ELSS SG1

Question 1

What are three reasons water is important for people?

Answer 1

Economic activity e.g. farming, Chemical reactions in the body and the circulation of oxygen and nutrients, Growth and reproduction

Question 2

What are three reasons water is important for flora?

Answer 2

Photosynthesis (to make glucose and starches to grow), Transport nutrients from the soil, Metabolic function

Question 3

What are three reasons water is important for fauna?

Answer 3

Chemical reactions in the body and the circulation of oxygen and nutrients, Cooling systems (evaporate cooling), Respiration

Question 4

What are three reasons water is important for climate?

Answer 4

Clouds reflect 1/5 of incoming solar radiation and lower surface temperatures, Water vapour absorbs long-wave radiation helping maintain average global temperatures, Precipitation

Question 5

Is the global water system a closed or open system?

Answer 5

Closed - transfers energy but not matter between the sun and earth

Question 6

Define Stores or Stocks

Answer 6

The total amount of material of interest held within a part of the system

Question 7

What are stocks expressed in?

Answer 7

Units of mass

Question 8

What are stores measured in?

Answer 8

Thousands of cubic kilometres

Question 9

What are the five global stores of water?

Answer 9

Lithosphere, Biosphere, Hydrosphere, Cryosphere, Atmosphere

Question 10

Define Lithosphere

Answer 10

The rigid outer part of the earth, consisting of the crust and upper mantle. It is divided into tectonic plates

Question 11

Define Biosphere

Answer 11

The space at the Earth’s surface and within the atmosphere occupied by living organisms

Question 12

Define Hydrosphere

Answer 12

All the waters on the Earth’s surface e.g. lakes and seas

Question 13

Define Cryosphere

Answer 13

The frozen part of the Earth’s surface e.g. ice caps, permafrost, glaciers

Question 14

Define Atmosphere

Answer 14

The envelope of gases surrounding the planet

Question 15

What % of water is stores on land (e.g. in ice, groundwater, soils, biosphere etc.)?

Answer 15

3%

Question 16

What % of water is stored in the atmosphere?

Answer 16

0.1%

Question 17

What % of water is stored in oceans?

Answer 17

97%

Question 18

What % of water is stored in polar ice and glaciers?

Answer 18

2%

Question 19

How long is water stored in oceans?

Answer 19

3,600 years

Question 20

How long is water stored in ice?

Answer 20

15,000 years

Question 21

How long is water stored in soil?

Answer 21

2-50 weeks

Question 22

What % of freshwater is stored in rocks below the ground surface as underground reservoirs called aquifers?

Answer 22

20%

Question 23

Where is most water vapour distributed?

Answer 23

Around the equator (between 15 degrees N and S) there is 55-770mm of water vapour

Question 24

Why is there more water vapour at the equator?

Answer 24

Rays are more concentrated around the equator due to curvature so the climate is warmer = more water evaporates so the air has more water vapour (is more humid)

Question 25

Define Drainage Basin

Answer 25

The area of land drained by a river

Question 26

Define Confluence

Answer 26

Where two rivers meet

Question 27

Define Tributary

Answer 27

Small river flowing into a larger river

Question 28

Define River Source

Answer 28

Where the river starts

Question 29

Define Watershed

Answer 29

Boundary between two drainage basins

Question 30

Why is a river drainage basin an open system?

Answer 30

Water enters (precipitation) and leaves (evaporation/flows to sea) the drainage basin and won't return

Question 31

Define Precipitation

Answer 31

Any form of moisture falling from the sky e.g. rain, snow, sleet, fog

Question 32

When does precipitation occur?

Answer 32

When water vapour cools to its dew point and condenses into water droplets. Precipitation only occurs when the droplets coalesce into larger ones. When they get large and heavy enough to overcome the uplift of the air, the droplets leave the cloud as precipitation

Question 33

Define Flows

Answer 33

Physical mechanisms that drive the flux of material between stores

Question 34

What is flows measured in?

Answer 34

Thousands of cubic kilometres/year

Question 35

Define Flux

Answer 35

A measurement of the rate of flow of material between stores

Question 36

Define Channel Precipitation

Answer 36

10% of precipitation falls directly into the river channel, before flowing out to the ocean

Question 37

Define Interception

Answer 37

Precipitation is stopped from reaching the ground by vegetation

Question 38

Define Stemflow

Answer 38

Water runs along branches and down the trunk of a tree

Question 39

Define Throughfall

Answer 39

Water drips off leaves to the ground

Question 40

Define Interception Loss

Answer 40

Water that is intercepted by plant surfaces and is later evaporated or absorbed by the plant. It never reaches the ground

Question 41

What are four factors affecting interception loss?

Answer 41

Interception storage capacity, Wind Speed, Vegetation type, Tree species

Question 42

How does interception storage capacity affect interception loss?

Answer 42

Before the onset of rain, the plant surfaces are dry so increasing the interception storage capacity. In prolonged rain interception storage capacity is reduced due to more stemflow and throughfall which could reduce the overall amount of interception loss which can happen

Question 43

How does wind speed affect interception loss?

Answer 43

Turbulence increases with wind speed, causing more throughfall and therefore reducing interception loss

Question 44

How does vegetation type affect interception loss?

Answer 44

Trees have the highest interception storage capacity due to their large surface area so interception losses will be higher compared to grasses and crops

Question 45

Hoe does tree species affect interception loss?

Answer 45

Interception losses are greater for coniferous trees (evergreens e.g. conifers) than broadleaved deciduous trees. This is because coniferous trees all year round and water adheres to the spaces between the needles

Question 46

Define Infiltration

Answer 46

The downward movement of water into the soil

Question 47

Define Percolation

Answer 47

Movement of soil water into underlying permeable rock

Question 48

What is the fastest flow of water?

Answer 48

Overland flow

Question 49

What is the slowest flow of water?

Answer 49

Groundwater flow

Question 50

What five factors affect infiltration?

Answer 50

High infiltration capacity, Saturation of soils, Arable land in winter, Coniferous trees, Rock type

Question 51

Define Discharge

Answer 51

The volume of water passing a given point in a given time

Question 52

What is discharge measured in?

Answer 52

Cubic meters per second (CUMECS)

Question 53

What two ways does water leave the drainage basin and enter the atmosphere?

Answer 53

Evaporation and Transpiration

Question 54

Define Evaporation

Answer 54

Water changes state from a liquid to water vapour due to heat

Question 55

Define Transpiration

Answer 55

Loss of water from vegetation stomata via evaporation

Question 56

What four factors affect transpiration?

Answer 56

Temperature, Wind speed, Water availability to plants, Seasons

Question 57

Define Water Balance

Answer 57

The balance between the inputs and outputs of a drainage basin

Question 58

Precipitation (P) =

Answer 58

Evaporation (E) + Streamflow (Q) +/- Storage

Question 59

Define Water Surplus

Answer 59

Precipitation is greater than evapotranspiration and streamflow, creating saturated soil

Question 60

Define Water Deficit

Answer 60

Precipitation is less than evapotranspiration and streamflow, creating dry soil