The Water Cycle On Earth

Question 1

What are the stores of water in the hydrosphere?

Answer 1

• atmospheric water = water vapour
• cryospheric water = permafrost, sea ice, glaciers
• oceanic water = largest store (72%)
• terrestrial water = soil water, groundwater, biological water, surface water

Question 2

Driving changes in the magnitudes of stores in the water cycle (FLOWS + TRANSFERS)

Answer 2

• cryospheric processes
• cloud formation and precipitation
• condensation
• evaporation

Question 3

Cryospheric processes (FLOW + TRANSFER)

Answer 3

• accumulation (input of ice and snow) and ablation (output of ice and snow) change the amount of water stores in ice
• dependent on temperature
• stores in ice sheets and glaciers

Question 4

Cloud formation and precipitation (FLOW + TRANSFER)

Answer 4

• clouds form when warm air rises, cools and condenses into water droplets = when they get to heavy there is precipitation
• precipitation is the main flow of water from the atmosphere to the ground
  CAUSES OF PRECIPITATION:
• other air masses
• topography
• convection

Question 5

Condensation (FLOW + TRANSFER)

Answer 5

• when water vapour changes state to become a liquid
• magnitude depends on the amount of after vapour in the atmosphere and temperature e.g. when water vapour condenses it can enter other subsystems such as forming dew on leaves = decreases the amount of water stores in the atmosphere

Question 6

Evaporation (FLOW + TRANSFER)

Answer 6

• when liquid changes into a gas = becomes water vapour ad gains energy
  RATE DEPENDS ON:
• solar energy
• availability of water
• humidity of the earth
• temperature of the earth

Question 7

What is the water cycle?

Answer 7

• a closed system
• no inputs or outputs of water

Question 8

What is latent heat?

Answer 8

• when water vapour rises as a result of convection (when the sun heats up the ground) latent heat is carried into and stored in the atmosphere
• takes up heat so atmosphere is cooled

Question 9

What are the physical factors affecting the water cycle?

Answer 9

• storms and precipitation
• seasonal changes and vegetation

Question 10

Physical factors - storms and precipitation

Answer 10

• intense storms generate more precipitation
• larger amounts of precipitation causes flows e.g runoff

Question 11

Physical factors - seasonal changes and vegetation

Answer 11

• the size of inputs can vary on the season
• winter = colder and more frozen water = reduces size of flows in the drainage basin
• plants have seasonal variations = less vegetation in winter
• less interception in the winter so more water flows

Question 12

What are the human factors affecting the water cycle?

Answer 12

• farming practices
• land use changes
• water abstraction

Question 13

Human factors - farming practices

Answer 13

• ploughing increases infiltration
• pastoral farming = compacted soil reduces infiltration = increases run off
• crops increase infiltration and interception = reduces run off and evapotranspiration increases

Question 14

Human factors - land use changes

Answer 14

• deforestation reduces interception and evapotranspiration
• construction of buildings reduces infiltration and evapotranspiration = increase run off and increases risk of flooding

Question 15

Human factors - water abstraction

Answer 15

• more water is taken from stores so reduces the amount in the surface (e.g. lakes, rivers, reservoirs)
• abstraction increases during dry seasons = stores are depleted further