Page 157 - Volt Elevate The World Around Us Book 4

Although three-fourths of the earth’s surface is covered with water, only a very small

portion of it can be used for drinking. This is because most of the water on the Earth is
present in the seas and oceans which contain salty water. This water is not fit for drinking

or other day-to-day activities.

Sources of Water

Rain

The main source of freshwater on the Earth is
rain. Rainwater fills ponds, lakes, seas, oceans

and other water bodies.

Underground Water

Some rainwater seeps into the soil and
reaches a layer of solid rocks. It collects here as
underground water. In some hilly areas, it comes

out to the surface as springs. rain

Surface Water

Rainwater slides off the ground as surface water
and fills ponds, lakes, rivers and seas.

A pond is a small body of water surrounded by
land. It fills up in the rainy season when it rains.
Some ponds dry up in summer. A lake is bigger

than a pond.
Rivers flow from the mountains, hills and other
places where it rains a lot.

When the snow or ice melts in high mountains, pond
water flows down to form rivers. Such rivers
are called snow-fed rivers or perennial rivers.

They carry plenty of water throughout the year.
Ganga, Yamuna and Brahmaputra are snow-fed
rivers. They flow from the Himalayas.

Rivers that carry only rainwater are called
rain-fed rivers. They have a lot of water during
the rainy season but almost dry up during
summer. Kaveri, Krishna and Godavari are some river

examples of rain-fed rivers in India.

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