global water resources-2
DESCRIPTION
TRANSCRIPT
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
2025
Estimates 2 / 3 of the world’s population underwater-stress conditions. 3 billion people 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 bathing, flushing, washing, cooking, drinking…
Extensive farming. High usage of water
Industry Increase demand
for goods
Increase in Population
Water stress!!!!
PowerAgriculture
People require food to eat
Global water use by Sector
Evolution Of Global Water Use
Withdrawal And Consumption By Sector
Accessed in November 2008
Source: http://www.unep.org/dewa/assessments/ecosystems/water/vitalwater/15.htm
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 30 secs, they get 3 points
Otherwise
The chance then goes to Team B and so on.
Rules: No mouthing of words
Round 1Team A –
AgricultureTeam B – Domestic use
Team C – Reservoir
Team D – PopulationTeam E – Industrial
production
Team A – Unequal access
Team B – Over exploitation
Team C – UrbanizationTeam D – Lifestyle
Team E – Lake destruction
Round 2
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