4.2

Question 1

saline water

Answer 1

salt water - this is the majority of Earth’s water

Question 2

desalination for water

Answer 2

removing salt from saline water to create potable (drinking) water
requires a lot of energy - extra salty water is often released back into the ocean damaging sea-bottom ecosystems (the salt water sinks)

Question 3

water crisis

Answer 3

the UN’s term to describe the situation we are in today where up to 40% of humans alive do not have access to sufficient clean water

domestic water use

Question 4

Domestic water use

Answer 4

water used for drinking, washing and cleaning at home

Question 5

agricultural water use

Answer 5

water used for irrigation (water for crops) and for animals to drink

Question 6

industrial water use

Answer 6

water used for processes such as machine cooling, manufacturing and mining

Question 7

20 litres to 40 litres?

Answer 7

the WHO (World Health Organisation) and Agenda 21 state that every human should have/needs access to this much water per day (on average)
much of the world has far less - other considerably more

Question 8

water scarcity

Answer 8

how much water we have and how we use it
there may be enough water in an area, but then it is diverted for non-domestic use

Question 9

aquifer

Answer 9

a layer of porous rock sandwiched between two layers of impermeable rock
refills where the porous rock meets the surface as water infiltrates
(flow can be as little as 1-10m per centrury - therefore refilling is extremely slow)

Question 10

sources of freshwater

Answer 10

surface freshwater - rivers, streams, reservoirs and lakes

Question 11

aquitard

Answer 11

the impermeable rock above (upper) and below (lower) the permeable rock forming an aquifer

Question 12

grey water

Answer 12

water used in the home for cleaning, brushing teeth, showering etc
often is not really dirty, but drains the same way as sewage

Question 13

black water

Answer 13

sewage - the water containing human waste - may carry disease-causing bacteria or parasites

Question 14

Tragedy of the commons

Answer 14

The tendency of a shared, limited resource (e.g. water) to become depleted because people act from self-interest for short-term gain

Question 15

sustainable water use

Answer 15

Use of water resources that allows full natural replacement and ecosystem recovery

Question 16

Fossil aquifer

Answer 16

Aquifers whose original recharge source is no longer at the surface so that they can’t be refilled. It is nonrenewable.

Question 17

Water degradation

Answer 17

The quality of the water is reduced

Question 18

Salinisation

Answer 18

As water evaporates in irrigation systems the water becomes too salty for agriculture

Question 19

Reservoirs

Answer 19

Artificial lakes that store water for human use

Question 20

Rainwater Harvesting Systems

Answer 20

Reduce demand for water by collecting rainwater from rooftops

Question 21

Drought resistant crops

Answer 21

Crops that need little water.

Question 22

Water Wars

Answer 22

Wars that break out due to competition between countries for shared water supplies e.g. Israel and Palestine 6 day war.