Population is described as the number of people in an area based on specific categories such as ethnicity, age, income, sex, and social economic status. Population is continually changing due to birth and death rate and relocation among families to explore good sources of income. Population is calculated by counting the actual number of people in a given area and measuring birth to death ratios. Population Growth can be defined as the change in population over time and can be quantified as the change in number of individuals in a population as “per unit time”.
CONCEPT OF POPULATION
- Density of population: is expressed as number of persons per unit area. It helps in getting a betterunderstanding of the spatial distribution of population in relation to land
- The population growth: refers to the change in number of inhabitants of a territory during a specific period of time. Population change in an area is an important indicator of economic development, social upliftment and historical and cultural background of theregion.
- Fertility refers to the actual reproductive performance of an individual or a group
- The crude birth rate is an important measure of fertility for which only live births, that is, children born alive are taken into account. The crude birth rate is calculated by dividing the number of live births occurring during a calendar year in specified areas by the midyear population of that year.The crude birth rate is generally expressed per thousand of population.
- General Fertility Rate: It is the number of live births per 1000 women, aged 15-49 years (child bearing age group), in a given period.
- Age-Specific Fertility Rate: The number of live births occurring during a given year or reference period per 1000 women of reproductive age classified in that age group.
- Total Fertility Rate: The total fertility rate refers to the total number of live births that a woman would have if she lived through the reproductive age group and had the average number of babies in each segment of this age group as determined by the age-specific fertility rates for that area.
- Crude Death Rate: It is the ratio of the total registered deaths occurring in a specified calendar year to the total mid-year population of that year, multiplied by 1000.
- Infant Mortality Rate: Infants are defined in demography as all those children in the first year of life who have not yet reached age one
- Maternal Mortality Rate: The maternal mortality ratio represents the risk associated with each pregnancy, i.e. the obstetric risk. Maternal death is the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes. It is measured as number of maternal deaths per 100000 livebirths.
- Natural Growth of Population: This is the population increased by difference betweenbirths and deaths in a particular region between two points oftime.
Natural Growth= Births-Deaths
- Actual Growth of Population = Births – Deaths + in Migration – out Migration
- Positive Growth of Population: This happens when the birth rate is more than the death rate between two points of time or when people from other countries migrate permanently to a region.
- Negative Growth of Population: If the population decreases between two points of time it is known as negative growth of population. It occurs when the birth rate falls below the death rate or people migrate to other countries.
- Potential Support Ratio (PSR)as the number of working age group (aged 20 to 60 years)divided by the number of retired(aged 65 and above)
- The Dependency ratio is a measure comparing the portion of a population which is composed of dependents (i.e., elderly people who are too old to work, and children who are too young to work) with the portion that is in the working age group, generally defined as 15 to 59 The dependency ratio is equal to the population below 15 or above 60, divided by population in the 15-59 age group; the ratio is usually expressed as a percentage.
- Sex Ratio refers to the number of females per 1000 males in a given area at a specified time period.
- Child Sex Ratio is the sex ratio in the age group 0-6 years (child) in a given area at a specified time period.
- Main Worker is a person who works for at least 183 days in a year.
- Marginal Worker is a person who works for less than 183 days in a year.
- Work participation rate is defined as the percentage of total workers (main and marginal) to total population.
- Total Fertility Rate at Replacement Level: It is the total fertility rate at which newborn girls would have an average of exactly one daughter over their In more familiar terms, every woman has as many babies as needed to replace her. It results into zero populationgrowth.
- Stable Population: A population where fertility and mortality are constant over a period of This type of population will show an unvarying age distribution and will grow at aconstant rate. Where fertility and mortality are equal, the stable population isstationary.
- Carrying capacity: Where the growth of a particular species stabilizes at the maximum population size that can be supported indefinitely by their environment, that point is known as carrying capacity.
- Demography is the science of systematic study of Demography studies the trends and processes associated with population including – changes in population size; patterns of births, deaths, and migration; and the structure and composition of the population, such as the relative proportions of women, men and different age groups.
Populations are characterized, not only by their size and growth rates, but also by their age structure and sex composition, as also by their birth, death and fertility rates, by their pattern of distribution within the country, and by migration within and across natural boundaries. Some of these characteristics are discussed below:
Fertility/Natality : Natality is an expression of the production of new individuals in the population. In human population natality is equivalent to the birth rate, and is usually expressed as the number of births per year per thousand persons in the population. The growth rate of the population can be zero or positive but never negative.
The crude birth rate is an important measure of fertility for which only live births, that is, children born alive are taken into account. The crude birth rate is calculated by dividing the number of live births occurring during a calendar year in specified areas by the midyear population of that year.The crude birth rate is generally expressed per thousand of population
General Fertility Rate: It is the number of live births per 1000 women, aged 15-49 years (child bearing age group), in a given period.
Age-Specific Fertility Rate: The number of live births occurring during a given year or reference period per 1000 women of reproductive age classified in that age group.
Total Fertility Rate: The total fertility rate refers to the total number of live births that a woman would have if she lived through the reproductive age group and had the average number of babies in each segment of this age group as determined by the age-specific fertility rates for that area.
Determinants of High Fertility:
Several factors contribute to the high fertility of Indian women. some of these factors are:
- Religion has no linkages with T.F.R.( Total fertility ratio )and population growth rates. Eg countries with Muslim population as majority like Turkey (TFR=1.6). Malaysia and Indonesia (TFR=1.8). No one is forcing any particular religion to have more babies. It is the inaccessibility of population of particular religion to Education, Health care and High prevalence of poverty amongst them that their TFR is higher than average.
- Universality of the institution of marriage.
- Early marriage and early child-bearing.
- Preference for sons ingrained in the Indian culture/Urge for male child
- Lack of right of self-determination (amongst women) with reference to reproduction
- High infant (IMR) and child mortality rates – (poor health, low nutritional status and poverty)also contribute to a large family size.
- Economic, social, cultural value of children in the Indian society.
- Accessibility to methods of contraceptions.
- States with poor literacy rates(among women) have high T.F.R.
Implications of High Fertility on family and society:
- The children, often unwanted, unloved and neglected, are left to their own to make life bearable. The children in large families often have to start working at a very early age to supplement the slender financial resources of the family. They even indulge in delinquency and are, therefore, denied the opportunity to go to school and get educated.
- The girl child is the worst sufferer in these circumstances. She is often not sent to school at all, or is withdrawn from school at an early age to help her mother in carrying out domestic chores and to look after her younger siblings when the mother is at work. Early marriage pushes her into child-bearing, and the vicious cycle continues.
- The children, both boys and girls, in a large family are thus often denied the joys of childhood, and are pushed into adult roles at a very early age.
- The head of the house(generally father) has to take the brunt of securing subsistence, education , health and all other expenses of the children and often struggles in daily life which leads to addictions to substance of abuse.
- The mother who bears 4-5 children spends most of her precious youthfull time and age in pregnancy and taking care of children.She is unable to express herself in social-economic aspects of life.Instead of spending time on self development, she is mostly engaged in children , which leads to frustration.
Mortality refers to death rate of individuals. In a population, members die due to various causes, such as malnutrition, disease and old age. Mortality is also expressed as death per year per thousand persons in the population.
Crude Death Rate: It is the ratio of the total registered deaths occurring in a specified calendar year to the total mid-year population of that year, multiplied by1000.
|Infant Mortality Rate:||Maternal Mortality Rate:|
|Infants are defined in demography as all those children in the first year of life who have not yet reached age one. In countries like India, where health conditions are poor, infant deaths account for a substantial number of all deaths.||Maternal death is the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management but not from accidental or incidental causes.|
|United Nations has recently set Sustainable Development Goals and Targets. For India is to attain Under 5 Mortality Rate of 25/1000 live births by 2030. ( As of 2013it was 40/1000 live births)||It is measured as number of maternal deaths per 100000 livebirth|
|As per Sample Registration System (SRS), 2011-13 reports Maternal Mortality Ratio (MMR) is 167 per 1,00,000 live births in the Country.|
Migration is the movement of people to new homes either within the boundaries of a country (internal migration) or across the boundaries to another country (international migration). Only international migration can affect the growth of population within a country
Immigration: Migrants who move into a new place are called Immigrants.
Emigration: Migrants who move out of a place are called Emigrants.
There are two sets of factors that influence migration.
The Push factors : make the place of origin seem less attractive for reasons like unemployment, poor living conditions, political turmoil, unpleasant climate, natural disasters, epidemics and socio-economic backwardness.
The Pull factors : make the place of destination seem more attractive than the place of origin for reasons like better job opportunities and living conditions, peace and stability, security of life and property and pleasantclimate.
Fertility , mortality and migration are also the determinants of population change.
FACTORS AFFECTING DISTRIBUTION OF POPULATION
1.GEOGRAPHICAL FACTORS :
- Water: people prefer to live in areas where fresh water is easily available. Water is used for drinking, bathing and cooking and also for cattle, crops, industries and navigation. It is because of this that river valleys are among the most densely populated areas of the world. Only oases within the deserts are densely populated and here the population is limited by the availability of water.
- Landforms (Relief): People prefer living on flat plains and gentle slopes. This is because such areas are favorable for the production of crops and to build roads and industries. The mountainous and hilly areas hinder the development of transport network and hence initially do not favor agricultural and industrial development.
- Climate: An extreme climate such as very hot or cold deserts is uncomfortable for human habitation. Areas with a comfortable climate, where there is not much seasonal variation attract more people. Areas with very heavy rainfall or extreme and harsh climates have low population.
- Soils: Fertile soils are important for agricultural and allied activities. Therefore, areas which have fertile loamy soils have more people living on them as these can support intensive agriculture.
2. ECONOMIC FACTORS :
- Minerals: Areas with mineral deposits attract industries. Mining and industrial activities generate employment. So, skilled and semi–skilled workers move to these areas and make them densely populated
- Urbanisation: Cities offer better employment opportunities, educational and medical facilities, better means of transport and communication. Good civic amenities and the attraction of city life draw people to the cities. It leads to rural to urban migration and cities grow in size
- Industrialization: Industrial belts provide job opportunities and attract large numbers of These include not just factory workers but also transport operators, shopkeepers, bank employees, doctors, teachers, cleaners, domestic helps ,and other service providers
3.SOCIO-CULTURAL FACTORS :
- Some places attract more people because they have religious or cultural significance (Varanasi, Amritsar, Allahabad etc ). In the same way – people tend to move away from places where there is social and political unrest(Syria-Isis), . Many a time governments offer incentives through various types of policies to people to live in sparsely populated areas or move away from overcrowded places.
4.WORLD DISTRIBUTION OF POPULATION
- Sixty per cent of the global population lives in Asia (4.4 billion), 16 per cent in Africa (1.2billion), 10 per cent in Europe (738 million), 9 per cent in Latin America and the Caribbean (634 million),and the remaining 5 per cent in Northern America (358 million) and Oceania (39 million).
Countries/continent Of the total population of world.
|china||1.4 billion.19% of population.|
|India||1.3 billion .(18%)|
|African continent||1.2 billion (16%)|
- China (1.4 billion) and India (1.3 billion) remain the two largest countries of the world, both with more than 1 billion people, representing 19 and 18 per cent ofthe world’s population,respectively.
- In 2015, 4 per cent of the world’s population is male and 49.6 per cent is female. The median age of the global population, that is, the age at which half the population is older and half is younger, is 29.6 years.
5. TRENDS IN POPULATION GROWTH
- Today, population is growing by 18 per cent per year, or approximately an additional 83 million people annually
- Africa is the fastest-growing major area: More than half of global population growth between now and 2050 is expected to occur in Africa. Africa has the highest rate of population growth among major areas, growing at a pace of 2.55 per cent annually in 2010- 2015.
- Asia is projected to be the second largest contributor to future global population growth,
- Europe is projected to have a smaller population in 2050 than in Europe is projected to experience shrinking population: the populations of European countries or areas in the world are expected to decrease between 2015 and 2050. Fertility in all European countries is nowbelow the level required for full replacement of the population in the long run(around 2.1 children per woman, on average), and in the majority of cases, fertility has been below the replacement level for several decades.
- High Population growth in least developed countries (LDCs)-High population growth will remain the feature of the least developed countries (LDCs),
- Increasing longevity around the world, significant gains in life expectancy have been achieved which will also contribute to population growth.
POPULATION HISTOGRAMS / AGE-SEX PYRAMIDS AND WHAT THEY INDICATE ?
A population histogram (see figure below) is a bar graph, drawn for a particular year, in which each horizontal bar represents a particular age group of the population. The length of the bar on the left tells us the number of percentage of male (of the total population) in this age group, and the same is shown for female on the right.
A histogram can tell us a number of things such as:
- The Age structure of the population i.e., the percentage of the population in a significant age group, such as those who are dependent on others for support, or those who can do–productive work.
- The sex composition i.e. the number (percentage) of males and females in each age group, from which we can also tell the number of females in the reproductive age group of 15 to 44 years.
- The impact of growth and changes in the population over several decades in the recent past, and
- The likely growth of the population in the next few decades, at the current growth rate
TYPES OF AGE-SEX PYRAMIDS / POPULATION HISTOGRAMS
- Expansive histogram — The population histogram with an expanding base is called an expansive histogram. It is typical for the developing countries, whose populations are growing very rapidly
- Constrictive histogram — In this type of histogram the base is smaller (constrictive). As you can see in Fig below which depicts a population constrictive histogram of There are fewer children being born in each 5-year group than before. However, this does not mean that the population in the Japan is not growing. You can see a definite bulge during the years 1950 to 1965 when there was a ‘baby boom’. As this bulge passes through the reproductive years this will result in more children than the parents.
- Stationary histogram — In this type of histogram each bar is not very different till we come to the age groups (over 75 years) where death rates are This means that for many years the average family size has just been sufficient to replace itself. Such a population is not growing at all, hence the name stationary.