The water cycle

1. Evaporation 2. Transpiration 3. Condensation 4. Precipitation 5. Runoff 6. Percolation 7. Groundwater 8. Fluvial transport


Évaporation : Heated by sun, the molecules in surface store enough energy to get free, they evaporate and mix with air to form unvisible water vapour.

Transpiration : Plant leaves liberate water vapour by transpiration. A growing plant looses every day de 5 to 10 times the quantity of water which it contains.

Condensation : During its rise in the atmosphere, water vapour cools down and condenses around little dust particles to water drops or solid ice particles. Clouds are made up by these particles.

Precipitation : Precipitation of rain, snow or hail comes from the clouds. Clouds circle around the atmosphere by the action of air streams. Rising above the mountains, they cool down and the droplets or ice particles get bigger so that they fall down in the form of rain, snow or hail.