ak 3.1-3.4

Fresh water

Water with a low concentration of dissolved salts, such as drinking water.

Groundwater

Water that is no longer visible because it has infiltrated into the ground and in rock.

Land ice

Masses of ice which are on land.

Ocean current

Movement by the wind of a large mass of seawater in a fixed direction.

Salt water

Water with a high concentration of dissolved salts, like seawater.

Surface water

Water that is visible, such as lakes, fens, rivers, and seas.

Aquifer

Layer that holds water underground.

Fossil water

Water under the ground that dates back from ancient times.

Infiltration

Water seeping into the ground.

Non-renewable water resources

Water that is not, or very slowly, replenished, meaning it may run out.

Renewable water resources

Water that is replenished at the same rate that it is being used.

Sustainable water management

Water management in which renewable water resources are used.

Useful precipitation

The difference between precipitation and evaporation, referring to the water that remains.

Water balance

The amount of water that goes into and out of an area.

Hurricane

A tropical storm with wind speeds over 200 km per hour.

Peak discharge

Time of the highest river channel level.

Soil subsidence

Sinking of the ground.

Economic water scarcity

Insufficient investment to distribute available water to the population.

Physical water shortage

Too little water in an area to meet the needs without disrupting nature.

Water stress

Problems arising from a shortage of clean drinking water.

Water war

Armed conflict over water between population groups within a country or between countries.