Population is a number of people, animals and plants (living things) living a certain area. Or the inhabitants of a particular place.
Human Population Is a group of people occupying a certain geographical unit. Demography is the scientific study of human population.
It covers its growth, density, distribution and movement as well as the aspect of social and economic development.
Characteristics of human population
The following is the characteristics of human population
(i) POPULATION SIZE
Is the total number of people living in the country; It is obtained through census.
(ii) POPULATION STRUCTURE
Population Structure is the composition of a given population in terms of age and sex at a particular time. Census, vital registration or sample survey is used to obtain information on age and sex of an individual person from the entire population.
Population composition refers to the geographical make up of persons in a given locality which includes, sex, age, marital status, education, occupation, income level, religion, ethnic group and race.
(iv) SEX RATIO
This is the number of males per 1000 females in a given population.
(v) DEPENDENCY RATIO
Is the part of the population that is not involved in productive activities.
The dependency ratio can be categorized into two;
a) Youth dependency ratio: Includes those who are under 15 years.
b) Old age dependency ratio: Includes those who are above 65 years.
IMPORTANCE OF STUDYING POPULATION
In studying population, population data are obtained through census, vital registration and sample survey. The data obtained are useful in different ways;
1. It can encourage intensification of agricultural activities as a result of the reduction in the size of arable land.
2. The information obtained during the National Census is used by the Government for Planning Public Services e.g Schools, Hospitals, Markets, etc.
3. Enable to know the age and sex in a country e.g In Tanzania the number of female is higher than of male. 4. Enables the government to combat mortality rate which may lead to loss of man power if not well managed.
5. Migration can lead to the expansion of market for the local goods in the destination regions
6. Enables to know the number of manpower skilled and unskilled.
7. It can stimulate the diffusion of technology into the destination from other areas the people who migrate posses different skills of different environmental orientations.
8. It can stimulate the growth of towns (urbanisation) and the associated advantages.
Population Distribution is the way in which people are spread out across the earth Surface.
Distribution is uneven and changes over period of time.
Population density is the number of people per unit of area.
This describes the concentration of people in a specific area.
There are places where people are concentrated in one area while the land in the neighborhood may be unoccupied. Population density is obtained by taking the number of people in a given area and dividing that number by the total area of the place.
Thus it gives us the number of persons per unit area of land. Population density can be described as dense, moderate, or sparse.
FACTORS INFLUENCING POPULATION DISTRIBUTION AND DENSITY
1. Relief (Topography)
Where the slope is steep there is low or no population due to poor soil and nature of the land, but on gentle slope or flat surface there is high population since soil is good and mechanization can take place easily. Also low land tends to flood usually since people avoid settling in those areas.
Areas with reliable (moderate) rain have attracted high population but where there is poor rain like in the desert there is low population. Also areas with high or very low temperatures do not attract population while areas with moderate temperature attract population (high).
In areas where dense vegetation is difficult to clear like in Tropical forest of Amazon and Congo basin discourage people to live leading to sparse population or no population at all. Dense vegetation hinders penetration and development. In less dense vegetation people are attracted since they grow crops after clearing for cultivation.
Thin, infertile and badly leached soil discourages settlement since they can’t support agriculture. Good soil attracts population.
5. Mineral and energy resources
Area with mineral and energy resources attract population e.g. rand of S. Africa, iron and coalfield in Europe and southern part of W. Africa where there are rich mineral deposits like diamond, oil, etc.
6. Natural Hazards
Areas with natural hazards like floods in low land, earthquakes, and tornadoes are avoided by people.
7. Diseases and Pests
People like settling in areas which are free of diseases and pests. There is high population in highlands of Tanzania which have healthy climate like Arusha. But areas with high incidence of disease and pests infestation like mosquitoes that causes malaria, tsetse flies discourage population settlement.
8. Social – cultural aspects
Some tribes have a tradition of going to live in areas which have been left by their ancestors. Traditional beliefs like superstitions can make people avoid living in certain areas due to fear of risking their life.
9. Political factors
Area with political stability and peace attract population but where there is political instability does not attract population. People avoid settled in area that has political conflict like in Sudan and Somalia.
10. Transport and communication Areas which are served with transport and communication attract high population since they can transport their goods to the markets areas. Also area where social services are ready available like in towns, unlike the rural areas where social services are poorly available.
Population change is the growth or decline in population i.e Increase or decrease population can change by positive growth and negative growth. The main factor for population change;
1. Fertility rate.
2. Mortality rate.
FACTORS FOR POPULATION CHANGE
It is also known as fertility rate. Fertility refers to the ability to conceive and produce. It is measured by counting the number of people (live births in a population). Fertility rate is influenced by factors like; Level of education. Urbanization. Birth control measures. Cultural belief. Prestige. Early marriage. Source of labour. Preference of sex.
2. MORTALITY/DEATH RATE
Is also called mortality. It refers to the number of deaths within a given population.
Death rate can be categorized into;
(a) Infant mortality rate The number of death from 0-2 years.
(b) Child mortality rate Number of death of children aged between 1-5 years per 1000 live birth.
(c) Adult mortality rate Number of adults dying per 1000 of the total population.
Hence; – Large scale mortality may be caused by;
Is the movement of people from one place or region to another which results in changes of residence which may be temporary or permanent.
Immigration: People come into a new area and are called immigrants. Emigration: People leave their native land for other lands and these people are called emigrants
Types of migration
There are two types of migration, namely;
i. Internal migration.
ii. External (International) migration.
And these types of migration can be permanent, temporary, voluntary and involuntary.
(i) INTERNAL MIGRATION
Is the movement of People within a country, it can be permanent, temporary, voluntary or forced (involuntary Factors influences internal migration Trade. Education Search for jobs. Settlement. Search for fertile soils.
FORMS OF INTERNAL MIGRATION
(a) Rural to Urban Migration Refers to the movement of People from rural to urban or towns search for jobs, better social services, education.
(b) Rural to Rural Migration Refers to the movement of People from rural to rural e.g Nomadic pastoralists.
(c) Urban to Rural Migration From towns to villages for investing, job purpose, setting up industries and other projects.
(d) Urban to Urban Migration From one town to another for business, better employment, education etc.
(ii) EXTERNAL MIGRATION
Is also called international, interstate or inter regional migration. Is the movement of people from their own countries to other countries.
CAUSES OF MIGRATION
There are many reasons why people choose to migrate. The following are some of them;
i. Pressure on land. People move to areas with available land for cultivation, settlement etc.
ii. Availability of employment opportunities. Move to areas where employment is possible e.g rural to rural, to work in plantations, mines,etc.
iii. Creation of wealth. People migrate to other countries with aim of making wealth quickly e.g Tanzanians move to South Africa iv. Religious conflicts. Which may result to chaos in a country
v. Political instability. Like civil wars cause people to migrate e.g Like that of Rwanda and Burundi has resulted to influx of refugees in East African countries.
vi. Natural disasters Epidemic diseases, floods, earthquakes, drought may cause people to migrate to better areas where it is safe.
vii. Forced migration People forced to move from the area e.g Asians were expelled in Uganda during the leadership or military regime of Iddi Amin, the slave trade of 17th and 18th century is an example of forced migration (Involuntary).
viii. Cultural beliefs People may move from one place to another due to cultural beliefs that are not friendly.
EFFECTS OF POPULATION CHANGE
The effect of population change are quite varied. Population change affects both the individuals as well as the nations at large. The effect can be positive or negative.
EFFECT ON THE INDIVIDUAL
A high fertility rate results in a large number of children that a family has to look after. Migration has its own effects on individuals in the number of ways.
1. Some individuals may change their life styles by becoming more sophisticated. This happens after gaining more skills and exposure to more sophisticated lifestyles where the individual migrated to.
2. Some individuals after migrating to urban areas and getting jobs, may take a much longer time to get married.
3. When spouses are separated for long periods of time, this may lead to break up of marriages. Either spouse may engage in extra marital relationships during the period of absence of the partner.
4. Some individuals who migrate to urban areas lose their cultural values and this lead to immorality. Some turn to crime.
5. Some people saves lot of money from the income they get from working. The income is used to improve their standards of living.
EFFECTS OF POPULATION CHANGE IN A NATION
Over population is a situation where by a region or country has such a high population that it cannot be supported fully due to a strain on the available resources. In such a situation, many people live in object poverty.
1. Over population also leads to unemployment or even under development of a nation or even under employment.
2. Over population lead to poor housing and health facilities because demand for these facilities is far greater than the supply.
3. Agricultural resources are underutilized because of shortage of land and traditional land tenure systems which hinder modernization of agriculture
4. Slow industrial growth because of shortage of skilled labor. Although there is a large labor force, it is largely unskilled.
A large population increases the demand for food. This demand reduces the production of cash crops while increasing production of food crops. Population Data Population data means information on population.
is the information pertaining to population and relate direct with some economic, social and demographic matters.
Sources of Population Data
There are two basic sources of population data, There are Primary sources and Secondary sources.
1. Primary sources
this is a source of population data which is obtained directly via registration of person like registration of births and deaths, data is also obtained first hand when there is population census and when sample survey are limited amount of data could also be obtained from resourceful persons.
2. Secondary sources of population data
include reports in population which are compiled and published as census reports, data is also obtained from textbooks and other reference books, atlases, magazines, newspaper, journals, periodicals and research papers.
It can also be obtained from draft reports, annual reports as well statistical abstracts which are published annually and are available in government offices. Population data may also be obtained or available in the electronic media as well as on the internet. Interpretation of Population Data When population data has been collected, it is subjected to processing or analysis.
It is during this process that calculations are made, these include means densities, birth and death rate, sex ratios and other relevant information population Statistics can be studied in their raw form or in a processed form by studying such information conclusion can be made and explanation sought.
USES OF POPULATION DATA
1. Population numbers and density enable the government to plan on low to allocate resources. Also the knowledge of population can be useful in solving land congestion.
2. Data birth and death rates as well as fertility and mortality enable government to plan how to provide medical services and health education, especially where the death rate is very high.
3. Data on migration can enable a government to plan how to curb influx of people into urban areas from the rural regions if corrective measure are taken, loss of man power in the rural areas would be curbed as well as reducing influx of immigrants in urban centres.
4. Knowing the number of dependents enable the government to plan for expansion of schools, medical and other social amenities to take care of large number of children below the age of 15. When the government has ideas about the number of the aged, It can budget for provision of welfare better.
5. It enable planning for creation of jobs, population census data provide information about overpopulation and under population.
Human population refers to the total number of people at a given place in specific period of time.
Population problem refers to the problems which human population face in a certain area
these problems include;
1. Lack of development policies and laws that support family stability.
2. Lack of development of talents and capabilities of the children and youth.
3. Lack of preparedness plan for handling refugees.
4. Failure in encouraging private sectors and religious organisation to invest in provision of social services for people with disabilities as well as poor government policies on people with disabilities
5. Lack of provision of social services especially health services to adult people
6. Lack of social security measure that address problems of elders
Analysis of Population Problems
Population problems are challenges associated with the existing population. Population increases should match the capacity of resources to support the growing population.
The extent to which resources are used determine whether there is over-population or under-population. Optimal population is when resources match with existing population. The effects of population change on Economic Growth, Labour, Human needs and Investment, and suggest possible solutions.
Population problems arising from birth rates, deaths rates and migration have an impact on economic growth, labor, human need and investment. Example if population increases very rapid it results to availability of labour which is cheap but people with low incomes. Investment in consumer goods will increase as the result of increasing demand.
Population policy refers to the statement law or regulations enacted to some demographic goals. It is a deliberate effort by the government to influence the demographic factors like fertility, mortality and migration.
Thus the ultimate goal of the population policy is to influence population size, composition, distribution and growth. The policy also tends to take into consideration the relationship between population and development as well as the impact on environment condition.
POPULATION POLICY CAN BE EXPLICIT OR IMPLICIT
EXPLICIT POPULATION POLICY
Refer to the document or clear statement issued by the government department and its commission which is intended to control population growth and raise the standard of life of the people in the country.
Explicit policies can also stem from the law, policy declaration by a party or directive issued by the President of the country. Explicit laws are well stipulated and strictly followed or reinforced.
Such policies prevailed in China where the limit in the number of children was set and incentives were given to all those who could follow while penalties were given to those who did not follow.
Other countries with explicit policy are Sweden and England. Hence the explicit policy is the elaborate statement that spells out the rationale objective, goals, targets policy program and implementation.
Refer to particular law, regulation or statement, which may have direct or indirect effect on population growth. Implicit policy is not as elaborate as explicit since it is somehow unclear and cannot be easily understood leading to failure in terms of implementation.
Population policies, whether explicit or implicit, have the ultimate aim of influencing a country’s population size, composition, distribution and growth.
PRINCIPLE TO GUIDE
1. Consideration of regional and district variation with regard to the level of socio-economic development
2. Adherence to the development vision which among other things emphasize the role of the market in determining resources allocation and uses
3. Continued democratization of the political system with its intended political pluralism as symbolized in the emergence of various political parties or actors and mushroom of independent mass media
4. Thrift exploitation of the country’s non-renewable resources taking consideration the needs of future generations.
5. Recognition and appreciation of the central role of the government, NGOs, private sector communities and individuals in population and development.
JUSTIFICATION OF THE POPULATION POLICY
This policy takes cognizance of the achievement, constraint and limitation of implementing post population policies as well as new development and continuing challenges.
The achievement of both implicit and explicit population policies includes the followings:
a. Considerable awareness of population issues particularly those related to reproductive health and child survival by the masses of the people for example fertility, infant and child mortality has decline overtime
b. Adoption of an explicit population policy in 1992, which recognised the links and interrelationship between population, resources, the environment and development.
c. Expansion and /or introduction of population studies in institutions of higher learning in the country
d. Increased number and capacity of NGOs engaged in population related activities including advocacy and social mobilisation, service delivery and capacity building.
e. High knowledge and use of contraceptive methods among both men and women and male involvement in family planning which has increased contraceptive prevalence from about 10 in 1980s to 16 in 1996.
Comparison of the National Population policy on Family Planning Strategies in Tanzania to the population policies of other countries Tanzania is not the only country which has adopted a population policy. In the 1950’s, China was overpopulated and in 1952 it became the first country to introduce a population policy. Nigeria is the most populous country in Africa and launched its first population policy in 1988.
EXERCISE (DISCUSSION QUESTIONS)
Question 1: a) What are the main characteristics of human population? b) State the main factors that influence population distribution.
Question 2 :(a) Using your knowledge of population studies, provide the meaning of urban growth. (b) Outline eight social and economic problems that result from urban growth.
Question 3: With vivid examples, explain the causes of population change in the Great lakes of East Africa.
Question 4: Some lakes and rivers in Tanzania are likely to lose their aquatic resources. Suggest any five (5) ways on how to overcome this threat.
Question 5: Explain the environmental factors which influence population distribution in Tanzania.
Question 6: (a) Describe five objectives of conducting census in a country. (b) Explain three limitation of census in African countries.
Question 7: Describe the natural and human causes of biodiversity.
Question 8: Give five reasons for decreasing death rates in many parts of the world.
TOPIC 7: APPLICATION OF SIMPLE STATISTICS | GEOGRAPHY FORM 3