Topic 1 - Water and carbon cycles Flashcards
Define input in terms of a system
Give a drainage basin example
Material or energy moving into the system from the outside
Eg precipitation
Define output in terms of a system
Give a woodland carbon cycle example
Material or energy moving from the system to the outside
Eg dissolved Carbon in runoff
Define stores in terms of a system
Give a drainage basin example
Individual parts of a system
Eg trees, puddles and soil
Define transfers in terms of a system
Give a woodland carbon cycle example
relationships/links between the components
Eg burning of fuels and absorption of carbon
by trees
Define positive feedback
Cyclical series of events that amplify change, often promoting environmental instability
can lead to tipping points where change becomes unpredictable
Define negative feedback
cyclical sequence of events that promote stability and state of equilibrium in a system
Open/closed systems
Water + carbon cycles
On a global scale, both are closed systems as there are no loses/gains from space
On a local scale they are both open systems, water can enter and leave, there are flows like throughflow of water and photosynthesis which uses carbon
Define system
Consist of components, flows and transfers and the relationship between them
Cryosphere store of water
Water stored in frozen areas of the earth:
Glaciers
ice sheets
frozen parts of the ocean
Lithosphere store of water
Water stored on solid outer crust/mantel
Stored within rock structures in oceanic crust
Stored in rocks, minerals and clay as groundwater.
Hydrosphere store of water
Water stored on the surface of the planet oceans rivers lakes ponds
Atmosphere store of water
Water stored as gas surrounding planet
clouds
microscopic particles of water
Water store states
Saline/freshwater stores
- 5% is saline water, most of which is in the oceans.
- 5% is freshwater, most of which stored as ice/snow or as groundwater
Surface freshwater only makes up 1.7% of all freshwater.
Define aquifers
Reservoirs of freshwater stores deep under ground surface
Types of rock in aquifers
Porous rocks tend to transfer more water than store.
Clay soils tend to store more water than transfer.
Water table
Upper level of saturated rock.
Rises/falls in response to:
- Ground water flows
- Abstraction by people
- Recharge, flow of additional water into reservoir
Fossil aquifers + few locations where they are found
Aquifers formed thousands of years ago when current desert climates were once wed:
- Africa
- Middle East
- Australia
Transfers that affect magnitudes of water stores define: Overland flow infiltration throughflow percolation Groundwater flow
Overland flow: Transfer of water over land surface
Infiltration: Transfer of water from the ground to soil
Throughflow: Water flowing through soil to river channel
Percolation: Water soaking into rocks
Groundwater flow: slow transfer of water through rocks
3 stat based facts about historic climate change
- 1800 years ago 1/3 of earth was covered in ice (glacial period)
- Sea levels during this time dropped 100m compared to present day
- 3 million years ago (interglacial period) sea levels were 50m higher compared to present day.
Define glacier and ablation
Glacier is a body of ice moving under its own weight, forms when accumulation exceeds ablation.
Ablation is the natural removal of snow by melting or evaporation.
Water balance
Equation
P = Q + E +/- S P = Precipitation Q = Total runoff E = Evaporation S = Storage in rocks/soil
Flashy hydrograph \+ 3 DB or precipitation characteristics (size of basin land-use rock type)
Short lag time/high peak discharge
- Size of basin, small basins often lead to rapid water transfers.
= Land-use, urbanisation encourages rapid water transfer. - Rock type, impermeable rocks encourage rapid overland flow
Flat hydrograph \+ 3 DB or precipitation characteristics (relief soil water rain intensity)
Usually longer lag time/lower peak discharge
- Relief aka build of the land, soft slopes = slower transfers
- Soil water, dry soil soaks up water = slow transfers. Baked soil can encourage rapid transfers
- Light rain will transfer slowly
Greenland ice-sheet
1 fact + physical cause of melting (Early melt)
Contains 8% of earth’s freshwater
Early glacial melting
- Melting in summer months has been occurring earlier
thought to be caused by rising temperatures.
- In 2016 17% of surface ice melting in a few days.
Greenland ice-sheet
1 fact + human impact of melting (environmental refugees)
If it melted, seas would rise by 24ft
Environmental refugees
- If ice-sheet further melts, sea levels will rise endangering coastal areas.
- 1/3 of the world lives in coastal areas.
- Would result in billions of refugees affecting societies and economies.
Drainage basin
2 physical factors that affect components of a DB
(Which affect stores/flows in a DB)
(Vegetation/precipitation intensity)
Vegetation: More vegetation means more evapotranspiration, more slow, stem flow. This decreases rapid surface runoff and peak discharge.
Precipitation intensity: intense storms = intense precipitation which leads to high peak discharge, flows intensify as input intensifies.