Key Word Definitions

Question 1

What is an aquifer?

Answer 1

A permeable or porous rock which stores water.

Question 2

What is a channel flow?

Answer 2

The water flowing in a rivulet, stream or river contained within the banks.

Question 3

What is a closed system?

Answer 3

A sequence of linked processes with a transfer of energy but not matter between parts of the system.

Question 4

What is the cryosphere?

Answer 4

Describes the set of all locations on Earth where water is found in solid form, including areas of snow, sea ice, glaciers, permafrost, ice sheets and icebergs.

Question 5

What is a deficit?

Answer 5

Where a resource is less than the necessary amount.

Question 6

What is a drainage basin?

Answer 6

The area of land drained by a river and its tributaries. Drainage basins are separated by a ridge of high land called a watershed.

Question 7

What is economic water security?

Answer 7

Occurs when water resources are available but there is insufficient capital to access the water to meet demand.

Question 8

What is evapotranspiration?

Answer 8

Combined loss of water to the atmosphere via the processes of evaporation and transpiration.

Question 9

What is a flux?

Answer 9

The flow or flowing of a liquid.

Question 10

What is fossil water?

Answer 10

Water that has been contained and undisturbed for millennia. There is no significant recharge therefore it is a non-renewable source.

Question 11

What is the global water budget?

Answer 11

The amount of water transferred and stored in the Earth’s hydrological cycle each year.

Question 12

What is hard engineering?

Answer 12

Often hi-tech and high-cost engineering schemes such as dams or the Thames Barrier.

Question 13

What is hydrological drought?

Answer 13

Occurs when there is insufficient soil moisture to meet the needs of vegetation at a particular time.

Question 14

What is infiltration?

Answer 14

The movement of water vertically downwards through the spaces (pores) in the soil.

Question 15

What is interception?

Answer 15

The process by which raindrops are prevented from falling directly onto the ground by leaves, branches, twigs of vegetation.

Question 16

What is a monsoon?

Answer 16

A seasonal prevailing wind which causes wet and dry seasons in many sub-tropical areas.

Question 17

What is an open system?

Answer 17

A sequence of linked processes with inputs and outputs, including transfers of energy and matter to and from other systems.

Question 18

Definition of orographic?

Answer 18

Relating to mountains, orographic uplift is when the uplift of an air mass, because of an orographic obstruction, causes the cooling of the air mass. If enough cooling takes place, condensation can occur and form into orographic precipitation.

Question 19

What is percolation?

Answer 19

A process similar to infiltration but travelling through rock surfaces towards the water table.

Question 20

What is permafrost?

Answer 20

Zone of permanently frozen water found in high latitude soils and sediments.

Question 21

What is permeability?

Answer 21

A measure of the ability of soil, sediments and rock to transport water horizontally and vertically. It depends on the porosity of what the water is flowing through. Some rocks like granite have very poor permeability, while rocks like shale are actually quite pervious. As for soils, sand is the most pervious, while clay has the lowest permeability. Silt is usually somewhere in the middle.

Question 22

What is physical water scarcity?

Answer 22

Occurs when there is a physical lack of available freshwater resources to meet demand due to over-abstraction by agriculture, industry and domestic activity.

Question 23

What is porosity?

Answer 23

A surface that allows water to pass through it, such as sand.

Question 24

What is precipitation?

Answer 24

Any form of water falling from the sky

Question 25

What is relief?

Answer 25

The range of topographic elevation within a specific area.

Question 26

What is resilience?

Answer 26

Ability to recover from or adjust easily to an event or change.

Question 27

What is a river regime?

Answer 27

The pattern of river discharge over a year; usually there are seasonal variations.

Question 28

What is runoff?

Answer 28

Water (from rain, snowmelt or other sources) that flows over the land surface; can be due to soil saturation.

Question 29

What is saltwater encroachment?

Answer 29

Where saline water beings to find its way into freshwater aquifers, especially near coastal aquifers which run low, allowing salt water to seep back in and cause contamination.

Question 30

What is saturated overland flow?

Answer 30

Occurs when the soil becomes saturated, and any additional precipitation causes runoff.

Question 31

What is a storm hydrograph?

Answer 31

Shows change in a river’s discharge at a given point on a river over a short period of time (usually before, during and after a storm)

Question 32

What is a water budget?

Answer 32

The annual balance between inputs (precipitation) and outputs (evapotranspiration and channel flow) at a place.

Question 33

What is water security?

Answer 33

The capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water.

Question 34

What is water stress?

Answer 34

When the demand for water exceeds the available amount during a certain period.