THEME:1POPULATION & MIGRATION

should be able to:

Describe the growth of the world’s population and associatedproblems and show an understanding of the causes and consequences of over-population and under-population.

Identify and suggest reasons for contrasting patterns of population growth (or decline) as influenced by migration, birth rate and death rate, especially the

impact of HIV/AIDS. Describe the consequences (benefits and problems) of different patterns of population growth.

Identify and suggest reasons for different types of population structure as shown by age/sex pyramids.

Describe the factors influencing the density and distribution of population and population migration.

POPULATION

Number of people living in an area or country or region is known as population.

Distribution of population: Describes the way in which people are spread out across the world. This distribution is uneven and changes over periods of time.

Distribution of population: Sparsely populated: Densely populated:

Population explosion The annual growth rate of the world’s

population rose slowly but steadily until the beginning of the 19th century. For the next 150 years it grew at an increasingly faster rate. This process called a POPULATION EXPLOSION.

Density of population:

•The number of people living in one square kilometer of an area. Density of population can be calculated by total population divided by total area. This is shown by choropleth map.

FACTORS AFFECTING DISTRIBUTION AND DENSITY OF POPULATION (Reasons for the differences in population distribution and density)

Physical factors such as relief, climate, vegetation, soil, natural resources, water supply and water supply.

Social factors such as the proportion of urban to rural population, better housing opportunities, education, health facilities and entertainment.

Economic factors such as the resources, amount of industrialization, transportation and development of tourism.

Political factors such as government policy on birth control.

A map of the world, with colours to highlight the population density of each country or territory. Numbers on the legend are in people per km2 and all countries smaller than 20,000 km2 are represented by a dot.

A Map shows the physical distribution of specific data for a geographic area. This style of map shows statistical information rather than topographical information 

THE POPULATION GROWTH

Birth rate: Birth rate describes the average number of live births in a year for every 1000 people per year.

  Death rate: Death rate describes the

average number of deaths per 1000 people in the population per year.

The difference between the birth rate and death rate is either the natural increase or natural decrease.

THE POPULATION GROWTH

Natural increase: where the birth rate is the higher is known as natural increase of population. (growth of population as a result of births and deaths)

Birth Rate - Death Rate = Natural Increase

 Natural decrease: where the death rate is the higher is known as natural decrease.

No of births ─ No of deaths X 100

Total populationExample:

60753 – 30457 X100 =1.03%2938475

The population growth rate (‘natural increase of population) is calculated by

THE DEMOGRAPHIC TRANSITION MODEL

This model shows the relationship between birth rates and death rates and it is used to represent population changes over a period of time

population change

Stage 1ss

Stage 1

High birth rate due to lack of family planning method, high infant mortality rate an Agricultural family needs more children to support agricultural field. Children’s are considered assign of virility and high religious belief. High death rate due to shortage of food, dangerous diseases such as plague, malaria etc poor hygienic and shortage of medical facilities.

Stage 2There is a sudden falling down of death rate

due to

improvements in medical facilities improvement in food production, improvement in sanitation and improvement in transport.

Stage 3 Sudden falling down of birth rate in the

3rd stage due toimprovements in family planning methods, improving in education especially in women, increased desire for material wealth emancipation of women( equal rights) and later marriage.

Stage 4Birth rate is falling more slowly Due to

family planning, government policy, improving in education, later marriage. And also death rate falling very slowly due to improvements in medical facilities improvement in food production.

Stage 5Zero population

it means neither increase nor decrease of population. E.g. Italy, Sweden, Germany, Switzerland.

It has a broad base due to high birth rate. It doesn’t have bulges at its middle, because of less number of working population. It goes on shaping towards the top due to short life expectancy rate.

Uses of the demographic transition model

Studying the way population change.

Understanding trends in births, deaths and natural increase.

Predicting the changing structure of population and planning to meet its changing needs.

The limitation of the Demographic Transition Model

LEDCs may not follow the patterns of change found in MEDCs 30 to 50 years ago.

Birth rates have not fallen as rapidly as might be expected in some LEDCs because of social customs and beliefs.

Government planning for population change may interrupt the model, e.g. the one child policy in china.

Some industrialising LEDCs are moving more rapidly through the stages than the MEDCs did.

Over population and under population

OVER POPULATION: The number of population is higher than the

availability of resources. E.g. china, India, Bangladesh, Pakistan, Indonesia.

UNDERPOPULATION The numbers of people are too few to fully exploit

the available resources. Quality of life can only slowly be improved.

Optimum population: the population is such that it can maximise the benefits from the resources available. It is only when we have optimum population that the quality of life is maximised.

CAUSES OF OVER POPULATION Reasons for High Birth rate:

High birth rate due to lack of education

Lack of medical facilities High infant mortality rate Agricultural family needs more

children to support the agricultural field.

Children are considered to be sign of virility and religious belief

PROBLEMS OF AN OVER POPULATED COUNTRY(The problems of population growth in LEDCs)

Unemployment House shortages Lack of food Shanty towns Crime prostitution Strain on services Overcrowded buses and trains Poor sanitation etc

POPULATION STRUCTURE(What are the reasons for

different types of population structure?) Population structure is important for future

planning of a country. The population structure can be studied using a

population pyramid of age and sex pyramid. The rate of natural increase, the birth rate, the

death rate and life expectancy all affect the population structure of a country.

POPULATION PYRAMID: the age and sex structure of a population can be present as a diagram known as population pyramid.

LIFE EXPECTANCY: is the number of years that the average person born in a country can expect to live.

POPULATION STRUCTUREThe population pyramid displays the age and sex structure of a country or given area

Population inFive YearAge bands

Usually, but not always,In % to make for easiercomparisonsbetween countries

OLD DEPENDANTS

ECONOMICALLYACTIVE

YOUNG DEPENDANTS

FEMALESTo the rightMALES

To the left

What Population Pyramids Show Us

KEY

slope of pyramid indicate the death rate

width of the base is related to birth rate/fertility rate

proportions of men and women can suggest male or female migrations

height of graph can indicate life expectancy (ignore the very thin end of the wedge as occurs on graph B as these people are a definite minority)

"kinks" indicate dramatic reductions in birth rate or increases in death rate in the past

area of graph indicates total population - compare areas of differentpopulation age groups or different sex on one graph

The overall shape of the population pyramid can indicate whether it is an Economically More Developed Country or Economically Less Developed Country

Economically More Developed Country

Economically LessDeveloped Country

Population Pyramids related to the Demographic Transition Model

Stage 1 Stage 2 Stage 3 Stage 4

Both birth rates andDeath rates areHigh, so populationgrowth rates are slow but populationIs usually restoredDue to high birth Rate. Short lifeExpectancy

EXAMPLESScotland before 1760New GuineaRemote parts ofAmazonia

Population startsto grow at anexponential rate due to fall in Crude Death Rate. More living In middle age.Life expectancy risesInfant mortality rate falls.

EXAMPLES

Scotland 1760 - 1830Republic of Congo

Population continuesto grow but at slowerrate. Low C Death Rate.Dramatically decliningCrude Birth Rate.

EXAMPLESScotland 1870 -1950Algeria, TunisiaMorocco

IMPLICATIONS IMPLICATIONS IMPLICATIONS IMPLICATIONS

Low Crude Birth Rate and Crude Death RateHigher dependancy ratioand longer life expectancyCrude Death Rate does Rise slightly because ofThe ageing population

EXAMPLES

Scotland today.Japan, USA

There is some merit in including or considering a Stage 5 today with a declining population

Population pyramid of a less developed nation

Population Pyramid of Nigeria (1995)

Importance of Population Pyramids

A BROAD BASE POPULATION

PYRAMID MEANS:

increase food productionbuild more homes & schoolsplan for more job opportunities for the young in futureimplement birth control programme/campaigns

Usually agricultural with problems of overpopulation.Many Dependents

Population pyramid of a developed nation

Population Pyramid of Sweden (1995)

Importance of Population Pyramids

A NARROW BASED POPULATION

PYRAMID MEANS:

Birth rate and Death rate low

•Work out incentives to encourage more births

•hiring foreign labour

•proper medical services & health care for the aged

Stages of development

THANK YOUBY:SURESH KUMAR KUNDUR BILLABONG HIGH INTERNATIONAL SCHOOLMALDIVES