Water and Carbon Cycles: The water cycle Flashcards
(63 cards)
1
Q
Outline aquifers:
A
- Underground water stores.
- Shallow groundwater aquifers can store water for 200 years.
- Deeper fossil aquifers created during wetter climatic periods can store water for 10,000 years.
2
Q
Define convectional precipiation:
A
Solar radiation heats the air above the ground causing it to rise, cool and condense forming precipitation.
3
Q
Define desalination plant:
A
The conversion of seawater to freshwater, suitable for human consumption.
4
Q
Define economic water scarcity:
A
When water resources are available but insufficient economic wealth limits access to it.
5
Q
Define global hydrological cycle:
A
The continuous transfer of water between land, atmosphere and the oceans (closed system)
6
Q
Define inorganic carbon:
A
Carbon stored in carbonated rocks.
7
Q
Define percolation:
A
Water moving from the ground/soil into porous rock or rock fractures.
8
Q
Define physical water scarcity:
A
A physical lack of available freshwater which cannot meet demand.
9
Q
Define phytoplankton:
A
Small organisms that rely on photosynthesis to survive, so intake carbon dioxide from the atmosphere.
10
Q
Define relief precipitation:
A
Warm air is forced upward by a barrier such as mountains, causing it to condense at higher altitudes and fall as rain.
11
Q
Define river regime:
A
The pattern of river discharge over a year
12
Q
Define smart irrigation:
A
Providing crops with a water supply less than optimal, to make crops resistant to water shortages.
13
Q
Define through flow:
A
Water moving horizontal through the soil, due to gravity
14
Q
Define water budget:
A
The annual balance between inputs and outputs within a system
15
Q
Define water sharing treaty:
A
International agreements for trans boundary sources.
16
Q
What is atmospheric water?
A
Water found in the atmosphere.
17
Q
What is cryospheric water?
A
The water locked up on the Earth’s surface as ice.
18
Q
What are the 4 forms of terrestrial water?
A
- Surface water
- Groundwater
- Soil water
- Biological water
19
Q
What is surface water?
A
The water of free-flowing rivers, ponds and lakes.
20
Q
What is groundwater?
A
Water that collects underground in the pore spaces of rock.
21
Q
What is biological water?
A
Water stored in biomass.
22
Q
What is soil water?
A
Water stored in soil.
23
Q
What are inputs into a system?
A
When matter/energy is added to a system
24
Q
What are outputs into a system?
A
When matter/energy leaves a system.
25
What are stores in a system?
When matter/energy builds up in a system
26
What are flows in a system?
Where matter/energy moves in a system.
27
What are boundaries in a system?
Limits to a system.
28
What is an open system?
A system that receives energy inputs and transfers outputs of matter/energy with other systems.
29
What is a closed system?
A system where energy inputs equals energy outputs.
30
What is a dynamic equilibrium in a system?
When energy inputs equals outputs despite changing conditions.
31
What causes positive feedback?
When a chain of events amplifies the impacts of the original event.
32
What causes negative feedback?
When a chain of events nullifies the impact of the original event.
33
Name the 3 types of rainfall:
- Convectional
- Relief
- Frontal
34
Explain frontal rainfall:
- Warm air rises over cool air when two different temperature bodies of air meet.
- The warm air is less dense meaning it condenses at higher altitudes and falls as rain.
35
What is the main input into systems in the water cycle?
Precipitation
36
What are the two main outputs of systems in the water cycle?
- Evapotranspiration
- Streamflow
37
Explain evapotranspiration:
- Both evaporation and transpiration.
- Evaporation occurs when water is heated by the sun, causing it to become a gas and rise into the atmosphere.
- Transpiration occurs when plants respire through their leaves and release water they absorb through their roots, which then evaporates.
38
Explain streamflow:
- All water that enters a drainage basin will either leave through the atmosphere or through streams that drain the basin.
39
Name the 7 main flows in a system in the water cycle:
- Infiltration
- Percolation
- Throughflow
- Surface runoff
- Groundwater flow
- Streamflow
- Stemflow
40
What is infiltration?
The process of water moving from above the ground into soil.
41
How do tree roots increase the rate of infiltration?
Create passages for water to flow through from the surface into the soil.
42
What is surface run-off?
When water flows above the ground as sheetflow or in rills.
43
What is groundwater flow?
When water moves through rocks
44
What is streamflow?
When water moves through established channels.
45
What is stemflow?
When the flow of water has been intercepted by plants or trees.
46
What are the 5 main stores in a system?
- Soil water
- Groundwater
- River channel
- Interception
- Surface storage
47
What is the water table?
The upper level at which the pore spaces and fractures in the ground become saturated.
48
Name the 5 factors that influence the water cycle on a local scale:
- Deforestation
- Storm events
- Seasonal changes
- Agriculture
- Urbanisation
49
Explain how deforestation impacts the water cycle on a local level:
- Less interception by trees so surface run off increases.
- Soil is no longer kept together by roots, so soil water storage decreases.
- Fewer plants so transpiration decreases
50
Explain how storm events impact the water cycle on a local level:
- Large events of rainfall quickly saturate the ground to its field capacity, no more water can enter the soil increasing surface run-off.
51
Explain how agriculture impacts the water cycle on a local level:
- Pastoral farming (livestock) trample on the ground, reducing infiltration.
- Arable farming (crops)- ploughing increases infiltration by creating a looser soil, which decreases run off.
- Irrigation can lead to groundwater deprivation as the waters path is changed compared to its natural course.
52
Explain how urbanisation impacts the water cycle on a local level:
- Creating roads with impermeable surfaces and a drainage system decreases infiltration, and increases surface run off and flood risk.
- SUDS aim to reduce the amount of impermeable surfaces and allows for water harvesting and use, reducing flooding risk in urban areas.
53
Outline the soil water budget:
- Shows the annual balance between inputs and outputs in the water cycle and their impact on soil water storage and availability.
- The budget is never the same due to varying conditions annually.
- The water budget is dependent on the type, depth and permeability of the soil.
- The maximum possible level of storage of water in the soil is the 'field capacity'. Once the field capacity has been reached, any rainfall after this will not infiltrate the soil and is likely to cause flooding.
54
How does the soil water budget vary between seasons?
Winter: Very low potential evapotranspiration rates due to colder temperatures; precipitation continues to refill the soil water stores; infiltration and percolation fill the water table.
Spring: Plants start to grow again, causing potential evapotraspiration increases as temperatures increase and plants start photosynthesising more. Water surplus present.
Summer: Highest temperatures causes utilisation of soil water as potential evapotranspiration peaks and rainfall is at a minimum. Output of evapotranspiration is greater than input precipitation so soil water stores deplete- water deficit may occur.
Autumn: Greater input of precipitation than output of evapotranspiration as many trees loose their leaves and cooler temperatures mean plants photosynthesise less. Soil moisture levels increase and water surplus occurs.
55
Name the 4 stores of water:
Hydrosphere - Any liquid water.
Lithosphere - Water stored in the crust and upper mantle.
Cryosphere - Any frozen water.
Atmosphere - Water vapour.
56
Outline global water stores:
- 97% of all water on Earth is stored within oceans.
- 2.5% of water stores are freshwater (majority are glaciers, icecaps and icesheets)
- Surface and other freshwater stores make up 1% of all water stores (stored in permafrost, rivers, lakes, living organisms).
57
Outline the Inter-tropical convergence zone (ITCZ):
- The global atmospheric circulation model predominantly determins cloud formation and rainfall.
- Different zones of rising and falling air leads to precipitation via convectional rainfall.
- Creates a low pressure zone on the equator, the ITCZ, which has very heavy rainfall.
- The ITCZ moves during the seasons as the suns positions changes. Where the Ferrel and Hadley cells meet, unstable weather occurs and is moved by air currents (jet stream).
58
Outline how natural processes causes the water cycle to change over time:
Seasonal processes: Changes in precipitation, evapotranspiration and interception causes systems to experiences changes in water stores, inputs and outputs.
Storm events: Causes sudden increase in rainfall, leading to flooding and the replenishment of some water stores.
Droughts: Causes major stores to be depreated and the flows of water activty to decrease. May cause long term change with increasing frequency due to climate change.
El Nino and La Nina: El Nino occurs every 2-7 years and causes predictable warmer temperatures. La Nina occurs every 2-7 years and causes predictable cooler temperatures.
Cryospheric processes: Shrinking glaciers causes sea levels to rise, with water accumulated in them now being stored within oceans.
59
Outline how human processes causes the water cycle to change over time:
Farming practices: Ploughing, arable farming and irrigation contributes to system changes with water stores, inputs and outputs.
Land use change: Deforestation reduces interception and evapotranspiration, but increases infiltration. Construction of impermeable surfaces reduces infiltration and increases surface run off.
Water abstraction (water removed for human use): Reduces the volume of water in surface stores (e.g. lakes). Human water abstraction in aquifers causes output demands to be greater than water input, leading to a decline in global long-term water stores.
60
Name A, B, C, D, E, F:
A = Rising Limb (discharge increasing)
B = Lag time (time between peak rainfall and peak discharge)
C = Falling Limb (discharge decreasing)
D = River in Flood
E = Stormflow (water that reaches the river from surface runoff and throughflow after a flood)
F = Base flow (level of groundwater flow)
Bankfull discharge: The maximum capacity of a river, if this is exceeded the river will burst its banks and flood.
Discharge: The volume of water passing a cross section of a point in a river at any one point in time.
61
What is a flashy hydrograph?
- Short lag time
- Steep rising and falling limb
- High peak discharge
-Higher flood risk
(most likely to occur during a storm event)
62
What is a subdued hydrograph?
- Long lag time
- Gradually rising and falling limb
- Low peak discharge
- Lower flood risk
63
Outline natural factors that contribute to a flashy hydrograph (more severe storm):
High rainfall: Higher discharge ptoential from the river so soil is more liekly to reach field capacity, increasing SRO and decreasing lag time.
Previous rainfall: Increased SRO as ground is already saturated, so soil is more likely to reach field capacity.
Small basin: Rainfall reaches the central river more rapidly, decreasing lag time.
Precipitation type: Snow/hail takes time to melt before moving towards the river, so rainfall increases flooding risk.
Vegetation cover: Forested areas intercept more rainfall, decreasing flood risk, but exposed areas will transfer water to the river more rapidly, decreasing lag time.
(human factors are repeated throughout the W cycle: urbanisation for impermeable surfaces and SUDS, arrable farming trampling on soil, deforestation means less interception and more SRO and greater flood risk)
