4.1 - Water Systems

Question 1

What are movements of water in the hydrosphere driven by?

Answer 1

Solar radiation and gravity

Question 2

The hydrological cycle

Answer 2

Question 3

Accumulation, snowmelt, meltwater, sublimation, deposition

Answer 3

Snow and ice accumulate, later melting back into liquid water or turning into vapor

Question 4

Surface runoff, channel runoff, reservoirs

Answer 4

Water flows above ground as runoff, forming streams, rivers and lakes

Question 5

Plant uptake, interception, transpiration

Answer 5

Plants take up water from the ground and later transpire it back into the air

Question 6

Infiltration, percolation, subdurface flow, aquifer, water table, seepage, well

Answer 6

Water is soaked into the ground, flows below it and seeps back out enriched in minerals

Question 7

Volcanic steam, geysers, subduction

Answer 7

Water penetrates the earth’s crust and comes back out as geysers or volcanic steam

Question 8

Evaporation

Answer 8

Heat from the sun causes the water to evaporate

Question 9

Condensation

Answer 9

Water vapour rises and codenses to form clouds and fog

Question 10

Advection (transfer)

Answer 10

Winds move clouds through the atmosphere

Question 11

Percipitation, deposition, desublimation

Answer 11

Water droplets fall from clouds as drizzle, rain, snow or ice

Question 12

Percolation (transfer)

Answer 12

The downward movement of water through the soil and underlying rock layers, eventually reaches aquifers or groundwater reservoirs

Question 13

Hydrosphere

Answer 13

All Earth’s water, such as oceans, rivers, lakes and atmospheric moisture

Question 14

Componnts and propotions of water on Earth

Answer 14

• saline 97.5%
• freshwater 2.5%
  
  • 69% in glaciers
  • 30% stored as groundwater
  • 1% in rivers, lakes and atmosphere

Question 15

What impacts do human activities have on the hydrological cycle? (2)

Answer 15

Alter the natural processes of surface run-off and infiltration

Question 16

Human activities that have significant impact on hydrological cycle (3)

Answer 16

• agriculture (specifically irrigation)
• deforestation
• urbanisation

Question 17

Irrigation

Answer 17

The process of artificially supplying water to crops

Question 18

What can increased irrigation lead to? (2)

Answer 18

• artificially high evapotranspiration rates (more water is supplied to plants that normal): increased atmospheric moisture levels - localised increase in percipitation
• increased surface run-off (water applied faster than soil can absorb): causes water to flow over soil surface, carry sediments, fertilisers and pesticides - water pollution, nutrient imbalances

Question 19

Deforestation

Answer 19

The clearing or removal of forests

Question 20

Why are forests crucial in the hydrological cycle?

Answer 20

• Act as natural sponges that absorb rainfall and facilitate infiltration
  
  • helps recharge groundwater and maintain stream flows

Question 21

What can increased deforestation lead to? (2)

Answer 21

• increased surface runoff (without canopy and vegetation to intercept and slow rainfall, more water reachers ground): too high water concentration in ground - increased erosion
• reduced evapotranspiration rate (trees removed, less transpiration and evaporation): reduced moisture released into atmosphere

Question 22

Urbanisation

Answer 22

The transformation of natural landscapes into urban areas with buildings, roads and infrastructure

Question 23

What can increased urbanisation lead to? (2)

Answer 23

• impermeable surfaces (concrete and asphalt replaces soil and vegetation): prevent infiltration and reduces groundwater recharge - higher surface runoff means likely floods
• drainage systems (redirection of excess water): accelerates surface run-off - overload natural water bodies and cause downstream flooding

Question 24

Urban heat island effect

Answer 24

Higher temperatures in urban areas than rural ones due to human activities, buildings and pavement absorbing and retaining heat

Question 25

Steady state

Answer 25

A condition where the inputs and outputs of a system are balanced - no net change in the system's state over time

Question 26

Flow diagrams

Answer 26

Visually represent the water inputs and outputs for water body

Question 27

Examples of water inputs

Answer 27

* percipitation: rain, snow - directly into body * surface run-off: flow over land into body * groundwater flow: water moving into water body from underground sources

Question 28

Example of water outputs

Answer 28

* evaporation * river outflow * groundwater flow

Question 29

Sustainable water harvesting

Answer 29

Taking water from a water body at a rate that does not exceed the rate of natural replenishment * if total outputs are greater than inputs, the water body will decrease in size