Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology - Environment > Water > Flashcards

Water Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Why is water becoming so scarce?

A
  • low, variable rainfall and high evaporation rate, and climate change
  • rapid population growth, increasing demand for supply
  • economic growth, increase water for industrial use
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why are dams so important?

A

They provide our water requirements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the purpose of large storage dams and inter-basin transfer schemes?

A

For irrigation, domestic and industrial water supply and hydroelectric power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is the Gariep dam important?

A

supply of water to drier parts of the vaal, fish and sundays river

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the negative impacts of dam?

A
  • Large cost

- creates a reservoir , which disrupts functioning of river ecosystem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do dams effect environment?

A
  • Natural habitats are flooded
  • organic material limited
  • Surface area of water is increased, rate of evaporation increased
  • large quantities of methane gas are produced.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does reduced natural flooding prevent?

A
  • flood water from bringing beneficial silt and nutrients to the crops
  • silt in rivers being flushed out and washed down to beaches
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are wetlands?

A

Areas where teresstrial and aquatic ecosystems come together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does a wetland consist of?

A
  • water table,near the surface of the ground. Land with shallow water.
  • areas be fresh water, forming vleis, bogs, pans, marshes, swamps and floodplains
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

why are wetlands so impotant?

A
  • purify the water, act as filters, removing pollutants and excess nutrients.
  • act as sponges, storing water. Help to recharge underground aquifers when water released to downstream areas.
  • prevent severe damage during floods. soak up excess water.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is causing wetland destruction?

A
  • by need for development by humans e.g crop prodution,pastures etc.
  • ‘reclaimed’ for industrial use, construction of airports, harbours, housing development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the Ramsar Convention?

A

an international agreement for the conservation and wise use of wetlands and their resources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what farming practices, results in the loss of protective vegetation and causes erosion?

A
  • Overgrazing
  • ploughing of marginal lands
  • cultivation without protecting lands from excessive run off.
  • allowing cattle to form paths, which soon form gullies.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the cause for the loss of availability of water?

A
  • excessive runoff
  • sedimentation in storage dams when valuable topsoil is washed away from sediment in streams. reduces capacity in storage dams
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are floods?

A

An overflow of a large amount of water over dry land.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How are floods caused?

A
  • heavy rains

- human interferences, impact on flooding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why are floods important?

A
  • provide water to irrigate crops

- replenish the soil in flood plains.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a drought?

A

An extended period of months or years where water availability falls below requirements for a reigon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happen in drought?

A

a region consistently receives below average rainfall

more severe by humans using more water than is available in particular.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are exotic plants?

A

specie growing in an area where they do not naturally grow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a plantation?

A

even-aged monoultures grown over a large area/

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What varieties does Plantations include?

A
  • Crops such as tea, coffee, cotton, tobacco, sugar cane.
  • Trees such as pine, eucalyptus and acacia are planted because of their:
  • Fast growth
  • tolerance of rich or degraded land
  • potential to produce large volumes of timber for industrial use
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do plantations affect water availability?

A

trees may reduce the amount of goundwater, lowering the water table because:

  • deep root systems, which absorbs more water that natural vegetation
  • Groundwater is drawn by the large number of leave transpiring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is groundwater?

A

Water found in pores, cavities and cracks in hard rocks and soil off aquifers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What factors cause plantations to deplete the water table?

A
  • What species make up the plantations
  • What type of vegetation is being replaced
  • The properties of the soil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is a water table?

A

topmost level of groundwater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is an aquifer?

A

A layer of earth and rock that holds water

28
Q

What is the main source of aquifers?

A

rainwater

29
Q

How do boreholes affect aquifers?

A
  • groundwater is reached through wells or pumped out through boreholes.
  • water is abstracted and water table is lowered.
  • Borehole yields then drop, wells begin to dry up, groundwater is depeleted.
  • supply of water is reduced.
30
Q

How is water wasted agriculturally?

A
  • overwatering of high pressure sprinkler systems used
  • Watering crops on sloping ground, result in run-off.
  • using old or broken pipelines and fittings, causing leaks
31
Q

How is water wasted through urban usage?

A

excess water for gardening, bathing.

  • appliances used unnecessarily
  • substandard cheap or damaged fittings in houses.
32
Q

How using water affects the quality?

A

Human activities result in effulent (waste water) which contains pollutants (harmful substances). If effluent finds its way into streams and rivers,it pollutes the water.

33
Q

How is water used for domestic purposes?

A

washing machines, dishwashers, baths, showers and toilets

34
Q

What is the use of water in agriculture?

A

use large quantities of:
herbicides( to kill weeds) - toxic
pesticides(kill pests) - toxic
chemical fertilisers - replenish nutrients

35
Q

What is leaching?

A

chemicals washed away when it rains.
contaminate ground -water, rivers, streams and lakes.
water contamination can effect humans,livestock and crops downstream

36
Q

What is eutrophication

A

enhanced growth of algae due to too many nutrients, mainly phosphates and nitrates.

37
Q

Where do nutrients of eutrophication come from?

A
  • run-off/inorganic fertiliser
  • natural run-off of nutrients from soil and weathering rocks
  • run-off of manure
  • waste fro abattoirs or feedlots
  • discharge of deterents
  • discharge of untreated sewage.
38
Q

How nutrients cause eutrophication?

A

excessive growth of aquatic weeds and blue-green algae. forms thick, green scum on surface of area. known as ‘agal bloom.’

39
Q

What are the effect of eutrophication?

A
  • bloom causes clear water to become cloudy so light cant penetrate, so plants below cant photosynthesise.so die, increase dead plant biomass
  • some cyanobacteria produce toxins called cyanotoxins, very poisonous, may affect humans.
  • increased vegetation may slow down water flow and movement of boats, decrease recreational value of water.
40
Q

What is the biochemical oxygen demand test?

A

refers to the amount of oxygen that bacteria in water will consume in breaking down the waste.the less oxygen there is, more bacteria, greater amount of pollutants.

41
Q

Where does waste from mining come from?

A

abandoned surface and underground mines, processing plants, water -disposal areas or ponds containing tailings

42
Q

What are tailings

A

Waste remaining after ore has been processsed

43
Q

What cause does mining have an increasein?

A

change inPH
salinity
metal content
sediment load

44
Q

What is acid mine drainage?

A
  • pyrite occurs in large quantities in different types of mineral deposits.
  • when mineral deposits are exposed to oxygen and water,pyrite weathers and oxidises to form sulphuric acid (very acidic water)
45
Q

What is pyrite?m

A

mineral composed of iron and sulphur

46
Q

What is the function of operating mines?

A

pump acid drainage into reserviors, treated with limestone to lower levels of acididty.

47
Q

What is neutralisation

A

The lowering of of acid levels

48
Q

How do heavy metals become toxic?

A

not metabolised by the body.

49
Q

What can heavy metal toxicity cause?

A
  • damaged or reduced neurological functioning/

- damage to blood compositon, lungs, kidneys , liver and other vital organs.

50
Q

What are long -term exposures?

A

slowly progressing physical, muscular an neurological degeneration
similar to Parkinson’s disease, Alzheimer’s disease, muscular dystrophy and multiple sclerosis.

51
Q

What is fracking?

A

an abbreviation for hydraulic fracturing.

exploits shale gas reserves locked in underground rock formations

52
Q

What is the process of fracking?

A

drill millions of water, sand and chemicals at high pressure into underground rock to fracture it, creating cracks for gas to escape

53
Q

What are the disadvantages of fracking?

A
  • uses huge volumes of water
  • affect quality of water in aquifers
  • lifetime of shale gas limited to 5-8 years.
54
Q

What are the advantages

A

needed source of energy, cleaner and cheaper than coal.

job creation and an incentive for foreign investment

55
Q

What is thermal pollution?

A

degradation of water quality by any process that change water temperature.

56
Q

What causes water temp to change?

A
  • Power plants use water as a coolant
  • Iron and steel industries release heated water.
  • urban run-off, warmer than water running of vegetated land
  • Removing trees and tall plants, removes source of shade, water heat up.
  • lack of aeration, cause water in lagoons to heat up.
57
Q

What are the consequences of thermal pollution?

A
  • increase in kinetic energy,increases the movement of oxygen molecules, lowering the amount of dissolved oxygen in the water. death of aquatic animals
  • redistribution of organisms in the community.
  • blue-green algae to bloom as warmer water encourages this.
58
Q

What is water purification?

A

The process of removing undesirable chemicals and pathogens from raw water in water purification plants.

59
Q

What is raw water?

A

Water that is drawn from a stream, lake, or dam that has not been treated.

60
Q

What methods are used to purify raw water?

A
  • Physical ( filtration and sedimentation)
  • chemical ( flocculation and chlorination)
  • electromagnetic radiation (UV radiation)
61
Q

What is water recycling?

A

It is cleaning waste water to remove solids and impurities so that it can be re-used or discharged back into the water.

62
Q

How does water recycling take place?

A
  • waste water treatment plants

- in a septic tank system

63
Q

Why recycle water

A
  • reduces the amount taken from natural resources.
  • Decreases the amount of untreated discharge sent back into water supply.
  • conserves water, sustainable amount can be provided to the public.
  • requires far less energy.
  • using grey water saves municipal water.
64
Q

What is grey water?

A

Waste water generated from domestic activities that can be recycled on site for watering the garden.

65
Q

After rain what happens to the water?

A

seep into the ground , recharging levels of ground water

form surface run -off,replenishes streams and rivers

Biology - Environment (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions