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SAI INTERNATIONAL SCHOOL
Class-7

Lesson Note
Subject-Physics
Ch.- Water: The Life-giving Liquid

Subtopic- Scarcity of Water & Water Conservation
Scarcity of Water
 Water scarcity is due to lack of enough clean and safe water.
 Water scarcity occurs when there is an imbalance between the availability and the
demand for water.
Causes of Scarcity of Water
The major reason for water scarcity given below:
Population Growth
 As the population increases demand of water increases.
 Various uses of water and the increase in the standard of living has further
increased the demand for water in the recent years.
Wastage
 Wastage of water is a major concern for the shortage of water.
 Some people leave their taps running even when they are not in use. All this water
is lost to the ground.
Over exploitation of the groundwater:
 One of the biggest problems related to groundwater shortage is the replenishment
of ground water.
 Increase in human population has adversely affected the natural process of
replenishing ground water.
 The demand of water is more compared to the amount of water that gets
replenished naturally.
Urbanisation and industrialization: Setting up of new factories and industries increased
the demand of water.
Global Warming:
 Global Warming is tremendously responsible for water scarcity in the world.
 The increase in the global temperature causes changes in the seasons, which can
again lead to a decrease in the rain that falls over the earth thereby causing water
scarcity.
Deforestation
Forests are being cut at an alarming rate which results in decrease in the rain, there by
affecting the recharge of groundwater.
Water conservation
Saving water using it efficiently and reducing unnecessary wastage so that it is available
for future use is called water conservation.
Few simple actions we can do for water conservation are:
 Water your lawn and garden in the morning or in the evening when outside
temperature is low to minimize evaporation.
 Avoid flushing the toilet unnecessarily.
 Don't let water run while shaving or washing your face, dishes and clothes.