NCERT Book Class 12 Geography (India People And Economy) Chapter 4 Water Resources

Do you think that what exists today will
Unit III continue to be so, or the future is going to be
Chapter 4 different in some respects? It can be said with
some certainty that the societies will witness
demographic transition, geographical shift of
population, technological advancement,
degradation of environment and water scarcity.
Water scarcity is possibly to pose the greatest
challenge on account of its increased demand
coupled with shrinking supplies due to over
utilisation and pollution. Water is a cyclic
resource with abundant supplies on the globe.
Approximately, 71 per cent of the earth’s
surface is covered with it but freshwater
WATER RESOURCES constitutes only about 3 per cent of the total
water. In fact, a very small proportion of
freshwater is effectively available for human use.
The availability of freshwater varies over space
and time. The tensions and disputes on sharing
and control of this scarce resource are becoming
contested issues among communities, regions,
and states. The assessment, efficient use and
conservation of water, therefore, become
necessary to ensure development. In this
chapter, we shall discuss water resources in
India, its geographical distribution, sectoral
utilisation, and methods of its conservation and
management.

Water Resources of India
India accounts for about 2.45 per cent of the
world’s surface area, 4 per cent of the world’s
water resources and more than 17 per cent of
the world’s population. The total water available
from precipitation in the country in a year is
about 4,000 cubic km. The availability from
surface water and replenishable groundwater
is 1,869 cubic km. Out of this, only 60 per cent
can be put to beneficial uses. Thus, the total
utilisable water resource in the country is only
1,122 cubic km.

Surface Water Resources
There are four major sources of surface water.
These are rivers, lakes, ponds and tanks. In
the country, there are about 10,360 rivers
and their tributaries longer than 1.6 km each.
The mean annual flow in all the river basins