The factors that affect population size can be either growth or decline. The factors are birth rate, Death rate and migration.
This is the number of birth per thousand of the population in a year.
Factors that Influence Birth Rate
- The number and pattern of marriage
- Early marriage or later marriage in life
- people’s knowledge and their ability to accept family planning (i.e. birth control system)
- The desire to have big family
- The number of female and their ability to have children.
This is the number of death per thousand of the population in a year.
Factors that Influence Death Rate
(a) Infant mortality – i.e. the rate at which children die at their early age.
(b) Civilization leading to improved public sanitation and medical Facilities (c) The standard of living.
(d) Epidemics, war, natural disasters (floods and earthquakes.)
This is the movement of people from one country to the other. There are two aspects of migration namely:
IMMIGRATION, which is the movement of people from other country into a given country. In other words, it is the inward movement of people into a country, and EMIGRATION, which is the movement of people out of a country to another country.
The movement within a country is referred to as INTERNAL MIGRATION OR INTERNAL MOBILITY. The difference between the number of immigrants and emigrants is known as NET MIGRATION.
Factors that Influence Migration
- Availability of employment opportunities.
- The desire to find job and hence improve ones standard of living.
- The desire to acquire better skill and education.
- The quest for suitable climate.
- Natural disaster like erosion, flood and earthquakes.
- Influence of war and political instability
RURAL – URBAN MIGRATION:
This is the movement of people from rural areas to urban centres/Cities. E.g. somebody moves from Elele to Port-Harcourt or somebody leaving Ozubulu for Onitsha. Or somebody leaving Orlu for Lagos.
REASONS FOR RURAL URBAN MIGRATION
- Quest for jobs
- Desire to enjoy basic infrastructures/ comfort
- Desire to acquire a better skill and standard education.
EFFECTS OF RURAL- URBAN MIGRATION
- Increases unemployment problems in urban cities
- Causes depopulation of the rural areas.
- Causes inflation in urban cities.
- Causes a fall in the output of the rural areas.
- Causes accommodation problem in the urban cities.
- Increases social problems and crimes in urban centres.
REMEDIES TO RURAL-URBAN MIGRATION
- There should be industrial location and/or development in the rural areas.
- There should be adequate provision of basic infrastructures in rural areas such as electricity and pipe-borne water.
- There should be good and accessible communication network.
- Educational institution should be sited in the rural areas.
NATURAL GROWTH RATE: This is the difference between the birth rate and death rate of a country.