Presentation on theme: "Water MA ( Dev) Semester I Azim Premji University P.S.Narayan and Purnendu S Kavoori."— Presentation transcript:
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
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 20 th 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)
11 One Estimate of Global Water Distribution (Numbers are rounded) Water source Water volume, in cubic miles Water volume, in cubic kilometers Percent of freshwater Percent of total water Oceans, Seas, & Bays321,000,0001,338,000,000--96.5 Ice caps, Glaciers, & Permanent Snow 5,773,00024,064,00068.61.74 Groundwater5,614,00023,400,000--1.7 Fresh2,526,00010,530,00030.1 0.76 Saline3,088,00012,870,000-- 0.93 Soil Moisture3,95916,5000.050.001 Ground Ice & Permafrost71,970300,0000.860.022 Lakes42,320176,400--0.013 Fresh21,83091,0000.260.007 Saline20,49085,400--0.007 Atmosphere3,09512,9000.040.001 Swamp Water2,75211,4700.030.0008 Rivers5092,1200.0060.0002 Biological Water2691,1200.0030.0001 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 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
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 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 metricsDisadvantages 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)
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 ?
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 TitleAuthor references Water Scarcity : Fact or FictionFrank 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 2025Alcamo, Henrichs and Rosch for Kassel World Water Series Report 2 Videos on waterThe Water Channel at www.thewaterchannel.tvwww.thewaterchannel.tv Reading references