Sub-topic 4.1 Introduction to Water Systems

Hydrological cycle

The water cycle - how water moves around the Earth's systems

Solar radiation

sun's energy

aquifers

a permeable rock containing water

groundwater

water held underground in the soil, permeable rocks or cracks in the rock under ground.

glaciers

A slowly moving mass or river of ice formed by the accumulation and compaction of snow on mountains or near the poles.

ice caps

ice covering a large surface, especially in polar regions

evapotranspiration

the combination of evaporation from the earth's surface and transpiration from plants

transpiration

the process by which water moves through a plant and evaporates from the stomata (pores) in the plants' leaves

sublimation

the transformation of ice directly to water vapour. (Sublimation is actually the process of solid - gas in any substance).

Evaporation

transformation of water liquid to water vapour

condensation

transformation of water vapour to water liquid

advection

the wind-blown movement of water (as clouds)

Precipitation

the release of water from clouds - this is a transfer process and not a transformation

melting

transformation of ice/snow to water

freezing

transformation of water liquid to ice

flooding

an overflow of water onto land that is normally dry

surface runoff

water that flows over the surface of land after melting or precipitation

infiltration

the process by which water enters the ground surface of the soil

percolation

the process of water filtering through the soil

stream flow

the flow of water in streams, rivers and other water channels

Current

the flow of water in a water body such as a lake, sea or ocean.

agriculture

The deliberate effort to modify a portion of Earth's surface through the cultivation of crops and the raising of livestock for sustenance or economic gain.

deforestation

The removal of trees faster than forests can replace themselves.

Urbanization

An increase in the percentage and in the number of people living in urban settlements.

Ocean Conveyor belt (thermohaline cycle)

The difference in water density drives the ocean conveyor belt, which distributes heat around the world, and thus affects climate.

ocean circulation systems

driven by differences in temperature and salinity that affect water density thus driving the ocean conveyor belt.

Temperature

A measure of how hot or cold something is.

Salinity

A measure of the amount of dissolved salts in a given amount of liquid