Population Explosion

Population

Topics

• Development of Habitat patterns Environmental factors governing settlement

• Population and Pollution• Reasons for Over Population• Production of Food• Population Growth Demographic Projections

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.

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.

Over Population

Reasons for Over Population

• Increase in birth rate• Decrease in death rate• Better medical facilities• Increase Immigration• Decrease in Emigration• Illiteracy

• 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.

• 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

• 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

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

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)

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.

Various Population Forecasting

• Arithmetic Increase method• Geometric Increase method• Incremental Increase method• Decrease rate of growth method• Graphical extension method• Graphical Comparison Method

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

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

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

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.

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

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.

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

• 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.

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.

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

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.

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

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

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.

• 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.

• 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.

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.

• 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.

• 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.

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

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.

• 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.

• The theory is further explained graphically, by plotting size of population on X- Axis and per capita output on y-axis

PR

Q

A

Per Capita/Income

Population SizeP: Under population

Q: Optimum PopulationR: Over Population

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

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

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

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

ln Nt = Rt + Z ( R & Z are Constants)

When t=0, the initial size of pollution is ‘No’ i.e.

Nt= No

 

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 = No e Rt

Case StudyThe 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!

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.

Dharavi

Dharavi

Activity

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

Assignment

• Enlist adverse effect of Population Explosion• Explain eqn Nt= No e rt

• Explain Malthusian theory of population• Explain Demographic Projections.