Brainscape's Knowledge GenomeTM

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


See full index

IB Environmental Systems and Societies > Chapter 4 > Flashcards

Chapter 4 Flashcards

1
Q

Water budget

A

A quantitative estimate of the amounts of water in storages and flows of the water cycle

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

What drives the water cycle

A

Energy from solar radiation and the force of gravity

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

Water: renewable and non-renewable

A

Depending on where it is stored, can easily slide from being renewable to non-renewable if poorly managed

Renewable: atmospheres, rivers
Middle ground: groundwater aquifers
Non-renewable: oceans and icecaps

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

Aquifer

A

A layer of porous rock, sand or gravel underground that holds water. In aquifers, it takes longer than a human lifetime to replenish the water extracted

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

Water cycle - transfers

A

Stays in the same state: advection (wind-blown movement), flooding, surface run-off, infiltration and percolation (when water runs into and through soil or rocks), stream flow and current

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

Water cycle - transformations

A

Evapotranspiration (liquid to water vapour), condensation (water vapour to liquid), freezing (into solid snow and ice)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Water cycle - storages

A

Oceans, soil, groundwater (aquifers), lakes, rivers and streams, atmosphere, glaciers and ice caps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Human impact on water cycle

A

Withdrawals (domestic use, irrigation in agriculture/industry)

Discharges (adding pollutants to water, chemicals, fertilisers, sewage)

Changing speed at which water can flow/where it flows (building roads, channelling rivers, canalizing, dams, barrages and dykes, reservoirs)

Diverting rivers or sections of rivers (to avoid flood damage, to improve storage)

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

Canalizing

A

Straightening large sections of rivers in concrete channels to facilitate more rapid flow through sensitive areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Flash floods

A

Occur when rainfall or snowmelt cannot infiltrate the soil and runs off on the surface

Due to land being hard-baked in hot, dry areas, but due to the CITY-based surface (urbanization!!!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ocean currents

A

Movements of water both vertically and horizontally. They move in specific directions and are found on the surface and in deep water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ocean currents importance

A

Global distribution of energy

Without them, we could not understand the global atmospheric energy changes

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

Surface currents

A

Upper 400m of ocean, are moved by the wind

Earth’s rotation deflects them and increases their circular movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Deep water currents (thermohaline currents)

A

Make up 90% of ocean currents and cause the oceanic conveyor belt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Deep water currents key ideas

A

Due to differences in water density caused by salt and temperature

Warm water can hold less salt than cold water so is less dense and rises - cold water holds more, sinks

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

Upwellings

A

When warm water rises, cold has to come up from depth to replace it

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

Downdwellings

A

When cold water rises, it has to be replaced by warm water

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

Cold ocean currents

A

Runs from the poles to the equator (e.g. Humboldt Current and Benguela Current)

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

Warm ocean currents

A

Flow from the equator to the poles (e.g. Gulf Stream and Angola Current)

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

Water and its effect on temperature

A

Water has a higher specific heat capacity than land
Water masses heat up and cool down more slowly than landmasses
Land CLOSE to seas and oceans has a mild climate with moderate winters and cool summers

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

How ocean currents affect local climate

A

Gulf Stream moderates the climate of Northwestern Europe, which otherwise would have a sub-arctic climate

(Cold) Benguela Current moderates the climate of the Namibian desert

Humboldt Current impacts the climate in Peru

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

El Niño Southern Oscillation (ENSO)

A

A phenomenon in the Pacific Ocean - pressure differences across the ocean is reversed (called the Southern Oscillation)

These pressure differences alter both the directions of the wind and the warm surface current

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

El Niño Southern Oscillation (ENSO) effects

A

Local effects - collapse of anchovy fish stocks, massive death of sea birds and storms and flooding in the coastal plain of Peru

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Humans use fresh water for…

A

Domestic purposes (drinking, washing, cleaning), agriculture (irrigation, for animals to drink), industry (manufacturing, mining), hydroelectric power generation, transportation (ships), marking the boundaries between nation states (rivers and lakes)

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

Water scarcity

A

A measure of how much water there is and how we use it

26
Q

Major rivers

A

Danube River - runs through 19 countries and is shared by 81 million people

Who owns the water? another Tragedy of the Commons -> many disputes over who owns it, especially since it becomes increasingly needed and scarce

27
Q

Sources of freshwater

A

Surface freshwater (rivers, streams, reservoirs and lakes) and underground aquifers

28
Q

Aquifer

A

A layer of porous rock (holds water) sandwiched between two layers of impermeable rock (does not let water through)

29
Q

Aquifers key ideas

A

water flow in aquifers is extremely slow -> aquifers often used unsustainably

many are also ‘fossil aquifers’, meaning that the recharge source is no longer exposed at the surface and they are never refilled -> these can NEVER be used sustainably

30
Q

Problems related to freshwater use

A

Climate change disrupts rainfall patterns, causing further inequality of supplies

Low water levels in rivers and streams (e.g. Colorado River, now is a tiny stream)

Slow water flow in the lower courses of rivers results in sedimentation, which makes the already shallow river even shallower

Underground aquifers are being exhausted, aquifer cannot be used anymore -> strongly affects agriculture

31
Q

Problems related to freshwater use (part 2)

A

Pumping rates from aquifers are too fast -> causes exhaustion making the well unusable

Freshwater becomes contaminated and unusable

Fertilisers and pesticides used in agriculture often pollute water streams and rivers

Industries release pollutants into surface water bodies

Industries and electricity plants release warm water into rivers

32
Q

Irrigation

A

Often results in soil degradation, especially in dry areas

33
Q

Salinisation

A

Water used in irrigation evaporates before it is absorbed by the crops. Dissolved minerals remain in the top layer of soil, making it too saline (salty) for further agriculture

34
Q

Effects of warm water in rivers

A

Holds less dissolved oxygen than cold water, so aquatic organisms that take oxygen from water (fish) are negatively affected

Changes the species composition in the water

35
Q

Solutions to problems related to freshwater use

A

increase freshwater supplies by reservoirs, redistribution, desalinisation plants, rainwater harvesting systems (large and small scale), artificially recharging aquifers

Reduce domestic use of freshwater by using more water-efficient showers, dishwashers, and toilets

Wash cars in car washes with a closed water system

Grey-water recycling - water from showers, baths etc that can be reused for garden irrigation, flushing, etc

Selecting drought resistant crops can reduce the need for irrigation

36
Q

Solutions to problems related to freshwater use (part 2)

A

Reduce the amount of pesticide and fertiliser used, prevent over-spray directly into a stream

Replace chemical fertilisers with organic ones (release of nutrients is slower and more likely to be absorbed)

Use highly selective pesticides instead of generic pesticide

Industries can remove pollutants from their wastewater with water treatment plants

Regulate maximum temperatures of released cooling water (don’t release warm water)

37
Q

Grey water

A

Very lightly used water that can be reused (to irrigate gardens, clean cars, flush WCs, etc)

38
Q

case study: Israel’s water shortage

A

greatest water drought in the past decade, caused by population growth and an improvement in quality of life (greater desire to water lawns and gardens)

will launch a conservation campaign, targeting mostly household use - has already reduced by more than 50% the drinking water supplied to farmers, increasing their need for recycled water

has two desalinisation plants that supply about 1.3 of water needed

39
Q

case study: China’s Three Gorges dam

A

this hydroelectric dam on the Yangtze river was one of the largest engineering projects in the world (estimated cost US$30 billion)

provides 9% of all China’s output, savings in CO2 emissions are huge, also stops river from flooding

criticisms: environmental degradation, refugees, destroy archaeological sites, threaten wild species, silt up, pollution from building the dam

risk of energy security - if it is destroyed, all of this power generation is lost ( too dependant?)

40
Q

Marine ecosystems

A

Oceans, mangroves, estuaries, lagoons, coral reefs, deep ocean floor - are usually very biodiverse and so have high stability and resilience

41
Q

Continental shelf

A

The extension of continents under the seas and oceans

42
Q

Importance of continental shelf

A

Has 50% of oceanic productivity but 15% of its area

Upwellings bring nutrient-rich water up to the continental shelf

Light reaches the shallow seas (producers can photosynthesise)

Countries can claim it as theirs to harvest and exploit

43
Q

UN Convention on the Laws of the Sea (UNCLOS)

A

1982 - designated continental shelves as belonging to the country from which they extend

44
Q

Phytoplankton

A

Single-celled organisms that can photosynthesise and are the most important producer in the oceans, producing 99% of primary productivity

45
Q

Zooplankton

A

Single-celled animals that eat phytoplankton and their waste

46
Q

Marine organisms can be classified as…

A

Benthic - living on or in the sea bed

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

47
Q

Fishery

A

When fish are harvested in some way. It includes capture of wild fish (also called capture fishing) and aquaculture or fish farming

48
Q

Aquaculture

A

The farming of aquatic organisms in both coastal and inland areas involving interventions in the rearing process to enhance production

49
Q

Why is fish farming increasing?

A

Diets changing - more fish instead of meat with saturated fat

50
Q

Ways in which fish farming is sustainable

A

Fishmeal uses more trimmings and scraps which would have been wasted in the past

Livestock and poultry processing wasted is also substituted for fishmeal

US Department of Agriculture has proven that 8 species of carnivorous fish can get enough nutrients from alternative sources without eating other fish

51
Q

Fish farms impacts

A

Loss of habitats

Pollution (with feed, antifouling agents, 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

52
Q

Fish stocks are shrinking because

A

Industrialised nations subsidise their modern fleets by an estimates US$50 billion a year

Demand outstrips supply

53
Q

Sustainable yield (SY)

A

The increase in natural capital (e.g. natural income that can be exploited each year without depleting the original stock or its potential for replenishment)


54
Q

Sustainable yield of an aquifer

A

The amount that can be taken each year without permanently decreasing the amount of water stored

55
Q

Maximum sustainable yield

A

Highest amount that can be taken without permanently depleting the stock

56
Q

Carrying capacity for each species depends on

A

Its reproductive strategy, its longevity, the indigenous resources of the habitat/ecosystem

57
Q

Sustainable yield formula

A

(Total biomass at time t + 1 / energy) - (total biomass at time t / energy)

or

Annual growth and recruitment - annual death and emigration

58
Q

Why harvesting the MSY leads to population decline and loss of resource base

A

Population dynamics of the target species are normally predicted (modelled) rather than the species numbers being measured (counted)

Often impossible to be precise about the size of a population

Estimates are made on previous experience

Model does not allow for monitoring of the dynamic nature of the harvest in terms of age and sex ratio

Disease may strike the population

59
Q

If you extract/harvest at the MSY, you will…

A

Deplete a population in poor recruitment years

60
Q

Optimal sustainable yield (OSY)

A

Requires less effort than MSY and maximises the difference between total revenue and total cost

Has a much greater safety margin than MSY, still may have an impact on population size if there are other environmental pressures within a system

IB Environmental Systems and Societies (4 decks)

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