A population may be defined as a group of individual of the same species, that interbreed with each other, under natural conditions.

1. POPULATION

2. POPULATION
• A population may be defined as a group of
individual of the same species, that interbreed with
each other, under natural conditions.
• The study of characteristics of population is called
as demography.
• Population Size: It refers to the number of
individuals within a population.

3. PARAMETERS
• Population Density refers to number of individuals
occupying a unit area or volume.
• Population Density = Number of individuals
Unit Area

4. PARAMETERS
• Fecundity: It refers to number of births per
unit time.
• Mortality: It refers to number of deaths in a
given period.
• Sex – Ratio: It refers to the ratio between
number of males and females in a given
population.

5. POPULATION EXPLOSION
• Population explosion refers to the exponential
growth of the population at an ever – increasing
rate.
• The world has experienced unprecedented growth
in population in recent decades.
• Studies indicate that the human population growth
curve follows a J – Shaped curve or an exponential
curve.

7. POPULATION EXPLOSION
• Since the beginning of time to about the year 1810,
our planet earth was home to one billion human
beings and this number is ever – increasing.
• The global human population now stands at 7.4
billion approximately, which is already more than
our planet can support.
• It is estimated that the global population increases
at the rate of 1.14% per annum.

8. REASONS
• Improvement in trade & global transportation.
• Resistance to various diseases.
• Increase in life span and decrease in infant mortality
owing to better medical technology.
• Improvement in general living conditions of
individuals.

9. POPULATION EXPLOSION
• At present, the rate of increase in such that there
are too many people for our planet to support.
• The increase in the population has polluted the
natural environment, ruined it, created and
intensified a variety of problems.
• A few of the problems of over population are the
disappearing forests, increasingly polluted fresh
water and air, depleting the soil and water
resources, increasing green house gas emissions,
ozone depletion.

10. Problems associated with
Population Explosion
• For the overgrowing population to live, land is not
available, hence the forests, grasslands and
wetlands are cleared off.
• Increased population in the rural areas is leading to
fragmentation of farmlands.
• Clearing of forests is leading to extinction of wild
animals and wild plant species, hence some
ecological balance is disturbed.

11. Contd…
• As the pollution is increasing, more number
of people are polluting the water, air and
land resources.
• To meet the basic requirements of people,
more industries are coming up. These lead to
dump the chemicals from the factories into
the rivers, ponds their by polluting the water.

12. Contd…
• Usage of soap, detergents and bleaching
agents, while washing clothes, pollutes the
water and affects the aquatic life.
• Increased usage of AC’s by the humans is
leading to damage of the ozone layer, which
prevents the ultra-violet rays of the sun to
reach the earth.

13. Contd…
• More number of houses are constructed
which requires wood, hence trees are felled.
• Depletion of forest lands, to make the land
available for agriculture, that leads to reduce
rainfall.
• Massive destruction of trees in the forest is
contributing to the loss of top soil also.

14. Contd…
• To meet the water demands by overgrowing
population, more number of bore wells are
dug. This leads to decrease in the surface
water or ground water table.
• To meet the demand of food, new
agricultural methods are followed. The
usage of fertilizers and pesticides of the
crops in polluting the waters indirectly.

15. Contd…
• As more number of vehicles are increased,
large amounts of sulphurous compounds are
released, which leads to acid rains.
• Dumping of garbage, solid wastes from the
factories into the land also poses
environmental problems.