heats liquid water, turning it into water vapour

Transpiration

Water vapour released into the air by plants

Condensation

Vapour cools and turns back into droplets, forming cloud

Precipitation

Rain, snow, sleet or hail falling from cloud

Infiltration

Water soaking down into soil and rock

Surface runoff

Water flowing over the land into rivers

Storage

Oceans, lakes, rivers, ice and groundwater

• The sun is the engine and gravity is the return path. Naming both is usually worth a mark, and it explains why the cycle never stops.
• Condensation happens because air cools as it rises. That is why clouds form high up and why hills and mountains force rain out of moving air.
• Precipitation is the collective word for everything that falls — rain, snow, sleet and hail — so it is the safer term to use when labelling.
• Evaporation from surfaces and transpiration from plants are often combined under one term, evapotranspiration, because together they are what returns water to the air from the land.
• Water that infiltrates takes the slow route. It becomes groundwater and may not reach a river or the sea for years, while surface runoff gets there in hours — a useful contrast when studying flooding.
• The total amount of water on Earth does not change. The cycle moves it between stores rather than creating or destroying it, so the water in a glass today has been round the loop countless times.