water + carbon cycles Flashcards
System
A system is an assemblage of interrelated parts that work together by some driving force
Inputs
When matter of energy is added to the system
Outputs
When matter or energy leaves the system
Stores
Where matter or energy builds up
Flows
When matter or energy moves from one store to another
Boundaries
The limits of the system
Open system
Where energy and matter can enter and leave e.g. a drainage basin
Closed system
Matter can’t leave or enter, it can only CYCLE between stores e.g. the carbon cycle
Feedback:
- Positive
- Negative
The way a system responds to a change in flows or inputs is called feedback.
Positive feedback: when the effects of an action are amplified by changes to the inputs/ outputs/ processes.
Negative feedback: occurs when the effects of an action are nullified by changes to the inputs/ outputs/ processes.
What are the 5 sub- systems on earth?
- Cryosphere (ice)- all parts of the earth cold enough to freeze.
- Atmosphere (air)- the layer of gas between the earth’s surface and space, held in place by gravity.
- Hydrosphere (water)- al of the water on earth in solid or liquid form. Can be saline or fresh.
- Lithosphere (geology)- the outermost part of the earth, includes the crust and the upper parts of the mantle.
- Biosphere (organic life)- part of the earth’s systems where all living organisms are found. This includes all living animals, fungi, bacteria, insects, etc.
Fusion
When a solid becomes a liquid and vice versa
Vapourisation
When a liquid becomes a gas and vice versa
Sublimation
When a solid becomes a gas, skipping out the liquid phase
Latent heat (required for sublimation)
Molecules become heated by the sun but it doesn’t provide them with enough energy to break the bonds.
Water molecules absorb energy from their surroundings to give them final energy that they need to break the bonds between them. This energy is known as latent heat.
As latent heat is taken from the surroundings it cools the surroundings down.
Factors slowing the rate of evaporation
- temperature
- surface area
- wind speed
- humidity
Condensation
When condensation occurs the opposite happens.
- Latent heat is released by water molecules as they slow down and join together.
- Therefore condensation can be thought of as a warming process, evaporation is the opposite (cooling).
Total global water statistics
Oceans- 96.5%
Other saline water- 0.9%
Freshwater- 2.5%
Of that freshwater:
glaciers and icecaps- 68.7%
groundwater- 30.1%
surface/ other freshwater- 1.2%
What are the 4 main stores of water in the hydrosphere?
- Oceanic water- the water contained in the earth’s oceans and seas but not including inland seas such as the Caspian Sea.
- Atmospheric water- water found in the atmosphere, mainly water vapour with clouds and water droplets.
- Terrestrial water- groundwater, lakes, soil, wetlands and rivers.
- Cryospheric water- water locked up on earth as ice.
Sub-stores of crysopheric water
- Ice shelf- large areas of ice on the sea
- Sea ice- found largely in parts of the Arctic Ocean. Sea levels do NOT rise when this melts
- Ice caps- covers just less then 50,000km^2
- Permafrost- land frozen for 2 or more consecutive years
- Ice sheet- covers more than 50,000km^2
Sub-stores of terrestrial water
- Surface water- ponds, rivers and lakes. These are important as they are huge transfers and stores. e.g. they take water from land to oceans.
- Wetlands- main ecosystems of the arctic.
- Groundwater
- Biological- stored in biomass (all living and formerly living material).
Oceanic water
- approx 1,350,000,000km^3 of oceanic water. Av depth is 3,700km. Only 5% is explored. It covers 72% of the earth’s surface.
Atmospheric water
Water held within the atmosphere. Approx. 12,400km^3.
- water exists within 3 states in the atmosphere.
- DOUBLES with a 10 degree temperature rise.
What is a drainage basin? What kind of system is a drainage basin viewed as?
An area of land surrounding a river, from which a river receives water and subsequently drains water. In other words, the area surrounding the river where the rain falling on the land flows into that river. Also called the river’s CATCHMENT.
Drainage basins are viewed as open hydrological systems.
What is the boundary of a drainage basin called?
Watershed
Precipitation
Rain, snow, hail and sleet.
Infiltration
When water enters permeable surfaces.
Interception
When water is caught by trees and plants
Stem flow
Water running down a plant stem or tree trunk
Overland flow
Water flows over the lands surface by a river or channel
Through flow
Water flowing horizontally in the ground when the soil is saturated
Transpiration
Water is transferred from the roots to the leaves and then evaporates from the leaves into the atmosphere
Evapotranspiration
Total amount of evaporation and transpiration
Ground water
Water stored underground in bedrock
Soil water
Water held between soil particles
Groundwater flow
Slow movement of ground water through permeable rock
Percolation
Deep transfer of water into permeable rock
Surface storage
Volume of water stored on the earth’s surface e.g. lakes, ponds and puddles
Groundwater storage
Storage of water underground in permeable rock
Inputs of a drainage basin
Precipitation commonly rain but also includes snow, hail, dew and frost
Stores in a drainage basin
- Vegetation storage
- Interception storage (although this is only temporary as water may evaporate quickly).
- Surface storage, including puddles, ponds and lakes.
-Soil storage - Groundwater storage- stored either in the soil or rocks. Porous rocks are called aquifers.
- Channel storage
Flows in a drainage basin
- infiltration as water is soaked up into the soil.
- Overland flow (runoff). Can flow in small channels or over the whole surface.
- Throughfall- water dripping from one leaf (or another plant) to another.
- Percolation- water seeping down the soil into the water table.
- Groundwater flow- water flowing slowly below the water table through permeable rock.
- Baseflow- groundwater flow that feeds into rivers through river banks and beds.
- Interflow- water flowing downhill through permeable rock above the water table.
- Channel flow- water flowing into the river of stream itself (also called river DISCHARGE).
Outputs of a drainage basin
- Evapouration- water turning into water vapour.
- Transpiration is evaporation from within the leaves of plants and trees.
-Evapotranspiration. Two types: PET (potential that could occur and be lost and ACTUAL evapotranspiration is what actually happens. - River discharge or river flow
Water balance
The water balance is the difference between the inputs and outputs (and the subsequent change in storage) in the drainage basin.
It is worked out using precipitation, runoff and evapotranspiration.
- If precipitation exceeds evapotrns then and runoff there will be a POSITIVE water balance.
- If evapotrns and runoff exceed exceed precipitation = NEGATIVE water balance.
Equation for the water balance
P= Q+E +/- change in storage
OR
+/- change in S = P-(Q+E)
P= precipitation
Q= total runoff
E= evapotranspiration
Soil moisture budget
the change in the amount of water stored in the soil throughout the year
Main factors affecting the soil moisture budget
- precipitation
- potential evaporation
The river regime
the variability in a rivers discharge throughout the course of the year in response to precipitation, temperature, evapotranspiration and drainage basin characteristics
river discharge
how much water is in a river at a precise moment in time
equation for measuring discharge
CSA (cross sectional area) X velocity (speed)
what are the two controls on the level of discharge in a river
- volume
- speed
discharge is higher if there is lots of water in the river because lots can flow past you per second in M^3
if water is flowing fast then lots will flow past you per second therefore higher speed = higher discharge
river discharge is only accurate when…
at the time measured and in the area measured
why is it useful to know river discharge?
- track movement in a drainage basin
- look at seasonal changes in evapotranspiration
- amount of water in the river will have an impact on the drainage basin
- allows for a wider understanding of a drainage basin
factors affecting the river regime
- land use changes
- climactic variation
- water abstraction
- influenced by landscape that it runs through
- excess rainfall
what physical factors can change the water cycle over time?
- precipitation rates
- vegetation cover
- higher temperature = more evaporation
- soil properties
- intensity of precipitation
- antedecent rainfall
- saturated ground
what human factors can change the water cycle over time?
- burning fossil fuels
- desertification
- deforestation
- water abstraction
- afforestation
- irrigation methods
- agriculture
- growth of urbanisation = more impermeable surfaces
river catchment
river catchment is the area of land where water collects when it rains, often bounded by hills
where does pickering beck start and end?
pickering beck is located in pickering. its source is located in the north York moors national park and it ends at a confluence with costa beck at Kirby misperton
pickering beck is a tributary of what river?
the derwent, found in North Yorkshire
how large is pickering beck’s catchment area?
68km^2 catchment area
characteristics of pickering beck
- usually between 3.9 inches and 1 metre high in its normal range
- highest ever level recorded June 2007 at 1.98m high
- there is a degree of flashiness to the beck. no notable patterns throughout the year
- large flat moorland either side receives large amounts of rainfall which flows quickly to the beck when the moorland is saturated.
what is the main aim of the management strategies at pickering beck?
to slow the flow by effectively managing the whole catchment. 33% of the catchment is publicly owned so this makes changes easier to instigate
causes of flooding in pickering beck
- inappropriate cultivation of arable soils
- overstocking of grassland
- excessive moorland and forestry drainage
- steep catchment area- particularly susceptible to summer fish floods
what management strategies have been implemented in pickering beck?
- 29 large woody debris (LWD) dams were installed which allow slower moving water through. these has previously been removed due to concerns of timber breaking during peak flows.
- 187 heather bale check dams were constructed at various smaller streams that feed into pickering beck to hold more water back
- eroding footpaths have been repaired which are used as a rapid transit route for floodwater
- a new floodplain was created to the north east of the town of pickering. storage allows for 120,000km^3 of floodwater to be retained when the beck is at peak flow
management strategies at pickering beck (part 2)
- planned to plant 50Ha of riparian woodland either side of the river for 30m. this woodland contains hydrophilic plants like willow which will survive wet roots. this slows the passage of water and traps sediment preventing channel accumulations.
- education to farmers and homeowners in what they can do to reduce flood risk e.g. moving livestock feeders so land doesn’t get churned up, encouraging rapid runoff.
- ‘no burn zones’ which are 10m wide either side of streams inn the moorland. heather is often burned off and this removes vegetation and accelerates water flow into the streams
name some carbon based molecules
- CO2: carbon dioxide
- CH4: methane, a gas found in the atmosphere, oceans, soils and sedimentary rocks.
- CaCO3: calcium carbonate, a solid compound found in oceans, rocks and skeletons
- hydrocarbons: solid, liquid or gas found in sedimentary rocks
- bio-molecules: produced in living things, e.g. fats, oils and DNA
what is the primary source of carbon
the earth’s interior. it is stored in the mantle when the earth was formed and escapes at constructive and destructive plate boundaries.
are carbon stores evenly distributed?
no
carbon stores
the main stores of carbon are the lithosphere, hydrosphere, cryosphere, biosphere and the atmosphere
carbon sink
a store that absorbs more than it releases
carbon source
a store that releases more carbon than it absorbs
carbon transfer
processes that transfer carbon between the stores. e.g. photosynthesis takes carbon out of the atmosphere as co2 and converts it into carbohydrates such as glucose.
GtC
a gigatonne of carbon dioxide
- it is used to measure the amount of carbon in carbon stores.
1GtC= 10^9 tonnes (1 billion tonnes)
transfer (flux) of carbon within the cycle is measured in gigatons per year (GtC/year)
anthropogenic CO2
carbon dioxide generated by human activity
greenhouse gas
any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere.
lithosphere
the crust and uppermost mantle; this constitutes the hard and rigid outer layer of the earth
weathering
the breakdown of rocks in situ (in the original location) by a combination of weather, plants and animals
biosphere
the total sum of all living matter
carbon sequestration
the capture of CO2 from the atmosphere or capturing anthropogenic CO2 from large scale stationary sources such as power plants before it is released into the atmosphere. once captured it can be pu into long term storage.
stores of carbon (detailed)
- marine and sedimentary rocks (largest by far): 100,000 mt
- ocean: 38,000 metric tonnes
- fossil fuels deposits: 4000 mt
- soil organic matter: 1500 mt
- atmosphere: 750 mt
- terrestrial plants: 560 mt
is the carbon cycle an open or closed system
closed- inputs + outputs of energy but the amount of carbon stays the same
-carbon moves from one store to another in a continuous cycle
what is the process called of carbon moving between stores
fluxes or transfers
fluxes
measurements of the rate of flow of material between the stores
total sum of carbon in the biosphere and what is it
3170GtC
the biosphere is the total sum of all living matter
distribution of carbon in the biosphere
- living vegetation (19%)
- plant litter
- soil humus (2500GtC)
- peat (250GtC)- undecayed organic matter
- animals
biosphere links to other stores
- peat must be formed in water-saturated conditions e.g. hydrosphere
- decomposition is important in returning carbon to the atmosphere from biosphere
- carbon from decomposition can also end up in the pedosphere (soils) and lithosphere (rocks)
lithosphere
the crust and uppermost mantle; this constitutes the hard and rigid outer layer of the earth
transfers of carbon from biosphere to other stores
- to atmosphere through respiration
- to atmosphere during photosynthesis
- combustion from biosphere to atmosphere and hydrosphere
main stores of carbon in the lithosphere
sedimentary rocks: 99.9%
fossil fuels: 0.004%
main stores of carbon in the cryosphere
- methyl clathrates are molecules of methane that have frozen into ice crystals. these form under high pressure and low temperatures deep in the earth or underwater
- organic frozen dead matter in permafrost. if permafrost melts then organic matter will decay releasing carbon. estimated 1400 gigatonnes of carbon frozen in permafrost.
what % is carbon dioxide in the atmosphere
0.04%
atmosphere
An atmosphere is made of the layers of gases surrounding a planet or other celestial body. Earth’s atmosphere is composed of about 78% nitrogen, 21% oxygen, and one percent other gases.
how much of the earth’s carbon does the cryosphere contain
- 0.01%
cryosphere
The cryosphere refers to the frozen components of the Earth’s system, including frozen rivers, lakes, snow, glaciers, ice caps, ice sheets, and permafrost
hydrosphere
A hydrosphere is the total amount of water on a planet. The hydrosphere includes water that is on the surface of the planet, underground, and in the air.
main store of carbon in the hydrosphere
oceans- 0.04% of carbon
how does the hydrosphere link to other stores?
organisms die in the sea, sink to bottom, decay releases co2 into the water, some materials sinks right to the bottom to form rich sediments, over millions of years chemicals turn sediment into rocks, interacting with the lithosphere as there are sedimentary rocks being added.
photosynthesis
photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar (glucose)
respiration
release of CO2 into the atmosphere, soils and oceans by animals as they exhale
decomposition
breakdown of animals and plant structures by bacteria and the release of carbon compounds into the atmosphere, soil and to the ocean floor. when oxygen is present it releases CO2, where it is not it releases CH4.
combustion
combustion is when natural fires release carbon compounds from vegetation into the atmosphere
burial and compaction
where organic matter is buried by sediment and becomes compacted. over millions of years these sediments can form hydrocarbons such as oil and coal.
carbon sequestration
capturing, removal and storage of CO2 from the earth’s atmosphere
ocean take up and loss - carbon pumps
carbon pump is a biologically meditated process which results in the sequestering of carbon in the deep ocean away from the atmosphere and land
ocean take up is the process by which oceans or plants and forests absorb carbon
ecological succession
Ecological succession is the process of change in the species that make up an ecological community over time.
weathering
describes the breaking down or dissolving of rocks and minerals on the surface of the earth
lithosere
When a new rock surface begins to be colonised and the habitat changes.
This may be from a volcanic ash fall or lava flow, where glacial retreat exposes a bare rock or till surface, or where a raised beach occurs as a result of tectonic uplift.
hydrosere
A wet fresh-water environment that gradually becomes drier as plants grow, die and decay in lakes or on a river bank, raising the level of the bed and trapping more sediment.
psammosere
A beach where sand dunes start to be stabilised as plants colonise the surface and change the nature of the dune ecosystem.
halosere
Occurs in salt-water – as in tidal mudflats or lagoons and saltmarshes.
explain what happens in the lithosere (local scale)
- rock exposed first time e.g. after glacier retreat, tectonic uplift, raised beach or volcanic eruption and becomes vulnerable due to weathering
- rock slowly broken down- carbon remains in the remaining water
- this through transfers within the water cycle moves to other stores
- litchens mosses first to colonise the rock
- they take their nutrients directly from the rock
- carbon exchange occurs through respiration and photosynthesis
- over time organic matter and leaf litter is added to the broken fragments of rock
- beginning of soil formation: as it develops it can support further vegetation
- environmental state of equilibrium is reached usually in response to climactic climax. in the UK climactic climax is deciduous woodlands.
which flows are found at a plant scale?
- respiration
- decomposition
- photosynthesis
which flows are found at an ecosystem scale?
- sequestration
- weathering
which flows are found at a continental scale?
- combustion
- ocean take up + loss
carbon budget
describes the amount of carbon that is stored and transferred within the carbon cycle
how is the carbon budget measured?
in petegrams
1 pt = 15x 1 gram
slow carbon cycle
The slow carbon cycle moves carbon between the atmosphere, lithosphere and oceans. occurs over 100-200 million years
fast carbon cycle
the fast carbon cycle operates through the movement of carbon through living things. this means it takes as much shorter time of years and decades.
example of a slow carbon cycle
- transfer of carbon into the oceans from the atmosphere and land surface
- deposition of carbon compounds on the ocean floor
- conversion of ocean sediments into rich rocks
examples of fast carbon cycles
- respiration
- digestion
- decomposition
- combustion
- photosynthesis
- ocean atmosphere exchange
enhanced greenhouse effect
the impact on the climate from the additional heat retained due to increased amounts of carbon dioxide and other ghgs that humans have released into the atmosphere since in the Industrial Revolution
geo- sequestration
technology capturing ghg emissions from power stations and pumping them into underground reservoirs
radiative forcing
the difference between incoming solar energy absorbed by earth and energy radiated back into space
soil organic carbon (SOC)
the organic constitutes in the soil; tissues from dead plants and animals, products produced as these decompose and the soil microbial biomass.
impacts on carbon budget
- increasing atmospheric co2
- radiative forcing
vegetation removal - volcanic eruptions
impacts of an unbalanced carbon budget on land
- causes soil to have less nutrients
- plant growth less
- increased season for growing plants due to warmer temperatures
impacts of an unbalanced carbon budget on oceans
- decrease of salinity of ocean in North Atlantic
- more freshwater being added to ocean
- melting sea ice
- sea levels rising
- coral reefs disrupted
