Chapter 2

The world Population: Distribution, Density and Growth

FACTS THAT MATTER

A population is all the organisms that both belong to the same group or species and live in the same geographical area. In sociology, population refers to a collection of human beings. Demography is a social science which entails the statistical study of human populations.

A country is known by it's population. It is the human resource, which is responsible for the development of other resources in a country.

Population characteristics vary over the earth's surface giving rise to several questions-like when and from where did people come on the surface of the earth? How many people were there? Where did they settle? Why? .....etc.

Population Distribution

it has been observed that the distribution of population on the surface of the earth is highly uneven. This uneven distribution of population over the earth's surface is the most Significant aspect of human resource. It implies that people are concentrated in some areas and are not spread out evenly over the earth's surface. The distribution in terms of continents and countries is very ill balanced.

The common questions that arise are

1. Where and how are people distributed?

2. Why is the distribution, uneven?

3. What are the repercussions of this uneven distribution of population?

It has been observed over time that the distribution of population has direct relationship with the uneven distribution of natural endowments on the earth's surface.

In the earlier, agrarian economy fertile soils with favourable climatic conditions used to attract people to reside. With development, the concentration of people gathered around mining centres of the world. So it can be concluded that people broadly like to live in places where agriculture is easily possible or in areas of rich mineral deposits.

Patterns of Population Distribution in the World.

The term population distribution refers to the way people are spaced Over the earth's surface. It can be said that 90% of the world's population live on only 10% of its land while 909 of the land is home to only 10% of the world's population!

A high percentage of people live in Asia which has only 1/5th of the world's land while the rest of the continents together share the rest. The 10 most populous countries of the world share 60%% of the world's population.

The population distribution within the continents is also not even. For example in Asia, China and India share the largest percentage. Of the 10 most populous countries, 6 are in Asia.

Density of Population

Population density reflects upon the quantitative aspect of population of an area. it expresses the number of people residing per unit of area for a particular region.

Density of population reveals the concentration of people in an area. It gives an average number of people per unit of land i.e. it denotes a relationship between the number of people and the total area of the region/country. It does not tell us about the region on sign Concentration of population or low concentration within the area. It is the ratio between the number of people to the size of the land. It is calculated as:

Density of Population = total population / total geographical Area

It does not mention anything about the quality of land within the country it just gives an average numerological figure.

The world usually is divided into 3 density zones:

1. High density zone with> 200 p/km² 2. Medium density zone with 11-50 p/km²

3. Low density zone with <1 p/km²

High Density Zone (HDZ): (200 p/km²)

It has been observed that there are three distinct H.D.Z.

•S, S.E. and E Asia

•NW Europe

•N.E U.S.A

South, East and South east Asia has the largest population of the world. Half of world's population live in this part specially in China, India, Bangladesh, Indonesia and Japan.

People generally are concentrated in the river valleys and coastal lands with fertile soil and favourable climate for carrying out agricultural activity.

The High Density Zones of Europe and the USA are primarily due to the availability of minerals like coal, iron etc. which are used for manufacturing. Industrialisation is the main cause for the concentration of people in these parts. In both these areas soil and climate are also quite favourable for agriculture. These regions are also favourably located for trade and transport through the Atlantic ocean.

Medium Density Zone: (11 50 p/km²)

This zone is the transition zone around the densely populated regions of Asia, (western China, southern India), Norway and Sweden in Europe. In South America, Africa and

Australia- moderate densities are found along the coasts.

Low Density Zone: (< 1 p/km²)

Most of the land areas on the earth's surface is unfavourable for human habitation. This zone is a vast area of empty lands like:

•The extensive hot and cold deserts of Sahara, through Arabia and Central Asia, Kalahari desert of South Africa, most of Australia, the dryland of south America and the western U.S.A.

•The high rainfall lands of tropical rainforest in the Asia, South America and Equatorial Africa.

•The cold Polar Regions.

•Other than these virtual empty lands there are other scattered regions of low population density.

Factors Influencing the Distribution of Population

There are several factors which play their roles in this uneven distribution of population on the earth's surface. They can be broadly categorised as Geographical, Economic and Socio-Cultural factors.

I. Geographical factors again can be divided as under:

1. Availability of water: Since the beginning, people preferred to live in areas closer to fresh water. Water is life and is essential for our survival - so easy availability of fresh water is one of the most important guiding factors.

2 Landforms: It has been observed that the human civilisation started along the fat, fertile river valleys- like the Indus Valley Civilization, Tigris - Euphrates, Nile, etc. because of fertile, soil, plain land, easy access to water - which is essential for survival etc. Plain land is always preferred to raised highlands, or barren plateaus or swampy terrains. Coastal plains and river valleys are always preferred

Example; Ganga plain, Nile valley, Hwang Ho in China. Coastal areas are always preferred over interior location. The coastal areas of the continents are all densely populated - barring a few regions. Areas with high altitude like the Roof of the world- Tibetan plateau are very thinly populated. Even the higher mountainous regions-Asia, Europe and North and South Americas are almost uninhabited. These areas not only have extreme climate but also almost inaccessible.

3. Climate: People always prefer to settle in areas which have moderate pleasant climate and not in areas with extreme hostile climate. Temperature, precipitation and seasonal variation of temperature directly impact distribution of population. Deserts (both cold and hot) with extreme climate and aridity and wet Equatorial areas are sparsely populated zones of the earth - while the temperate zone and tropical areas are favourable for habitation. Mediterranean regions are always preferred for their pleasant climate.

4. Soils: Soil has a direct bearing on agricultural activity so the quality of soil infuences to a great extent the distribution of population. As already mentioned, all the river valleys of the world Indus, Ganga, Brahmaputra, Nile, Hwang ho, Si Kiang of China are thickly populated - where as the Ravines of Chambal' in India, which has badland topography and parts of interior USA are very sparsely populated.

II. Economic Factors: There is a negative correlation between economic development and population growth, this can be explained through the Demographic Transition Theory

1. Availability of mineral resources: Mirneral resources attract people to settle for mining and industrial purposes mineral rich areas like Ruhr valley of Germany,

Chhotanagpur plateau of India, oil rich countries like Kuwait, Katanga Zambia copper belt in Africa, have attracted people over the years.

2. Urbanisation: Cities offer better facilities, like-infrastructure, job opportunities, entertainment and the attractions of city life draw people towards cities leading to migration from rural to urban areas.

3. Industrialisation: Attract a large number of people as industrialisation provides job opportunities in various sectors-right from factories, transport banks, shops and different institutions. Kobe-Osaka region of Japan, Hugli industrial region oi

India are thickly populated because of industries.

(i) Socio Cultural Factors: Agricultural and technological developments, close links among clans, ethnic similarity, migration of people to this 'comfort areas, cultural heritage - play a significant role in the distribution of people on the surface of the earth.

(ii) Political factors: These often play a very crucial role in the distribution of people. People generally move away from war torn region as refugees to neighbouring countries. Even within the country also, people move away from the 'Conflict Zone' to Peace areas' to settle. Ethnic conflict and political war are responsible for movement of people from Balkan State, Palestine, Serbia, Egypt, Syria, etc.

(iii) Historical factors: Past history, legends, national/religious bondage influence population distribution pattern and growth to a great extent.

(iv) Government policy: Sometimes government give incentives to people to live in sparsely populated areas or to move away from over populated areas.

Natural factors like famines, droughts., earthquakes, epidemics, volcanic eruptions are other factors that influence the distribution of population on the earth's surface along with easy accessibility through transportation and communication facilities.

The favourable factors that affect the distribution of population, to some extent, ar complex and results of a combination of factors.

Population Growth

Population growth or population change denotes the change in the number of people of a region between two points of time. The change in the number of inhabitants can be both positive or negative and can be expressed in terms of the absolute numbers or percentage.

Population change of an area reflects not only the economic and social conditions of an area but also states about its historical and cultural backgrounds. At present the growth of population is of great concern though some countries in Western Europe are experiencing a negative growth. But rest of the world would experience a high rate of population growth and as a result the world population would increase due to its large base. The world population has crossed 7 billion mark (7.033 billion ) and so even a lesser growth rate would add up a huge number to its present size.

At the present rate of growth it will double in another about 37 years! 1.e. another 7 bilion people will be added!! It will exert tremendous amount of pressure on the present available resources!!

Components of Population Change

The three main components of population change are birth, death, migration.

1. Crude birth rate (CBR) is the number of live births per thousand of population for a region in a year.

2. Crude Death rate or Mortality rate: CDR is expressed in terms of number of deaths per thousand population for a region in a year.

CDR is a vital determinant it reflects upon health care, living conditions, economic condition, nutrition, degree of development etc. Low mortality shows better health facilities, effective measures against epidemics. An increase in the population takes place not only with an increase in birth rate but also with declining death rate in a region.

3. Migration: It gives rise to immediate change in the number of people in an area. It is a spontaneous effort to achieve a better balance between population and resources by the movement of people from one area to the other. It is universal in nature People move from areas of lesser opportunities to areas with better opportunities with more natural endowments. They move from the place of origin' to the place of destination thereby leading to an increase in population of their 'adopted' place of residence aas immigrants' and a decrease in population in their 'original' place of residence aas emigrants.

Migration can be of several types permanent, temporary or seasonal.

There are two factors-Push and Pull factors which influence migration. As the name suggest, push factors play their roles in pushing the people away from their place of origin due to lack of infrastructures, education facilities, employment opportunities, political unrest, epidemics, natural/man made disasters etc.

The pull factors, on the other hand, attract the people in their place of destination with better job opportunities, housing, medical facilities, political stability, security, better climate and other facilities for comfortable living.

Trends in Population Growth

In the early stage of evolution the growth rate was very very slow. Man was totally depended on nature for survival. He was depended on food gathering and hunting from his surroundings. So, the limited supply from a given territory could support only a limited number of people.

Around 10,000 years back the most significant cultural change came in the form of Agricultural Revolution. The population that time was around 8 million. In the 1st century it was 300 million.

The 16th and 17th centuries set the stage for growth of population with expanding trade.

The 2nd most significant cultural change that impacted the growth of population came around the 1750 in the dawn of Industrial Revolution' with approx 550 million population it exploded after the industrial revolution in the 18th century.

The major cultural and technological change that influenced the population growth came in the 20th century through Medical Revolution'- which drastically brought down the 'death rate with the introduction of several life saving drugs and improved medical facilities through better connectivity and paved the path for rapid population growth.

Population Doubling Time

Time taken to double the population of an area at the current rate of growth is referred to as the population doubling time. For the world population, it took million years to attend the one billion mark, but it only took 12 years to rise from 5 to 6 billion. Since the beginning of the Christian era the population took 1650 years to reach 500 million.

The doubling of population after that was very fast and it took 200 years, 80 years and 45 years. It is estimated that the next doubling will take around 35-37 years which will put tremendous pressure not only on agriculture for providing food but also on other resources for providing the other basic needs of life.

Spatial Pattern of Population Change

Population growth is low in developed countries than the developing countries. Population growth and economic developments are negatively correlated.

In a developing country with a large population, even a small annual growth rate will lead to a huge change in population.

Presently the population of the world is 7.033 billion and is increasing at an alarmine rate with more than 8 crores being added every year. Though the developed nations have stabilised their growth, the developing nations are yet to reach that target. The population in the developing nations is bound to increase in the coming years as the proportion of their youthful population is high.

Impact of Population Change

In order to have a growing economy a small increase in population is a boon but when it grows beyond limit then it creates all sorts of problems -Like dearth in resources, infra structural facilities, pollution, unrest, etc.

Both a very small and large population are a cause of concern. A small population may lead to lack of man power for developing the available resources while a large population put pressure on the limited resources of a country. So both the cases may lead to low economic development. It is not only quantity but also the quality of people that matters.

Demographic Transition

The Demographic Transition Theory gives us the relationship between the level of economic development of a country and its demographic characteristics. This model gives us well documented trends of modern times over places, periods and events. It mentions the transition of a society from a phase of high fertility and mortality to a phase where both come down to low.

This impacts their demographic

characteristics in significant ways over the years and the countries move from primitive agricultural, illiterate and rural economy to a modern industrial, literate and urban state.

Initially, there were three stages of the theory:

1. Stage of slow population growth.

2. Stage of the beginning of industrial revolution.

3. Stage of late Industrialisation revolution.

Stage-1: Stage of slow population growth

It started with human civilisation and continued till the recent past, thereby marking it as the longest period of population growth. This stage was marked by both high birth rate and high death rates. So population growth rate was very low. Agriculture oriented activities depended on the vagaries of nature leading to low productivity. Society was highly illiterate with poor technology. Large families with high birth rates were the norms - as they had to compensate the high death rate.

About a couple of centuries back all the economies were at this stage of demographic transition.

Stage-2: Stage of the beginning of Industrial Revolution

With betterment of economic conditions and living standards, this stage started wit improvement of medical facilities, sanitation and as a result death rate went down but birth rate remained high. This gave rise to a sudden increase in population which i common in a developing economy.

In this stage, the significant feature was the rate at which the birth rate and death T rate were declining. Though both of them were falling, the rate of fall in death rate was in faster than that of birth rate - creating a wide gap between them -which in turn the much to sharp increase in population, often termed as population explosion triggered better medical facilities and food supply.

Stage-3: Stage of late Industrial Revolution and urban state.

typically characterised by low and stable growth rate of population. This stage is marked with a decline in birth rate along with a steady decrease in death rate. The mortality rate gets very low and stabilises by the later part of the 2nd stage and the birth rate also declines thereby almost bridging the gap between Birth rate (B.R) and Death rate. This Demographic Transition theory clearly shows how an economy changes from an agraian, llliterate rural state with High B.R. and D.R. to an industrial, literate and urban state with low B. R. and D.R. through technological innovations and medical improvements.

Population Control Measures

Spacing or preventing the birth of children in family planning. The significant factor in limiting population growth and improving women's health is the family planning.

Measures like propaganda, free availability of contraceptives and tax disincentives for large families help in population control. Thomas Malthus states that the number of people would increase faster than food supply. For the sustainability of our resources the world will have to control rapid population increase. Any further increase would result in a population crash caused by famine, disease and war. Preventive checks are better than physical checks.

We hope CBSE/MP Board Class 12th "Geography" Chapter 2 "The world Population: Distribution, Density and Growth" will help you.

Written By - HIMANSHU SHARMA