4. notes and revision

Question 1

The hydrological cycle aka the water cycle

Answer 1

this is a system of waterflows and storages that may be disrupted by human activity

Question 2

transfers in the water cycle include

Answer 2

flooding

Question 3

transformations in the water cycle include

Answer 3

freezing
condensation
evapotranspiration because its both from trees and water bodies

Question 4

storages in the water cycle include

Answer 4

ocean
lakes
rivers

Question 5

Human impact on the water cycle

Answer 5

Water pollution
Intense irrigation
DEFFORESTATION
GWEICO

Question 6

Ocean currents

Answer 6

These are movements of water both vertically and horizontally.

Question 7

Surface currrents

Answer 7

These are moved by the wind

Question 8

deep currents

Answer 8

these are moved by the ocean belt

Question 9

draw the water cycle

Question 10

water scarcity

Answer 10

This is when there is insufficient water to meet the needs of a population

this is the reduction of water levels

Question 11

Water degredation

Answer 11

This is the reduction of water quality making it unsustainable for use

Question 12

Problems faced with fresh water

Answer 12

GWEIC
Global warming
Waterpollution
intense irrigation
Eutrophication
Climate change = less rain
Low water level in water bodies due to evapouration due to increasing global temperatures
Fertilizers polluting streams
Intensive irrigation; water evapourates even before reaching plants

Question 13

Solutions to fresh water problems

Answer 13

Increase reserviours
Rainwater harvesting
Plant drought resistant crops
reduce pesticide use
Education
Legislation
restoration

Question 14

continental shelf

Answer 14

The continental shelf is the extension of continents under the seas and oceans.

Question 15

Phytoplankton

Answer 15

Phytoplankton are single-celled organisms that can photosynthesize

Question 16

Benthic

Answer 16

Benthic – living on or in the sea bed

Question 17

Pelagic

Answer 17

Pelagic – living surrounded by water from above the sea bed to the surface.

Question 18

Aquaculture

Answer 18

aquaculture is the farming of aquatic organisms with interventions
in the rearing process.

Question 19

Impacts of fish farms

Answer 19

Impacts of fish farms include:
●➔ loss of habitats
●➔ pollution (with feed, antibiotics and other medicines added to the fish pens)
●➔ spread of diseases
●➔ escaped species including genetically modified organisms which may survive to interbreed with wild fish
●➔ escaped species may also outcompete native species and cause the population to crash. reducing biodiversity

Question 20

the tragedy of the commons

Answer 20

the tragedy of the commons is when the selfish actions of the individual to exploit common resources affect society as a whole.

Question 21

maximum sustainable yield (MSY)

Answer 21

A maximum sustainable yield (MSY) is the greatest amount of yield that can be exploited each year without depleting the original stock.

Question 22

Water pollution

Answer 22

This is the contamination of a waterbody by pollutants either directly or indirectly.

Question 23

Types of water pollution

Answer 23

Point source/ non-point source
organic eg human waste/ inorganic eg nitrates

Question 24

Effects of water pollution

Answer 24

BLEW
Water borne disease
Eutrophication (pollutingfertilizers with phosphates)
Bioaccumulation/ Biomagnification in food chain
Lossof aquatic life

Question 25

Measuring water pollution

Answer 25

1. Biochemical oxygen demand (BOD) is a measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity by microorganisms.
2. Indicator species are plants and animals that show something about the environment by their presence, absence, abundance or scarcity.
3. A biotic index indirectly measures pollution by assaying the impact on species within the community according to their tolerance, diversity and relative abundance.

Question 26

Biochemical oxygen demand (BOD)

Answer 26

1. Biochemical oxygen demand (BOD) is a measure of the amount of dissolved oxygen required for decomposers
2. increased demand is bad = eutrophication

Question 27

Indicator species

Answer 27

2. Indicator species are plants and animals that show something about the environment by their presence, absence, abundance or scarcity.

Question 28

biotic index

Answer 28

The biotic index provides a measure of water quality using indicator species

Question 29

Eutrophication (phosphate caused)

Answer 29

Eutrophication is when excess nutrients are added to an aquatic ecosystem.

Question 30

Impacts of eutrophication

Answer 30

Oxygen deficient water
death of fish and plants
increased cloudiness of water eg turbidity

Question 31

The process of eutrophication

Answer 31

. Fertilizers wash into the river or lake.
2. High levels of phosphate in particular allow algae to grow faster
(as phosphate is often limiting).
3. Algal blooms form (mats of algae) that block out light to plants beneath them, which die.
4. More algae mean more food for the zooplankton and small animals that feed on them. They are food to fish which multiply as there is more food so there are then fewer zooplankton to eat the algae.
5. Algae die and are decomposed by aerobic bacteria.
6. But there is not enough oxygen in the water so, soon, everything dies as food chains collapse.

Question 32

Strategies to reduce eutrophication

Answer 32

Ban use of phasphates
Educate farmers about better farming methods
Plant buffer zones to prevent wash away of fertilizer into water bodies from farms