Water

MA ( Dev) Semester I Azim Premji University

P.S.Narayan and Purnendu S Kavoori

The Science: Hydrologic cycle

Culture: Water as a intimate part of the human

narrative

Technology: Engineering water for anthropogenic

uses : Dams, Irrigation, Water treatment..

Socio-economics: Measuring and Assessing Water

Scarcity, Costs, Pricing

The Politics: Equity of access, Entitlement and

rights, Governance, Institutions

The many dimensions of water

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• The anthropogenic impacts of biogeochemical cycles stem from certain fundamental drivers – Energy Production in the case of Carbon and Food Production in the case of Nitrogen

• What about Water ? Human use of water touches almost all aspects of our socio-economic infrastructure

– For growing food and other crops– For energy production : Washing coal, Running steam turbines, Hydropower– For domestic use : Cooking, Drinking and Hygiene– Widespread use in industry

• Water is not just another biophysical resource though…..it is part of people’s lives and cultures in an intimate manner that C and N are not. We can touch, feel, see and taste it. In its fluid and frozen forms, it is part of our living landscapes

• The hydrologic cycle is closely linked with climate change and other cycles in nature

Carbon, Nitrogen and Water

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• The Living Planet Index has declined the most for freshwater habitat over the period 1970-2000 – by 50% as compared to 30% each for terrestrial and marine biomes

• Freshwater withdrawals increased eightfold over the 20th century – whereas the population just quadrupled

• Humans appropriate nearly half of the global runoffs ( or Net precipitation on land)

• Pollution and Eutrophication of many freshwater systems

• Washing of coal before being sold results in severe toxification of water systems including heavy metals like mercury, arsenic and lead

The anthropogenic impact on water

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• Large irrigation projects have ensured that most of the great rivers do not reach the sea during the dry season

• More than 41000 large dams ( > 60 ft high) across the world and many more that number of small dams. These

– Regulate the flow of more than 60% of the world’s rivers– Retain more than 10000 cubic KM of water, more than five times the volume of

all the world’s rivers– Eighty million people have had to be forcibly relocated– Represent a 700% increase in the stock of rivers in the last six decades– Have resulted in a massive redistribution of weight with accompanying

changes in the earth’s magnetic field and gravity patterns– Result in outbreaks of infectious diseases like schistosomiasis– Loss of biodiversity by preventing the natural flow of nutrients

The anthropogenic impact on water….(cont’d)

The fundamentals of the Water Cycle

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The water cycle: a visual summary

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The water cycle: Flows

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The water cycle: Stocks and Flows

Units in Million KM3

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The distribution of earth’s water

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One Estimate of Global Water Distribution(Numbers are rounded)

Water sourceWater volume, in cubic miles

Water volume, in cubic kilometers

Percent offreshwater

Percent oftotal water

Oceans, Seas, & Bays 321,000,000 1,338,000,000 -- 96.5

Ice caps, Glaciers, & Permanent Snow

5,773,000 24,064,000 68.6 1.74

Groundwater 5,614,000 23,400,000 -- 1.7

    Fresh 2,526,000 10,530,000 30.1   0.76

    Saline 3,088,000 12,870,000 --   0.93

Soil Moisture 3,959 16,500 0.05 0.001

Ground Ice & Permafrost 71,970 300,000 0.86 0.022

Lakes 42,320 176,400 -- 0.013

    Fresh 21,830 91,000 0.26 0.007

    Saline 20,490 85,400 -- 0.007

Atmosphere 3,095 12,900 0.04 0.001

Swamp Water 2,752 11,470 0.03 0.0008

Rivers 509 2,120 0.006 0.0002

Biological Water 269 1,120 0.003 0.0001

Source: Igor Shiklomanov's chapter "World fresh water resources" in Peter H. Gleick (editor), 1993, Water in Crisis: A Guide to the World's Fresh Water Resources (Oxford University Press, New York).

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97%

2%

0.67%

0%

0%

0%0%0.00%

Water in '000 KM3

OceansCryosphereGround WaterLakes and StreamsSoilsAtmosphereRiversBiosphere

Of this, approximately 109 000 KM3 is in continuous flow as part of the hydrologic cy-cle

Only around 0.003% water is available for human use ( around 35 000 cubic KM – realistic availability of only 14000 KM3)

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• Blue water is that which is available from runoffs in streams and rivers and from recharge to aquifers in the ground this constitutes about 40% of the rainfall

• Green water refers to the balance 60% of the rainfall that infiltrates the soil, becomes soil moisture and evapotranspires without having entered into rivers or groundwater

• Irrigation draws from the ‘Blue Water’ to make up for deficiencies in Green Water for agriculture

Blue and Green Water

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The unique characteristics of water

Fluid

Often Invisible

Cyclical but Unpredictable

No substitutability

Solvent

Problem in Excess & Scarcity

Water and its interfaces with other planetary parameters

Climate Change (i) Decreased C sequestration due to loss of green water (ii) Decline in moisture feedback of vapor flows affecting climate regn (iii) Positive feedback loop because of higher water holding capacity at higher temps

Interference with N and P flows

(i) Eutrophication because of overloaded N nutrients (ii) Acid rain due to increased precipitation of atmospheric N compounds

Ocean Acidification (i) Increased CO2 absorption has severe effects on marine life

Biodiversity Loss (i) Collapse of biological sub-systems due to regional drying including that of riverine habitats and lake systems (Aral Sea) (ii) Increase of Anoxic events leading to local biodiversity loss

Land System Change (i) Land degradation leading to soil moisture loss affecting biomass production (ii) Increased water runoffs and loss of water integrity (iii) Changes in green water patterns – higher evaporation, lesser transpiration (iv) Increased salinization

Chemical Pollution (i) Sulfate, Heavy Metal and other toxic pollution reduce fresh water availability for human use (ii) Impact on coastal ecosystems

The science and politics of water scarcity

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Where is water primarily used ?

Vegetarian diet Non-Veg diet0

1000

2000

3000

4000

5000

6000

7000

2600

54001000

1000

OthersFood productionDomestic use

The Water content of things

The multiple dimensions of water scarcity

Water Availability

Too much or too little ?

Temporal or spatial scale

Physical vs Economic Scarcity

Domestic / Food /

Industry / Environment

Is it polluted or unfit for

use ?

The different dimensions of water scarcity*

* As defined by IWMI

Physical Water Scarcity

Countries that will not be able to meet their demand by 2025 even after accounting for future

adaptive capacity

Economic Water Scarcity

Countries that have sufficient water resources but would have to make significant investments in

making this water available

Ecological Water Scarcity

Where water is not available adequately for the provisioning of ecological services – forests,

wetlands, freshwater systems

The metrics Disadvantages

The Falkenmark indicator

-Minimum of 1700 m3 of renewable fresh water PCPA-Water stress at < 1700 m3- Water scarcity at < 1000 m3- Abs water scarcity at < 500 m3

-Hides important scarcity at smaller scales- Does not reflect variations in demand due to climate, lifestyles, adaptive capability etc

Water Resources Vulnerability Index

Annual water withdrawals from rivers, streams and groundwater aquifers of-20-40% Water Scarcity->40% Severe water scarcity

-Does not consider how much water is available for human use or- How much is consumptively used or lost through evapotranspiration or- How much is available through return flows

Water Poverty Index

-Access to water- Water quantity, quality ad variability-Water use for domestic, food and productive purposes-- Adaptive capacity for water management - Availability for ecological integrity

- Complicated and not easy to understand intuitively

The different measures of water scarcity

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Projected global water scarcity in 2030 (Based on Falkenmark indicator)

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Economic Vs Physical Water Scarcity

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Projected global water scarcity in 2025 (Based on Water Gap Indicator)

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Projected global water scarcity after accounting for environmental indicators

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Projected global water scarcity in 2025 (Based on Water Poverty Index)

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Peak Ecological Water

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1. Is Water physically scarce ( Supply problem) or is it available but not used and allocated well i.e. poor governance, inadequate economic access?

2. What is the scarcity for – for domestic purposes, for food production, for industrial use, for the environment ?

3. Is water scarcity a local, national or global issue ?

4. Average measures of water availability hide a number of realities ; A national or regional aggregate may be of little use if local contexts are different and varying

5. If water is available for anthropogenic use but not for the environment, what does it imply for long term stability of ecosystems ?

The questions on water scarcity

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Should domestic water availability be an issue at all ?

Agriculture; 3350; 72%

Industry; 1150; 25%

Domestic; 150; 3%

Water for Human Use

Domestic Water0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

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Cooking; 96

Hygiene; 50

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Comparisons between Peak Oil and Peak Water

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• Water scarcity projected as absolute and monolithic ; in reality, its dimensions are many –ecological, socio-political and temporal.

• Water as a resource does not get lost – it is always present in the hydrologic cycle ; But its availability for human use is spatio-temporally changed

• Tremendous inequity in distributional access – 10 ltrs per day in certain regions Vs 700 Lts PD in N.America

• Mis-engineered and Mis-governed : Drying up of Aral Sea, Broken hand pumps, Pipeline losses

The Kutch story• No decrease in average rainfall between the two 30 periods – 1968-98 and 1938-68• Appropriation of scarce water by the more powerful affecting equitable access• Singular fixation with the silver bullet of an unrealistic supply side solution – water

transported over a long distance from a large dam• No water harvesting being done….all runoffs

Is water scarcity therefore real or constructed ? – Lyla Mehta’s case study of Kutch

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Was the water scarcity in Kutch real or constructed ?

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1. Water is physically scarce in Central and West Asia and N.Africa with projected availabilites of less than 1000 m3 per capita per annum ( PCPA) ; however, this scarcity is principally for food production and not for domestic use ( 20 m3 per annum)

2. Upto 70% of the world’s population will be affected by water scarcity over the next few decades

3. When it comes to water provisioning for the environment, even water-abundant geographies in the developed world become water scarce ; without including environmental needs, there is no water scarcity in much of the developed world ( N.America, Japan, Europe, Australia)

4. Latin America does not seem to have physical water scarcity ; yet, millions do not have access to adequate water, indicating economic scarcity rather than physical

5. Demand side management – e.g. improving water efficiency, shift from large infrastructure to decentralized micro irrigation etc – will be more effective than the futile effort in increasing supply

Some definitive conclusions

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1. 1.2 billion people across the world lack access to safe and affordable water for domestic use Likely to be physically available but economically unavailable

2. About 900 million people in rural areas – with an income of less than a dollar a day – do not have access to water for their livelihoods Likely to include both, physical and economic unavailability

3. 2.18 million deaths per year due to water related diseases of whom 75% are children less than 5 years old

4. Global burden of disease measured as 82 million disability adjusted life years

The social costs of water scarcity

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• Deforestation leading to increased surface runoffs and evaporation without reverse precipitation i.e. decrease in groundwater stock

• Increase in global warming induced temperatures leading to increased evaporation losses from surface waters without reverse precipitation

• Accelerated loss of soil moisture with consequences for food yields

• The reverse effect of the water cycle on climate change : changes in precipitation and drought patterns

The exacerbating biophysical factors

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• Fixation with Supply Management, driven by Technology and Engineering; Vs Local, Decentralized ‘Demand’ approaches that evolve solutions aligned with the local context

• Poor water literacy even among the educated – no idea or sense of aquifer based groundwater management / water-sensible cropping patterns / micro-irrigation

• Pricing does not reflect true costs – ecological and social – of water e.g. inadequate ecological provisioning will have severe long term effects. Ironically, the poor pay more for water.

• Equitable access seems a distant possibility – existing power structures will continue to ensure so

The exacerbating sociopolitical factors

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Title Author references

Water Scarcity : Fact or Fiction Frank R Rijsberman, International Water Management Institute, Colombo

Fundamentals of Ecology – the chapter on Water Cycle

Odum and Barrett

Contexts and Constructions of Water Scarcity

Lyla Mehta in ‘the Economic and Political Weekly’, Nov 2003

Supply Side Hydrology in India – The last gasp

Rohan D’Souza ‘The Economic and Political Weekly’. September 2003

Water for India in 2050 : first order assessment of available options

S.K.Gupta and R.D.Deshpande in ‘Current Science’, May 2004

Peak Limits to freshwater withdrawal and use

Peter H.Gleick and Meera Palaniappan in PNAS journal June 22 2010

World Water in 2025 Alcamo, Henrichs and Rosch for Kassel World Water Series Report 2

Videos on water The Water Channel at www.thewaterchannel.tv

Reading references