Dharavi in Mumbai is Asia's largest slum but also houses many small industries, with an annual turnover of $280 million. Despite being overcrowded with 45,000 people per hectare and lacking proper sanitation, Dharavi's residents have built thriving businesses in leather, pottery, textiles and food processing. The slum is home to around 1 million people during the day who have migrated from across India and built prosperous industries within its narrow alleys.

1. Population Explosion

2. Population

3. Topics
• Development of Habitat patterns Environmental factors
governing settlement
• Population and Pollution
• Reasons for Over Population
• Production of Food
• Population Growth Demographic Projections

4. Environmental Factors Governing
Settlement
• The environment has considerably affected human being right
from his evolution. The environment effects human in many
ways. The environment has affected humans settlements in
many ways. The main factors which affect the distribution of
population and human settlement are
• 1) Relief of a land
• 2)Climate
• 3) Soils
• 4) Mineral Deposits
• 5) Water Supply
• Environment plays an Important role in deciding population
distribution, density, settlement type and patterns.

5. POPULATION
• POPULATION may be defined as a group of organisms of the
same species occupying a particular space.
• OVER POPULATION: Over population is a condition when an
organism number exceeds the carrying capacity of its habitat.
• Over population is not a function of size or density it is
determined using the ratio of population to available resources.

6. Over Population

7. Reasons for Over Population
• Increase in birth rate
• Decrease in death rate
• Better medical facilities
• Increase Immigration
• Decrease in Emigration
• Illiteracy

8. • Increase in birth rate: Birth rate
is the no of child born /1000
people/year. With the advent of
better medical facility, economic
prosperity, social beliefs the birth
rate increases which causes
increase in population
• Decrease in Death Rate: Death
rate is expressed in units of
deaths/ 1000 persons/year. The
development of technologies has
resulted in decrease in death rate.
Good and clean atmosphere,
sufficient nutrients, better medial
facility has provided longer and
healthy life.

9. • Better Medical facility: New
inventions of medicines, awareness
towards better health and control of
various diseases like TB, Small pox,
cancer, has resulted in increase of
population
• Increase Immigration: The countries
like USA where the development had
brought good environment for
citizens to stay, earn , and enjoy had
resulted in increase in immigration
• Decrease Emigration: In case of
Developing Countries the basic
requirement of citizens like peace,
development opportunities are
satisfied hence migration is avoided
this may cause over population

10. • Illiteracy: Due to some social beliefs, lack of knowledge towards
family planning, desire for male child are some of the factors
which causes increase in population

11. POPULATION EXPLOSION
• Effects of Population explosion
• Over use of natural resources
• Increase in Food Demand
• Increase in waste generation
• Other effects like
• Unemployment
• Poverty
• Increase in crime rate
• Energy crisis
• Over crowding of cities

12. POPULATION GROWTH
• Population growth is the change in population overtime and can
be quantified as the change in number of individuals in a
population per unit time of measurement
• According to population clock every second on an average 4-5
children's are born, and 2 persons die, thus resulting increase is
of 2.5 persons every second. That means every hour there is a
growth of 9000 persons and in one day population increase is of
the order of 2,14,000
• Current Population of India in 2012 - 1,170,938,000
(1.17,938 billion)

13. Population Forecasting
• To Design various infrastructures facilities like water supply
scheme, sewage disposal unit, the basic record of current
population and future population is must
• Therefore an estimate of future population is necessary for
designing this facilities.

14. Various Population Forecasting
• Arithmetic Increase method
• Geometric Increase method
• Incremental Increase method
• Decrease rate of growth method
• Graphical extension method
• Graphical Comparison Method

15. Arithmetic Increase Method
• This method is based on the assumption that population
increase at a constant rate
• Thus future population is given as
• Pn= Po + n X
• Where,
• P n= Future population
• P o= Population at present
• n= No of decades between now and future
• X= average of population increase
• This method of population forecasting is used for large cities
which have reached their saturation population

16. Geometric Increase Method
In this method per decade percentage increase or
growth rate is assumed to be constant and the increase
is compounded over the existing population every
decade.
Where,
• Pn= Future Population
• Po= Initial Population
• r= rate of growth
• N= no of decades

17. Incremental Increase Method
• In this method per decade growth rate is not assumed to be
constant as in the arithmetic or geometric increase method but
it is progressively increased or decreased depending on past
data
• P n= Po + n X +
• P n= Future Population
• P o= Initial Population
• X= Average increase in population
• Y= Average of Incremental Increase
• n= no of decades

18. Decrease rate of Growth Method
• Since the growth rate of Increase in population goes on reducing
as the cities reach their saturation, a method which makes use of
decrease in the percentage increase, is many a times used. In
this method, average decrease in the percentage increase is
found out and is then subtracted from the latest percentage
increase for each successive decades. This method is however
applicable only in cases, where the growth rate shows a
downward trend.

19. Simple Graphical Method
• In this method a graph is plotted from the available data
between time and population. The curve is then extended
smoothly up to the desired year. This method however
gives very approx results

20. Comparative Graphical Method
• In this method, Cities having Condition and characteristics
similar to cities whose future population is to be predicted are
first of all selected. It is then assumed that the city under
consideration will develop, as the selected city has developed in
past. This method has logical background and if statics of similar
cities are available vary precise readings can be obtained.

21. Control of Population growth
• Education: Literacy plays a major role in
checking population growth. Improving
the literacy rate particularly in woman,
can help in population control
• Incentives: Certain Incentives in the form
of government benefits, scholarships, to
children, subsidies, exemptions from tax,
promotion In jobs, should be offered

22. • Government Benefits: The government benefits should be
allowed only for those having smaller families.
• Publicity: The Importance of birth control methods for family
planning, the significance of small families and related
information should be published through various media, schools,
books, and other sources.

23. Food Production
• Nutritious food is the basic
need of human beings at every
stage of life
• Sources of Food
• Agriculture crop: Like wheat,
rice, maize, pulses, vegetables
etc
• Meat and Milk: The meat of
domestic animals like sheep,
goat, hens are used as
important food resource. The
other important food resource,
like milk produced by goat, cow,
buffalo etc
• Sea Food: Fish and sea food
contributes 70 MMT of high
quality protein to world’s diet.

24. Worlds Food Problem
• Food is one of the basic requirement of human beings it is the
most important material that our body needs. During last 50
years food production has increased by 50 % by at the same
time the population growth has out stripped food production.
The FAO estimated that about 840 million people remain
chronically hungry, nearly 820 million of them in the
developing countries

25. Food Problems
• Undernourishment
• Malnutrition
• Every year 40 million people die of
undernourishment and malnutrition.
• Undernourishment: It is lack of
sufficient calories in available food, so
that one has little or no ability to move
or work. People who receive less than
90 % of their minimum dietary intake
on a long term basis are considered
undernourished.
• Unnourished children can suffer from
stunted growth and mental retardation.
• This can be prevented by better diet,
clean water, and simple medicines.

26. Malnutrition
• Malnutrition is the lack of specific
components of food such as protein,
vitamins, or essential elements in diet. It is
nutritional imbalance due to lack of specific
dietary component. It may occur In both
rich and poor .Major problems due to
malnutrition
• Marasmus: Lack of protein and calories
• Anemia: Lack of Iron
• Goiter: Due to Iodine deficiency

27. Population Theories
• There are three important theories of population, which are of
relevance to the present trends of population growth. The
theories are
• The Demographic Transition theory
• Malthusian Theory of maximum population
• The Optimum population theory

28. The Demographic Transition theory
• This Method is used to represent the process of shift from high
birth rates and death rates to low birth rates and death rates as
a part of the economical development of a country from a pre-
industrial to an industrialized economy. It is based on an
interpretation begun in 1929 by American demographer Warren
Thomson who observed changes in birth and death rates in
industrialized society over the past 200 years.

29. • This method represents that there is a relationship between the
population change and industrial growth with time.
• Stage 1 In pre-industrial society , death rates and birth rates
were both high and fluctuated rapidly accordingly to natural
events, such as droughts, and diseases, to produce a relatively
constant and young population
• Stage 2 In developing countries the death rate drops rapidly due
to improvement in food supply and sanitation, which increases
life span and reduces diseases, basic health care units and the
countries in this stage experiences great increase in population
• Stage 3 In this stage birth rate falls due to increase in status and
education of women, increase in parental investments.
Population growth begins to level off.
• Stage 4 There are both low birth rates and low death rates. Birth
rate has dropped due to change and life style and due to medical
advances and death rate has dropped too. As a result total
population is high and stable.

30. • Stage 5 This stage represents developed countries where
population are now reproducing well below their replacement
level. And the population growth may tend to be zero or
negative.

31. Malthusian Theory of maximum population
• English economist and demographer Dr. Robert Malthus gave
this theory, according to this theory
• In his first Proposition Population if unchecked, increases at a
faster geometric rate (i.e. 1,2,4,8,16…) whereas the food supply
grow at an arithmetic rate (i.e. 1,2,4,6,8…) . The necessary effect
of these two different rate of increase will be striking as after
sometime the population will outgrow the food supply and
people will starve and undergo misery.

32. • In the second preposition Malthus suggests that the food is
essential for the survival of the man and that the size of
population is determined by availability of the food. Greater is
the production of food larger the size of population which can be
sustained, this result Less production per capita. This will
ultimately lead to a situation where the number of people will
out weight the food production and the population will plunge
into starvation & misery.
• In the third proposition, Malthus concludes that the tendency of
the population to indefinite increase may be controlled by two
types of checks viz.
• Preventive checks: reduce birth rate
• Positive checks: Increase death rate
• Preventive checks:
• The preventive checks are moral restrained adopted by the
people voluntarily. Such checks includes marrying late or not at
all. It reduces the birth rate.

33. • The positive checks are more savage and are natural. If people do
not act on their own, the nature acts in the form of famines, wars,
outbreak of diseases. They increase in death rate.

34. Population grows in quick
geometric progression
(2,4,8,16,32)
Food supply grows in
slow arithmetic
progression
(2,4,6,8,10)
Imbalance between population and food supply
Corrective measure of imbalance
Positive
checks
Preventive
checks
Malthusian Theory of population

35. The Optimum theory of Population
• This is the modern theory of population, propagated by modern
economist such as Sidewide, Cannon, Dalton, and Robbins
• Optimum means the best or the ideal. Optimum population
means the ideal population or the ideal number of population
the nation should have relative to the natural resources, stock of
capital investment and state of technology. In other words,
optimum population is that size of population at which the per
capita output is the highest.

36. • A country is said to be under-populated if the population is less
than the optimum and over-populated if it is more than the
optimum. Initially population is small relative to availability of
resources hence due to specialization and efficient use of
resources per-capita output/ income increases to a maximum.
This size of population is the optimum population.
• Beyond this point, if population increases, the country will
become over populated and per capita output will start
decreasing. Overpopulation leads to low living standards,
frustration and unemployment
• Both under and overpopulation have short comings . It is the
optimum population which is best suited for a country. The
optimum population is not static number as it keep on changing
with discovery of new resources and technological
developments.

37. • The theory is further explained graphically, by plotting size of
population on X- Axis and per capita output on y-axis
P
R
Q
A
Per
Capita/Income
Population Size
P: Under population
Q: Optimum Population
R: Over Population

38. Population Dynamics
• Population Dynamics is the study of Change in population.
• The basic Equation of Population Dynamics
• The rate of change in the size of population (N), in the course of
time, is the function of population size (N) itself. i.e. the rate of
change of N is the function of N

39. Where,
•
𝑑𝑁
𝑑𝑡
= Rate of change of N with time ‘t’
• r= Instantaneous rate of increase
• N= The size of Population

40. The Exponential Growth
• The basic equation of population Dynamics,
relates the Increase with the population size itself, but doesn’t
establish a relation between population at two different
times, i.e. who to calculate Nt, population after time ‘t’ in
years
• Therefore Integrating eq
•
• Leads to Nt=No.ert

41. The Exponential Growth
• In case of Exponential growth, the rate of change of population is
directly proportional to the size of population at that time.
• If in a specified time ‘t’ the population size be Nt the population
growth or rate of change of population can be expressed as

42. 𝒅𝑵 𝒕
𝒅𝒕
⍺ 𝑵 𝒕
𝒅𝑁𝑡
𝑑𝑡
= 𝑅 𝑁𝑡
𝑑𝑁𝑡
𝑁𝑡
= 𝑅 𝑑𝑡
𝑑𝑁𝑡
𝑁𝑡
= 𝑅𝑑𝑡
ln Nt = Rt + Z ( R & Z are Constants)
When t=0, the initial size of pollution is ‘No’ i.e.
Nt= No

43. Thus,
ln No= R.0+ Z -------------I
Z= ln No
Now, putting value of Z in eq I,
ln Nt= Rt + ln No
ln Nt - ln No= Rt
ln
𝑁𝑡
𝑁 𝑜
= 𝑅𝑡
𝑁𝑡
𝑁 𝑜
= 𝑒 𝑅𝑡
Nt = No e Rt

44. Case Study
The Story of Dharavi: Largest Slum, Enterprising
People
• The Story of Dharavi: Largest Slum, Enterprising People
• There are around 5000 small industries in the area with a total
annual turnover of Rs. 20 billion. The industries include plastic
recycling, garment making, printing, zari making, leather
products, and pottery. Leather products made here are exported
to France & Germany. Everyday, about 200 tons of snacks like
banana wafers, and groundnut sweets are produced in over
1000 units. Surely it is a prosperous and developed place with
good roads and nice buildings? Well, it happens to be Asia’s
largest slum and all the people here are ‘ illegal’ occupants!

45. The Story of Dharavi: Largest Slum, Enterprising
People
Spread over 175 hectares and swarming with one million people
during the day, Dharavi in Mumbai is extraordinary mix of most
unusual people’. They have come from many parts of India.
Living in Dharavi is not easy. Within congested Mumbai, Dharavi has
the highest density of population, an unbelievable 45,000 persons per
hectare.
Everywhere there are open drains, piles of uncleaned garbage, filth,
and pitiful shakes. The other parts of the city’s population would like
to believe that Dharavi does not exist. For them, the slums are dirty,
and the inhabitants are criminals.
Over the years, unsuccessful attempts were made to ‘develop’ Dharavi.
The story of Dharavi tell us that managing the urban population
is becoming a bigger and more complex problem with each
passing day.

46. Dharavi

47. Dharavi

48. Activity
• Make a list of NGOs working for slum areas in your
city, and prepare a report on works carried out by
them.

49. Assignment
• Enlist adverse effect of Population Explosion
• Explain eqn Nt= No e rt
• Explain Malthusian theory of population
• Explain Demographic Projections.