its about water cycle, water conflicts, water hazards etc

1. The WaterThe Water
ByBy
NIKHIL KADAMNIKHIL KADAM 153010003153010003

2. A blue planet: ….

4. The world’s waterThe world’s water
resourcesresources
Glaciers,
Snow &
permafrost
1.725%
Ground
water
0.075%
Lakes,
swamps &
rivers
0.025%
Oceans
97.5%

6. Water never leaves the Earth. It is constantlyWater never leaves the Earth. It is constantly
being cycled through the atmosphere, ocean,being cycled through the atmosphere, ocean,
and land. This process, known as theand land. This process, known as the waterwater
cyclecycle, is driven by energy from the sun. The, is driven by energy from the sun. The
water cycle is crucial to the existence of life onwater cycle is crucial to the existence of life on
our planet.our planet.

8. The Water CycleThe Water Cycle

9. During part of the water cycle, the sun heats
up liquid water and changes it to a gas by the
process of evaporation. Water that
evaporates from Earth’s oceans, lakes, rivers,
and moist soil rises up into the atmosphere.

11. The process of evaporation from plants isThe process of evaporation from plants is
calledcalled transpirationtranspiration. (In other words, it’s like. (In other words, it’s like
plants sweating.)plants sweating.)

13. As water (in the form of gas) rises higher in the
atmosphere, it starts to cool and become a liquid
again. This process is called condensation.
When a large amount of water vapor condenses, it
results in the formation of clouds.

15. When the water in the clouds gets too
heavy, the water falls back to the earth.
This is called precipitation.

17. When rain falls on the land, some of the water is
absorbed into the ground forming pockets of water
called groundwater. Most groundwater eventually
returns to the ocean. Other precipitation runs
directly into streams or rivers. Water that collects
in rivers, streams, and oceans is called runoff.

20. Water Resources Management
Water
supply &
sanitation
Irrigation
&
drainage
Energy
Environ-
mental
services
Infrastructure forInfrastructure for
management ofmanagement of
floods and droughts,floods and droughts,
multipurposemultipurpose
storage, waterstorage, water
quality and sourcequality and source
protectionprotection
InstitutionalInstitutional
frameworkframework
ManagementManagement
instrumentsinstruments
Political economy ofPolitical economy of
water managementwater management
Other uses
including
industry
and
navigation
Water Resources – Many Uses, Many
Users
…
7

21. Water ResourcesWater Resources
• WaterWater
– Earth’s surface is covered by 71% waterEarth’s surface is covered by 71% water
– Essential for life – can survive only a fewEssential for life – can survive only a few
days without waterdays without water

22. cc

23. Supply of Water ResourcesSupply of Water Resources
Small fraction (.014%) is readily
available for human use

25. WatershedWatershed
• Definition -an area of land that separatesDefinition -an area of land that separates
waters flowing to different rivers, basins,waters flowing to different rivers, basins,
or seas.or seas.
• AA watershedwatershed describes the total areadescribes the total area
contributing drainage to a stream or rivercontributing drainage to a stream or river
• May be applied to many scalesMay be applied to many scales
– A large watershed is made up of manyA large watershed is made up of many
small watershedssmall watersheds

26. Water sourcesWater sources
Surface runoff – 2/3 lost to floods and not availableSurface runoff – 2/3 lost to floods and not available
for human use.for human use.
• Reliable runoff = one thirdReliable runoff = one third
• Amount of runoff that we can count on year to yearAmount of runoff that we can count on year to year
GroundwaterGroundwater
• Zone of saturationZone of saturation
• Water table – top of zone of saturationWater table – top of zone of saturation
• Aquifer – water saturated layers of sand, gravelAquifer – water saturated layers of sand, gravel
or bedrock through which groundwater flows.or bedrock through which groundwater flows.
• Recharge slow ~ 1 meter per yearRecharge slow ~ 1 meter per year

27. Use of Water ResourcesUse of Water Resources
Humans directly or indirectly use about 54% ofHumans directly or indirectly use about 54% of
reliable runoffreliable runoff
Withdraw 34% of reliable runoff for:Withdraw 34% of reliable runoff for:
• Agriculture – 70%Agriculture – 70%
• Industry – 20%Industry – 20%
• Domestic – 10%Domestic – 10%
Leave 20% of runoff in streams for human use:Leave 20% of runoff in streams for human use:
transport goods, dilute pollution, sustaintransport goods, dilute pollution, sustain
fisheriesfisheries
Could use up to 70-90% of the reliable runoff byCould use up to 70-90% of the reliable runoff by
20252025

28. Tapping GroundwaterTapping Groundwater
• Year-round useYear-round use
• No evaporation lossesNo evaporation losses
• Often less expensiveOften less expensive
• Potential Problems:Potential Problems:
• Water table lowering – too much useWater table lowering – too much use
• Depletion – U.S. groundwater beingDepletion – U.S. groundwater being
withdrawn at 4X its replacement ratewithdrawn at 4X its replacement rate
• Saltwater intrusion – near coastal areasSaltwater intrusion – near coastal areas
• Chemical contaminationChemical contamination
• Reduced stream flowsReduced stream flows

29. SolutionsSolutions
Sustainable Water UseSustainable Water Use
• Not depleting aquifersNot depleting aquifers
• Preserving ecological health of aquatic systemsPreserving ecological health of aquatic systems
• Preserving water qualityPreserving water quality
• Integrated watershed managementIntegrated watershed management
• Agreements among regions and countries sharingAgreements among regions and countries sharing
surface water resourcessurface water resources
• Outside party mediation of water disputes betweenOutside party mediation of water disputes between
nationsnations
• Marketing of water rightsMarketing of water rights
• Raising water pricesRaising water prices
• Wasting less waterWasting less water
• Decreasing government subsides for supplyingDecreasing government subsides for supplying
waterwater
• Increasing government subsides for reducingIncreasing government subsides for reducing
water wastewater waste
• Slowing population growthSlowing population growth

31. Pollution Source terminologyPollution Source terminology
• Point source = pollution comes fromPoint source = pollution comes from
single, fixed, often large identifiablesingle, fixed, often large identifiable
sourcessources
– discharge drainsdischarge drains
– tanker spillstanker spills
• Non-point source = pollution comesNon-point source = pollution comes
from dispersed sourcesfrom dispersed sources
– agricultural runoffagricultural runoff
– street runoffstreet runoff

32. Types of Water PollutionTypes of Water Pollution
from Table 9-1 p. 187from Table 9-1 p. 187
• SedimentSediment
– logging, roadbuilding, erosionlogging, roadbuilding, erosion
• Oxygen-demanding wastesOxygen-demanding wastes
– human waste, storm sewers, runoff fromhuman waste, storm sewers, runoff from
agriculture, grazing and logging, many othersagriculture, grazing and logging, many others
• Nutrient enrichment = EutrophicationNutrient enrichment = Eutrophication
– N, P from fertilizers, detergentsN, P from fertilizers, detergents
– leads to increased growth in aquatic systems,leads to increased growth in aquatic systems,
ultimately more non-living organic matterultimately more non-living organic matter

33. BOD -BOD - Biological Oxygen DemandBiological Oxygen Demand
• As micro-organisms decompose (throughAs micro-organisms decompose (through
respiration) organic matter, they use up allrespiration) organic matter, they use up all
the available oxygen.the available oxygen.
• Biological Oxygen Demand (BOD) AmountBiological Oxygen Demand (BOD) Amount
of oxygen required to decay a certainof oxygen required to decay a certain
amount of organic matter.amount of organic matter.
• If too much organic matter is added, theIf too much organic matter is added, the
available oxygen supplies will be used up.available oxygen supplies will be used up.

34. Groundwater PollutionGroundwater Pollution
• Agricultural productsAgricultural products
• Underground storage tanksUnderground storage tanks
• LandfillsLandfills
• Septic tanksSeptic tanks
• SurfaceSurface
impoundmentsimpoundments

35. Oil SpillsOil Spills
• Exxon Valdez released 42 million liters of oilExxon Valdez released 42 million liters of oil
in Prince William Sound, contaminating 1500in Prince William Sound, contaminating 1500
km of Alaska coastline in 1989km of Alaska coastline in 1989
• Was the cleanup effective?Was the cleanup effective?
• Most marine oil pollution comes from non-Most marine oil pollution comes from non-
point sources:point sources:
– runoff from streetsrunoff from streets
– improper disposal of used oilimproper disposal of used oil
– discharge of oil-contaminated ballast water fromdischarge of oil-contaminated ballast water from
tankerstankers