Water and carbon key definitions/notes Flashcards
(68 cards)
1
Q
equilibrium
A
- state of balance
- all inputs and outputs are equal
- processes operate to maintain the balance
- disturbances will affect balance
- e.g. human activity
2
Q
positive feedback loops
A
- amplify change
- one change leads to another
- becomes bigger and moves system away from balance
- e.g. global warming increases permafrost thawing which increases methane which leads to more warming
3
Q
negative feedback
A
- ‘checks’ and dampens change
- self-regulating to promote stability and maintain equilibrium
- e.g. rock suffers freeze-thaw weathering which causes debris to fall on to rocks which protect it from future weathering
4
Q
dynamic equilibrium
A
- nature is constantly changing so small changes are required to maintain balance
e.g. storm on coast increases sediment loss on a beach due to high energy waves. Sediment is deposited offshore. After storm, low energy waves bring sediment back to shore and begin to rebuild the beach profile.
5
Q
processes driving change in the water cycle
A
- flows/transfers
- global factors e.g. climate change
- local factors e.g. human activity
6
Q
precipitation
A
- transfer of stored water from the atmosphere to Earth’s surface
7
Q
interception
A
- precipitation that is temporarily caught and stored on its way to the surface by vegetation
8
Q
surface flow
A
- water flows over the lands surface
9
Q
infiltration
A
- water enters ground through smell pores and openings in the surface
10
Q
throughflow
A
- lateral movement of water through the upper soil
11
Q
percolation
A
- water flows down through soil layers and underlying rock
12
Q
groundwater flow
A
- water that has infiltrated and percolated into the bedrock and below the water table
13
Q
evapotranspiration
A
- combination of evaporation and plant transpiration
14
Q
condensation
A
- transfer of water from a gaseous state to a liquid state as cloud formation
15
Q
sublimation
A
- water changes from solid to gas without passing through liquid state or vice versa
16
Q
trunk + stem flow
A
- flow of water down stems of plants or trunks of trees
17
Q
zone of saturation
A
- height of the water table will vary according to the season
- permanent saturation is called the phreatic zone
18
Q
how does climate change drive change in the water cycle
A
- last ice age meant there was lots of ice cover
- increased magnitude of cryospheric stores
- lowered hydrosphere store
19
Q
how do clouds and precipitation drive change in the water cycle
A
- equator receives more sun leading to higher temps and evapotranspiration
- warm air condenses to form clouds in the inter-tropical convergence zone
- brings low pressure rain/monsoon conditions
20
Q
how do cryospheric processes drive change in the water cycle
A
- 2nd largest water store is ice
- melting adds water to hydrosphere stores
- ice shelves can be destabilised leading to further ice melt
- positive feedback loop
21
Q
transfers/flows driving change in the water cycle (local)
A
- throughflow
- stemflow
- infiltration
- groundwater flow (can fill spaces between soil particles and fractured rock beneath Earth’s surface
22
Q
inputs driving change in the water cycle (local)
A
- energy from the sun for evaporation
- precipitation
- vary throughout the year with intensities and frequency
23
Q
outputs driving change in the water cycle (local)
A
- move moisture out of locale
- evapotranspiration
- run–off into sea
- water percolates into deep underground stores where it is effectively ‘lost’ from the system
24
Q
how does farming practice impact stores
A
- ditches drain and increase water flow away from the land
- interception from vegetation (prevents as much as 40% from reaching surface)
- over-abstraction of groundwater for irrigation removes stores of water
25
how does deforestation reduce interception and infiltration
- interception reduces time taken for water to reach surface
- affects surface stores as natural depressions such as puddles and ponds are removed
- roots help to break up soil, increasing rate of infiltration and groundwater recharge
26
how does urbanisation affect the water cycle
- creates impermeable surfaces which reduces natural depression stores
- reduce infiltration
- surface runoff and river channel stores are increased which may lead to flooding
27
how does industrialisation affect the water cycle
- burning of fossil fuels generates CO2 in the atmosphere enhancing greenhouse effect and global warming
- affects precipitation rates therefore affecting magnitudes of the stores
- can produce acid rain, affecting vegetations and limiting infiltration rates, causing an increase in flooding
28
drainage basin definition
- area of land drained by a river and its tributaries
- can also be called a 'catchment'
29
drainage basin facts
- influenced by climate, vegetation, soil structure and land use
- spatial and geological differences
- e.g. Nile River Basin is over 12 countries
30
drainage basin features
- watershed (imaginary boundary)
- source (where it starts furthest from the mouth)
- confluence (two or more rivers meet)
- tributary (river flowing into a larger river)
- mouth (river enters sea/ocean/lake)
31
drainage density
- number of tributaries
- lots of tributaries have high drainage density
- few tributaries have low drainage density
32
water balance equation
precipitation = total runoff + evapotranspiration +/- changes in storage
33
soil water balance
- shown through water budget graph
- shows balance between precipitation and potential evapotranspiration of the soil as a store over a year
34
discharge
- volume of water passing over a point
- calculated by area x velocity
- influenced by precipitation levels and speed of water transfer
35
hydrographs
- annual vs storm
- measured in cumecs
36
storm hydrographs
- compare precipitation and river discharge
- lag time
- peak discharge and flow
- channel precipitation and overland flow
- rising limb
- recessional limb
- throughflow
- groundwater/base flow
37
3 ways in which water in a drainage basin is transferred
- directly into channel
- surface flow
- infiltration
38
natural impacts on the water cycle
- natural climate change
- extreme climatic events
- ecosystem changes (e.g. dominant vegetation or animals burrowing causing higher infiltration)
- seasonal changes (wet vs dry)
39
human impacts on the water cycle
- climate change
- water abstraction (stores are depleted, can allow seawater ingress if water table drops below seawater)
- land use change (increased impermeable surfaces)
- deforestation (less soil moisture + transpiration)
- farming practices (desertification, ploughing breaks up soil leading to infiltration)
40
how does photosynthesis relate to the carbon cycle
- plants remove CO2 from the atmosphere
- convert into 02 and glucose
41
how does respiration relate to the carbon cycle
- produces waste products of water and CO2
42
how does combustion relate to the carbon cycle
- fossil fuels and organic matter are burnt
- emit CO2
- wildfires
43
how does decomposition relate to the carbon cycle
- dead organisms are broken down by decomposers
- decomposers respire and release CO2
- some stored as carbon matter in soil
44
how does diffusion relate to the carbon cycle
- oceans absorb CO2 from atmosphere (30% increase in acidity since pre industrial times)
- causes coral bleaching
45
how does weathering and erosion relate to the carbon cycle
- carbonation weathering breaks down rocks
- releases CO2 into oceans
- marine organisms use carbon in water to build shells
46
how does burial and compaction relate to the carbon cycle
- shell organisms die and their shells become compacted over time to for limestone
- forms fossil fuel deposits from decaying marine organisms
47
how does carbon sequestration relate to the carbon cycle
- transfer of carbon from atmosphere to other stores
- photosynthesis (natural)
- carbon capture and storage (artificial)
48
carbon capture and storage advantages
- can be fitted to existing factories
- captures 90% carbon produced
- potential to capture 50% world's CO2 emissions
49
carbon capture and storage disadvantages
- high cost
- increases energy demand of power stations
- may not be space in existing power stations
50
natural changes in carbon cycle over time
- wildfires
- volcanic activity (can also reduce photosynthesis rates which can affect the water cycle)
- greenhouse effect
51
human changes in the carbon cycle over time
- fossil fuel use
- deforestation (slash + burn)
- farming (pastoral + ploughing)
- ENHANCED greenhouse effect
52
how does Milankovitch cycle disprove the fact that humans are the cause of global warming
- Vostok ice core data from Antartica shows that temperature change occurred before CO2 change
- it is possible that Earth's orbit causes the Earth to heat up
53
impact of carbon cycle on tropical rainforests
- high photosynthesis and respiration rates increase humidity, cloud cover and precipitation
- deforestation and wildfires decrease this
54
impact of carbon cycle on oceans
- warmer oceans produce more plankton growth and planktons produce chemicals that cause clouds to form
- warmer oceans store less CO2
55
positive feedback loop carbon cycle example
- wildfires release CO2 which contributes to global warming which causes more wildfires
56
negative feedback carbon loop example
- increased photosynthesis allows plants to grow, absorbing carbon, decreasing the warming effect
- same with phytoplankton
- phytoplankton also release chemicals that cause cloud formation, limiting radiation from the sun being absorbed by the oceans
57
largest carbon store
moorlands/peatlands
58
mitigation of climate change
- targets
- renewable energy resources
- carbon capture and sequestration
59
Paris climate agreement
- limit increase of below 2 degrees above pre-industrial temps
- supports developing countries
- global
60
EU climate agreement
- 20% reduction in GHG emissions
61
UK climate agreement
- reduce 90% GHG emissions from 1990 by 2050
62
local scale climate mitigation strategies
- improving home insulation
- recycling
- smart meters
- public transport/walking/cycling
63
how can changing industrial combustion help mitigate the effects of climate change
- target setting
- renewable resources of energy
- CCS
64
how can carbon capture and storage changes help mitigate the effects of climate change
- can catch 90% of emissions
- could cut global carbon emissions by 19%
- stored in places such as deep mines, deep oceans and saline aquifers
65
how can changing peatlands mitigate effects of climate change
- peatlands store CO2 (50% carbon)
66
how can grassland carbon storage be improved
- avoiding overgrazing by livestock
- adding manures rather than artificial fertilisers
- stock and crop rotations allows recovery
- irrigation and water management techniques
67
how can changing deforestation help to mitigate the effects of climate change
- protecting existing forests will help preserve carbon stores
- reforesting degraded lands
- carbon payments made to offset carbon emissions e.g. USA converted Brazils debt to conserving the rainforest
- selective management systems e.g. in Malaysia
68
how can changing photosynthesis levels help mitigate climate change
- increasing number of primary producers (e.g. phytoplankton) increases photosynthesis levels
- higher CO2 levels do increase plant growth (negative feedback loop)
- genetically engineered crops
- water is photosynthesis main limiting factor
- rising temperature will negatively affect crop production
