Global Water RESOURCES

THE

BLUE PLANET

From outer space, the Earth looks BLUE in colour. That’s because approximately 70% of the Earth is covered with water

Q. Do we have less water today than a million years ago?

Then

Now

A. The same

amount of water

Sources of Fresh Water

• Surface water:

Surface water is water in a river, lake or fresh water wetland. Surface water is naturally replenished by precipitation and naturally lost through discharge to the oceans, evaporation, and sub-surface seepage.

• Ground Water:

Sub-surface water, or groundwater, is fresh water located in the pore space of soil and rocks. It is also water that is flowing within aquifers below the water table.

• Desalination:

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Desalination is an artificial process by which saline water (generally sea water) is converted to fresh water.

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• Frozen Water:

Several schemes have been proposed to make use of icebergs as a water source, however to date this has only been done for novelty purposes. Glacier runoff is considered to be surface water.

• Under River flow

The water cycle

Transpiration

Fate of Precipitation

E-T

interflow

E-T

groundwater

flow

precipitation

Is there a �water problem?

Approximately 70% of the Earth’s surface is covered with water.

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The absolute quantity of water has not changed over the years.

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Then why are we talking of a water crisis?

Why do we need to conserve water?

DISTRIBUTION OF GLOBAL WATER

If all the world’s water could fit into a bucket

Water available for drinking would be less than a teaspoon

Sustainable freshwater supply for human use = 0.01%

Recommended activity - A drop of water

Salt Water = 97.5%

Global Water Use

Water Availability per region (2012)

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• Lakes, tanks and ponds being destroyed. Land filled for construction purposes.

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• Unsustainable extraction of groundwater in urban areas, affecting groundwater quality.

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• Receive sewage that cannot be handled by sewage

treatment plants.

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• Disposal of solid and liquid wastes

above or into groundwater

aquifers.

Additional stress in urban areas

For more details refer to the presentation on ‘Water resources of our city’

GLOBAL WATER PROBLEMS

Distribution of population and water resources

Mismatch between regions of large population and available freshwater resources

Fresh Water Stress

By 2025

2 / 3 of the world’s population estimated to be underwater-stress conditions.

3 billion people may be affected by water scarcity.

Source: http://www.unep.org/dewa/assessments/ecosystems/water/vitalwater/21.htm#21b

The total amount of water in the world is the same, but there are more people wanting to use this water

1940

World population doubled ( increased by 3 bn )

Freshwater use increased more than 4 times

1995

Population and water Resources

There is just not enough water!!!!

2050

Estimated population increase = 2.7 bn

Every item

that we use needs

water for production

CAUSES FOR WATER STRESS

Water evaporation

from reservoirs of large

hydro power projects

Domestic

Extensive farming.

High usage of water

Industry

Increase in Population

Water stress!!!!

Power

Agriculture

People require

food to eat

Increased demand

for goods

bathing, flushing, washing,

cooking, drinking…

Global water use by Sector

Evolution Of Global Water Use

Withdrawal And Consumption By Sector

Source: http://www.unep.org/dewa/assessments/ecosystems/water/vitalwater/15.htm, accessed November 2008

India, with more than a billion people, needs a lot of water to grow food for its population

Agriculture

Source: http://www.unep.org/dewa/assessments/ecosystems/water/vitalwater/15.htm

Problems related to Water crisis

• Inadequate access to safe drinking water by over 1.1 billion people
• Groundwater overdrafting leading to diminished agricultural yields
• Overuse and pollution of water resources harming biodiversity
• Regional conflicts over scarce water resources sometimes resulting in warfare.

Threats to fresh water resources

• Climate change causes change in frequencies of droughts and floods.
• Depletion of aquifers caused by over-consumption as a result of population growth.
• Pollution and contamination by sewage, agricultural and industrial runoff.

Run off

from agricultural

fields

Untreated

municipal sewage

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Air pollutants

Dissolve in

rainwater

It’s not just increased consumption…

For more details refer to the presentation on ‘Water pollution’.

Increasing pollution of freshwater sources

( surface and groundwater )

Untreated

industrial

wastes

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Good and bad uses of water

• Ways people waste water: (How to save it).
• Dishwasher -Dishwashers can waste so much water if you run it when it is not full. A way to prevent this is to wash your dishes without use of the dishwasher.
• Brushing Teeth / Washing Dishes WITH the Water Running- DO NOT keep water running while brushing your teeth/ doing the dishes. When you brush your teeth, wet the toothbrush first and turn the water off.
• Shaving - When you taking the shower, do you really need the water running? Turn off the water while you shave your legs. I put conditioner in my hair, fill cup with water, sit in the bathtub and shave, with the water off.

• If Its Yellow, Let it Mellow. If Its Brown, Flush it Down- Some people are bothered by this, but it is essential. Every time you flush the toilet, you waste 10 gallons of water.
• Car Wash-This may be hard for us city folks, but if you have a lawn, Wash your car on it! Use Biodegradable soap, and a bucket of water. Only turn on the hose for the final rinse.
• Bath time! Bath time is no longer Fun time. It wastes an unnecessary amount of water. an average shower uses 1/5 the amount of water that is needed for a bath!
• Using the Toilet as a Garbage Can- Do Not Do This! Throw out everything in a garbage can, even if it is tempting to just throw it in the toilet.
• Hot Water-Only use hot water when absolutely necessary. Hot water uses a lot more energy, and it isn’t always necessary.

SO…

Is there a Water

Problem?

Yes, there definitely is.

There is a greater demand for freshwater

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Freshwater resources are being polluted and are therefore unfit for consumption

Skewed distribution of population and freshwater resources leads to unequal access

1,5 million people internally displaced because of the 2006-2011 drought

March 2011: Anti-Assad Revolution erupts

Water Scarcity and Conflicts: Syria

India – status and projections

1 / 6 of World’s Population

1 / 25 of world’s Freshwater

Resources

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Source: TERI

INDOOR CONSERVATION�

• Shorten your shower by a minute or two and you'll save up to
• 150 gallons per month.
• Monitor your water bill for unusually high use. Your bill and
• water meter are tools that can help you discover leaks.
• Grab a wrench and fix that leaky faucet. It's simple,
• inexpensive, and you can save 140 gallons a week.
• Teach children to turn off faucets tightly after each use.
• Turn off the water while brushing your teeth! This will, on the
• average, save 3 gallons of water for each time you brush.
• Use conserving appliances, such as low-volume shower heads,
• efficient dishwashers and washing machines etc.
• Use low-flow toilets, and flush the toilet only when really
• necessary

OUTDOOR CONSERVATION�

• Use a bucket of water to clean your car instead of a
• hose
• Sweep sidewalks, driveways and patios instead of
• hosing.
• Clean gutters and downspouts manually, without using a
• hose.
• Cultivate the soil regularly so water can penetrate and
• develop a good root system.
• In arid and semi-arid regions, replace lush green lawns
• with decorative rock garden
• Methods to harvest rainwater should be provided

• Use gray water from washing machines to water vegetation
• Water lawns and plants in the early morning, late afternoon or
• at night so as to reduce evaporation
• Use drip or sprinkle irrigation and place water-holding mulch
• around garden plants
• In arid and semi-arid regions, plant drought-resistant
• vegetation that needs less water
• Local bodies should install water-meter and encourage water
• pricing policies in which water is much more expensive beyond
• some baseline amount.

INDUSTRIAL CONSERVATION�

• Water conservation measures that can be taken by industries and
• manufacturing units include:
• Using dry cool cooling systems or cooling towers that use less
• water
• Reuse the cooling water for irrigation or other purposes
• Industries and manufacturing units should curb water
• withdrawals wherever possible by increasing in-plant treatment
• and recycling of water or by developing new equipment and
• processes that require less water
• Recycled water should be used for floor washing, and other such
• purposes

AGRICULTURAL CONSERVATION

• Agriculture is the biggest water user and perhaps half of all the
• agricultural water used is lost to leaks in irrigation canals and
• application to areas where plants do not grow, runoff and
• evaporation. Improved agricultural irrigation could reduce
• withdrawals by between 20 to 30%. Tremendous saving may be
• achieved by implementing following agricultural conservation
• measures:
• Use lined or covered canals that reduce seepage and
• evaporation
• Use improved irrigation techniques, such as sprinklers or drip
• irrigation
• Irrigate fields in the early morning or at night when evaporation

is minimal

• Adopt better farming techniques, such as minimum tillage,
• leaving crop residue on fields and ground cover on drainage
• ways, intercropping etc.
• Use mulch to help retain water around plants
• Price agricultural water to encourage conservation
• Integrate the use of surface and ground water so as to have a
• more effective use of the total resources. For instance,
• irrigate with surplus surface water when it is abundant and
• also use surplus surface water to recharge groundwater
• aquifers; and when surface water is in short supply, use more
• ground water for irrigation
• In arid and semi-arid regions, encourage the development of
• crops that require less water and are drought resistant

Proposals: How to conserve water

If you want to learn how to conserver water and protecting the environment, learning to conserve water is a great way to make a positive impact. A four-minute shower may not sound like much, but in reality can cost up to 40 gallons. But don't worry--there are ways to change water-hogging household habits into leaner, greener activities.

Water Conservation Tips

• Run your dishwasher for only full loads.
• Turn off the tap when you brush your teeth.
• Check your faucets and toilets for leaks.
• Take shorter showers.
• Water your lawn in the morning.
• Use a cover on your pool.
• Wash your car with a nozzle on the hose.

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• We are fortunate enough to live in a place where clean water flows freely on demand, it can be easy to take it for granted. From your daily dishwashing routine to your daily shower, every drop of this natural resource is precious. Practicing conservation is not only good for the environment, but can save you money in energy bills.

Desalination of sea water as fresh water supply

• Desalination of sea water can be done either via distillation or membrane process.
• Both process requires large amount of energy and thus costly, which means desalination remains an expensive option for providing reliable fresh water supply, restricted to only economically well-off countries.