WATER (CLASS VII)
From DEP-SSA WiKi
|WATER : A PRECIOUS RESOURCE (CLASS VII)|
You are perhaps aware that 22 March is celebrated as the world water day! The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene is a minimum of 50 litres per person per day. This amount is about two and a half buckets of water per person per day. Is your family getting at least t his much of water? If yes, you should consider yourself fortunate e because millions of people in our country do not get enough water.
HOW MUCH WATER IS AVAILABLE
Look at the picture of the earth taken from space. Why does it appear blue?
Surely, you can guess! You are aware that about 71% of the earth is covered with water.
Almost all the water on the earth is contained in the seas and oceans, rivers, lakes, ice caps, as groundwater and in the atmosphere.
However, most of this water is not fit for human consumption. The water that is fit for use is fresh water.
FORMS OF WATER
Are you afraid that continuous use will
someday exhaust all the water available
for use? You know that water on the earth
has been maintained for millions of years
by various processes which make the water
cycle. When water circulates through the
water cycle it can be found in all the
three forms, i.e., solid, liquid and gas
at any given time somewhere on the earth.
GROUND WATER AS AN IMPORTANT SOURCE OF WATER
If we dig a hole in the ground near a water body we may find that the soil is moist. The moisture in the soil indicates the presence of water underground. If we dig deeper and deeper, we would reach a level where all the space between particles of soil and gaps between rocks are filled with water The upper limit of this layer is called the water table
WATER CHANGES EVERYTHING
DISTRIBUTION OF WATER
Water drawn from under the ground gets replenished by seepage of rainwater. The water table does not get affected as long as we draw as much water as is replenished by natural processes. However, water table may go down if the water is not sufficiently replenished. This may happen due to many reasons. Increase in population, industrial and agricultural activities are some common factors affecting water table
We have seen that most of the water that we get as rainfall just flows away. This is a waste of precious natural resource. The rainwater can be used to recharge t he ground water. This i s referred to as water harvesting or rainwater harvesting. A farmer using water in the field can also use water economically. Maybe you have heard of drip irrigation.
Drip irrigation is a technique of watering plants by making use of narrow tubings which deliver water directly at the base of the plant
WHAT ROLE YOU CAN PLAY
- Turn off taps while brushing
- Mop the floor instead of Washing
What you have learnt
- Water is essential for all living beings. There can be no life without it.
- Water exists in three forms: solid, liquid and vapour.
- Though water is maintained by the water cycle, yet there is an acute scarcity of water in many parts of the globe.
- Rapid growth of industries, increasing population, growing irrigation requirements and mismanagement are some of the causes for water shortage.
- Unnecessary use of water and overdrawing from groundwater should be avoided. Recharge of water to the ground should be increased.
- The need of the hour is that every individual uses water economically.
CHECK YOUR KNOWLEDGE
- RAM KUMAR SHAHI
- JOHNSON P JOHN
- VINEETH KUMAR
- SITA RAM YADAV
- K BHASKAR RAO
- K ANITHA
- JAMEELA BEGAM