Water Flashcards
What are the 5 stores in the global hydrological cycle?
Ocean
Atmosphere
Cryosphere
Groundwater flow
Lake/reservoir
What are the 9 flows in the global hydrological cycle?
Evaporation
Condensation
Precipitation
Evapotranspiration
Interception
Surface run-off
Through flow
Infiltration
Percolation
What is the difference between infiltration and percolation?
Infiltration is when water travels through the top layers of soil. Percolation is when water travels through deeper soil layers.
What are the 2 types of water stores?
Blue water (liquid form)
Green water (in vegetation + soil)
What are flows?
Physical mechanisms changing the flux (rate of flow) between stores
Why is the global hydrological cycle a closed system?
Fixed volume of water in the earth-atmosphere system
No external input/output
But water can exists in different states
What 2 processes drive the global hydrological cycle?
Solar energy
Gravitational potential energy
In 3 steps, how does solar energy drive the global hydrological cycle?
- Water on the surface/in plants is heated and evaporated
- Humid air rises but condenses at a cooler temperature to form clouds
- Precipitation returns water to land/oceans
How does GPE drive the global hydrological cycle?
Converted to kinetic energy and water falls as precipitation, or rivers flow downstream to ocean
What % contribution does the ocean water store have? Evaluate
96.9%
Drives huge precipitation, but water is saline
What % contribution does the cryosphere water store have?
1.9%
large store, but not accessible to use
What % contribution does the groundwater and surface water water store have?
1.11%
Keeps vegetation alive, holds 30% of freshwater stores
What % contribution does the atmosphere store have?
0.001%
Small but provides opportunity for precipitation (freshwater)
What % contribution does the biosphere water store have?
0.0001%
Small but regulates environment and climate
When temperature is higher (summer), how do the ocean, atmosphere, and land stores flux?
Atmosphere store increases
Ocean/land stores decrease
When temperature is lower (winter), how do the ocean, atmosphere, and land stores flux?
Ocean/land stores increase
Atmosphere store decreases
What is the global water budget?
Takes into account all water held in stores/flows of the hydrological cycle
However, only 2.5% is freshwater
Of that, only 1% easily assessible
What is residence time?
Average time a water molecule spends in a store
Which stores have a short residence time?
Biosphere- 1 week
Atmosphere- 10 days
Surface water- 2 weeks-10 years
Which stores have a long residence time?
Ocean- 3600 years
Groundwater- up to 10,000 years
Cryosphere- 15,000 years
Why are water stores with a longer residence time more easily polluted?
In situ for longer, more exposure
What is fossil water?
Ancient, deep groundwater from pluvial (wet) periods in geological past
Undisturbed for over a millenia
What are the 8 parts to a drainage basin?
Source
Tributary
Confluence
River/channel
Watershed
Drainage basic
Mouth
Sea/lake
What are the 3 types of input to the hydrological cycle? (precipitation)
Cyclonic/frontal
Orographic
Convectional
What is cyclonic/frontal rainfall?
Warm air is lighter and less dense so is forced to rise over cool air (low pressure)
Cools and condenses to form clouds
Rains along front
What is orographic rainfall?
Warm air is forced to rise over a mountain
Cools and condenses at high altitude
Rain falls on slope facing wind direction
Leeward slope has little rain (rain shadow)
What is convectional rainfall?
Sun heats the land, and air above it becomes warmer
Warm air rises and its ability to hold water vapour decreases
Cools and condenses, then heavy rainfall
What are 2 factors that could affect the input (precipitation patterns)?
Space (mountains vs tropics; continentality = drier)
Time (season; intensity; climate change on long-term scale)
What does the flow interception depend on?
Trees in full-leaf season
What does the flow infiltration depend on?
Rain volume, saturation level, angle
What does overland flow depend on?
Precipitation intensity > infiltration rate
What is saturated overland flow?
When soil/urban drains full (or backed) so cannot infiltrate
What does throughflow depend on?
Porus, sandy soils
What does the flow percolation depend on?
Permeable/porous rock
Greater in humid climates with vegetated slopes
What does groundwater flow depend on?
Permeable/porous rock increases rate of flow
What are the outputs of the hydrological cycle?
Evaporation + transpiration (evapotranspiration)
Channel flow
What are the 5 physical factors within drainage basins that determine the relative importance of inputs flows and outputs?
Climate
Soils
Geology
Relief
Vegetation
How does climate determine the relative importance of inputs flows and outputs?
Influences type/amount of precipitation
Influences evaporation
Also impacts vegetation type
How do soils determine the relative importance of inputs flows and outputs?
Determines the amount of infiltration and throughflow
Indirectly determines vegetation type
How does geology determine the relative importance of inputs flows and outputs?
Impacts on sub-surface processes (percolation and GW flow)
Indirectly alters soil formation
How does relief determine the relative importance of inputs flows and outputs?
Altitude impacts on precipitation totals
Slopes can affect amount of runoff
How does vegetation determine the relative importance of inputs flows and outputs?
Presence/absence affects interception, infiltration and overland flow
Also affects transpiration rate
In what 4 ways can humans disrupt the drainage basin cycle?
Urbanisation
Deforestation
Creating water storage reservoirs
Overabstraction
How does urbanisation disrupt the drainage basin cycle?
Impermeable layer so direct overland flow
Thus, less infiltration and percolation
Less evapotranspiration -> reduced rainfall
How does deforestation disrupt the drainage basin cycle?
Reduced interception = reduced EVT = reduced rainfall
Also no roots to bind soil, so it erodes/compacts
Direct runoff/overland flow increase speed of cycle (possible floods)
Give background to deforestation in the Amazon
Over 20% destroyed, rate accelerating
What are 2 impacts of deforestation in the Amazon?
Normally 75% intercepted water, decreases to 25% when the dense canopy is cleared
Soil is now thin and vulnerable to erosion and tropical rains, so farmers relocate
What are some issues of reservoirs?
Decreases the river flow downstream, forests die
Salinity levels and pollution level increases
What are some issues with the reservoir created from the Three Gorges Dam?
Low water quality
1.3 million people relocated
What is the issue with overabstraction in Israel?
Water struggles to infiltrate down to the groundwater store, reducing store
20% reduction in ground for rainwater to infiltrate
Marine aquifers are salty and merge with drinking water aquifers
When the drainage basin urbanised, aquifers aren’t recharged
What are the 4 parts of the water budget graph?
Soil moisture recharge
Soil moisture surplus
Soil moisture utilisation
Soil moisture deficit
Regarding the water budget graph, what is the best condition for growing?
Soil moisture utilisation
What is the water budget graph?
Balance of inputs and outputs in a drainage basin
What is the equation for water budget?
Change in storage = precipitation - (runoff + EVT)
What does a river regime show, and how is it measured?
Difference in discharge of river throughout the year
A flow of volume, measured in cumecs (cubic metres/sec)
What can affect river regimes?
Climate/latitude- affects meltwater/evaporation rate
Geology + soils- permeability/porosity, GW regulates flow
What are long complex river regimes?
When drainage basin crosses several relief and climatic zones
Give information about the variation in discharge in the Amazon River, South America
Moderate seasonal variability, but always high discharge
Rainforest climate (wet/drier seasons)
EVT levels high, but so is conventional rainfall
Dams have little effect
Give information about the variation in discharge in the Yukon River, USA
High seasonal variability
High summer temp and high mid-lat rainfall + snowmelt
Snow refreezes around September
Some HEP but little human influence
Give information about the variation in discharge in the Murray-Darling River Australia
High seasonal variability
Sub-tropical/monsoon climate
Suffers from mid-lat depressions in wet season, not in dry
High relief, a lot in drought from rain shadow
Lots of irrigation drawing water
What is lagtime on a storm hydrograph?
Time between peak rainfall and peak discharge
What 6 physical features of a drainage basin does the shape of a storm hydrograph depend on?
Size
Shape
Drainage density
Soil/rock type
Relief
Vegetation
How does size of drainage basin affect the shape of a storm hydrograph?
Small
- discharge peaks quick, but low
- as fills quickly, but small volume
Large
- slow, but high
- water has longer distance to travel to river, but more water
How does shape of drainage basin affect the shape of a storm hydrograph?
Elongated
- discharge peaks slow + low
- takes longer to travel down
Circular
- quick + high
- less distance for rain to travel from where it fell
How does drainage density (number of tributaries) of drainage basin affect the shape of a storm hydrograph?
High
- discharge peaks quick + high
- point of rainfall close to river so fills quick
Low
- slow + low
- longer to travel so may infiltrate/intercept
How does soil/rock type of drainage basin affect the shape of a storm hydrograph?
Impermeable
- discharge peaks quick + high
- can’t infiltrate so flows quick as overland flow
Permeable
- slow + low
- some ‘lost’ to infiltration
How does relief of drainage basin affect the shape of a storm hydrograph?
Steep
- discharge peaks quick + high
- gravity speeds flow
Gentle
- slow + low
- water travels slowly to river, more likely to infiltrate
How does vegetation in drainage basin affect the shape of a storm hydrograph?
Bare
- discharge peaks quick + high
- rain hits ground directly to flow to river, oversaturation may also occur
Forest
- slow + low
- can store water or slow flow
How does urbanisation of a drainage basin affect the shape of a storm hydrograph?
Discharge peaks quick + high as impermeable land, quick overland flow
How does agriculture in a drainage basin affect the shape of a storm hydrograph?
Discharge peaks quick + high as furrows channel water
How does deforestation in a drainage basin affect the shape of a storm hydrograph?
Discharge peaks quick + high as trees can’t trap water and slow flow
What is the role of planners in managing land use in drainage basins?
- determines if development increases flood risk
- have to show that land-use change doesn’t increase runoff beyond estimation for a greenfield site
- give weight to environmental considerations and need for development
Sustainable drainage systems (SuDS) can decrease runoff eg:
1. Greenroofs
2. Permeable pavements
3. Rain water harvested + recyled
What is meteorological drought?
Degree of dryness compared to normal precipitation
Rainfall deficit
What is hydrological drought?
Drainage basins suffer shortfalls, rainfall deficit affects water supply
Evident in reduced GW levels, river flow etc
What is agricultural drought?
Insufficient water for crops, they wilt without irrigation
How do blocking anticyclones cause meteorological drought in the mid-latitudes?
Large subsiding air masses break away from the ferrel cell into mid-lats bringing high pressure
Usually rainy as polar maritime + tropical maritime airmasses meet, polar/tropical continental airmasses are rarer and cause the high pressure when they break away from normal cells
What conditions do blocking anticyclones/high-pressure zones bring to the UK in summer/winter?
Summer- hot + dry
Winter- bitter cold + frost from absence of clouds
Give some facts from the 2003 Paris drought
3 week blocking anticyclones
15,000 killed from dehydration + heatstroke, mostly elderly
What are some longer-term trends for blocking anticyclones?
Drought persistent in European summer over the last 2 decades
Climate change increases temp –> larger BAC
How is hydrological/agricultural drought caused in semi-arid zones?
In intertropical convergence zone (ITCZ) sun rays concentrated, rainfall high- 300km wide
ITCZ moves north/south, providing 12 week wet season. H+A drought conditions for 9 months
How can meteorological drought be caused in semi-arid zones?
If a blocking anticyclone of high pressure in the ITCZ blocks the arrival of the wet season
What are some longer-term trends for drought in semi-arid zones?
Land conversion collapses local water cycle, thus just seasonal wet season
Climate change increases temp –> larger BAC, unreliable wet season
What are 2 other causes of dry land (not latitude)?
Rain-shadow effect
Continentality (far removed from rain-bearing winds)
What are ENSO cycles?
El niño southern oscillations (changes in conditions in Pacific Ocean)
What are teleconnections?
Knock-on effects of El Niño worldwide
What happens in an El Niño event?
- Trade winds weaken and lead to eastward flow
- Warm water stays near South America, cold Humboldt current suppressed
- Warm water rises, cools and condenses to form clouds + heavy rain over South America (low pressure), flood risk
- Air circulation reverses
- Warm water near Australia moves eastward, reinforcing El Niño
- Australia has cool water and high pressure, risk of droughts and fires
How often do El Niño events occur?
Every 3-7 years
Frequency increasing due to climate change
How long do El Niño events typically last?
9-12 months
When was the latest El Niño event?
Started in summer 2023
What happens in a La Niña event?
Stronger trade winds, so neutral conditions intensify
Severe drought in South America
When was the last La Niña event? When can they occur?
2010/11
Can follow El Niño- this followed 2009/10 El Niño
How has desertification occurred in the Sahel?
- Colonialism + population growth –> shift from mainly nomadic to rain-red agriculture
- Land conversion- deforestation + agriculture
- More cattle- overgrazing + land conversion
- Soil exposed, increased soil erosion
- Agriculture leads to overcultivation
- Even less crops can grow, reduced EVT –> less local rainfall
Wet season also unreliable due to climate change
Leads to desertification, all encouraging over-abstraction
What are 3 socioeconomic causes worsening the desertification cycle of decline in the Sahel?
Poverty- no other choice of jobs
Civil wars/conflict- destroys land
China into Africa- takes best land, pushes farmers to worst-effected parts
What are some consequences of the 2015/16 El Niño Ethiopia (teleconnections)? (Sahel)
PS: a lot from aid fatigue too
Malnutrition
Vulnerable to disease from dirty drinking water eg: Cholera
100,000 displaced
What are 4 physical factors causing drought in Australia?
High-pressure
El niño
Continentality
Rain-shadow
What are the 2 ways humans contribute to drought in Australia?
Over-abstraction of surface + ground water: drought from high-tech water management in the Murray Darling basin
Over-abstraction of groundwater –> salinisation: large commercial farms in the southeast
Give background information on the Murray Darling Basin
Size of France and Spain
Provides 75% of Australian water
5x increase in extractions in last 100 years
How is the Murray Darling Basin managed?
30 dams to create reservoirs for irrigation, helps water variability
1974 Snowy Mountain Project is a water transfer project (series of dams, pipelines, reservoirs). Moves water from less used drainage basin (Snowy river) to in-demand drainage basin (Murray Darling River). Expensive and complex as water is pumped against gravity
What are 4 stakeholders who benefit from management in the Murray Darling Basin?
Commercial farming (before the Big Dry)
Residents of the MDR drainage basin
Government as increases drinking water supply
Fishing
What are 3 reasons why the management of the Murray Darling basin is not sustainable?
- Reduced river flow results in salinisation
- Ecosystems lost
- Eutrophication
How do commercial farms in Australia lead to salinisation via over-abstraction?
- Land cleared and replaced with crops
- Irrigation systems often used, rain fills up groundwater and raises water table. Heat pulls water table up more. This is capillary action
- Water table reaches the surface and the groundwater is salty due to being in natural rock
How can salinisation in Australia be fixed?
Sometimes high-tech solutions used to wash out the salt
Give some facts on the Australian Big Dry (2003-2012)
Commercial farms financially ruined, in debt so many had to abandon land
Ghost towns as people abandoned, local economy collapsed
Water restrictions in households/cities eg: no re-filling pools
Water bills increased by 20%
What is another name for the Australian Big Dry?
The Millennium drought from 1996
What is ecological resilience?
Capacity of ecosystem to withstand/recover from natural event/humans
What is the tipping point?
Where a system changes from one state to another with likely no reversal
What 2 ecosystems can drought impact?
Forest stress
Wetlands
Why are forests important? 4 ways
Regulation of hydrological processes
Wildlife habitats
Carbon sink
Human use eg: medicine, timber
What are the 3 physical factors causing forest stress in the Amazon?
Drought occurred due to ENSO
Blocking anticyclones
Deforestation increasing
What is the positive feedback loop causing drought in the Amazon?
- Due to physical causes, younger, less resilient trees die
- This reduces canopy layers, decreasing evaporation/humidity, thus decreasing rainfall
- More ground exposed to sun, tree litter creates tinderbox which can catch fire
- Storms/wind spreads wildfires
- Less dense forest cover dies back, savannah grassland replaces rainforest
How is drought in the Amazon exacerbated by human causes?
Land conversion
70% of wells illegal (overabstraction) –> industrial pollutants, high bacteria levels
Why are wetlands important? 8 ways
Nutrient cycling
Food chain
Carbon sink
FLood control
GW recharge/discharge
Fuelwood + peat
Fisheries
Aesthetic or cultural heritage
How is drought caused in wetlands?
Lower rainfall and declining water from upstream
But climate change means more evaporation, more tree mortality + soil erosion
Reduced ability to store water = decreased evaporation (breaking of water cycle)
Also a fire hazard
What is desiccation?
Removal of water
Why is the Pantanal freshwater ecosystem (south America) important?
UNESCO world heritage site
Aquatic and bird life dependent on ecosystem
What is the issue in the Pantanal freshwater ecosystem?
Increased tree mortality decreases habitats
Purposeful wildfires to clear vegetation become out of control
What is the resilience of the Pantanal freshwater ecosystem?
Ramsar convention: schemes to protect it are developed at different scales
What are the 3 meteorological causes of flooding?
Intense storms and heavy, prolonged rainfall (short term)
Extreme monsoonal rainfall in tropics (medium term)
Snowmelt (medium term)
How are storms formed?
Due to cold polar air meeting warm tropical air at polar front, jet stream formed
Jet stream strengthens in autumn/winter, leaving to stronger winds and heavier rains
How do intense storms + heavy, prolonged rainfall cause flooding?
- Increased volume of water in drainage basin
- Series of successive storms leads to antecedent conditions, ground saturated
- Low-pressure systems also pull up on ocean –> localised coastal flooding
How does extreme monsoonal rainfall in the tropics cause flooding?
ITCZ moves throughout the year, brings convectional rainfall for 3 months
70% of rainfall in just 100 days –> widespread floods very damaging
Which areas are even more at risk from extreme monsoonal rainfall?
Low lying plains in rivers eg: bangladesh
Coastal areas in region due to rainfall from cyclones
How can snowmelt cause flooding?
Melting snow in late spring causes extensive flooding due to quick transition from winter to spring
Lower layers remain frozen, limiting infiltration
Ice dams hold up floodwater, leads to flash floods upstream, or they collapse
What are 3 case studies of snowmelt causing flooding?
York- spring melt in pennines rapidly adds water to the river
Bangladesh- snow in Himalayas flows into local rivers, also ice dams collapse. Exacerbated by climate change
Iceland- volcanic heat melts water beneath ice sheet/glacier, leads to sudden release of meltwater (jokulhlaup)
What are the 2 broad ways humans can exacerbate flood risk?
Changing land use
Mismanagement of rivers
How can humans exacerbate flood risk via changing land use?
Urbanisation- impermeable surfaces reduce infiltration and speeds water flow, fills drains. If 100% impermeable, only 5% infiltrates
Agricultural- ‘sheep-wrecked uplands’ + plowing compacts soil, leading to more overland flow. deforestation increases soil erosion and adds to river + reduced flow
How can humans exacerbate flood risk via mismanagement of rivers?
Channelisation- straightens and increases flood risk downstream
Dams- blocks downward flow of sediment, reservoir fills with silt increasing river bed erosion
Embankments- can fail when floods exceed capacity
What are 6 socio-economic impacts from the flooding from UK Storm Desmond 2015 (mid-latitude depression)?
3000 homes flooded, residents put into temporary accommodation
Insurance claims exceeded £6 bil
Roads and services disrupted
Stress, anxiety, trauma
Decreased house prices
Decreased tourism
In developing countries, what is flooding more likely to spread?
Water-bourne diseases
What are 4 environmental impacts of the flooding from UK Storm Desmond 2015 (mid-latitude depression)?
Landslides
River banks eroded –> contaminated rivers
Soils eroded, habitats destroyed so ecosystems affected
Saturated ground led to decomposition of dead plants/animals, releasing harmful gases threatening foodchain + wildlife
What is the counterargument for environmental impacts of flooding?
May have positive impacts eg:
- recharges groundwater
- moves nutrients around landscape
- can trigger breeding
In synoptic charts, what do isobars (black lines) do/show?
Connect areas with similar pressure
Closer lines = stronger winds
Clockwise in Northern hemisphere
What are the 3 different fronts in synoptic charts and how are they represented?
Warm front (red semicircle)
Cold front (blue triangle)
Occluded front (purple triangle + semicircle) where faster cold front catches up with warm front. Frontal rainfall
In synoptic charts, why is the warm sector in between the warm and cold front?
Moist air trapped between 2 fronts
What is the model that explains the causes of rainfall in the UK through mid-latitude depression formation? (Skill 6)
Bergen model
What are the 5 steps of the Bergen model?
Step 1+2- origin and infancy. Meeting of ferrel and polar cell, frontal rainfall forms.
Step 3- maturity. Warm air rises into upper atmosphere, warm sector decreases, low pressure area forms. Weather pattern = cold, rain, warm, rain, cold.
Step 4- occlusion. When warm air has fully risen, cold and wet conditions
Step 5- death of depression. When all warm air has risen out of the way, no rain, just cold.
How can the Bergen model explain UK weather?
Storm reaches Britain when depression is in mature/occluded as origin is over the Atlantic
Location over UK depends on the Jet Stream which causes faster winds from west –> east. Whether it is flat of meandering
What are the 3 key climate change processes that impact the hydrological cycle?
Climate/radiative forcing
Positive feedback loop
Albedo effect
What is climate/radiative forcing? How does this lead to positive feedback?
Enhanced GHE- pollutants add to greenhouse gases and trap more heat, heating the surface
Warming –> evaporation –> condensation –> heavy rainfall
More latent heat (released in state change) further increases evaporation
Increase in runoff, so in long-term drainage basin loses water (collapse of local water cycle), less water for evaporation
How does the Albedo effect impact the hydrological cycle?
Ice melt creates darker sea and land, which absorbs more heat
Thus, atmosphere above heated, generally heats region –> more ice melts (positive feedback)
What are recent flood trends?
Concentrated in tropics, Asia, northern mid-latitudes
Concentration of rainfall events in last 50 years
What are recent drought trends?
Concentrated in semi-arid (eg: Sahel), landlocked (eg: central Asia)
Often dry periods globally eg: 1980s, much more more recently
What are other anthropogenic factors that may cause drought/flood (not climate change)?
Deforestation- both increase as local water cycle collapses, creates positive feedback loop
Urbanisation- increases flood risk
Large scale commercial farming- dams, canals, irrigation, groundwater abstraction
More vulnerable people- impacts more people, also more people = more of above (positive feedback)
How can climate change impact inputs (diminishing water supply)?
ENSO more intense
Lack of rainfall so drought occurs, local water cycle collapse
eg: Sahel, Australia
How can climate change impact outputs (diminishing water supply)?
Greater evaporation from surface water eg: lakes
Greater EVT
BUT also high spring melt
eg: Bolivia
What is the impact of climate change on stores and flows?
Snow/glacier mass- melting, especially in N-hemisphere, affects communities
Reservoirs/lakes- linked to climate, evaporation
Permafrost- deepening of active layer released groundwater and thawed lake releases methane
Soil moisture- little change as rain/evaporation cancels out, ambiguous as related/affected by many factors
Runoff + stream flow rates- increase in extreme low/high flows, more intense rainfall increases rate and reduces infiltration
What are 4 current features of the Californian mega-drought?
Forecasted 30 years
Worst in 1200 years
Increase temperature (and evaporation), decreased rainfall
Water rationing in cities
What are 3 current issues of the Californian mega-drought, predicted to become worse?
Groundwater levels fell 30 metres in 4 years
Castaic Lake at half of normal capacity
Decreased surface runoff and soil moisture, reservoir levels decreased
What does it mean to have water security?
Sustainable access to adequate quantities of acceptable quality water
What happens with water insecurity?
Can’t sustain livelihoods/wellbeing/develop
What is water stress?
Between 1000-1700m³/person
Country exceeds 10% of renewable freshwater supply
What is water scarcity?
Below 1000m³/persom
What are 2 physical causes of water insecurity with examples?
Climate variability → Australian Big Dry + Californian Mega Drought + edge of tropics
Salt-water encroachment → Middle East
What are 2 human causes of water insecurity with examples?
Over abstraction → Aquifer abstraction in Ogallala, US, lake abstraction in Aral Sea
Contamination → East China with industrial pollution, Central Asia (Aral Sea) with agricultural pollution
What are 2 economic causes of water insecurity with examples?
Infrastructure → India lacks on local/national scale, especially in rural
Unaffordability → Bolivia fixed price to set up water infrastructure, IMF/FDI means water unafforable
Why do developing countries struggle with water insecurity?
Lack of infrastructure/purifying tech
Rain-fed agriculture
Neocolonialism
Overpopulation
Why do emerging countries struggle with water insecurity?
Industrilisation + urbanisation
Rising middle class + slums
Why do developed countries struggle with water insecurity? What is the counter to this?
High personal consumption
Commercial farms
But, increased awareness of environmental impacts (sustainability)
How has the freshwater supply changed in the Aral Sea? Why?
Was once 4th largest freshwater supply in the world
Now 80% dried up
Due to USSR wanting farmland, so canals divert water for cotton/rice farming
What are 3 environmental issues with lake over abstraction/agricultural pollution in the Aral Sea?
Toxic gas in the atmosphere (climate change), found in blood of Antarctic penguins
Summers are shorter/drier/hotters, winters are longer/colder
Plants/animals eg: wild horses not enough food so died/migrated
What are 2 impacts on human welfare that have occurred from lake over abstraction/agricultural pollution in the Aral Sea?
High rates of respiratory illness- accounts for 1/2 children’s deaths, throat cancer
80% has blood disorder, increase in anaemia
What are some economic impacts resulting in economic decline from lake over abstraction/agricultural pollution in the Aral Sea?
40,000 employed in fishing industry lost jobs as fish died + farms ruined by salinisation = unemployment
Outmigration as services collapsed, just small elderly communities left
Why is the Ogallala aquifer in the US important?
One of the largest aquifers in the world
Supplies 30% of water irrigation in USA
What is the rate of over abstraction in the Ogallala aquifer?
Aquifer reducing 2x as fast as 60 years ago as dry + recharge slow
What is the solution to over abstraction in the Ogallala aquifer?
Improving irrigation efficiency: better equipment, no waste
Why is there industrial water pollution in the East of China?
‘Factory of the world’
Very high population density
Fashion industry uses many hazardous chemicals in clothing as global demand for cheap clothing
What are 2 impacts of industrial water pollution in East China?
Rise of cancer village, including rare cancers
Rivers green from algae blooms/thick with garbage + dead fish
What is the solution to industrial water pollution in the East of China?
Green Peace ‘detox campaign’
Exposes links between global clothing brands and toxic water pollution in China
Challenges popular brands to work with suppliers to eliminate releases of hazardous chemicals into water
What does the UN predict for the increase in water demand by 2050?
55% increase
What are 4 reasons as to why there is a rising water demand?
Increasing population
Improving living standards
Industrialisation
Agriculture
Where is an increased population increasing water demand?
Rapidly growing in emerging (slums) + developing
Where are improved living standards increasing water demand? Why?
Emerging
More water consumed directly eg: washing machines
And indirectly eg: house building, food choice
Where is industrialisation increasing water demand? Why?
Emerging as have less environmental regulation and more corruption than developed
Heavy metals leaking to river + groundwater
Fossil fuels use water
Where is agriculture increasing water demand? Why?
Emerging + developed
Commercial farming + centre-point irrigation
Uses 70% of global water but food demand increasing
What are 3 projections of future water scarcity?
Hope emerging countries reach turning point of Kuznets curve and improve regulations/economic shift
UN predicts 40% of world in water deficit by 2030
Biggest demand increases from electricity + manufacturing + domestic demand
What is the world water gap?
The difference between the 60% of the world with physical/economic water scarcity and those with ready + reliable water supply
Why is there a positive correlation between GDP and access to safe water?
Increased tax increases the money spent on water infrastructure
Why is there a positive correlation between GDP and access to sanitation?
Availability > quality
Expensive infrastructure not prioritised over development/ economic growth
What is the GDP in Indonesia compared to the % with access to safe water + sanitation?
GDP → US$1.2 trillion
Access to safe water → 78%
Access to sanitation → 55%
What is the GDP in Ethiopia compared to the % with access to safe water + sanitation?
GDP → US$111 billion
Access to safe water → 24%
Access to sanitation → 12%
Why is Haiti suffering economic water scarcity?
1/2 live on <$1/day
Earthquake damaged few clean water supply + wells
Why is the US suffering economic water scarcity?
Ageing water systems
Inherited debt and bills increasing in Rustbelt
What is the lived experience of people in Haiti with economic water scarcity?
70% no access to potable water
Waterborne illnesses as have to gather from garbage-filled rivers –> accounts for >1/2 of all deaths/year
What is the lived experience of people in the USA with economic water scarcity?
Taps turned off with unpaid bills
Liens on property to satisfy debt
Have to purchase bottles of water to drink
Why does the price of water vary globally?
- Developing have just built water infrastructure, so it is expensive to repay cost
- Need to build more infrastructure as urban growth outgrown colonial, limited infrastructure. Now privatised (eg: England) so consumers pay higher for profit. But now cities taking back control (eg: Paris) as too important for health/environment
- High cost if has to be piped from mountain reservoirs (eg: LA gets water from Colorado)
- If scarce (eg: Californian mega-drought) price increases to manage demand
- If no infrastructure, cost from informal vendors 2x price of tap water (eg: Ghana)
What 2 sectors of economic development is water important for?
Agriculture
Industry & energy
Why is agriculture important for economic development?
Water needed for commercial farming/irrigation
1/3 under irrigation which is water intensive
Agriculture uses 2/3 global water extractions, is growing rapidly (due to nutrition transition + rising middle class)
How much water does industry/energy use?
Uses 20% of world’s water
Global shift transfers water pressure to emerging world, consumption rising
But HEP returns water
Why would the economy not thrive without water?
Limited harvest + exports/efficiency
Ill-health has economic implications due to loss of productive workforce
How can poor water impact health (human wellbeing)?
Diahorreal diseases lead to dehydration
Time drain as women + children walk ages to collect water (time away from school, dangerous)
Emotional trauma from high mortality rate + loans for medications
How can poor water impact food preparation (human wellbeing)?
New river dams allow insects to breed (eg: mosquitos breed in stagnant water)
Lack of education risks disease from crops
How can poor water impact sanitation (human wellbeing)?
No toilets, human excreta enters water supply (+ soil, affecting food prep)
Why is there water insecurity in rural Bolivia?
Lack of access to water infrastructure + sanitation
High birth rate (population increasing)
Why is there water insecurity in urban Bolivia?
R–>U migration puts pressure on services, creates slums that lacks infrastructure
Dead glacier reduces spring melt in La Paz
Water infrastructure owned by TNCs
What are 2 human consequences from water insecurity in rural Bolivia?
Diahorrea leading cause of child death, leads to other conditions eg: anaemia
Difficult to access healthcare
What are 3 human consequences from water insecurity in urban Bolivia?
No plumbing, go to toilet on streets
40 families obtain water from an open tap, or have to walk
1/3 lack access to drinking water/sanitation
What are 4 environmental problems resulting from inadequate water?
Ecosystems collapse, reducing biodiversity
Drier regional climate
Domestic pollution with no sanitation system
Eutrophication
What is the impact of inadequate water on wetlands?
Important to reduce floods, but half have been lost
What is the impact of inadequate water on forest highlands?
Important to recharge aquifers, but not sustained as importance overlooked
What is the impact of inadequate water on farming at Salton Sea, USA?
Water levels falling so salinity increases
Water diverted for Californian agriculture as high demand
Damages usually productive ecosystem which feeds 400+ bird species
What is a transboundary river?
River that crosses at least 1 political border, may be national or international
What is territorial sovereignty?
Country claims ownership over water when source of river is in their country
What is territorial integrity?
Country claims they should get the same amount of water as they always have from shared water source that doesn’t begin there
Describe the global picture of water conflict
Africa- main conflict in NIle (neocolonialism)
Asia- several areas eg: Mekong, lower basin countries left unhappy
Middle East- high geopolitical tensions so may be actual conflict over water
South America- dying glaciers + Amazon drying out from climate change, water rioting eg: urban Bolivia
What are 4 reasons for water conflict? Give examples
Too much used upstream in transboundary eg: mega dams on Nile
Pollution occurs upstream in transboundary eg: Aral sea
Existing geopolitical conflict, political relations strained eg: India/Bangladesh
One country having more economic power eg: USA over Mexico
The intersection of what can lead to water conflict? (water pressure point/hotspot)
Supply issues
Demand issues
Different users with different beliefs
How many countries does the river Nile go through?
Sources in Uganda + Ethipoia
Crosses 10 national borders
Why may conflict occur over the international transboundary river Nile?
300 mil live in basin, to double by 2030 = pressure on water
Eygpt relies on it for 90% of water
Neocolonialism = increased industrial water demand
Eygpt have veto power over upstream projects, but Ethiopia doesn’t feel bound = tensions
What is a possible solution to conflict in the Nile?
New/heightened dams
Cooperation
Why may conflict occur over the national transboundary river Murray Darling?
Increase in water extraction
Agriculture major consumer as irrigation increases profit
Conflict between resitdents/industrial users/environmental groups
What is a possible solution to conflict in the Murray Darling?
Basin plan to determine the volume of water extracted to avoid environmental impact
Why may conflict occur over the national local river Cochabamba, Bolivia?
1999 water privitised, prices rose
But after protests for 4 days, decision reversed
What are the 3 different approaches to managing water supply?
Technofix engineering
Sustainable restoration/conservation
Integrated drainage basin management (IDBM)
What are technofix hard engineering schemes?
Large scale, capital-intensive schemes to solve water insecurity
What do water transfer schemes do?
Divert water from surplus DB to a deficit DB by diverting river or building canals
Created LT change to hydrological cycle- eg: evap increases, so does rainfall (and flooding!)
What are mega dams?
Dams with ability to hold 15% of rivers’ annual flow
Multi-purpose schemes (eg: reservoir storage, HEP)
What is the case study for water transfer/mega dams?
China
South-North water transfer project as Bejing has 1/3 of population but only 7% of water
Building of 3 artificial canals
What are 2 strengths of water transfers/mega dams?
Economic growth is successful
Reduces pressure on groundwater
What are 4 weaknesses of water transfers/mega dams?
Environmental impacts (ecosystems, water polluted)
Top-down
Forced migration
Limited to emerging/developed countries as expensive
What is desalination and its use to manage water supply?
Removal of salt to produce potable water
4% world reliant, global boom
Recent tech breakthroughs eg: reverse osmosis
What is the case study for desalination?
Israel
Desalination provides 70% of its water
5 new plants in 2013
World leader
What are 2 strengths of desalination?
More sustainable as decreases pressure on groundwater
Very efficent
What are 3 weaknesses of desalination?
Fossil fuels = CO2 emissions (but becoming increasingly solar powered)
Salt waste (brine) harms ecosystems
Top down (but Israeli population can afford)
What is sustainability?
Meeting the needs of the present without compromising needs of the future
What are the 3 legs of the sustainability stool?
Social + economic + environmental
What are the 4 sectors of the sustainability quadrant?
Equity
Public participation
Environment
Futurity
What is restoration of water supplies?
Restoring rivers/lackes/wetlands to play full part in the natural hydrological cycle
What is the case study for water restoration?
Aral Sea
Planting local grassland + trees to restore biodiversity and create local woodland ecosystem
Building a dam reduced salinity so fish returned
What is a disadvantage of restoration?
Very slow process, decades to see improvement
Less equity for current generations
What is water conservation? What are 4 methods?
Protecting the usage of water
Smart/drip irrigation
Recycled/grey water
Virtual water
Domestic solutions
What is smart/drip irrigation used in Israel?
Slowly gives water to plant roots, reducing wastage
But high initial cost so more suited to developed
What is recycled/grey water used in Singapore?
‘NEWater’ uses membrane tech and UV disinfectant (holistic management) to provide 30% water in Singapore
Expensive but population can afford
What is virtual water used in Saudi Arabia?
Imports grains and wheat that uses water in other countries
Dependent on other countries
Expensive
Water miles
What are 3 small-scale water conservation solutions for developing countries, used in the Sahel?
Demi lunes- hand dug semi-circles to trap falling rain
Micro-dams- stones trap water for agriculture + domestic use
Magic stones- circle of boulders holds water so it doesn’t run off
What is a larger-scale water conservation solution used in the Sahel region?
Great Green Wall
Agroforestry across 11 countries
8000km
How can domestic solutions conserve water?
Attitudinal fix
Eg; Smart meters, which also saves money for consumers)
What does integrated drainage basin management (IDBM) aim to achieve?
Balanced and coordinated approach to river basin planning and management, agreed by all stakeholders
What does the UN’s integrated water resource management (IWRM) do?
Promotes coordinated management of water/land to maximise economic/social welfare without compromising sustainability of vital ecosystems
What are 2 political features of the IWRM?
Freedom from corruption
Decentralisation of descisions
What are 3 socioeconomic features of the IWRM?
Food + water security
Economic productivy
Maximum efficiency
What is an environmental feature of the IWRM?
Protection of all supplies + ecosystems
What is an example of a large-scale IWRM?
Colorado
Supplies 50 million Americans with drinking water
97% USA, 3% Mexico
Major dam use- 29
What are 3 challenges river Colorado faces?
Land conversion for urbanisation + agriculture –> drought
Population growth
Climate change
What are historical agreements over the river Colorado?
1922 Colorado Compact- divided into upper and lower basin, lower received more as more demand
1944- agreement with Mexico for increased share
By by 1990s, outdated as: increased demand, less rainfall, technofix consequences, conflicts
What are the 21st-century agreements over river Colorado?
2007 New Colorado Agreement- reduced allocation as reduced rain, main user California promised 20% reduction
2012 Minute 139 agreement- guaranteed water to Mexico, US can buy water if wish. sustainable wetland restoration from spring pulse (although only temporarily regenerates ecosystem)
What is the overall success of management of the river Colorado?
Not successful as not fully integrated, this is typical for transboundary
Some success in prioritising Mexico and soft engineering (pulses)
Where has IWRM been successful on a small scale?
Gujarat, India –> reduced water poverty
What are 2 strategies used to manage rivers in Gujarat?
Check dams- small, uses stones
Water harvesting- lots on farms, also recharges GW
Why have the strategies used to manage rivers in Gujarat been successful?
Farmers grow a range of crops, improving health
Income increased by 3x
Due to good governance
What is the aim of water-sharing treaties?
To avoid upstream/downstream water conflict
What are the Helsinki rules 1966?
Encouraged equitable use
But superseded by Berlin Rules 2004
What are the Berlin Rules 2004?
9 water sharing principles pushing sustainability and stakeholder consideration
What is the EU Water Framework Directive and hydropower?
Target to restore rivers/lakes/canals/coast to ‘good’ condition
Policy required basin-wide assessment of risks to environment posed by new developments
What is the UN Economic Commission for Europe (UNECE)?
Resolves transboundary issues via sustainable IWRMs
Are water-sharing treaties successful?
No-
Idealistic/very hard to achieve, countries sign to look good
Failure mirrors the power dynamics of countries involved
