The operation and importance of the hydrological cycle

Question 1

Systems approach

Answer 1

systems approaches study hydrological phenomena by looking at the balance of inputs and outputs, and how water is moved between stores and flows

Question 2

Stores

Answer 2

reservoirs where water is held, such as the oceans

Question 3

Fluxes

Answer 3

the rate of flow between the stores

Question 4

Processes

Answer 4

the physical mechanisms that drive the fluxes of water between the stores

Question 5

Cryosphere

Answer 5

areas of the Earth where the water is frozen in snow or ice

Question 6

Blue water

Answer 6

water is stored in rivers, streams, lakes and groundwater in liquid form (the visible part of the hydrological cycle)

Question 7

Green water

Answer 7

water stored in the soil and vegetation (the invisible part of the hydrological cycle)

Question 8

Precipitation

Answer 8

the movement of water in any form from the atmosphere to the ground

Question 9

Evaporation

Answer 9

the change in state of water from a liquid to a gas

Question 10

Residence time

Answer 10

the average time it takes a water molecule will spend in a reservoir or store

Question 11

Fossil water

Answer 11

ancient, deep groundwater from former pluvial (wetter) periods

Question 12

Transpiration

Answer 12

the diffusion of water from vegetation into the atmosphere, involving a change from a gas to a liquid

Question 13

Groundwater flow

Answer 13

the slow transfer of percolated water underground through pervious or porous rocks

Question 14

Catchment

Answer 14

the area of land drained by a river and its tributaries

Question 15

Watershed

Answer 15

the highland which divides and separates waters flowing to different rivers

Question 16

Condensation

Answer 16

the change from a gas to a liquid, such as when water vapour changes into water droplets

Question 17

Dew point

Answer 17

the temperature at which dew forms; it is a measure of atmospheric moisture

Question 18

Convectional rainfall

Answer 18

often associated with intense thunderstorms, which occur widely in areas with ground heating such as the Tropics and continental interiors

Question 19

Cyclonic rainfall

Answer 19

a period of sustained, moderately intensive rain; it is associated with the passage of depressions

Question 20

Orographic rainfall

Answer 20

concentrated on the windward slopes and summits of mountains

Question 21

Interception loss

Answer 21

this is the water that is retained by plant surfaces and later evaporated or absorbed by the vegetation and transpired

Question 22

Throughfall

Answer 22

this is when the rainfall persists or is relatively intense, and the water drops from the leaves, twigs, needles, etc

Question 23

Stem flow

Answer 23

this is when water trickles along twigs and branches and then down the trunk