Hydrologic cycle (water cycle)

Water cycle overview

Movement of water between sources and sinks

- State of water (solid/liquid/gas) as well as location are key in water cycle

- Energy from the sun drives the water cycle (changes states)

Ocean

largest water resevoir

Ice caps and groundwater

smaller but important sources of freshwater

Evaporation (aka vaporization)

Energy from the sun turns liquid water into gas

Transpiration

Loss of water vapor from leaves into the atmosphere

- Pores in leaf called stomata open, allowing water to evaporate from the leaf.

- Movement of water out of leaf creates low water potential in leaf, pulling water up from roots

Evotranspiration

amount of water that enters the atmosphere from evaporation+transpiration combined

Runoff

Precipitation (rain) flows over earth's surface into a body of water

- It recharges surface waters, but can also carry pollutants into water sources

Infiltration

Precipitation trickles through soil down into groundwater aquifers

Groundwater (aquifers) + surface waters (lakes/rivers)

important freshwater reservoirs for humans and animals

Precipitation

Precipitation recharges groundwater through infiltration, but only if ground is permeable (able to let water pass through)