The following points highlight the three main factors influencing growth of human population. The factor are: 1. Geographical Factors 2. Socio-Economic Factors 3. Demographic Factors.
1. Geographical Factors:
The north and south poles are free of human habitation mainly because they are extremely cold and also agriculturally unproductive. Human settlements occur in places where adequate sources of water are available.
The fertility of the soil for farming is another important determinant of population distribution. For instance, the main basis of the highly dense populations in the Indus valley and Indo-Gangetic plains is the alluvial nature of the soils in these regions.
In certain places both iron ore and coal and other fossil energy sources are located close together. Industrial cities based around steel plants have come up in Jamshedpur, Bokaro, Durgapur, Bhilai and Rourkela.
Means of transportation have played an important role in the redistribution of population. This made it possible for the first time for persons to live far away from the source of produce or of goods required for living. Transportation by water is cheaper than by land or air and this is probably the main basis for the coastal location of most big cities such as Kolkata, Mumbai, London, New York and Tokyo.
2. Socio-Economic Factors:
The size of population, and birth and death rates has great significance on the standard of living of the people, their aspirations, and their economic and social development.
The birth rate of human population is regulated more by socio-economic factors than biological factors. These factors may be social status of women, age of women at marriage, family structure, education, acceptability of family planning practices, and religious beliefs.
Prosperity in the cities is the basic cause of continued urban growth. Some important consequences of increasing urbanization are-overcrowding, leading to problems of sanitation and sewage disposal; transportation and associated traffic problems; environmental pollution generated by industrial activities and automobiles; noise pollution and various socio-economic and cultural changes and problems related to juvenile delinquency and crime.
Urbanization involves progressive increase in the use of our fertile agricultural lands for housing new industries, factories, government offices, schools, hospitals and residential quarters.
3. Demographic Factors:
The birth-rate, death-rate, and the rate of natural increase are called vital rates because any change in these parameters will determine the overall pattern of population density.
The study of trends in human population growth and the prediction of future development make a special branch of knowledge called demography. Such studies involve parameters, that is, the number and proportion of different age-groups requiring education, training and employment.
Countries with a wide gap between birth rate and death rate tend to have a population age structure in which a higher percentage of its population consists of pre-school and school-going rate of a narrow gap between birth and death rates would contain relatively much lower proportion of preschool and school-going age groups.
Data of age distribution and economic status of different social groups are also needed for economic and social welfare planning.
The human population is increasing at an enormous rate. However, the rate of growth is not uniform in all countries. It may vary even is different groups of the same country. Unlimited population growth leads to over-crowding, has adverse environmental implications, especially in urban areas It tends to reduce food, water, fuel, land and other natural resources.
It is a fact that the growth of human population is more stable in the developed countries, i.e., both the birth rates and death rates are low.
When the birth rate of a population is high, the population increases, and on the other hand when the death rate is high the population decreases. In the United States of America, France and Germany, the population growth is more stable than in the developing countries like Pakistan, Bangladesh, India and China.
Usually, the relationship between population growth rate and the level of industrial development and education is inversely proportional. Such relationship is also found among different groups of the people in the same country.