Global Water

RESOURCESCBSE – Std X

As per NCERT geography textbook – Contemporary

India II

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

The water cycle

Transpiration

Is there a water problem?

Approximately 70% of the Earth’s surface

is covered with water.

The absolute quantity of water has not

changed over the years.

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%

Mismatch between regions of large population and available freshwater resources

Fresh Water Stress

By 20252 / 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 tim

es

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

Run off from agricultural

fields

Untreated municipal sewage

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

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

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

• Receive sewage that cannot be handled by sewage treatment plants.

• 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’

SO…Is there a Water

Problem?

Yes, there definitely is.There is a greater demand for freshwater

Freshwater resources are being polluted and are therefore unfit for consumption

Skewed distribution of population and freshwater resources leads to unequal access

India – status and projections

1 / 6 of World’s Population

1 / 25 of world’s Freshwater

Resources

Source: TERI

Dumb CharadesA game to check how much you have learnt

Play

Divide the class into 5 teams.

Team A selects 2 people who will guess the answer.

These 2 people turn their face to the wall or go out of the room, so that they can’t see the clue.

Play

Team A have to act out the clue for the 2 guessers.

Either all members of Team A can act it out (very boisterous, but all children are involved) or a representative is selected to do the acting.

The other members of Team A (and the rest of the class) see the clue.

If the guessers got the right answer in 30 secs, they get 5 points

If the guessers get the right answer in 60 secs, they get 3 points

Otherwise

The chance then goes to Team B and so on.

Rules: No mouthing of words

Round 1Team A

– Team B –

Team C –

Team D –

Team E –

Ready ?

Agriculture

Domestic use

Reservoir

Population

Industrial production

Team A –

Team B –

Team C –

Team D –

Team E –

Round 2

Unequal access

Over exploitation

Urbanization

Lifestyle

Lake destruction

Round 3

Team A – Fertilizer runoff

Team B – Sewage disposal

Team C – Industrial waste water

Team D – Pesticides

Team E – Domestic waste water

Team A – Water stressTeam B – Groundwater depletionTeam C – Diseases

Team D – Life threateningTeam E – Slum dwellers

Round 4