2. Water resources are sources
of water that are useful or
potentially useful. Uses of water
include agricultural, industrial,
household, recreational and enviro
nmental activities. The majority of
human uses require fresh water.
97 percent of the water on the
Earth is salt water and only three
percent is fresh water; slightly over
two thirds of this is frozen
in glaciers and polar ice caps.
3. Life is possible on earth due to the presence
of water. Nearly three-fourths of the earth's
surface is covered with water. Water is also
found below the earth's surface. It is present
in air in the form of water vapour. About 70
per cent of the human body is water. The
bodies of all plants and animals contain water.
Sources of Water:
Rainwater, oceans, rivers, lakes, streams, pond
s and springs are natural sources of water.
Dams, wells, tube wells, handpumps, canals, etc, are man-made sources of
water.
4. Rain Water:
Rain water collects on the earth in
the form of surface water and
underground water.
Underground Water:
Some of the rainwater seeps
through the soil on to the nonporous rocks below. This is
underground water. Sometimes
due to high pressure, this water
sprouts out in the form of springs.
It can be obtained by digging
wells, sinking tube wells, etc.