Demography can be defined as scientific, mathematical, statistical study of population in reference to population density, population density, population distribution, population size and structure, population composition. The word Demography was first coined by a Greek Mathematician, Achelle Guillard.
What means Population?
Population means the total number of children, youths, adults and old people of a certain locality, village, town, city, district, region or a country. In other words population can also be defined as a group of people living in a place with respect to socio-economic and cultural background. Population determines the total number of people living in a place. The use of natural resources totally depends upon the growth and distribution of population. Population is dynamic in nature. It keeps on changing from time to time. World Population Situation
The population of the world has crossed 7 billion and is increasing day by day. There is rapid growth of population in the world. There is more increase of population in developing and undeveloped countries and decrease in population in developed nations. But in average, the population of the world is increasing. Initially the world’s population was very less. The existence of Humans in this Earth is believed before the agricultural society. After 19th century and the industrial revolution, the population of the world started to increase in a rapid manner. There was increase in technology, facilities in the sector of education, health and many more. There was invention of different instruments and devices that changed the history of the world. Many medicines and preventive measures of many diseases were also invented. Due to increasing population, the demands of the people will also increase but the available resources are constant. There will be lack of natural recourses if there is rapid increase in overutilization of natural resources. Now the population of the world has crossed 7 billion and it is believed that the population will reach 9 billion in 2050 A.D. There will be many problems due to increasing population. It is believed that human beings evolved about 30 million years ago on Earth. It is said that before the agricultural society, the population was 15 million only. By 1 A.D. like after 8000 years, the population of the world reached 250 million. There was continuous increase of population. In 1650 A.D. after 1600 years, the population doubled and reached 545 million. In 1850 A.D. after 200 years, world population reached 1 Billion. In next 80 years in 1930 A.D. the world population reached 2 billion. Then in 1975 A.D. after 45 years only, the population doubled to 4 million. . This was the time when the population increased in a huge rate. On July 11th, 1999 A.D. the population reached 6 Billion after 24 years. Since then July 11th is celebrated as the World Population Day every year. On 31st October, 2011 A.D. the population of the world reached 7 Billion. So on 31st October, 2011 A.D. people celebrated day of 7 Billion population in the world.
Size and growth rate of Population
Size of the population means the total number of people. Since population is dynamic in nature, the size of the population never remains constant. It changes in respect to time. However it can be indicated in number, time and place.
At present, the annual population growth rate in the world is 1.2% . With that population growth rate, it is estimated that the world population will reach 9 billion by 2050 A.D. At present, China has the highest population in the world with 1 billion and 30 million. Next to China is India with 1.2 billion populations. Asia is the continent with highest population among the continents.
Table Showing the top 10 countries with world’s largest population COUNTRIES TOTAL POPULATION
China| 1,347| ,000,000|
India| 1,241| ,000,000|
United States| 312| ,000,000|
Indonesia| 238| ,000,000|
Brazil| 197| ,000,000|
Pakistan| 177| ,000,000|
Nigeria| 162| ,000,000|
Bangladesh| 151| ,000,000|
Russia | 143| ,000,000|
Japan| 128| ,000,000|
Actually there was continuous increase of population of world since 19th century onwards. Some of the reasons are improvement of science and technology, extension of life expectancy, improvement in health sectors and control over many diseases, reduction of wars, etc.
Population density means total number of people living in a certain unit area or 1 sq km area is known as population density.
Population Density = Total no. of people in a place
Total area of that place
In urban areas, density may be expressed as persons per household or even persons per room. The density of population differs with respect to economic and social environment like industry, trade, transport, communication, health, education and security. Due to these reasons, the areas near productive lands, industrial sectors and district headquarters and sideways of highways are overcrowded. When the population of a place increases then the population density also increases because the land is limited and it does not increase.
Density of population of Nepal
In case of Nepal too places like Jhapa, Morang, Kathmandu, Rupandehi, Kaski are overcrowded due to the availability of facilities.
The density of population in Nepal is increasing is a vast way as the population in increasing. The increasing rate of population is getting higher and higher. The density of population per sq. km during 1971 census period of Nepal was 79 persons which increased to 102 and 126 during 1981 and 1991 respectively. Thus we can say that Nepal is a small country with high population density. The population density of Nepal is higher than China (107 per 1 sq. km) and near to India (128 sq. km).
Density and distribution of population by Development regions, Nepal, 2001.
Development Regions| Area| Population % Density| | Sq. Km| %| |
EDR| 28456| 19.3| 5344476| | 188|
CDR| 29410| 18.6| 8031629| 34.69| 293|
WDR| 29398| 20.6| 4571013| 19.74| 155|
MWDR| 42378| 28.8| 3012975| 13.01| 71|
FWDR| 19539| 13.3| 2191330| 9.47| 112|
Total| 147181| 100.0| 23151423| 100.0| 157|
The above table shows the distribution and population density of Nepal by Development regions according to the census of 2001 A.D. In the above table we can see that Central Development region has the highest population density i.e. 293 per sq. km and the Far Western Development region has 112 per square km. The Terai region has more population density than the Hilly and the Himalayan region because it has more fertile land and many people in Nepal are farmers.
A society is the place where we absorb people with different sex, culture, religion, age, language, occupation, etc. There is distribution of population on the basis of their characteristics.
Population Composition can be defined as the distribution of population on the basis of age, sex, marital status, caste, religion, language, occupation, socio-economic status and so on. The study of the population composition helps to find out the size, structure and the demography of the population if a country. It also depends o various demographic indicators like age, sex, dependent people, independent people, etc. Such study helps us to evaluate the overall composition of population.
The importances of Population Composition are;
* IT helps to develop demographic theories.
* It helps to study social, economic and cultural aspects of the society. * It provides important information for the government to develop different developing plans. * It shows the real picture of the society.
Types of population composition:
* Population Composition by Age
* Population Composition by Sex
* Population Composition by Caste
* Population Composition by Language
* Population Composition by Religion
* Population Composition by Occupation
Population Composition by Age: It can be simply defined as the distribution of the population according to age. Every population is made of the population of people in different age groups. The age composition of population means the composition of population of a certain age group in the certain place or region. The age of population can be classified corresponding to the age composition. We can study the population composition by age by dividing the population into three different groups. * (0-14) years for Children
* (15-59) years for Adults
* (60+) years for Old age
Children and Old