Page 107 - ICSE Science 3 : E-book

There are diff erent ways in which rainwater can be harvested.

• One of the methods is rooftop rainwater harvesting in which rainwater is
collected from the rooftops and stored in built-up tanks. Stored rainwater

can be used for both indoor and outdoor
activities. Such as fl ushing toilets, doing

laundry, mopping, washing and gardening.

• We can also collect rainwater in large
containers like buckets, drums and tubs,

and use it later.

• Rainwater harvesting is also done by

digging wells and borewells for increasing
Rooftop rainwater harvesting
the groundwater levels.

TERMS TO KNOW

1. Melting: The process during which a rise in temperature changes a matter from
solid to liquid

2. Evaporation:The process during which heating or increased temperature changes
a matter from liquid to gas
3. Condensation: The process during which cooling or decreased temperature
changes a matter from gas to liquid

4. Freezing: The process during which a liquid changes into a solid by cooling or
decreased temperature

5. Water cycle: The continuous movement of water between the sky and the earth
6. Impurities: Substances that make something dirty or impure

7. Soluble impurities: Impurities that are soluble in water
8. Insoluble impurities: Impurities that are not soluble in water

9. Water purifi cation: The process of removing harmful substances from water to
make it fi t and safe for drinking
10. Filtration: The process of removal of insoluble impurities from water by fi ltering it

11. Boiling: The method of purifying water by heating it for some time
12. Chlorination: The process of purifying water using chlorine

13. Rainwater harvesting: The collection and storage of rainwater in man-made
structures for use in future

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