Water Flashcards
(139 cards)
1
Q
Hydrological Cycle
A
The movement of moisture and energy between air, land and sea.
Varies from place and over time.
2
Q
System
A
A system is any set of interrelated components connected together to form a working whole , characterised by Inputs , stores , processes (flows) and outputs.
3
Q
Types of Systems
A
- Closed
- Open
4
Q
Closed System
A
- Occurs when there is a transfer of energy but not matter between a system and its surroundings
- Inputs come from within the system
5
Q
Example of a Closed System
A
- The Hydrological Cycle
- Water moves around the cycle by means of inputted energy (solar radiation) but no inputs or outputs of water
6
Q
Open System
A
A system that receives inputs from and transfers outputs of energy and matter to other systems
7
Q
Example of a Open System
A
- Drainage Basin
- Water moves out of the system to the ocean (matter) + atmosphere by precipitation input / evaporation output (energy)
8
Q
Drivers of the Water Cycle
A
- Solar energy
- Gravitational Potential Energy
9
Q
Solar Energy
A
- Sun heats Earth’s surface , evaporating water into atmosphere
- Evapotranspiration = water drawn from soil + evaporates from leaves / stems
- Humid air condensing + forming clouds , leading to precipitation
10
Q
Gravitational Potential Energy
A
- Mass of Earth exerts a pull on water
- Causing it to fall down as precipitation
- Causing it to flow downhill back to rivers
11
Q
Parts of the Hydrological Cycle
A
- Inputs
- Stores
- Flows
- Outputs
- Processes
12
Q
Input
A
Energy / Material added into a system
13
Q
Types of Inputs
A
- Orographic
- frontal
- convectional
14
Q
Orographic Rainfall
A
Warm moist air forced to rise over a barrier of hills / mountains , causing it to eventually cool and condense as rainfall
15
Q
Convectional Rainfall
A
Hot sun heats ground
Solar radiation heats air above the ground
Air rises
Air condenses
Forming clouds
Clouds rain
16
Q
Frontal Rainfall
A
Two air masses of diff temperature meet
Warm + lighter air rises
Cools
Condenses
Forms clouds
Rains
17
Q
Store
A
Where matter is kept for a long period of time
18
Q
Residence Times
A
- Average amount of time a water molecule will spend in a reservoir (where water exists at any point in the water cycle)
- Short residence time = better as less chance of water being polluted
19
Q
Calculation for Residence Times
A
Mass in reservoir
/
Rate of transfer to or from reservoir
20
Q
Examples of Stores and Residence times
A
- Biggest = Ocean at (1,335,040 x 10³) km³ annually (3.6k years)
- Cryosphere = 26,350,000 km³ annually (15k years)
- Groundwater = 15,300,000 km³ annually (10k years)
- Surface Water = 178,000 km³ annually (2 weeks to 10 years)
- Soil Moisture = 122,000 km³ annually (2-15 weeks)
- Atmospheric Moisture = 13,000 km³ annually (10 days)
- Smallest = Biological water at 1000 km³ annually (1 week)
21
Q
Non-Renewable stores
A
- Fossil water = ancient groundwater in aquifers below , takes long to replenish + not replenishable under current climate
- Cryosphere loss - takes long for meltwater to turn back into ice + not replenishable due to climate change
22
Q
Flows
A
Transfer of material or energy between stores
23
Q
Types of Flows
A
- Interception
- Infiltration
- Direct Runoff
- Saturated Overland flow
- Throughflow
- Perlocation
- Groundwater flow
24
Q
Interception
A
- interception loss = water lost through evotranspiration
- Through flow = precipitation falls through vegetation + reaches ground
- Stemflow = precipitation goes through plant stem into ground
25
Infiltration
Water soaks into soil
26
Saturated Overland Flow
Water table underground rises due to high infiltration , leading to no more water being able to be soaked into the ground
27
Throughflow
Lateral transfer of water through soil via interconnected roots or percolines
28
Perlocation
Water seeping down through soil into water table due to permeable rock
29
Groundwater flow
Water flowing slowly under water table via permeable rocks into rivers (baseflow)
30
Output
The movement of matter out of a system
31
Types of outputs
- Evaporation
- Transpiration
- Channel Flow
32
Transpiration
Water lost from a plant through stomata
33
Channel Flow
Water flowing along a river
34
Fluxes
- Measurement of the rate of flow between stores
- Occurs greatest over oceans
35
Examples of Fluxes
- Biggest = Ocean Evaporation at 413,000 km³ annually
- Smallest = evaporation of water held in surfaces and vegetation at 12,700 km³ annually
36
Processes
Physical mechanisms that drive the fluxes of water between stores
37
Examples of Processes
- Evaporation
- Precipitation
- Condensation
- Cryospheric Processes
etc ....
38
Evaporation
- Liquid water turning into gas (water vapour)
- Gains energy from solar radiation
- increasing water stored in the atmosphere
39
Conditions of Evaporation
- Solar radiation
- Supply of water
- Dry OR saturated air
40
Condensation
- Gas turning into liquid water
- Energy lost to surrounding
- Occurs when air cools to dew point (-15°C)
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Conditions of Condensation
- Rate at which temperature drops
- Amount of water vapour in the air
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Precipitation
Water in atmosphere that forms water on the ground
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Formation of Clouds
- Cannot form through condensation as water droplets too small on their own
- Tiny particles (soot / dust) act as cloud condensation nuclei , giving water a surface to condense on thus allowing clouds to form (rather than droplets dispersing)
44
Cryospheric Processes
- Accumulation = build up of ice + snow
- Ablation = melting of ice + snow
45
Conditions of Cryospheric Processes
- Temperature
- Season
46
Global Water Budget limiting human use
- Balance between different parts of the hydrological cycle (inputs / outputs)
- 2.5% freshwater but most locked away in glaciers etc
- accessible freshwater = 0.007%
47
Water Budget formula
P = Q +E +/-S
P = Precipitation
Q = River Discharge
E = Evapotranspiration
S = Surface storage
48
Water Budget in the UK
- wet season = precipitation > evapotranspiration thus water surplus
- Dry season = evapotranspiration > precipitation so ground stores depleted and water lost from river channel etc might not be replaced
49
Water Budget in a Temperate Zone (UK)
- January to April = surplus
- April to September = depletion
- September to December = atmosphere temp decreases + evapotranspiration decreases and precipitation increases = soil water recharged
50
Physical factors affecting drainage basins
- Climate
- Soils
- Vegetation
- Geology
- Relief
51
Water Storage
- More dams = more surface water stores +
more evaporation + less downstream discharge
- E.g Mississippi + Lake Nasser and Aswan Dam
52
Water Abstraction
- Using water for irrigation and both domestic and industrial uses
- E.g London , China , Aral Sea
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Deforestation
- Less evapotranspiration
- Oversaturated soil as water table rises
- More overland / surface runoff
- Rivers flodding
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Changing Land Use
- More cities means more tarmic + less trees = less infiltration
- sewers take in water in times of rain
- transport large quantities of water into rivers = flooding
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Mississippi Case Study
- 43 dams
- 6% total runoff transferred to atmosphere
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Lake Nasser Case Study
- Behind Aswan Dam in Egypt
- Evaporation loss = 10-16b m³ annually
- 20-30% of water lost from Nile
57
China Case Study
China :
- Groundwater used to irrigate 40% of farmland
- Provides 70% drinking water up North
- Increased by 2.5b m³ annually
- Levels dropped a metre a year in North between 1974-2000
58
The Aral Sea Case Study
- Between Kazakhstan and Uzbekistan
- Over extraction of water due to 1960 Soviet irrigation scheme for cotton
- Water taken from Syr Darya and Amu Darya
- 1994 , volume declined by 75% , SA by 50% , sea level by 16m
- Salinity increased by 300%
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London Case Study
- Reduction of water using manufacturing
- Polluted groundwater rising = flooding in basements + tunnels leaking etc
60
Amazonia Case Study
- Deforestation for farmland (cattle , palm oil , soy)
- Development of new town + roads = more illegal logging as easier access to forest which is majority unmonitored
- Leads to more droughts as water cycle disrupted
- In normal rainforest , 75% returned to atmosphere but only 25% in cleared
- No trees = waterlogged soil = hard to grow back
- Hydroelectric Dams e.g Belo Monte Dam
- Contains 60% of world’s rainforest
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River Regime
- Annual variation in the discharge or flow of a river at a particular point
- Measured in Cumecs
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Equitorial Climate of River Regimes
- Tropical Rainforest
- High river discharge
- 2000mm annually
- 28°C so high evapotranspiration
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Tundra Climate of River Regimes
- Russia
- 250mm precipitation annually
- most discharge takes place in short period during summer months
- Permafrost so low evapotranspiration
- Daily fluctuations as morning time = more melting but night = freezing
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Alaska Case Study - River Regimes
- Yukon River
- Low discharge in winter but high discharge in summer as snow melts
- Soils prone to permafrost thus impermeable all year round
- High overland flow after melting
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Brazil Case Study - River Regimes
- Amazon River
- High levels of rainfall infiltrate quickly due to thin soils
- High amount of sedimentary rock
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Indus River Case Study - River Regimes
- Central Asia
- Input is snowmelt from Himalayas
- During monsoon , has high precipitation
- Water deficit for 5-6 months during dry season
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Australia Case Study - River Regimes
- Murray Darling
- Sub tropical
- Rain shadow as surrounded by mountains run water runs off into river
- Wet during August to November
68
Types of River Regimes
- Simple : river experiencing seasonally high/low discharge due to one factor e.g glacial melt
- Complex : large rivers in multiple climate zones + relief zones affected by many factors e.g humans
69
Types of Droughts
- Meteorological
- Hydrological
70
Hydrological Drought
Less water in :
- groundwater stores
- streams
- rivers
71
Meteorological Drought
Less precipitation entering a local system
72
Short Term Droughts
- Meteorological (precipitation defecit)
- changes in frequency of frontal precipitation
- localised
- cool descending air creates a high pressure system (anticyclone) = blocks warm air ascending + making cloud = less rain = drought
73
Long Term Drought
- Hydrological
- Climate change = long term changes to warming / cooling of oceans = frequency of drought changing
- Climate change = unpredictable seasonal rainfall = maybe a lot = depletion of groundwater + reservoir stores = drought
74
ENSO Cycle
Natural change in the patterns of ocean temperatures in the Pacific Ocean
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ENSO Cycle Droughts
- Usually low pressure in W + high in E = trade winds from E to W
- El Niño event = high pressure in W + low in E = weak trade winds OR direction change = W to E trade winds
- increasing pressure in West e.g Australia = less precipitation = wildfires risk
76
ENSO Cycle timelines
- Occurs every 3-4 years
- Lasts for 9-12 months
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La Niña Event
- normal conditions become extreme
- Stronger trade winds = lower pressure E = cold water rising = drier conditions
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La Niña Timeline
2 to 7 years
79
Define Aquifer
Saturated layer of permeable rock below the water table
80
Over-abstraction
Abstraction water from an aquifer at a faster rate than the aquifer rechargers
81
The Millennium Drought - Australia
- SE Australia severe drought 2001 - 2009
- Worst hit = Murray Darling Basin
- Causes : 30* high pressure belt = El Niño
High Temperatures = more evaporation
Years of over-abstraction
- Impacts : Irrigation reliant crops failed e.g rice
N.o of sheep fell by 7m (2002-2003) from dehydration = less incomes = >100k unemployed
82
Define Ecological Reliance
The Capacity for a Natural area to survive and recover from a disturbance
83
Wetlands
- limited reliance + sensitive to droughts
- water store for humans + habitat for animals
- water purifier as reeds / rushes trap pollutants
- droughts = wetlands during up + vegetation dying + less nesting spaces
- More concentrated algae = less oxygen for aquatic life = migration for deeper water
84
Forest Stress
- susceptible to droughts
- mild drought = tree growth slowing + young trees die = land exposed to wind erosion
- knock on effect to organisms that rely in trees etc
85
Meteorological Factors causing Floods
- Prolonged rainfall
- Extreme Monsoonal Rainfall
- Intense Storms
- Snowmely
86
Prolonged Rainfall
- slow onset flooding
- occurs when series of low pressure systems (depression) continually move across UK = time gap between each is smaller
87
Extreme Monsoonal Rainfall
- Monsoon = season change in prevailing wind = wetter weather in sub-tropical regions
- rain lasts longer + is heavier
- more overland flow + runoff = inundate waterways
88
Intense Storms
- fast onset
- high rainwater + storm surge = high levels of standing water on land = flash flood
89
Snowmelt
high temp = ice melting = flooding in glacial valleys (jokunhaups)
90
Other factors causing flooding
- shape of land
- geology
91
Human Activity Increasing flood risk
- Floodplain Use
- Land Use Change
- Hard Engineering
92
Floodplain Use
More urbanisation = need to build on floodplains = impermeable concrete near rivers = reduced rate of infiltration = more surface runoff = flooding
93
Land Use Change
- less vegetation = less interception = soild easily eroded by rain into rivers = rivers holding capacity is less = less water in river = flooding
- more buildings = more impermeable rock etc
- more farming = more bare soil = less interception etc
94
Hard Engineering
- river mismanagement e.g removing meanders = shift risk of flooding more downstream as rate of flow increases
-Dredging rivers = deeper rivers = more water = faster moving water = more flooding downstream past dredged area
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Impacts of Flooding - Economic Activity
- flooding = weather warnings = people not likely to go outside + business cannot operate and access customers
- farmland flooding = deep saturated soil = crops drowning = lack of oxygen to crops = susceptible to diseases = cannot sell = less incomes
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Impacts of Flooding - Infrastructure
- transport + communication networks = down e.g railway tracks have standing floodwater
- fresh water inundated worth floodwater = cross contamination = supplies cut off whilst water is sterilised = people have no water
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Impacts of Flooding - Settlements
- Property damage e.g water soaking into buildings = weak structures = prone to collapsing
- Homeowners near floodplains = hard to get insurance
- flooding = loss of life + injury due to water borne diseases or drowning
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Negative Environmental Impacts of flooding
- Eutrophication = runoff fertiliser into rivers = algae grows = takes up more oxygen = aquatic life dying
- Floodwater erodes soil = difficult for future growth
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Positive Environmental Impacts of flooding
- flooding = more silt = better growing agriculture
- lakes / wetlands recharged = more biodiversity + habitat
100
2007 UK floods
- Low pressure system caused by polar jet stream being more South then usual
- Flooding mainly on River Sever , Thames , Don
- 13 deaths
- 48,000 homes destroyed
- £3.2b damages
- Upton-upon-Severn = worst hit due to few defences + half village was cut off = hard for rescue services to come , £4.5m now spent on defences
- Level of govt intervention criticised but other blames unusually high flooding
101
Climate Change affecting Precipitation
- wet areas (tropics) , expected to get wetter = rapid + increased evaporation a = more low pressure systems = more rainfall
- hot areas (tropics) , expected to get hotter = warm atmosphere has increase capacity to hold water vapour = intense rain events
Vice versa
- extreme weather events expected to be frequent + intense e.g heatwaves , storms etc
- precipitation more likely to fall as rain then snow in glacial areas
- more evaporation = more clouds = warmer air = more energy in atmosphere to create water vapour = more transpiration / evapotranspiration
102
Climate Change altering Size of Stores
- sea levels rise as glaciers melt
- oceanic thermal expansion
- smaller glacial ice stores due to ablation
- shallower snow cover + shorter snowy seasons
- permafrost melting = more meltwater in soil
- greater fluctuation in reservoirs , lakes , wetlands between full capacity / low levels
103
Climate Change affecting Change of Rates of Flow
- rates of direct runoff + streamflow
- climate change = more intense rain events = flows faster after + high volume
- soil moisture decreases between rain periods = drier ground = harder ground = harder soil = impermeable = more surface runoff
104
Climate Change - Positive Feedback
Temp increase
More evaporation
More water vapour in atmosphere
Greenhouse effect increases
105
Climate Change - Negative Feedback
Temp increases
Evaporation increases
More water vapour in the atmosphere
More clouds forming
Sun radiation reflected back to space
106
Climate Change affecting Water Security
- upland communities depends on meltwater from glaciers > meltwater = deluges rather than constant = wasted > once used can’t get back
- rainfall = unpredictable + unreliable = hard to plan water use in agriculture
- more storms = more flooding = more saline water = contaminated groundwater
107
Water Stress
- demand > supply
- < 1700m^3 per person annually
- areas w/ high population density + unreliable water supplie
108
Countries with High Availability and Low Demand
- Brazil
- Russia
109
Countries with Low Availability and High Demand
- Mexico
- India
110
Countries with Low Availability and Low Demand
Kenya
111
Water Scarcity
- < 100m^3 per person annually
- physical water scarcity = not enough freshwater to meet demand = low rainfall + high evaporation = Saudi Arabia
- Economic Water Scarcity = water is their but inaccessible due to lack of investment e.g sub-Saharan Africa
112
Water Insecurity caused by Physical Factors
- unpredictability of seasonal rainfall
- high evaporation but low rainfall
- low water levels = less energy heat up = bacteria growing quickly = harmful
- rising sea levels = salt waters encroachment e.g Bangladesh = saltwater replacing freshwater in wells dug into aquifers
113
California
- high demand for water to irrigate crops
- Main reservoir = Shasta Lake was lowest capacity ever at 31% in 2022 due to increasing temps
- 11 / 20 droughts resourced in 2000s
- low rainfall = more wildfires
114
Water Insecurity caused by Human Factors
- chemical pollution contaminating freshwater e.g pesticides from agriculture , coolant from industries etc
- poor management of wastewater = pollution
- industrial waster = arsenic / lead = polluted groundwater
- over-abstraction
- HEP increases downstream water stress
115
Reasons why global water demand is rising
- population growth
- industrialisation
- living standards
- Agriculture
116
Why water price varies globally
- bulk buying = cheaper e.g farmers buy for less
- cost of water depends on : transportation costs + infrastructure to dig it out , market price e.g scarcer = more expensive etc
- expensive water = poor countries have insuffient , poor quality water
- profitable + expensive = buyers likely to conserve it to save money + sellers have better infrastructure to prevent leaks and increase quality
117
Water Poverty index
- Access
- Capacity
- Use
- Environment
- Resources
Low WPI = developing
118
Importance of water supply for economic development
- Energy supply : water heated to make steam + turn turbines for energy / electricity e.g Hydroelectric power plants , fracking , biofuel crops
- Industry : machinery used which needs water cooling , cleaning raw materials , making cotton for clothes
- trade : Canals used to transport
- Agriculture : irrigate crops , raise livestock
119
Water supply used for human wellbeing
- sanitation : clean hand , shower etc
- Health : bad sewage system = human waste in rivers = diseases e.g cholera
- Food preparation : clean water to wash fruit etc
120
Water supply causing economic problems
- poor countries cannot afford to import water / hard engineer = hindered development + less trade in certain industries
- high sanitation = more clean water in school = better education etc
- kids don’t go to school to spend hour walking + collecting water = opportunity cost
121
Water supply causing environmental problems
- less water = less healthy plants + animals
- eutrophication
- wetlands running out = less nesting places + toxins in water due to less rushes
122
Water Insecurity causing trans-national conflicts
- many rivers cross boundaries
- countries upstream have more power as they can divert water / pollute it
123
The River Nile
- flows through 11 countries
- Only Egypt + Sudan have full rights to water
- Conflict between upstream (Uganda) and downstream (Egypt) as upstream was more water
- 1959 agreement gave E+S priority and stopped developments near river
- 2020 Ethiopia built Gran Ethiopian Renaissance Dam , causing Egypt to be concerned about water supply
124
Water Transfer Schemes
Moving water from areas of surplus to deficit through pumping e.g canals or redesigning river courses to flow to a different ares
125
Pros of Water Transfer Schemes
- increased water security in deficit area
- controlling volumes of water / less flooding
126
Cons of Water Transfer Schemes
- Water stress in source
- expensive infrastructure
- affect river ecosystems
- rivers heavy with sediment from construction
127
Water Transfer in China
- North has 35% pop , 40% arable land but 7% water
- water table fell 300m since 1970
- 2003 , building 3 canal routes to take water from Yahtze
- $79b
PROS:
- more water security in north
- greater control of water
- reduce abstraction
CONS:
- submerge 370km^3 of land
- 345k people displaces
- affects ecosystem of 3 Gorges Dam
128
Mega Dam
Where water is stored during surplus to ensure there’s enough water during deficit
60% of rivers impeded by a Dam
129
Three Gorges Dam
PROS:
- controls flooding
- stores water for china
- HEP
CONS:
- 1.3m relocations from 1500 villages
- low water quality as waste from industry flows into Dam
- Decomposing vegetation produces methane when passed through HEP turbines
- Hold back silt from farming
130
Desalination Plants
Factories that remove salt from seawater , making it useable for human use
131
Israel Desalination project
- 5 plants opened in 2013
- aims to provide 70% of water to Israel
- from Mediterranean
PROS:
- Sustainable
- leaves river water for animals etc
- 600 tonnes/h of potable water
CONS:
- expensive
- energy intensive. , each plant needs its own power station
- produces lots of salt/brine = harming ecosystems
132
Water Restoration
- recharging aquifers through wells + infiltration structures
- restoring rivers to natural course e.g building meanders
- habitat restoration
133
Reducing Domestic Water Consumption
- using more efficient toilets e.g displacement bag in Cistern
- take showers instead of baths
- more efficient modern appliances e;g washing machines
- rainwater harvesting techniques e.g collecting rainwater in large basins to use domestically
134
Reducing Agricultural Water Consumption
- smart irrigation monitors local weather + only uses water where necessary
- soil moisture of individual plants monitored
- collecting storm water for irrigation
- Contour ploughing to reduce direct runoff
- genetic modification for drought resistant crops
135
Recycling Water
- treating used water so that it can be used straight away
- using grey water for gardens / flushing toilets etc without being treated first
136
Singapore Water Management
- high demand = 400m gallons daily
- 5 desalination plants which meet 40% of countries needs as few sources of freshwater
- strong campaigns to encourage citizens to use water wisely
- Water Scaling system - ppl who constants use a lot of water are charged more
- 2011to 2061 water agreement with Malaysia but tensions encourage Singapore to be more self-sufficient
- 40% of water comes from UV treatment (new method) called NEWater
137
Integrated Drainage Basin Management
Looks at whole drainage basin as a geographical unit and countries works together to manage large river system
138
Colorado River
- crosses 7 states
- supplies 40m ppl w/ drinking water
- 2007 plan : rather than divide it equally, it is divided proportionally in accordance to deficit in each state
139
International Water Treaties
- UNEC has a set of guidelines to encourage collaborative management + conservation of shared water resources BUT only guidelines and aren’t law
- Water Framework Directive and Hydropower = convention Berlin 2007 to promote HEP sustainably
