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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
5
3
• 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
4
• 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
5
• 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
7
The water cycle: a visual summary
8
The water cycle: Flows
9
The water cycle: Stocks and Flows
Units in Million KM3
10
The distribution of earth’s water
11
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).
12
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)
13
• 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
14
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
18
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
23
Projected global water scarcity in 2030 (Based on Falkenmark indicator)
24
Economic Vs Physical Water Scarcity
25
Projected global water scarcity in 2025 (Based on Water Gap Indicator)
26
Projected global water scarcity after accounting for environmental indicators
27
Projected global water scarcity in 2025 (Based on Water Poverty Index)
28
Peak Ecological Water
29
30
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
31
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%
4
Cooking; 96
Hygiene; 50
32
Comparisons between Peak Oil and Peak Water
33
• 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
34
Was the water scarcity in Kutch real or constructed ?
35
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
36
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
37
• 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
38
• 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
39
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